U.S. patent application number 16/931484 was filed with the patent office on 2020-11-05 for terminal device, base station apparatus and communication method.
The applicant listed for this patent is Sharp Kabushiki Kaisha. Invention is credited to Kimihiko IMAMURA, Naoki KUSASHIMA, Toshizo NOGAMI, Kazuyuki SHIMEZAWA.
Application Number | 20200350969 16/931484 |
Document ID | / |
Family ID | 1000004969757 |
Filed Date | 2020-11-05 |
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United States Patent
Application |
20200350969 |
Kind Code |
A1 |
SHIMEZAWA; Kazuyuki ; et
al. |
November 5, 2020 |
TERMINAL DEVICE, BASE STATION APPARATUS AND COMMUNICATION
METHOD
Abstract
There is provided a terminal device that communicates with a
base station apparatus. The device includes: a higher layer
processing unit that configures a discovery signal which includes
cell-specific reference signals present in DwPTSs of all downlink
subframes and all special subframes, a first synchronization signal
present in a prescribed subframe, a second synchronization signal
present in a first subframe, and one or more non-zero power CSI
reference signals during a period of continuous subframes in a
predetermined cell; and a reception unit that receives the
discovery signal. A subframe offset between the second
synchronization signal and the non-zero power CSI reference signal
is independently configured for each of the non-zero power CSI
reference signals.
Inventors: |
SHIMEZAWA; Kazuyuki; (Sakai
City, JP) ; NOGAMI; Toshizo; (Sakai City, JP)
; KUSASHIMA; Naoki; (Sakai City, JP) ; IMAMURA;
Kimihiko; (Sakai City, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sharp Kabushiki Kaisha |
Sakai City |
|
JP |
|
|
Family ID: |
1000004969757 |
Appl. No.: |
16/931484 |
Filed: |
July 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16291013 |
Mar 4, 2019 |
10763936 |
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16931484 |
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15314157 |
Nov 28, 2016 |
10298306 |
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PCT/JP2015/065547 |
May 29, 2015 |
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16291013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 24/10 20130101;
H04L 1/0026 20130101; H04W 72/042 20130101; H04W 72/0446 20130101;
H04B 7/0626 20130101; H04W 72/04 20130101; H04B 17/309 20150115;
H04L 69/22 20130101; H04W 28/06 20130101 |
International
Class: |
H04B 7/06 20060101
H04B007/06; H04W 24/10 20060101 H04W024/10; H04W 72/04 20060101
H04W072/04; H04B 17/309 20060101 H04B017/309; H04L 1/00 20060101
H04L001/00; H04L 29/06 20060101 H04L029/06; H04W 28/06 20060101
H04W028/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2014 |
JP |
2014-111820 |
Claims
1: A terminal device that communicates with a base station
apparatus, the terminal device comprising: reception circuitry
configured to receive a discovery signal which includes a primary
synchronization signal present in a subframe, a secondary
synchronization signal present in the subframe, and one or more
Channel State Information (CSI) reference signals during a period
of consecutive subframes in a cell; and higher layer processing
circuitry configured to receive Radio Resource Control (RRC)
signaling which indicates, for each of the one or more CSI
reference signals, (a) a physical cell ID of the cell and (b) a
subframe offset between (i) the secondary synchronization signal
and (ii) the each of the one or more CSI reference signals.
2: A base station device that communicates with a terminal
apparatus, the base station device comprising: transmission
circuitry configured to transmit a discovery signal which includes
a primary synchronization signal present in a subframe, a secondary
synchronization signal present in the subframe, and one or more
Channel State Information (CSI) reference signals during a period
of consecutive subframes in a cell; and higher layer processing
circuitry configured to send Radio Resource Control (RRC) signaling
which indicates, for each of the one or more CSI reference signals,
(a) a physical cell ID of the cell and (b) a subframe offset
between (i) the secondary synchronization signal and (ii) the each
of the one or more CSI reference signals.
3: A method for a terminal device that communicates with a base
station apparatus, the method comprising: receiving a discovery
signal which includes a primary synchronization signal present in a
subframe, a secondary synchronization signal present in the
subframe, and one or more Channel State Information (CSI) reference
signals during a period of consecutive subframes in a cell; and
receiving Radio Resource Control (RRC) signaling which indicates,
for each of the one or more CSI reference signals, (a) a physical
cell ID of the cell and (b) a subframe offset between (i) the
secondary synchronization signal and (ii) the each of the one or
more CSI reference signals.
4: A method for a base station device that communicates with a
terminal apparatus, the method comprising: transmitting a discovery
signal which includes a primary synchronization signal present in a
subframe, a secondary synchronization signal present in the
subframe, and one or more Channel State Information (CSI) reference
signals during a period of consecutive subframes in a cell; and
sending Radio Resource Control (RRC) signaling which indicates, for
each of the one or more CSI reference signals, (a) a physical cell
ID of the cell and (b) a subframe offset between (i) the secondary
synchronization signal and (ii) the each of the one or more CSI
reference signals.
Description
TECHNICAL FIELD
[0001] The present invention relates to a terminal device, a base
station apparatus and a communication method.
[0002] The present disclosure contains subject matter related to
that disclosed in Japanese Priority Patent Application JP
2014-111820 filed in the Japan Patent Office on May 30, 2014, the
entire contents of which are hereby incorporated by reference.
BACKGROUND ART
[0003] A radio access scheme and a radio network for cellular
mobile communication (hereinafter, referred to as "Long-Term
Evolution (LTE)" or "Evolved Universal Terrestrial Radio Access:
EUTRA") have been examined in the 3rd Generation Partnership
Project (3GPP). In the LTE, a base station apparatus (base station)
is also referred to as Evolved Node B (eNodeB), and a terminal
device (mobile station, mobile station apparatus, or terminal) is
also referred to as user equipment (UE). The LTE is a cellular
communication system in which a plurality of areas within the
coverage of the base station apparatus is arranged in the form of
cells. A single base station apparatus may manage a plurality of
cells.
[0004] The LTE supports frequency-division duplexing (FDD) and
time-division duplexing (TDD). The LTE that adopts the FDD system
is also referred to as FD-LTE or LTE FDD. The TDD is a technology
that enables full-duplex communication in at least two frequency
bands by performing frequency-division multiplexing on uplink
signals and downlink signals. The LTE that adopts the TDD system is
also referred to as TD-LTE or LTE TDD. The TDD is a technology that
enables full-duplex communication in a single frequency band by
performing time-division multiplexing on uplink signals and
downlink signals. The details of the FD-LTE and the TD-LTE are
disclosed in NPL 1.
[0005] The base station apparatus may transmit, to the terminal
device, a reference signal (referred to as RS) which is a known
signal between the base station apparatus and the terminal device.
As the reference signal, a plurality of reference signals may be
transmitted for various purposes such as demodulation of a signal
channel or reporting of a channel state. For example, a
cell-specific reference signal is transmitted as a reference signal
specific to the cell in all downlink subframes. For example, a
UE-specific reference signal is transmitted as a reference signal
specific to the terminal device in a resource to which a data
signal for the terminal device is mapped. The details of the
reference signals are disclosed in NPL 1.
[0006] In the 3GPP, the introduction of a small cell has been
examined. The small cell is the general term for cells of which a
transmit power of the base station apparatus constituting this cell
is low and coverage is narrower than that of the cell (macrocell)
of the related art. For example, since the small cell is applied in
a high frequency band, it is possible to arrange the small cells
with high density, and an effect of improving spectral efficiency
per area is exhibited. In the examination of the introduction of
the small cell, dual connectivity which is an operation in which a
prescribed terminal device consumes radio resources provided from
at least two different network points (master base station
apparatus and secondary base station apparatus) has been examined.
The details thereof are disclosed in NPL 2.
CITATION LIST
Non Patent Literature
[0007] NPL 1: 3rd Generation Partnership Project; Technical
Specification Group Radio Access Network; Evolved Universal
Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation
(Release 11), 3GPP TS 36.211 V11.5.0 (January 2014). [0008] NPL 2:
3rd Generation Partnership Project; Technical Specification Group
Radio Access Network; Small cell enhancements for E-UTRA and
E-UTRAN--Physical layer aspects (Release 12), 3GPP TR 36.872
V12.1.0 (December 2013).
SUMMARY OF INVENTION
Technical Problem
[0009] However, if the appropriate transmit power of the uplink
transmission is not configured for the master base station
apparatus and the secondary base station apparatus, a great
deterioration may be caused in transmission efficiency.
[0010] The invention has been made in view of such problems, and it
is an object of the invention to provide a base station apparatus,
a terminal device, a communication system, a communication method
and an integrated circuit which are capable of improving
transmission efficiency in the communication system in which the
base station apparatus and the terminal device communicate.
Solution to Problem
[0011] (1) In order to achieve the above-described object, the
present invention provides the following means. That is, a terminal
device according to the present embodiment is a terminal device
that communicates with a base station apparatus. The device
includes: a higher layer processing unit that configures a
discovery signal which includes cell-specific reference signals
present in DwPTSs of all downlink subframes and all special
subframes, a first synchronization signal present in a prescribed
subframe, a second synchronization signal present in a first
subframe, and one or more non-zero power CSI reference signals
during a period of continuous subframes in a predetermined cell;
and a reception unit that receives the discovery signal. A subframe
offset between the second synchronization signal and the non-zero
power CSI reference signal is independently configured for each of
the non-zero power CSI reference signals.
[0012] (2) In the terminal device according to the present
embodiment, a subframe in which the non-zero power CSI reference
signal is present is determined based on a subframe in which the
second synchronization signal is present and the subframe
offset.
[0013] (3) In the terminal device according to the present
embodiment, a subframe in which the non-zero power CSI reference
signal is present is a subframe subsequent to the subframe in which
the second synchronization signal is present during the period of
the continuous subframes.
[0014] (4) In the terminal device according to the present
embodiment, the higher layer processing unit configures the period
of the continuous subframes.
[0015] (5) In the terminal device according to the present
embodiment, the higher layer processing unit independently
configures a parameter for generating a pseudo-random sequence for
each of the non-zero power CSI reference signals.
[0016] (6) In the terminal device according to the present
embodiment, it is assumed that the terminal device does not
transmit a signal and a channel except for the discovery signal in
the predetermined cell in a case where at least the predetermined
cell is not activated.
[0017] (7) In the terminal device according to the present
embodiment, the higher layer processing unit independently
configures a parameter related to a quasi-co-location for each of
the non-zero power CSI reference signals.
[0018] (8) In the terminal device according to the present
embodiment, the higher layer processing unit configures one or more
zero power CSI reference signals, and a resource element indicated
by the zero power CSI reference signal is a resource element
assumed not to be used in transmission of a prescribed channel.
[0019] (9) There is provided a base station apparatus according to
the present embodiment is a base station apparatus that
communicates with a terminal device. The apparatus includes: a
higher layer processing unit that configures a discovery signal
which includes cell-specific reference signals present in DwPTSs of
all downlink subframes and all special subframes, a first
synchronization signal present in a prescribed subframe, a second
synchronization signal present in a first subframe, and one or more
non-zero power CSI reference signals for the terminal device during
a period of continuous subframes in a predetermined cell; and a
transmission unit that transmits the discovery signal. A subframe
offset between the second synchronization signal and the non-zero
power CSI reference signal is independently configured for each of
the non-zero power CSI reference signals.
[0020] (10) There is provided a communication method in a terminal
device that communicates with a base station apparatus according to
the present embodiment. The method includes: a step of configuring
a discovery signal which includes cell-specific reference signals
present in DwPTSs of all downlink subframes and all special
subframes, a first synchronization signal present in a prescribed
subframe, a second synchronization signal present in a first
subframe, and one or more non-zero power CSI reference signals
during a period of continuous subframes in a predetermined cell;
and a step of receiving the discovery signal. A subframe offset
between the second synchronization signal and the non-zero power
CSI reference signal is independently configured for each of the
non-zero power CSI reference signals.
[0021] (11) There is provided a communication method in a base
station apparatus that communicates with a terminal device
according to the present embodiment. The method includes: a step of
configuring a discovery signal which includes cell-specific
reference signals present in DwPTSs of all downlink subframes and
all special subframes, a first synchronization signal present in a
prescribed subframe, a second synchronization signal present in a
first subframe, and one or more non-zero power CSI reference
signals for the terminal device during a period of continuous
subframes in a predetermined cell; and a step of transmitting the
discovery signal. A subframe offset between the second
synchronization signal and the non-zero power CSI reference signal
is independently configured for each of the non-zero power CSI
reference signals.
[0022] As described above, it is possible to improve communication
efficiency between the terminal device and the base station
apparatus.
Advantageous Effects of Invention
[0023] According to the present invention, it is possible to
improve transmission efficiency in a wireless communication system
in which a base station apparatus and a terminal device communicate
with each other.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a conceptual diagram of a wireless communication
system according to the present embodiment.
[0025] FIG. 2 is a diagram showing a schematic structure of a radio
frame according to the present embodiment.
[0026] FIG. 3 is a diagram showing a structure of a slot according
to the present embodiment.
[0027] FIG. 4 is a diagram showing an example of the arrangement of
physical channels and physical signals in a downlink subframe
according to the present embodiment.
[0028] FIG. 5 is a diagram showing an example of the arrangement of
physical channels and physical signals in an uplink subframe
according to the present embodiment.
[0029] FIG. 6 is a diagram showing an example of the arrangement of
physical channels and physical signals in a special subframe
according to the present embodiment.
[0030] FIG. 7 is a schematic block diagram showing a structure of a
terminal device 1 according to the present embodiment.
[0031] FIG. 8 is a schematic block diagram showing a structure of a
base station apparatus 3 according to the present embodiment.
[0032] FIG. 9 is a diagram showing an example of a structure of
DRS.
[0033] FIG. 10 is a diagram showing an example of a structure of
CRS and/or a structure of DRS.
[0034] FIG. 11 is a diagram showing another example of a structure
of DRS.
[0035] FIG. 12 is a diagram showing an example of designation of a
resource element in configuration of DRS.
[0036] FIG. 13 is a diagram showing a measurement model.
[0037] FIG. 14 is a diagram showing an expression of a search space
of PDCCH and EPDCCH.
DESCRIPTION OF EMBODIMENTS
[0038] Hereinafter, embodiments of the present invention will be
described.
[0039] In the present embodiment, a plurality of cells may be
configured for a terminal device 1. Here, a technology in which the
terminal device 1 communicates through a plurality of cells is
referred to as cell aggregation, carrier aggregation, or dual
connectivity. The present invention may be applied to each of the
plurality of cells configured for the terminal device 1. The
present invention may be applied to some of the plurality of
configured cells. The cell configured for the terminal device 1 is
referred to as a serving cell.
[0040] In the carrier aggregation (CA), the plurality of configured
serving cells includes one primary cell (PCell), and one or a
plurality of secondary cells (SCell).
[0041] The primary cell is a serving cell in which an initial
connection establishment procedure is performed, a serving cell in
which a connection re-establishment procedure is started, or a cell
indicated as a primary cell in a handover procedure. The primary
cell is operated at a primary frequency. The secondary cell may be
configured when or after the connection is (re)established. The
secondary cell is operated at a secondary frequency. The connection
may be referred to as RRC connection.
[0042] One primary cell and one or more secondary cells are
aggregated for the terminal device 1 that supports the CA.
[0043] The dual connectivity is an operation in which a prescribed
terminal device 1 consumes radio resources provided from at least
two different network points (a master base station apparatus
(MeNB: master eNB) and a secondary base station apparatus (SeNB:
secondary eNB)). In other words, the dual connectivity means that
the terminal device 1 performs RRC connection in at least two
network points. In the dual connectivity, the terminal device 1 may
be connected in an RRC connection (RRC_CONNECTED) state and through
non-ideal backhaul.
[0044] In the dual connectivity, a base station apparatus 3 which
is connected to at least S1-Mobility Management Entity (MME) and
serves as mobility anchor of a core network is referred to as a
master base station apparatus. The base station apparatus 3 that is
not the master base station apparatus which provides additional
radio resources to the terminal device 1 is referred to as a
secondary base station apparatus. A group of serving cells
associated with the master base station apparatus is referred to as
a master cell group (MCG) and a group of serving cells associated
with the secondary base station apparatus is referred to a
secondary cell group (SCG) in some cases. The cell group may be a
serving cell group.
[0045] In the dual connectivity, the primary cell belongs to the
MCG. In the SCG, a secondary cell corresponding to the primary cell
is referred to as a primary secondary cell (pSCell). The pSCell is
referred as a special cell or a special secondary cell (SCell) in
some cases. The special SCell (the base station apparatus
constituting the special SCell) may be supported by the same
function (capability or performance) as that of the PCell (a base
station apparatus constituting the PCell). Only a part of the
function of the PCell may be supported by the pSCell. For example,
the pSCell may be supported by a function of transmitting PDCCH.
The pSCell may be supported by a function of performing the PDCCH
transmission by using a search space different from that of CSS or
USS. For example, the search space different from that of the USS
is a search space determined based on a value defined by the
specification, or a search space determined based on RNTI different
from that of C-RNTI. The pSCell may be constantly in an activated
state. The pSCell is a cell capable of receiving PUCCH.
[0046] In the dual connectivity, a radio bearer (data radio bearer
(DRB) and/or signalling radio bearer (SRB)) may be individually
assigned in the MeNB and the SeNB.
[0047] In the dual connectivity, a duplex mode may be individually
configured in the MCG and the SCG, or the PCell and the pSCell.
[0048] In the dual connectivity, the MCG and the SCG, or the PCell
and the pSCell may not be synchronized. That is, in the MCG and the
SCG or the PCell and the pSCell, the timing when the subframe is
started may not be synchronized. Hereinafter, the subframe number
of the MeNB, the MCG or the PCell is denoted by i, and the subframe
number of the SeNB, the SCG or the pSCell is denoted by j. The
subframe i of the MCG and the subframe j of the SCG overlap with
each other in a partial timing.
[0049] In the dual connectivity, a parameter (timing advance group:
TAG) for adjusting a plurality of timings may be configured in each
of the MCG and SCG (or the PCell and pSCell). That is, the MCG and
the SCG may be not be synchronized. In a case where different TAGs
are configured in the MCG and the SCG, the MCG and the SCG may not
be synchronized.
[0050] In the dual connectivity, the terminal device 1 transmits
UCI corresponding to the cell within the MCG to only the MeNB
(PCell), and transmits UCI corresponding to the cell within the SCG
to only the SeNB (pSCell). For example, the UCI is SR, HARQ-ACK,
and/or CSI. In the transmission of each UCI, a transmission method
using the PUCCH and/or the PUSCH is applied to each cell group.
[0051] All signals can be transmitted and received in the primary
cell, but there are signals that are not able to be transmitted and
received in the secondary cell. For example, physical uplink
control channels (PUCCHs) are transmitted only in the primary cell.
Physical random access channels (PRACHs) are transmitted only in
the primary cell between the cells as long as the plurality of
timing advance groups (TAGs) is not configured. Physical broadcast
channels (PBCHs) are transmitted only in the primary cell. Master
information blocks (MIB) are transmitted only on the primary
cell.
[0052] In the primary secondary cell, the signals that can be
transmitted and received in the primary cell are transmitted and
received. For example, the PUCCHs may be transmitted in the primary
secondary cell. The PRACHs may be transmitted in the primary
secondary cell irrespective of whether or not the plurality of TAGs
is configured. The PBCHs or the MIBs may be transmitted in the
primary secondary cell.
[0053] Radio link failure (RLF) is detected in the primary cell. In
the secondary cell, even though a condition in which the RLF is
detected is satisfied, it is not recognized that the RLF is
detected. In the primary secondary cell, if the condition is
satisfied, the RLF is detected. In the primary secondary cell, in a
case where the RLF is detected, a higher layer of the primary
secondary cell notifies a higher layer of the primary cell that the
RLF is detected.
[0054] In the primary cell and/or the primary secondary cell,
semi-persistent scheduling (SPS) or discontinuous transmission
(DRX) may be performed. The total number of SPS configurations and
DRX configurations may be determined by the total number of primary
cells and primary secondary cells. In the secondary cell, the same
DRX as that of the primary cell or the primary secondary cell of
the same cell group may be performed.
[0055] In the secondary cell, information/parameters related to the
configurations of the MAC are basically shared with the primary
cell/the primary secondary cell of the same cell group. A part (for
example, sTAG-Id) of the parameters may be configured for each
secondary cell.
[0056] A part of timers or counters may be applied to only the
primary cell and/or the primary secondary cell. The applied timer
or counter may be configured for only the secondary cell.
[0057] A frame structure type of a frequency division duplex (FDD)
or time division duplex (TDD) system is applied to a wireless
communication system according to the present embodiment. The frame
structure type is referred to as a frame format type or a duplex
mode in some cases. In the case of the cell aggregation, the TDD
system may be applied to all the plurality of cells. In the case of
the cell aggregation, the cells to which the TDD system is applied
and the cells to which the FDD system is applied may be aggregated.
In a case where the cells to which the TDD is applied and the cells
to which the FDD is applied are aggregated, the present invention
may be applied to the cells to which the TDD is applied.
[0058] A half-duplex FDD system or a full-duplex FDD system may be
applied to the cells to which the FDD is applied.
[0059] In a case where the plurality of cells to which the TDD is
applied is aggregated, a half-duplex TDD system or a full-duplex
TDD system may be applied.
[0060] The terminal device 1 transmits information indicating
combinations of bands in which the carrier aggregation is supported
by the terminal device 1 to the base station apparatus 3. The
terminal device 1 transmits information indicating whether or not
each of the combinations of the bands supports simultaneous
transmission and reception in the plurality of serving cells in a
plurality of different bands to the base station apparatus 3.
[0061] In the present embodiment, "X/Y" includes the meaning of "X
or Y". In the present embodiment, "X/Y" includes the meaning of "X
and Y". In the present embodiment, "X/Y" includes the meaning of "X
and/or Y".
[0062] FIG. 1 is a conceptual diagram of the wireless communication
system according to the present embodiment. In FIG. 1, the wireless
communication system includes terminal devices 1A to 1C, and the
base station apparatus 3. Hereinafter, the terminal devices 1A to
1C are referred to as the terminal devices 1.
[0063] Physical channels and physical signals according to the
present embodiment will be described.
[0064] In FIG. 1, uplink physical channels are used in uplink
wireless communication from the terminal devices 1 to the base
station apparatus 3. The uplink physical channel may be used to
transmit information output from the higher layer. The uplink
physical channel includes a physical uplink control channel
(PUCCH), a physical uplink shared channel (PUSCH), and a physical
random access channel (PRACH).
[0065] The PUCCH is the physical channel used to transmit uplink
control information (UCI). The uplink control information includes
channel state information (CSI) of the downlink, scheduling request
(SR) indicating a request for a PUSCH resource, and acknowledgement
(ACK)/negative-acknowledgement (NACK) of downlink data (transport
block (TB) or downlink-shared channel (DL-SCH)). The ACK/NACK is
also referred to as HARQ-ACK, HARQ feedback, or response
information.
[0066] The PUSCH is the physical channel used to transmit uplink
data (uplink-shared channel (UL-SCH)). The PUSCH may be used to
transmit the HARQ-ACK and/or the channel state information together
with the uplink data. The PUSCH may be used to transmit only the
channel state information, or only the HARQ-ACK and the channel
state information.
[0067] The PRACH is the physical channel used to transmit a random
access preamble. The PRACH is mainly used by the terminal device 1
to synchronize time domain with the base station apparatus 3. In
addition, the PRACH is used to indicate an initial connection
establishment procedure, a handover procedure, a connection
re-establishment procedure, synchronization (timing adjustment) of
uplink transmission, and a request for a PUSCH resource.
[0068] In FIG. 1, uplink physical signals are used in uplink
wireless communication. The uplink physical signal includes an
uplink reference signal (UL RS). As the uplink reference signal, a
demodulation reference signal (DMRS) and a sounding reference
signal (SRS) are used. The DMRS is associated with the transmission
of the PUSCH or the PUCCH. The DMRS is time-multiplexed with the
PUSCH or the PUCCH. The base station apparatus 3 uses the DMRS in
order to perform channel compensation of the PUSCH or the PUCCH.
Hereinafter, the transmission of both the PUSCH and the DMRS is
simply referred to as the transmission of the PUSCH. Hereinafter,
the transmission of both of the PUCCH and the DMRS is simply
referred to as the transmission of the PUCCH. The DMRS of the
uplink is also referred to as UL-DMRS. The SRS is not associated
with the transmission of the PUSCH or the PUCCH. The base station
apparatus 3 uses the SRS in order to measure a channel state of the
uplink.
[0069] As the SRS, there are two trigger types of SRSs (trigger
type 0 SRS, and trigger type 1 SRS). The trigger type 0 SRS is
transmitted by higher layer signalling in a case where a parameter
related to the trigger type 0 SRS is configured. The trigger type 1
SRS is transmitted by higher layer signalling in a case where a
parameter related to the trigger type 1 SRS is configured and
transmission is requested by an SRS request included in DCI formats
0/1A/2B/2C/2D/4. The SRS request is included in both the FDD and
the TDD for the DCI formats 0/1A/4, and is included only in the TDD
for the DCI formats 2B/2C/2D. In a case where the transmission of
the trigger type 0 SRS and the transmission of the trigger type 1
SRS occur in the same subframe of the same serving cell, the
transmission of the trigger type 1 SRS is prioritized.
[0070] In FIG. 1, downlink physical channels are used in downlink
wireless communication from the base station apparatus 3 to the
terminal device 1. The downlink physical channels are used to
transmit information output from the higher layer. The downlink
physical channel includes a physical broadcast channel (PBCH), a
physical control format indicator channel (PCFICH), a physical
hybrid automatic repeat request indicator channel (PHICH), a
physical downlink control channel (PDCCH), an enhanced physical
downlink control channel (EPDCCH), a physical downlink shared
channel (PDSCH), and a physical multicast channel (PMCH).
[0071] The PBCH is used to broadcast a master information block
(MIB, broadcast channel (BCH)) which is commonly used in the
terminal devices 1. The MIB may be updated at an interval of 40 ms.
The PBCH is iteratively transmitted at a cycle of 10 ms.
Specifically, initial transmission of the MIB is performed in a
subframe 0 in a radio frame that satisfies SFN mod 4=0, and
repetition of the MIB in the subframe 0 in all other radio frames
is performed. A system frame number (SFN) is a radio frame number
(system frame number). The MIB is system information. For example,
the MIB includes information indicating the SFN.
[0072] The PCFICH is used to transmit information indicating a
region (OFDM symbol) used to transmit the PDCCH.
[0073] The PHICH is used to transmit an HARQ indicator (HARQ
feedback or response information) indicating the acknowledgement
(ACK) or the negative acknowledgement (NACK) of the uplink data
(uplink shared channel (UL-SCH)) received by the base station
apparatus 3. For example, in a case where the terminal device 1
receives the HARQ indicator indicating the ACK, the corresponding
uplink data is not retransmitted. For example, in a case where the
terminal device 1 receives the HARQ indicator indicating the NACK,
the corresponding uplink data is retransmitted. A single PHICH is
used to transmit the HARQ indicator corresponding to single uplink
data. The base station apparatus 3 respectively transmits HARQ
indicators corresponding to a plurality of uplink data items
included in the same PUSCH by using a plurality of PHICHs.
[0074] The PDCCH and the EPDCCH are used to transmit downlink
control information (DCI). The downlink control information is also
referred to as a DCI format. The downlink control information
includes a downlink grant and an uplink grant. The downlink grant
is also referred to as downlink assignment or downlink
allocation.
[0075] The PDCCH is transmitted by the aggregation of one or a
plurality of continuous control channel elements (CCE). The CCE
includes 9 resource element groups (REGs). The REG includes 4
resource elements. The PDCCH constituted by n number of continuous
CCEs is started with a CCE that satisfies i mod n=0. Here, i is a
CCE number.
[0076] The EPDCCH is transmitted by the aggregation of one or a
plurality of continuous enhanced control channel elements (ECCEs).
The ECCE includes a plurality of enhanced resource element groups
(EREGs).
[0077] The downlink grant is used in scheduling a single PDSCH
within a single cell. The downlink grant is used in scheduling a
PDSCH within the same subframe as a subframe in which the downlink
grant is transmitted. The uplink grant is used in scheduling a
single PUSCH within a single cell. The uplink grant is used in
scheduling a single PUSCH within a subframe which is positioned
after four or more subframes from a subframe in which the uplink
grant is transmitted.
[0078] A cyclic redundancy check (CRC) parity bit is added to the
DCI format. The CRC parity bit is scrambled with a radio network
temporary identifier (RNTI). The RNTI is an identifier capable of
being defined or configured depending on the purpose of the DCI.
The RNTI is an identifier predefined in the specifications, an
identifier configured as information specific to the cell, an
identifier configured as information specific to the terminal
device 1, or an identifier configured as information specific to a
group belonging to the terminal devices 1. For example, the CRC
parity bit is scrambled with a cell-radio network temporary
identifier (C-RNTI), or a semi persistent scheduling cell-radio
network temporary identifier (SPS C-RNTI). The C-RNTI and the SPS
C-RNTI are identifiers for identifying the terminal devices 1
within the cell. The C-RNTI is used to control the PDSCH or the
PUSCH in a single subframe. The SPS C-RNTI is used to periodically
assign the PDSCH or PUSCH resource.
[0079] The PDSCH is used to transmit downlink data (downlink shared
channel (DL-SCH)). The PDSCH is used to transmit control
information of the higher layer.
[0080] The PMCH is used to transmit multicast data (multicast
channel (MCH)).
[0081] In FIG. 1, the following downlink physical signals are used
in downlink wireless communication. The downlink physical signal
includes a synchronization signal (SS), and a downlink reference
signal (DL RS).
[0082] The synchronization signal is used by the terminal device 1
to synchronize the frequency domain and the time domain of the
downlink. The synchronization signal is allocated to a prescribed
subframe within the radio frame. For example, in the TDD system,
the synchronization signals are allocated to subframes 0, 1, 5, and
6 within the radio frame. In the FDD system, the synchronization
signals are allocated to the subframes 0 and 5 within the radio
frame.
[0083] As the synchronization signal, there are a primary
synchronization signal (PSS) and a secondary synchronization signal
(SSS). The PSS is used to perform coarse frame/symbol timing
synchronization (synchronization of the time domain) or to identify
cell group. The SSS is used to more accurately perform frame timing
synchronization and to identify the cell. That is, the frame timing
synchronization and the cell identification can be performed using
the PSS and the SSS.
[0084] The downlink reference signal is used by the terminal device
1 to perform channel compensation of the downlink physical channel.
The downlink reference signal is used by the terminal device 1 to
calculate channel state information of the downlink. The downlink
reference signal is used by the terminal device 1 to measure a
geographical position of the terminal device.
[0085] The downlink reference signal includes a cell-specific
reference signal (CRS), a UE-specific reference signal (URS)
associated with the PDSCH, a demodulation reference signal (DMRS)
associated with the EPDCCH, a non-zero power channel state
information-reference signal (NZP CSI-RS), a multimedia broadcast
and multicast service over single frequency network reference
signal (MBSFN RS), a positioning reference signal (PRS), a new
carrier type cell-specific reference signal (NCT CRS), and a
discovery reference signal (DRS). The resource of the downlink
includes a zero power channel state information-reference signal
(ZP CSI-RS), and channel state information-interference measurement
(CSI-IM).
[0086] The CRS is transmitted in all bands of the subframe. The CRS
is used to demodulate the PBCH/PDCCH/PHICH/PCFICH/PDSCH. The CRS
may be used by the terminal device 1 to calculate channel state
information of the downlink. The PBCH/PDCCH/PHICH/PCFICH is
transmitted through an antenna port used to transmit the CRS.
[0087] The URS associated with the PDSCH is transmitted in the band
and the subframe used to transmit the PDSCH associated with the
URS. The URS is used to demodulate the PDSCH with which the URS is
associated.
[0088] The PDSCH is transmitted through an antenna port used to
transmit the CRS or the URS based on a transmission mode and a DCI
format. A DCI format 1A is used to schedule the PDSCH transmitted
through the antenna port used to transmit the CRS. A DCI format 2D
is used to schedule the PDSCH transmitted through the antenna used
to transmit the URS.
[0089] The DMRS associated with the EPDCCH is transmitted in the
band and the subframe used to transmit the EPDCCH with which the
DMRS is associated. The DMRS is used to demodulate the EPDCCH with
which the DMRS is associated. The EPDCCH is transmitted through an
antenna port used to transmit the DMRS.
[0090] The NZP CSI-RS is transmitted in the configured subframe.
The resource in which the NZP CSI-RS is transmitted is configured
by the base station apparatus 3. The NZP CSI-RS is used by the
terminal device 1 to calculate channel state information of the
downlink. The terminal device 1 performs signal measurement
(channel measurement) by using the NZP CSI-RS.
[0091] The resource of the ZP CSI-RS is configured by the base
station apparatus 3. The base station apparatus 3 transmits the
CSI-RS at zero power in the ZP CSI-RS resource. That is, the base
station apparatus 3 does not transmit the CSI-RS in the ZP CSI-RS
resource. The base station apparatus 3 transmits the ZP CSI-RS at
zero power. That is, the base station apparatus 3 does not transmit
the ZP CSI-RS. The base station apparatus 3 does not transmit the
PDSCH and the EPDCCH in the configured resource of the ZP
CSI-RS.
[0092] The resource of the CSI-IM is configured by the base station
apparatus 3. The resource of the CSI-IM is configured so as to
overlap a part of the resource of the ZP CSI-RS. That is, the
resource of the CSI-IM has the same characteristics as those of the
ZP CSI-RS, and the base station apparatus 3 transmits the CSI-IM at
zero power in the configured resource. That is, the base station
apparatus 3 does not transmit the CSI-IM. The base station
apparatus 3 does not transmit the PDSCH and the EPDCCH in the
configured resource of the CSI-IM. The terminal device 1 may
measure resource interference configured as the CSI-IM in the
resource corresponding to the NZP CSI-RS in a certain cell.
[0093] Hereinafter, the details of the mapping of the
channel-state-measurement reference signal (CSI-RS) to the resource
element will be described.
[0094] For the sake of convenience in the description, the resource
elements indicated by C1 to C4 are considered in one RB pair. Each
of the resource elements indicated by C1 to C4 is indicated by two
resource elements. The CSI-RSs of the antenna ports 15 to 22 are
mapped using the resource elements indicated by C1 to C4. The
resource elements indicated by C1 to C4 indicate the CSI-RSs of a
code division multiplexing (CDM) group 1 to a CDM group 4. The
CSI-RS includes a quadrature sequence (quadrature code) using Walsh
code and a scrambling code using a pseudo-random sequence. The code
division multiplexing is performed on the CSI-RSs using the
quadrature code such as the Walsh code within the CDM group. The
frequency division multiplexing (FDM) is mutually performed on the
CSI-RSs between the CDM groups.
[0095] The CSI-RSs of the antenna ports 15 and 16 are mapped to C1,
the CSI-RSs of the antenna ports 17 and 18 are mapped to C2, the
CSI-RSs of the antenna ports 19 and 20 are mapped to C3, and the
CSI-RSs of the antenna ports 21 and 22 are mapped to C4.
[0096] As the number of antenna ports of the CSI-RSs, a plurality
of antenna ports is defined. That is, the CSI-RSs of a prescribed
number of antenna ports are configured for the terminal device 1.
The prescribed number is 1, 2, 4 or 8. The CSI-RSs may be
configured as the reference signals corresponding to eight antenna
ports of the antenna ports 15 to 22. The CSI-RSs may be configured
as the reference signals corresponding to four antenna ports of the
antenna ports 15 to 18. The CSI-RSs may be configured as the
reference signals corresponding to two antenna ports of the antenna
ports 15 to 16. The CSI-RSs may be configured as the reference
signals corresponding to one antenna port of the antenna port
15.
[0097] The CSI-RSs may be mapped to some subframes, and may be
mapped to, for example, every plurality of subframes. The resource
elements to which the CSI-RSs are mapped may be different from the
resource elements shown in FIG. 4.
[0098] As the mapping pattern of the CSI-RSs to the resource
elements, a plurality of mapping pattern is defined. The base
station apparatus 3 may configure the plurality of CSI-RSs for the
terminal device 1.
[0099] The CSI-RS may set the transmit power to be zero. The CSI-RS
of which the transmit power is zero is also referred to as
zero-power CSI-RS. The zero-power CSI-RS is independently
configured of the CSI-RSs of the antenna ports 15 to 22. The
CSI-RSs of the antenna ports 15 to 22 are referred to as
non-zero-power CSI-RSs.
[0100] The base station apparatus 3 configures the CSI-RS as
UE-specific control information for the terminal device 1 through
RRC signaling. The CSI-RS is configured for the terminal device 1
through the RRC signaling by the base station apparatus 3. The
CSI-IM resource which is a resource for measuring an interference
power may be configured for the terminal device 1. The terminal
device 1 generates feedback information using the CRS, the CSI-RS
and/or the CSI-IM resource based on the configuration from the base
station apparatus 3.
[0101] As the channel state information (CSI), there are a channel
quality indicator (CQI), a precoding matrix indicator (PMI), a rank
indicator (RI), and a precoding type indicator (PTI). The channel
state information is measured using the CSI-RS or the CRS.
[0102] The MBSFN RS is transmitted in all the bands of the subframe
used to transmit the PMCH. The MBSFN RS is used to demodulate the
PMCH. The PMCH is transmitted through an antenna used to transmit
the MBSFN RS.
[0103] The PRS is used by the terminal device 1 to measure the
geographical position of the terminal device.
[0104] The NCT CRS may be mapped to a prescribed subframe. For
example, the NCT CRS is mapped to the subframes 0 and 5. The NCT
CRS may have the same structure as that of a part of the CRS. For
example, in each resource block, the positions of the resource
elements to which the NCT CRS is mapped may be the same as the
positions of the resource elements to which the CRS of the antenna
port 0 is mapped. A sequence (value) used for the NCT CRS may be
determined based on information configured through the PBCH, PDCCH,
EPDCCH or PDSCH (RRC signaling). A sequence (value) used for the
NCT CRS may be determined based on a parameter such as a cell ID
(for example, a physical layer cell identity) or a slot number. A
sequence (value) used for the NCT CRS may be determined by a method
(expression) different from a sequence (value) used for the CRS of
the antenna port 0. The NCT CRS may be referred to as a tracking
reference signal (TRS).
[0105] The downlink physical channel and the downlink physical
signal are generically referred to as a downlink signal. The uplink
physical channel and the uplink physical signal are generically
referred to as an uplink signal. The downlink physical channel and
the uplink physical channel are generically referred to as a
physical channel. The downlink physical signal and the uplink
physical signal are generically referred to as a physical
signal.
[0106] The BCH, MCH, UL-SCH and DL-SCH are transport channels. A
channel used in a medium access control (MAC) layer is referred to
as a transport channel. A unit of the transport channel used in the
MAC layer is also referred to as a transport block (TB) or a MAC
protocol data unit (PDU). Hybrid automatic repeat request (HARQ) is
controlled for each transport block in the MAC layer. The transport
block is a unit of data which is delivered to a physical layer by
the MAC layer. In the physical layer, the transport block is mapped
to a code word, and a coding process is performed on each code
word.
[0107] As a method of signaling (notifying and broadcasting)
control information to the terminal device 1 from the base station
apparatus 3, PDCCH signaling which is signaling through the PDCCH,
RRC signaling which is signaling through the RRC layer, and MAC
signaling which is signaling through the MAC layer are used. The
RRC signaling is dedicated RRC signaling for notifying of control
information specific to the terminal device 1 or common RRC
signaling for notifying of control information specific to the base
station apparatus 3. In the following description, in a case where
the RRC signaling is simply described, the RRC signaling is the
dedicated RRC signaling and/or the common RRC signaling. The
signaling, such as the RRC signaling or MAC CE, used in a layer
higher than the physical layer is referred to as higher layer
signalling.
[0108] Hereinafter, a structure of the radio frame according to the
present embodiment will be described.
[0109] FIG. 2 is a diagram showing a schematic structure of the
radio frame according to the present embodiment. Each radio frame
has a length of 10 ms. Each radio frame includes two half frames.
Each half frame has a length of 5 ms. Each half frame includes 5
subframes. Each subframe has a length of 1 ms, and is defined by
two continuous slots. Each slot has a length of 0.5 ms. An i-th
subframe within the radio frame includes a (2xi)-th slot and a
(2xi+1)-th slot. That is, each radio frame is defined by 10
subframes.
[0110] The subframe includes a downlink subframe (first subframe),
an uplink subframe (second subframe), and a special subframe (third
subframe).
[0111] The downlink subframe is a subframe reserved for downlink
transmission. The uplink subframe is a subframe reserved for uplink
transmission. The special subframe includes 3 fields. The three
fields are a downlink pilot time slot (DwPTS), a guard period (GP),
and an uplink pilot time slot (UpPTS). The total length of the
DwPTS, GP and UpPTS is 1 ms. The DwPTS is a field reserved for
downlink transmission. The UpPTS is a field reserved for uplink
transmission. The GP is a field in which the downlink transmission
and the uplink transmission are not performed. The special subframe
may include only the DwPTS and the GP, or may include only the GP
and the UpPTS. The special subframe is arranged between the
downlink subframe and the uplink subframe in the TDD, and is used
to switch the subframe from the downlink subframe to the uplink
subframe.
[0112] A single radio frame includes the downlink subframe, the
uplink subframe, and/or the special subframe. That is, the radio
frame may include only the downlink subframe. The radio frame may
include only the uplink subframe.
[0113] The wireless communication system according to the present
embodiment supports downlink-to-uplink switch-point periodicities
of 5 ms and 10 ms. In a case where the downlink-to-uplink
switch-point periodicity is 5 ms, the special subframes are
included in both the half frames within the radio frame. In a case
where the downlink-to-uplink switch-point periodicity is 10 ms, the
special subframe is included only in an initial half frame within
the radio frame.
[0114] Hereinafter, a structure of the slot according to the
present embodiment will be described.
[0115] FIG. 3 is a diagram showing a structure of the slot
according to the present embodiment. In the present embodiment,
normal cyclic prefix (CP) is applied to an OFDM symbol. Extended
cyclic prefix (CP) may be applied to the OFDM symbol. The physical
signal or the physical channel transmitted in each slot is
represented by a resource grid. In the downlink, the resource grid
is defined by a plurality of subcarriers in a frequency direction
and a plurality of OFDM symbols in a time direction. In the uplink,
the resource grid is defined by a plurality of subcarriers in a
frequency direction and a plurality of SC-FDMA symbols in a time
direction. The number of subcarriers or resource blocks depends on
a bandwidth of the cell. The number of OFDM symbols or SC-FDMA
symbols constituting one slot is 7 in the case of the normal CP and
is 6 in the case of the enhanced CP. Each element within the
resource grid is referred to as a resource element. The resource
element is identified using a subcarrier number and an OFDM symbol
or SC-FDMA symbol number.
[0116] The resource block is used to be mapped to the resource
element of a certain physical channel (PDSCH or PUSCH). The
resource block is defined by a virtual resource block and a
physical resource block. The certain physical channel is initially
mapped to by virtual resource block. Thereafter, the virtual
resource block is mapped to the physical resource block. One
physical resource block is defined by 7 continuous OFDM symbols or
SC-FDMA symbols in the time domain and 12 continuous subcarriers in
the frequency domain. In addition, one physical resource block
includes (7.times.12) number of resource elements. One physical
resource block corresponds to one slot in the time domain, and
corresponds to 180 kHz in the frequency domain. Numbers from 0 are
assigned to the physical resource blocks in the frequency domain.
Two resource blocks within one subframe which correspond to the
same physical resource block number are defined as a physical
resource block pair (PRB pair or RB pair).
[0117] Hereinafter, the physical channel and the physical signal
transmitted in each subframe will be described.
[0118] FIG. 4 is a diagram showing an example of the arrangement of
the physical channels and the physical signals in the downlink
subframe according to the present embodiment. The base station
apparatus 3 may transmit the downlink physical channel (PBCH,
PCFICH, PHICH, PDCCH, EPDCCH, or PDSCH) and/or the downlink
physical signal (synchronization signal or downlink reference
signal) in the downlink subframe. The PBCH is transmitted only in
the subframe 0 within the radio frame. The downlink reference
signals are allocated to the resource elements distributed in the
frequency domain and the time domain. In order to simplify the
description, the downlink reference signals are not shown in FIG.
4.
[0119] In PDCCH regions, a plurality of PDCCHs may be frequency-,
time- and/or spatial-multiplexed. In EPDCCH regions, a plurality of
EPDCCHs may be frequency-, time- and/or spatial-multiplexed. In
PDSCH regions, a plurality of PDSCHs may be frequency-, time-
and/or spatial-multiplexed. The PDCCHs, PDSCHs and/or EPDCCHs may
be frequency-, time- and/or spatial-multiplexed.
[0120] FIG. 5 is a diagram showing an example of the arrangement of
the physical channels and the physical signals in the uplink
subframe according to the present embodiment. The terminal device 1
may transmit the uplink physical channel (PUCCH, PUSCH, or PRACH),
and the uplink physical signal (UL-DMRS or SRS) in the uplink
subframe. In PUCCH regions, a plurality of PUCCHs is frequency-,
time-, spatial- and/or code-multiplexed. In PUSCH regions, a
plurality of PUSCHs may be frequency-, time-, spatial- and/or
code-multiplexed. The PUCCHs and the PUSCHs may be frequency-,
time-, spatial- and/or code-multiplexed. The PRACH may be allocated
to a single subframe or over two subframes. A plurality of PRACHs
may be code-multiplexed.
[0121] The SRS is transmitted using the last SC-FDMA symbol within
the uplink subframe. That is, the SRS is allocated to the last
SC-FDMA symbol within the uplink subframe. The terminal device 1
may restrict the simultaneous transmission of the SRS and the
PUCCH/PUSCH/PRACH in a single SC-FDMA symbol of a single cell. In a
single uplink subframe of a single cell, the terminal device 1 may
transmit the PUSCH and/or the PUCCH by using the SC-FDMA symbol
except for the last SC-FDMA symbol within the uplink subframe, and
may transmit the SRS by using the last SC-FDMA symbol within the
uplink subframe. That is, the terminal device 1 may transmit the
SRS, the PUSCH and the PUCCH in a single uplink subframe of a
single cell. The DMRS is time-multiplexed with the PUCCH or the
PUSCH. In order to simplify the description, the DMRS is not shown
in FIG. 5.
[0122] FIG. 6 is a diagram showing an example of the arrangement of
the physical channels and the physical signals in the special
subframe according to the present embodiment. In FIG. 6, the DwPTS
includes first to tenth SC-FDMA symbols within the special
subframe, the GP includes eleventh and twelfth SCFDMA symbols
within the special subframe, and the UpPTS includes thirteenth and
fourteenth SC-FDMA symbols within the special subframe.
[0123] The base station apparatus 3 may transmit the PCFICH, the
PHICH, the PDCCH, the EPDCCH, the PDSCH, the synchronization
signal, and the downlink reference signal in the DwPTS of the
special subframe. The base station apparatus 3 may restrict the
transmission of the PBCH in the DwPTS of the special subframe. The
terminal device 1 may transmit the PRACH and the SRS in the UpPTS
of the special subframe. That is, the terminal device 1 may
restrict the transmission of the PUCCH, the PUSCH and the DMRS in
the UpPTS of the special subframe.
[0124] FIG. 7 is a schematic block diagram showing a structure of
the terminal device 1 according to the present embodiment. As shown
in the drawing, the terminal device 1 includes a higher layer
processing unit 101, a control unit 103, a reception unit 105, a
transmission unit 107, and a transmit and receive antenna 109. The
higher layer processing unit 101 includes a radio resource control
unit 1011, a subframe configuration unit 1013, a scheduling
information interpretation unit 1015, and a channel state
information (CSI) report control unit 1017. The reception unit 105
includes a decoding unit 1051, a demodulation unit 1053, a
demultiplexing unit 1055, a wireless reception unit 1057, and a
channel measurement unit 1059. The transmission unit 107 includes a
coding unit 1071, a modulation unit 1073, a multiplexing unit 1075,
a wireless transmission unit 1077, and an uplink reference signal
generation unit 1079.
[0125] The higher layer processing unit 101 outputs uplink data
(transport block) generated through an operation of a user to the
transmission unit 107. The higher layer processing unit 101
performs processes of a medium access control (MAC) layer, a packet
data convergence protocol (PDCP) layer, a radio link control (RLC)
layer and a radio resource control (RRC) layer. In a case where the
carrier aggregation is performed, the higher layer processing unit
101 has a function of controlling the physical layer in order to
perform the activation/deactivation of the cell, and a function of
controlling the physical layer in order to manage the transmission
timing of the uplink. The higher layer processing unit 101 has a
function of determining whether or not to instruct the measurement
to be calculated in the reception unit 105 and to report the
measurement result calculated in the reception unit 105.
[0126] The radio resource control unit 1011 included in the higher
layer processing unit 101 manages various configuration information
items of the terminal device. The radio resource control unit 1011
generates information allocated to each channel of the uplink, and
outputs the allocated information to the transmission unit 107.
[0127] The subframe configuration unit 1013 included in the higher
layer processing unit 101 manages a subframe configuration in the
base station apparatus 3 and/or the base station apparatus (for
example, the base station apparatus 3A) different from the base
station apparatus 3 based on the information configured by the base
station apparatus 3. For example, the subframe configuration is a
configuration of the uplink or the downlink for the subframe. The
subframe configuration includes a subframe pattern configuration,
an uplink-downlink configuration, an uplink reference UL-DL
configuration (uplink reference configuration), a downlink
reference UL-DL configuration (downlink reference configuration),
and/or a transmission direction UL-DL configuration (transmission
direction configuration). The subframe configuration unit 1013 sets
the subframe configuration, the subframe pattern configuration, the
uplink-downlink configuration, the uplink reference UL-DL
configuration, the downlink reference UL-DL configuration, and/or
the transmission direction UL-DL configuration. The subframe
configuration unit 1013 may set at least two subframe sets. The
subframe pattern configuration includes an EPDCCH subframe
configuration. The subframe configuration unit 1013 is also
referred to as a terminal subframe configuration unit.
[0128] The scheduling information interpretation unit 1015 included
in the higher layer processing unit 101 interprets the DCI format
(scheduling information) received through the reception unit 105,
generates control information in order to control the reception
unit 105 and the transmission unit 107 based on the result acquired
by interpreting the DCI format, and outputs the generated control
information to the control unit 103.
[0129] The scheduling information interpretation unit 1015
determines timings when a transmission process and a reception
process are performed based on the subframe configuration, the
subframe pattern configuration, the uplink-downlink configuration,
the uplink reference UL-DL configuration, the downlink reference
UL-DL configuration, and/or the transmission direction UL-DL
configuration.
[0130] The CSI report control unit 1017 identifies a CSI reference
resource. The CSI report control unit 1017 instructs the channel
measurement unit 1059 to derive a CQI associated with the CSI
reference resource. The CSI report control unit 1017 instructs the
transmission unit 107 to transmit the CQI. The CSI report control
unit 1017 sets the configuration used when the channel measurement
unit 1059 calculates the CQI.
[0131] The control unit 103 generates control signals for
controlling the reception unit 105 and the transmission unit 107
based on the control information from the higher layer processing
unit 101. The control unit 103 outputs the generated control
signals to the reception unit 105 and the transmission unit 107,
and controls the reception unit 105 and the transmission unit
107.
[0132] The reception unit 105 separates, demodulates and decodes
the reception signal received by the transmit and receive antenna
109 from the base station apparatus 3 based on the control signal
input from the control unit 103. The reception unit 105 outputs the
decoded information to the higher layer processing unit 101.
[0133] The wireless reception unit 1057 converts the downlink
signal received by the transmit and receive antenna 109 into an
intermediate frequency (performs down conversion), removes an
unnecessary frequency components, controls an amplification level
such that a signal level is appropriately maintained, performs
orthogonal demodulation based on in-phase components and quadrature
components of the received signal, and converts an analog signal
acquired through the orthogonal demodulation into a digital signal.
The wireless reception unit 1057 removes components equivalent to
guard intervals (GIs) from the converted digital signal, performs
fast Fourier transform (FFT) on the signal acquired by removing the
guard intervals, and extracts a signal in the frequency domain.
[0134] The demultiplexing unit 1055 separates the extracted signal
into the PHICH, the PDCCH, the EPDCCH, the PDSCH, and/or the
downlink reference signal. The demultiplexing unit 1055 compensates
the channel of the PHICH, the PDCCH, the EPDCCH, and/or the PDSCH
from an estimation value of the channel input from the channel
measurement unit 1059. The demultiplexing unit 1055 outputs the
separated downlink reference signal to the channel measurement unit
1059.
[0135] The demodulation unit 1053 multiplies the PHICH by a
corresponding code to combine them, performs demodulation of a
binary phase shift keying (BPSK) modulation scheme on the combined
signal, and outputs the demodulated signal to the decoding unit
1051. The decoding unit 1051 decodes the PHICH addressed to the
terminal device, and outputs the decoded HARQ indicator to the
higher layer processing unit 101. The demodulation unit 1053
performs modulation of a QPSK modulation scheme on the PDCCH and/or
the EPDCCH, and outputs the demodulated PDCCH and/or the EPDCCH to
the decoding unit 1051. The decoding unit 1051 tries to decode the
PDCCH and/or the EPDCCH, and outputs the decoded downlink control
information and the RNTI corresponding to the downlink control
information to the higher layer processing unit 101 in a case where
the decoding succeeds.
[0136] The demodulation unit 1053 performs demodulation of a
modulation scheme, such as quadrature phase shift keying (QPSK), 16
quadrature amplitude modulation (QAM), 64-QAM, which is notified
through the downlink grant, on the PDSCH, and outputs the
demodulated PDSCH to the decoding unit 1051. The decoding unit 1051
performs decoding based on information related to a coding rate
notified through the downlink control information, and outputs the
decoded downlink data (transport block) to the higher layer
processing unit 101.
[0137] The channel measurement unit 1059 measures a path loss of
the downlink or a state of the channel from the downlink reference
signal input from the demultiplexing unit 1055, and outputs the
measured path loss and channel state to the higher layer processing
unit 101. The channel measurement unit 1059 calculates an
estimation value of the channel of the downlink from the downlink
reference signal, and outputs the estimation value to the
demultiplexing unit 1055. In order to calculate the CQI, the
channel measurement unit 1059 performs channel measurement and/or
interference measurement. The channel measurement unit 1059
performs measurement for notifying the higher layer from the
downlink reference signal input from the demultiplexing unit 1055.
The channel measurement unit 1059 calculates the RSRP and the RSRQ,
and outputs the calculated RSRP and RSRQ to the higher layer
processing unit 101.
[0138] According to the control signal input from the control unit
103, the transmission unit 107 generates the uplink reference
signal, codes and modulates the uplink data (transport block) input
from the higher layer processing unit 101, multiplexes the PUCCH,
the PUSCH, and the generated uplink reference signal, and transmits
the multiplexed signal to the base station apparatus 3 through the
transmit and receive antenna 109.
[0139] The coding unit 1071 performs coding such as convolutional
coding or block coding on the uplink control information input from
the higher layer processing unit 101. The coding unit 1071 performs
turbo coding based on information used in scheduling the PUSCH.
[0140] The modulation unit 1073 modulates coding bits input from
the coding unit 1071 by using a modulation scheme, such as BPSK,
QPSK, 16-QAM or 64-QAM, which is notified through the downlink
control information, or a modulation scheme previously determined
for each channel. The modulation unit 1073 determines the number of
sequences of data which is spatial-multiplexed based on the
information used in scheduling the PUSCH, maps a plurality of
uplink data items transmitted through the same PUSCH by using
multiple input multiple output spatial multiplexing (MIMO SM) to a
plurality of sequences, and performs precoding on the
sequences.
[0141] The uplink reference signal generation unit 1079 generates a
sequence acquired by a predetermined rule (expression) based on
physical cell identity (PCI) (referred to as Cell ID) for
identifying the base station apparatus 3, a bandwidth to which the
uplink reference signal is allocated, a cyclic shift notified
through the uplink grant, and a parameter value for generating a
DMRS sequence. According to the control signal input from the
control unit 103, the multiplexing unit 1075 rearranges the
modulation symbols of the PUSCH in parallel, and then performs
discrete Fourier transform (DFT). The multiplexing unit 1075
multiplexes the PUCCH and PUSCH signals and the generated uplink
reference signal for each transmit antenna port. That is, the
multiplexing unit 1075 arranges the PUCCH and PUSCH signals and the
generated uplink reference signal in the resource elements for each
transmit antenna port.
[0142] The wireless transmission unit 1077 performs inverse fast
Fourier transform (IFFT) on the multiplexed signal, performs
modulation of an SC-FDMA scheme, adds the guard intervals to the
SC-FDMA symbols acquired through the SC-FDMA modulation, and
generates a baseband digital signal. The wireless transmission unit
converts the baseband digital signal into an analog signal,
generates in-phase components and quadrature components of the
intermediate frequency from the analog signal, removes excessive
frequency components in the intermediate frequency band, converts
the signal having the intermediate frequency into a signal having a
high frequency (performs up conversion), and removes excessive
frequency components. The transmission unit amplifies power, and
outputs and transmits the amplified signal to the transmit and
receive antenna 109.
[0143] FIG. 8 is a schematic block diagram showing a structure of
the base station apparatus 3 according to the present embodiment.
As shown in the drawing, the base station apparatus 3 includes a
higher layer processing unit 301, a control unit 303, a reception
unit 305, a transmission unit 307, and a transmit and receive
antenna 309. The higher layer processing unit 301 includes a radio
resource control unit 3011, a subframe configuration unit 3013, a
scheduling unit 3015, and a CSI report control unit 3017. The
reception unit 305 includes a decoding unit 3051, a demodulation
unit 3053, a demultiplexing unit 3055, a wireless reception unit
3057, and a channel measurement unit 3059. The transmission unit
307 includes a coding unit 3071, a modulation unit 3073, a
multiplexing unit 3075, a wireless transmission unit 3077, and a
downlink reference signal generation unit 3079.
[0144] The higher layer processing unit 301 performs the processes
of the medium access control (MAC) layer, the packet data
convergence protocol (PDCP) layer, the radio link control (RLC)
layer and the radio resource control (RRC) layer. The higher layer
processing unit 301 generates control information in order to
control the reception unit 305 and the transmission unit 307, and
outputs the generated control information to the control unit 303.
The higher layer processing unit 301 having a function of acquiring
the reported measurement result.
[0145] The radio resource control unit 3011 included in the higher
layer processing unit 301 generates downlink data (transport
block), system information, RRC message or MAC control element (CE)
which is allocated to the PDSCH of the downlink or acquires the
information from a higher node, and outputs the generated or
acquired information to the transmission unit 307. The radio
resource control unit 3011 manages various configuration
information items of each terminal device 1.
[0146] The subframe configuration unit 3013 included in the higher
layer processing unit 301 manages the subframe configuration, the
subframe pattern configuration, the uplink-downlink configuration,
the uplink reference UL-DL configuration, the downlink reference
UL-DL configuration, and/or the transmission direction UL-DL
configuration for each terminal device 1. The subframe
configuration unit 3013 sets the subframe configuration, the
subframe pattern configuration, the uplink-downlink configuration,
the uplink reference UL-DL configuration, the downlink reference
UL-DL configuration, and/or the transmission direction UL-DL
configuration for each terminal device 1. The subframe
configuration unit 3013 transmits information related to the
subframe configuration to the terminal device 1. The subframe
configuration unit 3013 is also referred to as a base station
subframe configuration unit.
[0147] The base station apparatus 3 may determine the subframe
configuration, the subframe pattern configuration, the
uplink-downlink configuration, the uplink reference UL-DL
configuration, the downlink reference UL-DL configuration, and/or
the transmission direction UL-DL configuration for the terminal
device 1. The base station apparatus 3 may determine the subframe
configuration, the subframe pattern configuration, the
uplink-downlink configuration, the uplink reference UL-DL
configuration, the downlink reference UL-DL configuration, and/or
the transmission direction UL-DL configuration for the terminal
device 1 according to the indication from the higher node.
[0148] For example, the subframe configuration unit 3013 may
determine the subframe configuration, the subframe pattern
configuration, the uplink-downlink configuration, the uplink
reference UL-DL configuration, the downlink reference UL-DL
configuration, and/or the transmission direction UL-DL
configuration based on a traffic amount of the uplink and a traffic
amount of the downlink.
[0149] The subframe configuration unit 3013 may manage at least two
subframe sets. The subframe configuration unit 3013 may set at
least two subframe sets to each terminal device 1. The subframe
configuration unit 3013 may set at least two subframe sets to each
serving cell. The subframe configuration unit 3013 may set at least
two subframe sets to each CSI process. The subframe configuration
unit 3013 may transmit information indicating at least two subframe
sets to the terminal device 1 through the transmission unit
307.
[0150] The scheduling unit 3015 included in the higher layer
processing unit 301 determines subframes and frequencies to which
the physical channels (PDSCH and PUSCH) are assigned, coding rates
of the physical channels (PDSCH and PUSCH), a modulation scheme,
and a transmit power from the received channel state information
and the estimation value of the channel or the quality of the
channel input from the channel measurement unit 3059. The
scheduling unit 3015 determines whether to schedule the downlink
physical channel and/or the downlink physical signal or the uplink
physical channel and/or the uplink physical signal in the flexible
subframe. The scheduling unit 3015 generates control information
(for example, DCI format) in order to control the reception unit
305 and the transmission unit 307 based on the scheduling result,
and outputs the generated control information to the control unit
303.
[0151] The scheduling unit 3015 generates information used in
scheduling the physical channels (PDSCH and PUSCH) based on the
scheduling result. The scheduling unit 3015 determines timings
(subframes) when the transmission process and the reception process
are performed based on the UL-DL configuration, the subframe
pattern configuration, the uplink-downlink configuration, the
uplink reference UL-DL configuration, the downlink reference UL-DL
configuration, and/or the transmission direction UL-DL
configuration.
[0152] The CSI report control unit 3017 included in the higher
layer processing unit 301 controls the CSI report of the terminal
device 1. The CSI report control unit 3017 transmits information
indicating various configurations assumed in order to cause the
terminal device 1 to derive the CQI in the CSI reference resource
to the terminal device 1 through the transmission unit 307.
[0153] The control unit 303 generates control signals for
controlling the reception unit 305 and the transmission unit 307
based on the control information from the higher layer processing
unit 301. The control unit 303 outputs the generated control
signals to the reception unit 305 and the transmission unit 307 to
control the reception unit 305 and the transmission unit 307.
[0154] The reception unit 305 separates, demodulates, and decodes
the reception signal received from the terminal device 1 through
the transmit and receive antenna 309 according to the control
signal input from the control unit 303, and outputs the decoded
information to the higher layer processing unit 301. The wireless
reception unit 3057 converts the uplink signal received through the
transmit and receive antenna 309 into an intermediate frequency
(performs down conversion), removes unnecessary frequency
components, controls an amplification level such that a signal
level is approximately maintained, performs orthogonal demodulation
based on the in-phase components and quadrature components of the
received signal, and converts an analog signal acquired through the
orthogonal demodulation into a digital signal.
[0155] The wireless reception unit 3057 removes components
equivalent to guard intervals (GIs) from the converted digital
signal. The wireless reception unit 3057 performs fast Fourier
transform (FFT) on the signal acquired by removing the guard
intervals, extracts the signal in the frequency domain, and outputs
the extracted signal to the demultiplexing unit 3055.
[0156] The demultiplexing unit 1055 separates the signal input from
the wireless reception unit 3057 into signals such as the PUCCH,
the PUSCH and the uplink reference signal. The demultiplexing is
performed based on assignment information of a radio resource which
is previously determined by the radio resource control unit 3011 of
the base station apparatus 3 and is included in the uplink grant
notified to each terminal device 1. The demultiplexing unit 3055
compensates the channels of the PUCCH and the PUSCH from the
estimation value of the channel input from the channel measurement
unit 3059. The demultiplexing unit 3055 outputs the separated
uplink reference signal to the channel measurement unit 3059.
[0157] The demodulation unit 3053 performs inverse discrete Fourier
transform (IDFT) on the PUSCH, acquires the modulation symbols, and
demodulates the reception signal for the modulation symbols of the
PUCCH and the PUSCH by using a modulation scheme, such as binary
phase shift keying (BPSK), QPSK, 16-QAM or 64-QAM, which is
previously determined or previously notified through the uplink
grant to each terminal device 1 from the base station apparatus.
The demodulation unit 3053 separates the modulation symbols of a
plurality of uplink data items transmitted through the same PUSCH
by using the MIMO SM based on the number of sequences which are
previously notified through the uplink grant to each terminal
device 1 and are spatial-multiplexed, and the information
indicating that precoding is performed on the sequences.
[0158] The decoding unit 3051 performs decoding on coding bits of
the demodulated PUCCH and PUSCH by a predetermined coding scheme at
a coding rate which is previously determined or is previously
notified to the terminal device 1 from the base station apparatus
through the uplink grant, and outputs the decoded uplink data and
the uplink control information to the higher layer processing unit
101. In a case where the PUSCH is retransmitted, the decoding unit
3051 performs decoding by using coding bits which are input from
the higher layer processing unit 301 and are retained in an HARQ
buffer and the demodulated coding bits. The channel measurement
unit 309 measures the estimation value of the channel or the
quality of the channel from the uplink reference signal input from
the demultiplexing unit 3055, and outputs the measured result to
the demultiplexing unit 3055 and the higher layer processing unit
301.
[0159] The transmission unit 307 generates the downlink reference
signal according to the control signal input from the control unit
303, codes and modulates the HARQ indicator, the downlink control
information and the downlink data input from the higher layer
processing unit 301, multiplexes the PHICH, the PDCCH, the EPDCCH,
the PDSCH, and the downlink reference signal, and transmits the
signal to the terminal device 1 through the transmit and receive
antenna 309.
[0160] The coding unit 3071 performs coding on the HARQ indicator,
the downlink control information and the downlink data input from
the higher layer processing unit 301 by using a predetermined
coding scheme such as block coding, convolutional coding or turbo
coding, or performs coding by using a coding scheme determined by
the radio resource control unit 3011. The modulation unit 3073
modulates the coding bits input from the coding unit 3071 by using
a modulation scheme, such as BPSK, QPSK, 16-QAM or 64-QAM, which is
previously determined or is determined by the radio resource
control unit 3011.
[0161] The downlink reference signal generation unit 3079 generates
a sequence which is acquired by a predetermined rule based on the
physical layer cell identity (PCI) for identifying the base station
apparatus 3 and is known to the terminal device 1, as the downlink
reference signal. The multiplexing unit 3075 multiplexes the
modulation symbols of each modulated channel and the generated
downlink reference signal. That is, the multiplexing unit 3075
arranges the modulation symbols of each modulated channel and the
generated downlink reference signal in the resource elements.
[0162] The wireless transmission unit 3077 performs inverse fast
Fourier transform (IFFT) on the multiplexed modulation symbols,
performs modulation of an OFDM scheme, adds the guard intervals to
the OFDM symbols acquired through the OFDM modulation, and
generates a baseband digital signal. The wireless transmission unit
converts the baseband digital signal into an analog signal,
generates in-phase components and quadrature components of the
intermediate frequency from the analog signal, removes excessive
frequency components in the intermediate frequency band, converts
the signal having the intermediate frequency into a signal having a
high frequency (performs up conversion), and removes excessive
frequency components. The wireless transmission unit amplifies
power, and outputs and transmits the amplified signal to the
transmit and receive antenna 309.
[0163] Here, the PDCCH or the EPDCCH is used to notify (designate)
the terminal device of the downlink control information (DCI). For
example, the downlink control information includes information
related to resource assignment of the PDSCH, information related to
a modulation and coding scheme (MCS), information related to
scheduling identity (also referred to as a scheduling identifier),
and information related to a reference signal sequence identity
(also referred to as base sequence identity, base sequence
identifier, or base sequence index).
[0164] Hereinafter, a small cell will be described.
[0165] The small cell is the general term for cells which are
constituted by the base station apparatus 3 having a transmit power
lower than that of a macrocell and have narrow coverage. Since the
small cell can be configured to have narrow coverage, the small
cells can be operated by being densely arranged. The base station
apparatus 3 as the small cell is arranged in a place different from
the base station apparatus as the macrocell. The densely arranged
small cells may be synchronized with each other, and may be
provided as a small cell cluster. The small cells within the small
cell cluster may be connected through backhaul (optical fiber, X2
interface or S1 interface), and an interference suppression
technique such as enhanced Inter-Cell Interference Coordination
(eICIC), Further enhanced Inter-cell Interference Coordination
(FeICIC), or Coordinated Multi-point transmission/reception (CoMP)
may be applied in the small cells within the small cell cluster.
The small cell may be operated in a frequency band different from
that of the macrocell, or may be operated in the same frequency
band as that of the macrocell. Particularly, in view of channel
attenuation (path loss), it is possible to easily allow the small
cell to have narrower coverage by operating the small cell in a
frequency band higher than that of the macrocell.
[0166] The small cell operated in the different frequency band is
operated using the carrier aggregation technology or the dual
connectivity technology different from that of the macrocell.
[0167] The small cell may be operated in the same frequency as that
of the macrocell. The small cell may be operated out of the
coverage of the macrocell. The base station apparatus 3 as the
small cell may be arranged in the same place as that of the base
station apparatus as the macrocell.
[0168] The base station apparatus 3 recognizes whether a certain
cell is the macrocell or the small cell, and terminal device 1 does
not need to recognize whether a certain cell is the macrocell or
the small cell. For example, the base station apparatus 3 may
configure the macrocell as the Pcell may configure the small cell
as the Scell or the pSCell for the terminal device 1. In any case,
the terminal device 1 may recognize a certain cell as the PCell,
the SCell or the pSCell, and does not need to recognize a certain
cell as the macrocell or the small cell.
[0169] Hereinafter, the details of the carrier aggregation
technology and the dual connectivity technology will be
described.
[0170] The secondary cell may be configured such that the secondary
cell and the primary cell constitute a set of serving cells
depending on the capability (performance and function) of the
terminal device 1. The number of downlink component carriers
configured for the terminal device 1 needs to be equal to or
greater than the number of uplink component carriers configured for
the terminal device 1, and only the uplink component carriers are
not able to be configured as the secondary cells.
[0171] The terminal device 1 uses constantly the primary cell and
the primary secondary cell for transmitting the PUCCHs. In other
words, the terminal device 1 does not expect to transmit the PUCCH
in the secondary cell other than the primary cell and the primary
secondary cell.
[0172] The reconfiguration/addition/removal of the secondary cell
is performed by the RRC. When a new secondary cell is added, all
system information items required by the new secondary cell are
transmitted through the dedicated RRC signaling. That is, it is not
necessary to directly acquire the system information from the
secondary cell through the broadcasting in an RRC connected
mode.
[0173] When the carrier aggregation is configured, the mechanism of
the activation/deactivation of the secondary cell is supported. The
activation/deactivation is not applied to the primary cell. When
the secondary cell is deactivated, the terminal device 1 does not
need to receive the associated PDCCH or PDSCH, is not able to
perform the transmission in the associated uplink, and does not
need to perform CQI measurement. In contrast, when the secondary
cell is activated, since the terminal device 1 receives the PDSCH
and the PDCCH, it is expected that the CQI measurement can be
performed.
[0174] The mechanism of the activation/deactivation is based on the
combination of the MAC CE and a deactivation timer. The MAC CE
notifies of information of the activation and the deactivation of
the secondary cell as a bitmap. A bit set to be 1 indicates the
activation of the associated secondary cell, and a bit set to be 0
indicates the deactivation of the associated secondary cell.
[0175] The deactivation as an initial state is configured for the
secondary cell configured for the terminal device 1. That is, even
though various parameters for the secondary cell are configured for
the terminal device 1, the communication may or may not be
immediately performed using the secondary cell.
[0176] Hereinafter, an example of the MAC CE will be described.
[0177] An example of a structure of the activation/deactivation MAC
CE will be described. The MAC CE has a fixed size, and includes
seven Ci fields and one R field. The MAC CE is defined as follows.
As for the Ci, in a case where there is the secondary cell for
which a secondary cell index (SCellIndex) i is configured, the Ci
field indicates a state of the activation/deactivation of the
secondary cell accompanying by the secondary cell index i. In a
case where there is no secondary cell for which the secondary cell
index i is configured, the terminal device 1 ignores the Ci field.
A case where the Ci field is set to be "1" means that the secondary
cell accompanying by the secondary cell index i is activated. A
case where the Ci field is set to be "0" means that the secondary
cell accompanying by the secondary cell index i is deactivated. The
R is a reserved bit, and is set to be "0".
[0178] Hereinafter, an example of the deactivation timer for the
secondary cell will be described.
[0179] In a case where the deactivation timer is configured for the
secondary cell, the deactivation timer is a timer associated with a
maintaining time of the secondary cell. The terminal device 1
retains the deactivation timer for each secondary cell, and
deactivates the secondary cell associated with the expired
deactivation timer if the deactivation timer expires.
[0180] An initial value of the deactivation timer for the secondary
cell is configured using a parameter sCellDeactivationTimer-r10
from the higher layer (RRC layer). For example, one of rf2, rf4,
rf8, rf16, rf32, rf64 and rf128 which are values associated with
the number of radio frames is configured for the initial value of
the deactivation timer for the secondary cell. Here, rf2
corresponds to 2 radio frames, rf4 corresponds to 4 radio frames,
rf8 corresponds to 8 radio frames, rf16 corresponds to 16 radio
frames, rf32 corresponds to 32 radio frames, rf64 corresponds to 64
radio frames, and rf128 corresponds to 128 radio frames.
[0181] The field (parameter sCellDeactivationTimer-r10) associated
with the deactivation timer for the secondary cell is configured
for only the terminal device 1 for which one or more secondary
cells are configured.
[0182] In a case where there is no field associated with the
deactivation timer, it is assumed that the terminal device 1
removes an existing value of the field associated with the
deactivation timer and an infinity value is configured.
[0183] In a case where only one field associated with the
deactivation timer for the secondary cell is configured for the
terminal device 1, the same initial value of the deactivation timer
is adapted to each secondary cell (a function associated with the
deactivation timer is independently performed in each secondary
cell).
[0184] An example of the mechanism of the activation/deactivation
will be described.
[0185] In a case where the MAC CE indicating the activation of the
secondary cell is received, the terminal device 1 configures the
secondary cell for which the activation is configured by the MAC CE
as activation. Here, the terminal device 1 may perform the
following operation on the secondary cell for which the activation
is configured by the MAC CE. This operation includes the
transmission of the SRS in the secondary cell, the reporting of the
channel quality indicator (CQI)/precoding matrix indicator
(PMI)/rank indicator (RI)/precoding type indicator (PTI) for the
secondary cell, the transmission of the uplink data (UL-SCH) in the
secondary cell, the transmission of the RACH in the secondary cell,
the monitoring of the PDCCH in the secondary cell, and the
monitoring of the PDCCH for the secondary cell.
[0186] In a case where the MAC CE indicating the activation of the
secondary cell is received, the terminal device 1 starts or
restarts the deactivation timer associated with the secondary cell
for which the activation is configured by the MAC CE. The starting
means that the timer which retains the value starts to count. The
restarting means that the value is configured as the initial value
and the timer restarts to count.
[0187] In a case where the MAC CE indicating the activation of the
secondary cell is received, the terminal device 1 triggers the
transmission of a remaining power of the transmit power (power head
room (PHR)).
[0188] In a case where the MAC CE indicating the deactivation of
the secondary cell is received, or in a case where the deactivation
timer associated with the secondary cell expires, the terminal
device 1 configures the secondary cell for which the deactivation
is configured by the MAC CE as the deactivation.
[0189] In a case where the MAC CE indicating the deactivation of
the secondary cell is received, or in a case where the deactivation
timer associated with the secondary cell expires, the terminal
device 1 stops the deactivation timer associated with the secondary
cell for which the deactivation is configured by the MAC CE.
[0190] In a case where the MAC CE indicating the deactivation of
the secondary cell is received, or in a case where the deactivation
timer associated with the secondary cell expires, the terminal
device 1 flashes all the HARQ buffers associated with the secondary
cell for which the deactivation is configured by the MAC CE.
[0191] In a case where the PDCCH in the activated secondary cell
indicates the downlink grant or the uplink grant, or in a case
where the PDCCH in the serving cell in which the activated
secondary cell is scheduled indicates the downlink grant for the
activated secondary cell or the uplink grant for the activated
secondary cell, the terminal device 1 restarts the deactivation
timer associated with the activated secondary cell.
[0192] In a case where the secondary cell is deactivated, the
terminal device 1 does not perform the following operation on the
deactivated secondary cell. This operation includes the
transmission of the SRS in the secondary cell, the reporting of the
CQI/PMI/RI/PTI for the secondary cell, the transmission of the
uplink data (UL-SCH) in the secondary cell, the transmission of the
RACH in the secondary cell, the monitoring of the PDCCH in the
secondary cell, and the monitoring of the PDCCH for the secondary
cell.
[0193] In a case where the deactivation is configured for the
secondary cell on which the random access procedure is being
performed, the terminal device 1 stops the random access procedure
being performed.
[0194] Even in a case where the transmission and reception of data
to and from the terminal device 1 are not performed, the base
station apparatus 3 transmits the synchronization signal, the
reference signal and the broadcasting information such as the
PSS/SSS, the CRS, the PBCH, and the SIB in order for the terminal
device 1 in an idle state to be connected to the base station
apparatus 3. Thus, these signals cause inter-cell interference.
These signals are constantly transmitted, and thus, the power of
the base station apparatus 3 is wasted.
[0195] Thus, the base station apparatus 3 performs transmission to
an ON state (an operating state or an activated state) or an OFF
state (a deactivated state). In a case where the base station
apparatus 3 does not transmit and receive data to and from the
terminal device 1, the base station apparatus 3 may perform
transition to the OFF state. In a case where the base station
apparatus 3 transmits and receives data to and from the terminal
device 1, the base station apparatus 3 may perform transition to
the ON state.
[0196] For example, the deactivated state of the base station
apparatus 3 is a state in which at least one of the PSS/SSS, the
CRS, the PBCH, the PDCCH and the PDSCH is not transmitted. For
example, the deactivated state is a state in which the PSS/SSS is
not transmitted over one or more half frame (5 or more subframes).
For example, the deactivated state of the base station apparatus 3
is a state in which only the DRS is transmitted. The base station
apparatus 3 may perform the reception process in the reception unit
of the base station apparatus even in the deactivated state.
[0197] The activated state of the base station apparatus 3 is a
state in which at least one of at least PSS/SSS and the CRS is
transmitted. For example, the activated state is a state in which
the PSS/SSS is transmitted in one half frame.
[0198] The terminal device 1 may associate the ON state and the OFF
state of the base station apparatus 3 with a process (assumption or
operation) on a prescribed channel or a prescribed signal. Here,
the process is monitoring, a reception process or a transmission
process. That is, the terminal device 1 may not recognize that the
base station apparatus 3 is in the ON state or the OFF state, and
the terminal device 1 may switch to the process on the prescribed
channel or the prescribed signal. In the description of the present
embodiment, the transition to the activated state and the
deactivated state in the base station apparatus 3 includes the
switching of the processes between the prescribed channel and the
prescribed signal in the terminal device 1. The activated state in
the base station apparatus 3 corresponds to a first process on the
prescribed channel or the prescribed signal in the terminal device
1. The deactivated state in the base station apparatus 3
corresponds to a second process on the prescribed channel or the
prescribed signal in the terminal device 1.
[0199] For example, the ON state of the base station apparatus 3 is
a state in which the terminal device 1 can perform the same process
as that of the terminal device of the related art. A specific
example in the ON state of the base station apparatus 3 is as
follows. The terminal device 1 expects to receive the PSS, the SSS
and the PBCH. The terminal device 1 monitors that the PDCCH and/or
the EPDCCH in a prescribed subframe. The terminal device 1 performs
the CSI reporting based on the configured CSI reporting mode. The
terminal device 1 expects that the CSI reference resource and the
reference signal (for example, CRS or CSI-RS) for the CSI reporting
are present.
[0200] For example, the OFF state of the base station apparatus 3
is a state in which the terminal device 1 performs a process
different from that of the terminal device of the related art. A
specific example of the OFF state of the base station apparatus 3
is as follows. The terminal device 1 does not expect to receive the
PSS, the SSS and the PBCH. The terminal device 1 does not monitor
the PDCCH and/or the EPDCCH in all the subframes. The terminal
device 1 does not perform the CSI reporting irrespective of the
configured CSI reporting mode. The terminal device 1 does not
expect that there are the reference signal (for example, the CRS or
the CSI-RS) and the CSI reference resource for reporting the
CSI.
[0201] For example, the transition to the activated state and the
deactivated state of the base station apparatus 3 is determined
based on the connection state of the terminal device 1, a data
request status of the terminal device 1 connected to the base
station apparatus 3, and information of the CSI measurement and/or
the RRM measurement from the terminal device 1.
[0202] The base station apparatus 3 may explicitly or implicitly
configure or notify the terminal device 1 of information (cell
state information) related to the transition to the activated state
and the deactivated state of the base station apparatus 3. For
example, the base station apparatus 3 notifies explicitly the
terminal device 1 of the cell state information by using the RRC,
the MAC, the PDCCH and/or the EPDCCH. The base station apparatus 3
notifies implicitly the terminal device 1 of the cell state
information depending on whether or not there is the prescribed
channel or signal.
[0203] An example of a procedure in which the base station
apparatus 3 in the activated state performs transition to the
deactivated state (the cell state information is notified) will be
described.
[0204] The base station apparatus 3 (serving cell) connected to the
terminal device 1 determines whether or not to perform the
transition to the deactivated state from the activated state based
on the connection state of the terminal device 1, the data status
of the terminal device 1, and the measurement information of the
terminal device 1. The base station apparatus 3 which determines to
perform the transition to the deactivated state transmits
information indicating the transition to the deactivated state to
the base station apparatus 3 as the neighboring cell, and prepares
to stop the cell. The determination of whether or not to perform
the transition to the deactivated state from the activated state
and the transmission the information indicating the transition to
the deactivated state may not be performed in the serving cell, or
such determination and transmission may be performed in, for
example, the Mobility Management Entity (MME) or the Serving
Gateway (S-GW). In the preparing to stop the cell, in a case where
the terminal device 1 is connected to the base station apparatus 3,
the transmission of an indication indicating a handover to the
neighboring cell or the transmission of an indication indicating
the deactivation of the terminal device to the terminal device 1
are performed. The serving cell in which there is not the connected
terminal device 1 through the preparing to stop the cell performs
transition to the deactivated state from the activated state.
[0205] In a case where the terminal device 1 communicates with the
base station apparatus 3 in the deactivated state, the base station
apparatus 3 performs transition to the activated state to the
deactivated state. A time during which the transition to the
activated state from the deactivated state is performed and a time
during which the transition to the deactivated state from the
activated state is performed are referred to as a transition time.
The transition time is shortened, and thus, it is possible to
reduce various interferences or power consumption of the base
station apparatus 3.
[0206] For example, whether or not to perform the transition of the
base station apparatus 3 in the deactivated state to the activated
state is determined based on an uplink reference signal from the
terminal device 1, cell detection information from the terminal
device 1, and measurement information of the physical layer from
the terminal device 1.
[0207] An example of a procedure in which the transition of the
base station apparatus 3 in the deactivated state to the activated
state is performed based on the measurement information of the
physical layer will be described.
[0208] The base station apparatus 3 (serving cell) to which the
terminal device 1 is connected and the base station apparatus 3
(neighbour cell) in the deactivated state share the configuration
of the DRS through the backhaul. The serving cell notifies the
terminal device 1 of the configuration of the DRS. The neighbour
cell transmits the DRS. The terminal device 1 detects the DRS
transmitted from the neighbour cell based on the configuration of
the DRS notified from the serving cell. The terminal device 1
measures the physical layer by using the DRS transmitted from the
neighbour cell. The terminal device 1 reports the measurement of
the serving cell. The serving cell determines whether or not to
perform the transition of the base station apparatus 3 in the
deactivated state to the activated state based on the reporting of
the measurement from the terminal device 1, and notifies the base
station apparatus 3 in the deactivated state of information
indicating the activation through the backhaul in a case where it
is determined that the transition to the activated state is
performed. The determination of whether or not to perform the
transition to the activated state from the deactivated state and
the transmission of the information indicating the activation may
not be performed in the serving cell, or such determination and
transmission may be performed in, for example, the Mobility
Management Entity (MME) or the Serving Gateway (S-GW). The
neighbour cell that receives the information indicating the
activation performs the transition to the activated state from the
deactivated state.
[0209] An example of a procedure in which the transition of the
base station apparatus 3 in the deactivated state to the activated
state is performed based on the measurement information of the
physical layer will be described.
[0210] The base station apparatus 3 (serving cell) to which the
terminal device is connected and the base station apparatus 3
(neighbour cell) in the deactivated state share the configuration
of the SRS of the terminal device 1 through the backhaul. The
serving cell notifies the terminal device 1 of the configuration of
the SRS. The terminal device 1 transmits the SRS based on the
configuration of the SRS or the indication of the SRS request. The
neighbour cell detects the SRS transmitted from the terminal device
1. The neighbour cell measures the physical layer by using the SRS
transmitted from the terminal device 1. Based on the measurement
result through the SRS, the neighbour cell determines whether or
not to perform the transition of the base station apparatus 3 to
the activated state, and performs the transition to the activated
state from the deactivated state. The determination of whether or
not to perform the transition to the activated state from the
deactivated state may not be performed in the neighbour cell, or
such determination and transmission may be performed in, for
example, the serving cell, the Mobility Management Entity (MME), or
the Serving Gateway (S-GW). In this case, after the measurement of
the physical layer is performed using the SRS, the neighbour cell
transmits the measurement result to the serving cell, the MME or
the S-GW, and receives the information indicating the
activation.
[0211] The serving cell may notify the terminal device 1 of the
information indicating the activated/deactivated state of the
neighboring cell. The terminal device 1 switches the action of the
terminal device 1 by recognizing the activated state or the
deactivated state of the cell. The action of the terminal device 1
is, for example, an interference measurement method.
[0212] An example of a method of notifying of the cell state
information (information indicating the activated/deactivated state
of the cell) will be described.
[0213] The information indicating the activated/deactivated state
of a target cell is notified through Layer 1 signalling (L1
signalling). In other words, the information indicating the
activated/deactivated state of the target cell is notified through
the PDCCH or the EPDCCH. One corresponding bit is assigned to the
target cell. 0 (false or disable) indicates the deactivated state,
and 1 (true or enable) indicates the activated state. The bit
corresponding to the target cell includes a bitmap to be collected,
and may simultaneously notify the plurality of cells of the
activated/deactivated state. The association of the bit with the
target cell is notified through the dedicated RRC signaling.
[0214] The information indicating the activated/deactivated state
is notified through the downlink control information (DCI) format
1C. The information indicating the activated/deactivated state may
be notified through the DCI format 3/3A. The information indicating
the activated/deactivated state may be notified through a format
having the same payload size (bit number) as that of the DCI format
1C.
[0215] Hereinafter, the DCI format will be described.
[0216] As the DCI format, there are a DCI format associated with
the uplink scheduling and a DCI format associated with the downlink
scheduling. The DCI format associated with the uplink scheduling is
referred to as an uplink grant, and the DCI format associated with
the downlink scheduling is referred to as a downlink grant
(downlink assignment). One DCI format may be transmitted to the
plurality of terminal devices 1. For example, in a case where only
a transmission power control command (TPC command) is transmitted,
the command may be transmitted to the plurality of terminal devices
1 at once. Such scheduling (or triggering) is referred to as group
scheduling (group triggering). The terminal device 1 is
individually assigned an index, and detects a bit based on the
index.
[0217] The DCI format 0 is used to schedule the PUSCH in one uplink
cell.
[0218] The DCI format 1 is used to schedule one PDSCH code word in
one cell.
[0219] The DCI format 1A is used in the random access process
started by a PDCCH order and compact scheduling of one PDSCH code
word in one cell. The DCI equivalent to the PDCCH order may be
transmitted through the PDCCH or the EPDCCH. The DCI format 0 and
the DCI format 1A may be transmitted using the same bit information
field, and the terminal device 1 determines whether the DCI format
mapped to the received bit information field is the DCI format 0 or
the DCI format 1A based on a value represented in a certain bit
field.
[0220] The DCI format 1B is used in the compact scheduling of one
PDSCH code word in one cell accompanying by the precoding
information.
[0221] The DCI format 1C is used to notify of the change
(alteration) of the multicast control channel (MCCH) and to perform
the compact scheduling of one PDSCH code word. The DCI format 1C
may be used to notify of a random access response by being
scheduled using the random access-radio network temporary
identifier (RA-RNTI). Here, for example, the compact scheduling
means that the PDSCH having a narrow bandwidth is scheduled. A DCI
format size is determined depending on a bandwidth used by the
PDSCH in which the scheduling is performed. As the bandwidth is
narrow, a required DCI format size may also be decreased. The DCI
format 1C is scheduled using the RNTI (for example, eIMTA-RNTI)
related to dynamic TDD (a first type (mode) of TDD), and thus,
information indicating TDD UL-DL may be set to the DCI format 1C.
If the dynamic TDD is the first type (mode) of TDD, the TDD of the
related art is referred to as a second type (mode) of TDD.
[0222] The dynamic TDD is TDD of switching the TDD UL-DL
configuration by using the L1 signalling depending on a
communication status of the uplink/downlink. The dynamic TDD is
used to extend interference management and traffic adaptation
control. The dynamic TDD is referred to as enhanced interference
management and traffic adaptation (eIMTA) or TDD-ModeA in some
cases.
[0223] The DCI format 1D is used in the compact scheduling of one
PDSCH code word in one cell accompanying by information related to
power offset and precoding.
[0224] The DCI format 2/2A/2B/2C/2D is used to schedule two (or a
plurality of) PDSCH code words as well as one PDSCH code word.
[0225] The DCI format 3/3A indicates a value of the transmission
power control command for adjusting the transmit power of the PUSCH
or the PUCCH for the plurality of terminal devices 1. The terminal
device 1 may detect the value of the transmission power control
command corresponding to the PUSCH or the PUCCH by detecting bit
information corresponding to the index (TPC-index) assigned to the
terminal device. It is determined whether the DCI format 3/3A
indicates the transmission power control command corresponding to
the PUSCH or the transmission power control command corresponding
to the PUCCH depending on the type of the scrambled RNTI.
[0226] The DCI format 4 is used to schedule the PUSCH in one uplink
cell accompanying by a multi-antenna-port transmission mode.
[0227] A cyclic redundancy check (CRC) is used to detect a DCI
transmission error. The CRC is scrambled with each RNTI.
[0228] A CRC parity bit is scrambled with a cell-radio network
temporary identifier (C-RNTI), a semi persistent scheduling
cell-radio network temporary identifier (SPS C-RNTI), a system
information-radio network temporary identifier (SI-RNTI), a
paging-radio network temporary identifier (P-RNTI), a random
access-radio network temporary identifier (RA-RNTI), a transmission
power control-physical uplink control channel-radio network
temporary identifier (TPC-PUCCH-RNTI), a transmission power
control-physical uplink shared channel-radio network temporary
identifier (TPC-PUSCH-RNTI), a temporary C-RNTI, a multimedia
broadcast multicast services (MBMS)-radio network temporary
identifier (M-RNTI), or a TDD-ModeA-RNTI.
[0229] The C-RNTI and the SPS C-RNTI are identifiers for
identifying the terminal devices 1 within the cell. The C-RNTI is
used to control the PDSCH or the PUSCH in a single subframe.
[0230] The SPS C-RNTI is used to periodically assign the PDSCH or
PUSCH resource. The control channel having the CRC scrambled with
the SI-RNTI is used to control a system information block
(SIB).
[0231] The control channel having the CRC scrambled with the P-RNTI
is used to control paging.
[0232] The control channel having the CRC scrambled with the
RA-RNTI is used to control a response to the RACH.
[0233] The control channel having the CRC scrambled with the
TPC-PUCCH-RNTI is used to control the power of the PUCCH. The
control channel having the CRC scrambled with the TPC-PUSCH-RNTI is
used to control the power of the PUSCH.
[0234] The control channel having the CRC scrambled with the
temporary C-RNTI is used for the terminal device that is not
identified by the C-RNTI.
[0235] The control channel having the CRC scrambled with the M-RNTI
is used to control MBMS.
[0236] The control channel having the CRC scrambled with the
TDD-ModeA-RNTI is used to notify the terminal device 1 of the
information of the TDD UL/DL configuration of each TDD serving cell
in the dynamic TDD.
[0237] The DCI format may be scrambled using a new RNTI in addition
to the above-described RNTI.
[0238] Hereinafter, the details of the PDCCH or the EPDCCH will be
described.
[0239] A control region of each serving cell includes a set of
CCEs. The CCEs are assigned numbers from 0 to N.sub.CCE, k-1. Here,
the N.sub.CCE, k is the total number of CCEs within the control
region of the subframe k.
[0240] The terminal device 1 monitors a set of PDCCH candidates of
one or a plurality of activated serving cells configured through
the higher layer signalling for the control information. Here, the
monitoring means that decoding is tried to be performed on the
respective PDCCHs within the set corresponding to all the monitored
DCI formats.
[0241] The set of monitored PDCCH candidates is referred to as a
search space. As the search space, a common search space (CSS) and
a UE-specific search space (USS) are defined.
[0242] The common search space (CSS) is a search space configured
using a parameter specific to the base station apparatus 3 (cell or
transmission point) and/or a predefined parameter. For example, the
CSS is a search space capable of being commonly used in the
plurality of terminal devices. Thus, the base station apparatus 3
can reduce the resources for transmitting the control channel by
mapping the common control channel to the CSS in the plurality of
terminal devices.
[0243] The UE-specific search space (USS) is a search space
configured using a parameter specific to at least the terminal
device 1. Thus, since the control channel specific to the terminal
device 1 can be individually transmitted in the USS, the base
station apparatus 3 can efficiently control the terminal device
1.
[0244] The CSS may be configured for the terminal device 1 by
further using the unique parameter. In this case, it is preferable
that the parameter specific to the terminal device 1 is configured
such that the values are equal between the plurality of terminal
devices. Even in a case where the CSS is configured by further
using the parameter specific to the terminal device 1, the CSS is
common to the plurality of terminal devices for which the same
parameter is configured. For example, a unit for which the same
parameter is configured between the plurality of terminal devices
is the cell, the transmission point or the UE group. Since the
plurality of terminal devices for which the same parameter is
configured can receive the common control channel mapped to the
CSS, it is possible to reduce the resources for transmitting the
control channel. Such a search space may be referred to as the USS
instead of the CSS. That is, the USS which is the search space
common to the plurality of terminal devices may be configured. The
USS specific to one terminal device is referred to as a first USS,
and the USS common to the plurality of terminal devices is referred
to as a second USS.
[0245] A search space S.sup.(L).sub.k for each aggregation level is
defined by a set of PDCCH candidates. The number of CCEs used by
one PDCCH is also referred to as an aggregation level. The number
of CCEs used by one PDCCH is 1, 2, 4 or 8. In each serving cell in
which the PDCCH is monitored, the CCEs corresponding to the PDCCH
candidates of the search space S.sup.(L).sub.k is represented by
Expression (1) of FIG. 14. Here, Y.sub.k represents a value in the
subframe k. In the CSS, m'=m. In the USS of the PDCCH, in a case
where the CIF is configured for the terminal device 1 to be
monitored in the serving cell in which the PDCCH is monitored,
m'=m+M.sup.(L). n.sub.CI, and otherwise, m'=m. Here, m is a value
from 0 to M.sup.(L)-1, and M.sup.(L) is the number of PDCCH
candidates to be monitored in a prescribed search space.
[0246] In the CSS, Y.sub.k is a predefined value, or a value
determined based on the parameter specific to the base station
apparatus 3. For example, 0 is configured for Y.sub.k in a case
where an aggregation level L=4 and L=8. In the UE-specific search
space S.sup.(L).sub.k of the aggregation level L, Y.sub.k is a
value specific to the terminal device 1, and is obtained by, for
example, Y.sub.k=(AY.sub.k-1)modD. Here, as an initial value
Y.sub.-1 of the Y.sub.k, a value of the RNTI (for example, C-RNTI)
is used.
[0247] The aggregation level is defined for each search space. For
example, in the CSS, the aggregation levels 4 and 8 are defined.
For example, in the USS, the aggregation levels 1, 2, 4 and 8 are
defined.
[0248] The number of PDCCH candidates is defined by each
aggregation level of each search space. For example, in the CSS,
the number of PDCCH candidates is 4 for the aggregation level 4,
and the number of PDCCH candidates is 2 for the aggregation level
8. For example, in the USS, the number of PDCCH candidates is 6 for
the aggregation 1, the number of PDCCH candidates is 6 for the
aggregation level 2, the number of PDCCH candidates is 2 for the
aggregation level 4, and the number of PDCCH candidates is 2 for
the aggregation level 8.
[0249] The EPDCCH is transmitted using an aggregation of one or
more enhanced control channel elements (ECCEs). Each ECCE includes
a plurality of enhanced resource element groups (EREGs). The EREG
is used to define the mapping of the EPDCCH to the resource
element. In each RB pair, 16 EREGs numbered from 0 to 15 are
defined. That is, in each RB pair, EREG 0 to EREG 15 are defined.
In each RB pair, the EREG 0 to EREG 15 are periodically defined for
the resource elements other than the resource elements to which the
prescribed signal and/or channel are mapped by prioritizing a
frequency direction. For example, the resource elements to which
demodulation reference signals associated with the EPDCCH
transmitted through antenna ports 107 to 110 are mapped do not
define the EREG.
[0250] The number of ECCEs used by one EPDCCH depends on the EPDCCH
format and is determined based on another parameter. The number of
ECCEs used by one EPDCCH is also referred to as an aggregation
level. For example, the number of ECCEs used by one EPDCCH is
determined by the number of resource elements capable of being used
to transmit the EPDCCH in one RB pair, or the transmission method
of the EPDCCH. For example, the number of ECCEs used by one EPDCCH
is 1, 2, 4, 8, 16, or 32. The number of EREGs used by one ECCE is
determined based on the type of subframe and the type of cyclic
prefix, and is 4 or 8. As the transmission method of the EPDCCH,
distributed transmission and localized transmission are
supported.
[0251] The EPDCCH may be transmitted using the distributed
transmission or the localized transmission. The mapping of the ECCE
to the EREG and the RB pair is different between the distributed
transmission or the localized transmission. For example, in the
distributed transmission, one ECCE includes EREGs of a plurality of
RB pairs. In the localized transmission, one ECCE includes an EREG
of one RB pair.
[0252] The base station apparatus 3 performs the configuration
related to the EPDCCH for the terminal device 1. The terminal
device 1 monitors the plurality of EPDCCHs based on the
configuration from the base station apparatus 3. The set of RB
pairs in which the terminal device 1 monitors the EPDCCH may be
configured. The set of RB pairs is also referred to as an EPDCCH
set or an EPDCCH-PRB set. One or more EPDCCH sets may be configured
for one terminal device 1. Each EPDCCH set includes one or more RB
pairs. The configuration related to the EPDCCH may be individually
performed for each EPDCCH set.
[0253] The base station apparatus 3 may configure a prescribed
number of EPDCCH sets for the terminal device 1. For example, the
first and second EPDCCH sets may be configured as the EPDCCH set 0
and/or the EPDCCH set 1. Each EPDCCH set may include a prescribed
number of RB pairs. Each EPDCCH set includes one set of the
plurality of ECCEs. The number of ECCEs constituting one EPDCCH set
is determined by the number of RB pairs configured as the EPDCCH
set and the number of EREGs used by one ECCE. In a case where the
number of ECCEs constituting one EPDCCH set is N, each EPDCCH set
includes ECCEs numbered from 0 to N-1. For example, in a case where
the number of EREGs used by one ECCE is 4, the EPDCCH set
constituted by 4 RB pairs includes 16 ECCEs.
[0254] The EPDCCH candidates monitored by the terminal device 1 are
defined based on the ECCE constituting the EPDCCH set. The set of
EPDCCH candidates is defined as a search space (search region). The
UE-specific search space which is the search space specific to the
terminal device 1 and the common search space which is the search
space specific to the base station apparatus 3 (cell, transmission
point, or UE group) are defined. The monitoring of the EPDCCH
includes a case where the terminal device 1 tries to decode each of
the EPDCCH candidates within the search space according to the DCI
format to be monitored.
[0255] A UE-specific search space ES.sup.(L).sub.k of the EPDCCH in
the aggregation level L.di-elect cons.{1, 2, 4, 8, 16, 32} is
defined by the set of the EPDCCH candidates.
[0256] In the EPDCCH set, the ECCE corresponding to the EPDCCH
candidate m of the search space ES.sup.(L).sub.k is obtained by
Expression (2) of FIG. 14.
[0257] Here, Y.sub.p,k represents a value in an EPDCCH set p and
the subframe k. The Y.sub.p,k may be independently configured by
the search space. In the case of the common search space, the
Y.sub.p,k is a value specific to the base station apparatus 3
(cell). For example, in the case of the common search space, the
Y.sub.p,k is a predefined value or a value determined based on the
parameter specific to the base station apparatus 3. In the case of
the UE-specific search space, the Y.sub.p,k is a value specific to
the terminal device 1, and is obtained by
Y.sub.p,k=(AY.sub.p,k-1)modD. For example, the Y.sub.p,k is
determined based on the prescribed value, the subframe k and the
RNTI (for example, C-RNTI) of the terminal device 1. A plurality of
common search spaces and/or a plurality of UE-specific search
spaces may be configured for one EPDCCH set.
[0258] Here, in a case where the CIF corresponding to the serving
cell in which the EPDCCH is monitored is configured for the
terminal device 1, b satisfies b=n.sub.CI, and otherwise, b=0.
[0259] The DCI format monitored by the terminal device 1 depends on
a transmission mode configured for each serving cell. In other
words, the DCI format monitored by the terminal device 1 is
different depending on the transmission mode. For example, the
terminal device 1 for which Downlink Transmission Mode 1 is
configured monitors the DCI format 1A and the DCI format 1. For
example, the terminal device 1 for which Downlink Transmission Mode
4 is configured monitors the DCI format 1A and the DCI format 2.
For example, the terminal device 1 for which Downlink Transmission
Mode 10 is configured monitors the DCI format 1A and the DCI format
2D. For example, the terminal device 1 for which Uplink
Transmission Mode 1 is configured monitors the DCI format 0. For
example, the terminal device 1 for which Uplink Transmission Mode 2
is configured monitors the DCI format 0 and the DCI format 4.
[0260] A control region to which the PDCCHs for the terminal device
1 are allocated is not notified, and the terminal device 1 tries to
decode all the DCI formats corresponding to all the PDCCH
candidates and the transmission modes for all the aggregation
levels defined in each search space. In other words, the terminal
device 1 tries to decode all the aggregation levels, the PDCCH
candidates and the DCI formats that are likely to be transmitted to
the terminal device 1. The terminal device 1 recognizes the PDCCH
on which the decoding succeeds as the control information addressed
to the terminal device 1. Such decoding is referred to as blind
decoding.
[0261] Even though the DCI formats are different, if the different
DCI formats have the same bit size, the number of times the
decoding is performed is not increased. For example, since the DCI
format 0 and the DCI format 1A have the same bit size, two types of
DCI formats can be decoded by performing the decoding once.
[0262] For example, in the CSS, the terminal device 1 for which
Uplink Transmission Mode 1 is configured tries to decode the DCI
formats having two types of bit sizes and 6 PDCCH candidates in the
aggregation 4, and tries to decode two PDCCH candidates and the DCI
formats having two types of bit sizes in the aggregation 8. In the
USS, the terminal device 1 tries to decode 6 PDCCH candidates and
the DCI formats having two types of bit sizes in the aggregation 1,
tries to decode 6 PDCCH candidates and the DCI formats having two
types of bit sizes in the aggregation 2, tries to decode 2 PDCCH
candidates and the DCI formats having two types of bit sizes in the
aggregation 4, and tries to decode 2 PDCCH candidates and the DCI
formats having two types of bit sizes in the aggregation 8. That
is, the terminal device 1 tries to decode the PDCCH in one subframe
forty-four times.
[0263] For example, in the CSS, the terminal device 1 for which
Uplink Transmission Mode 2 is configured tries to decode 6 PDCCH
candidates and the DCI format having two types of bit sizes in the
aggregation 4, and tries to decode 2 PDCCH candidates and the DCI
format having two types of bit sizes in the aggregation 8. In the
USS, the terminal device 1 tries to decode 6 PDCCH candidates and
the DCI format having three types of bit sizes in the aggregation
1, tries to decode 6 PDCCH candidates and the DCI format having
three types of bit sizes in the aggregation 2, tries to decode 2
PDCCH candidates and the DCI format having three types of bit sizes
in the aggregation 4, and tries to decode 2 PDCCH candidates and
the DCI format having three types of bit sizes in the aggregation
8. That is, the terminal device 1 tries to decode the PDCCH in one
subframe 60 times.
[0264] Through the blind decoding, the terminal device 1 can decode
the PDCCHs of which the coding rates are different without using
preliminary information, and it is possible to efficiently transmit
the control information between the base station apparatus 3 and
the terminal device 1.
[0265] The information indicating the activated/deactivated state
is notified by the common search space. The common search space is
the common search space in the cell. The information indicating the
activated/deactivated state is notified by a UE-specific common
search space. Here, the UE-specific common search space is a search
space where starting points of the CCEs to which the PDCCH
candidates are allocated using the RNTI (UE-group C-RNTI, TP
specific-RNTI or SCE-RNTI) commonly assigned to the terminal group
are determined. The plurality of terminal devices 1 for which the
UE-group RNTI is configured detects the DCI format by using the
PDCCHs allocated to the same search space.
[0266] The notification of the information indicating the
activated/deactivated state is performed at a predefined timing or
a configured timing. For example, this notification timing is one
radio frame unit.
[0267] The notification of the information indicating the
activated/deactivated state indicates information of the next radio
frame in which the L1 signalling is received. In a case where the
L1 signalling is received in an initial subframe (subframe 0)
within the radio frame, the notification may indicate information
of the received radio frame.
[0268] An example of a method of notifying of the information
indicating the activated/deactivated state of the cell will be
described.
[0269] The activated/deactivated state of the target cell may be
implicitly represented by changing (altering) the structure of the
DRS. The information indicating the activated/deactivated state of
the target cell may be implicitly represented by allowing the DRSs
to have different structures between the activated state and the
deactivated state. The DRS may be transmitted from the target cell
such that the DRS has different structures between the activated
state and the deactivated state. The terminal device 1 may receive
information related to the structure of the DRS transmitted in the
activated state and information related to the structure of the DRS
transmitted in the deactivated state from the base station
apparatus 3.
[0270] The activated/deactivated state of the target cell may be
represented by changing (altering) the parameter (or the value of
the parameter) of a certain structure of the DRS. In other words, a
certain parameter included in the configuration of the DRS may be
different between the activated state and the deactivated state (or
may be individually configured). For example, the arrangement of
the resource elements may be different between the DRS transmitted
in the activated state and the DRS transmitted in the deactivated
state. An antenna port may be different between the DRS transmitted
in the activated state and the DRS transmitted in the deactivated
state. A scrambling sequence may be different between the DRS
transmitted in the activated state and the DRS transmitted in the
deactivated state. An initial value of the scrambling sequence or a
method (expression) for generating the initial value may be
different between the DRS transmitted in the activated state and
the DRS transmitted in the deactivated state. A transmit power may
be different between the DRS transmitted in the activated state and
the DRS transmitted in the deactivated state. A subframe interval
at which the DRS is transmitted may be different between the DRS
transmitted in the activated state and the DRS transmitted in the
deactivated state. A transmission bandwidth or the number of
resource blocks may be different between the DRS transmitted in the
activated state and the DRS transmitted in the deactivated state.
That is, the information related to the configuration of the DRS
transmitted in the activated state and the information related to
the configuration of the DRS transmitted in the deactivated state
may be individually set. These information items may be transmitted
to the terminal device 1 from the base station apparatus 3 by using
the higher layer signalling. That is, the information indicating
the activated/deactivated state of the target cell may be
configuration information of the parameter related to the structure
of the DRS. In other words, certain parameters are respectively
configured in the activated state and the deactivated state.
[0271] The terminal device 1 may monitor two structures, that is,
the structure of the DRS indicating the activated state and the
structure of the DRS indicating the deactivated state. The terminal
device 1 may monitor two structures by using a monitoring pattern
of the structure of the DRS indicating the activated state and a
monitoring pattern of the structure of the DRS indicating the
deactivated state. In this case, information related to two
monitoring patterns of the structures of the DRS is notified to the
terminal device 1. That is, in a case where information related to
one monitoring pattern of the structure of the DRS is not notified,
the terminal device may monitor the DRSs having two structures
based on one monitoring pattern.
[0272] In a case where the DRS in the activated state is measured
in the measurement subframe of the DRS in the deactivated state,
the terminal device 1 recognizes that the small cell in the
deactivated state is the activated state.
[0273] The terminal device 1 may implicitly acquire the information
of the activated/deactivated state of the target cell by the
monitoring pattern in which the DRS is detected. The monitoring
pattern of the structure of the DRS indicating the activated state
and the monitoring pattern of the structure of the DRS indicating
the deactivated state may be previously defined. The monitoring
pattern of the structure of the DRS indicating the activated state
and the monitoring pattern of the structure of the DRS indicating
the deactivated state may be notified through the dedicated RRC
signaling (higher layer signalling) from the base station apparatus
3.
[0274] Another example of the method of notifying of the
information indicating the activated/deactivated state of the cell
will be described.
[0275] The state of the activated/deactivated state of the target
cell may be implicitly represented by allowing the CRS to have
different structures (configurations of the CRS) between the
activated state and the deactivated state of the target cell. In
this case, the CRS transmitted from the target cell is transmitted
such that the CRS has different structures between the activated
state and the deactivated state. In this case, configuration
information of the CRSs having different structures is notified to
the terminal device 1.
[0276] The activated/deactivated state of the target cell may be
represented by changing a certain parameter (or a value of the
parameter) related to the structure of the CRS. For example, the
arrangement of the resource elements may be different between the
CRS transmitted in the activated state and the CRS transmitted in
the deactivated state. An antenna port may be different between the
CRS transmitted in the activated state and the CRS transmitted in
the deactivated state. A scrambling sequence may be different
between the CRS transmitted in the activated state and the CRS
transmitted in the deactivated state. An initial value of the
scrambling sequence may be different between the CRS transmitted in
the activated state and the CRS transmitted in the deactivated
state. A transmit power may be different between the CRS
transmitted in the activated state and the CRS transmitted in the
deactivated state. A subframe interval at which the CRS is
transmitted may be different between the CRS transmitted in the
activated state and the CRS transmitted in the deactivated state. A
transmission bandwidth or the number of resource blocks may be
different between the CRS transmitted in the activated state and
the CRS transmitted in the deactivated state. That is, the
information indicating the activated/deactivated state of the
target cell may be configuration information of the parameter
related to the structure of the CRS. In this case, certain
parameters are individually configured between the activated state
and the deactivated state. Here, the CRS has been described, but
the same is true of the PSS/SSS, the CSI-RS, and the PRS.
[0277] The terminal device 1 monitors two structures, that is, the
structure of the CRS indicating the activated state and the
structure of the CRS indicating the deactivated state. The terminal
device 1 monitors two structures by using a monitoring pattern of
the structure of the CRS indicating the activated state and a
monitoring pattern of the structure of the CRS indicating the
deactivated state. The terminal device 1 implicitly acquires the
information of the activated/deactivated state of the target cell
by the monitoring pattern in which the CRS is detected. The
monitoring pattern of the structure of the CRS indicating the
deactivated state may be previously defined. The monitoring pattern
of the structure of the CRS indicating the deactivated state may be
notified from the base station apparatus 3 through the dedicated
RRC signaling.
[0278] Another example of the method of notifying of the
information indicating the activated/deactivated state of the cell
will be described.
[0279] The information indicating the activated/deactivated state
of the cell may be notified through the dedicated RRC signaling.
The information indicating the activated/deactivated state of the
cell may be listed in association with a center frequency (carrier
frequency) and a cell ID, and may be notified.
[0280] The terminal device 1 can recognize the
activated/deactivated state of the target cell by the
above-described notification method. Hereinafter, any one of the
above-described methods is applied when the terminal device 1
switches an action by the activated/deactivated state of the target
cell.
[0281] Hereinafter, the detection of the cell (base station
apparatus 3) will be described.
[0282] The detection of the cell means that the terminal device 1
detects the synchronization signal (PSS or SSS) transmitted from
the base station apparatus 3 constituting the cell or/and the
reference signal (CRS or CSI-RS). The synchronization signal or/and
the reference signal used to detect the cell includes information
of the cell ID. The terminal device 1 detects the cell by the cell
ID of the cell and a detection criterion of the synchronization
signal or/and the reference signal.
[0283] The detection of the cell may include the detection of the
base station apparatus 3. The detection of the primary cell may
include the detection of the master base station apparatus. The
detection of the primary secondary cell may include the detection
of the secondary base station apparatus.
[0284] An example of the detection criterion of the synchronization
signal or/and the reference signal will be described.
[0285] The terminal device 1 determines the detection based on
received power strength or/and received power quality of the
synchronization signal or/and the reference signal from the cell.
The terminal device 1 compares the received power strength or/and
the received power quality of the synchronization signal or/and the
reference signal with a threshold, and determines that the cell is
detected in a case where the reception strength or/and the
reception quality is greater than the threshold. The received power
strength is, for example, RSRP. The reception quality is, for
example, interference amount, RSRQ, or SINR. The detection of the
cell may be determined by a measurement event to be described
below.
[0286] An example of the detection criterion of the synchronization
signal or/and the reference signal will be described.
[0287] The terminal device 1 determines the detection based on
whether or not the decoding of the information of the
synchronization signal or/and the reference signal from the cell
succeeds. For example, the cell (the base station apparatus 3
constituting the cell) transmits the synchronization signal or/and
the reference signal by adding a parity code such as CRC to the
synchronization signal or/and the reference signal. The terminal
device 1 performs the decoding by using the parity code included in
the synchronization signal or/and the reference signal, and
determines that the cell is detected in a case where it is
determined that the decoding correctly succeeds through parity
check.
[0288] After the cell is detected in the terminal device 1, the
terminal device 1 selects the cell to be connected/activated and
selects the cell to be disconnected/deactivated.
[0289] After the cell is detected in the terminal device 1, the
terminal device 1 reports information of the detected cell to the
connected base station apparatus 3. The information of the detected
cell includes the cell ID and the measurement information.
[0290] Hereinafter, the CRSs for describing the details of the CRS
are transmitted through the antenna ports 0 to 3. The CRSs are
allocated to all the downlink subframes which are non-MBSFN
subframes. In other words, the CRSs are allocated to all the
downlink subframes except for the MBSFN subframes. The resource
element and the signal sequence of the CRS are determined based on
the physical cell identity (PCI).
[0291] FIG. 10 is a diagram showing an example of the structure of
the CRS. The signal of the CRS is generated using a pseudo-random
sequence. The pseudo-random sequence is, for example, a Gold
sequence. The pseudo-random sequence is calculated based on the
physical cell identity (PCI). The pseudo-random sequence is
calculated based on the type of the CP. The pseudo-random sequence
is calculated based on the slot number and the OFDM symbol number
within the slot. The resource element of the CRS in the case of the
normal CP uses R0 to R3 of FIG. 10. R0 corresponds to the
arrangement of CRSs at the antenna port 0, R1 corresponds to the
arrangement of CRSs at the antenna port 1, R2 corresponds to the
arrangement of CRSs at the antenna port 2, and R3 corresponds to
the arrangement of CRSs at the antenna port 3. The resource
elements of the CRSs transmitted through one antenna port are
allocated to the frequency axis at a cycle of 6 subcarriers. The
resource elements of the CRSs transmitted through the antenna port
0 and the CRSs transmitted through the antenna port 1 are allocated
at intervals of 3 subcarriers. The CRS is shifted on the frequency
so as to be specific to the cell based on the cell ID. The resource
elements of the CRSs transmitted through the antenna port 0 and the
CRSs transmitted through the antenna ports 1 are allocated to the
OFDM symbols 0 and 4 in the case of the normal CP, and are
allocated to the OFDM symbols 0 and 3 in the case of the enhanced
CP. The resource elements of the CRSs transmitted through the
antenna port 2 and the CRSs transmitted through the antenna port 3
are allocated to the OFDM symbols 1. The CRSs are transmitted in a
broadband with a bandwidth configured for the downlink. The DRS may
have the same structure as that of the CRS.
[0292] Hereinafter, the details of the discovery reference signal
(DRS) will be described. The DRS is transmitted from the base
station apparatus 3 for various purposes such as synchronization
(time synchronization) in the time domain of the downlink,
synchronization (frequency synchronization) of the frequency of the
downlink, cell/transmission point identification, RSRP measurement,
RSRQ measurement, the measurement (UE positioning) of the
geographic position of the terminal device 1, and CSI measurement.
The DRS may be used as the reference signal used to support the ON
state and the OFF state of the base station apparatus 3. The DRS
may be used as the reference signal used by the terminal device 1
to detect the base station apparatus 3 in the ON state and/or the
OFF state.
[0293] The DRS includes a plurality of signals. As an example, the
DRS includes the PSS, the SSS and the CRS. The PSS and the SSS
included in the DRS may be used for the time synchronization, the
frequency synchronization, the cell identification and the
transmission point identification. The CRS included in the DRS may
be used to perform the RSRP measurement, the RSRQ measurement and
the CSI measurement. As another example, the DRS includes the PSS,
the SSS and the CSI-RS. The PSS and the SSS included in the DRS may
be used for the time synchronization, the frequency
synchronization, the cell identification and the transmission point
identification. The CSI-RS included in the DRS may be used for the
transmission point identification, the RSRP measurement, the RSRQ
measurement and the CSI measurement. The DRS including the
plurality of signals may be referred to a discovery burst. The
reference signal used in the RSRP measurement and/or the RSRQ
measurement may be referred to as the DRS.
[0294] The base station apparatus 3 may transmit a first DRS
including the PSS, the SSS and the CRS, and a second DRS including
the PSS, the SSS and the CSI-RS by switching between the first and
second DRSs. In this case, the base station apparatus 3 configures
the first DRS or the second DRS for the terminal device 1.
[0295] The DRS is transmitted in the downlink subframe. The DRS is
transmitted by the downlink component carrier.
[0296] The DRS is transmitted in the deactivated state (off state,
dormant mode, or deactivation) of the base station apparatus 3. The
DRS may be transmitted even in the activated state (on state,
active mode, or activation) of the base station apparatus 3.
[0297] The DRS may be independently configured in each base station
apparatus (cell or transmission point). For example, in the
plurality of small cells, the DRSs having different configurations
from each other are transmitted using different resources from each
other.
[0298] The base station apparatus 3 configures a list related to
the DRS and a measurement (detection, monitoring, or transmission)
timing of the DRS for the terminal device 1. The list associated
with the DRS is a list of information associated with the base
station apparatus that transmits the DRS which is likely to be
received by the terminal device 1. For example, the list related to
the DRS is a list of transmission points ID of the transmission
points that transmit the DRSs. The plurality of transmission points
transmits the DRSs specific to the respective transmission points
based on the measurement timing of the DRS configured for the
terminal device 1. The terminal device 1 measures the DRS
measurement based on the list related to the DRS configured for the
base station apparatus 3 and the measurement timing of the DRS. For
example, the terminal device 1 measures the DRS determined based on
the list related to the DRS in the subframe or the resource
determined based on the measurement timing of the DRS. The terminal
device 1 reports the measurement result through the measurement of
the DRS to the base station apparatus 3.
[0299] The respective transmission points transmit the DRSs in one
subframe. That is, the respective transmission points transmit the
PSS, the SSS, the CRS and/or the CSI-RS associated with one DRS in
one subframe. The terminal device 1 expects to transmit the DRS
corresponding to one transmission point in one subframe. One DRS
may be transmitted in the plurality of subframes.
[0300] The transmission of the DRS or the measurement timing of the
DRS is periodically configured on the time axis. The transmission
of the DRS or the measurement timing of the DRS may be configured
in continuous subframes. In other words, the DRS may be transmitted
through burst transmission. For example, the transmission of the
DRS or the measurement timing of the DRS is configured in N
continuous subframes at a cycle of M subframes. The subframe L to
which the DRSs are allocated within the cycle may be configured.
The value of the M, N and/or L is configured in the higher layer.
The number of subframes N continuously transmitted within the cycle
may be previously defined. If the subframe cycle M is configured as
a long period, the number of times the DRS is transmitted from the
base station apparatus 3 in the deactivated state can be reduced,
and thus, the inter-cell interference can be reduced. A different
configuration may be applied to the value of the M, N and/or L
between the deactivated state and the activated state. The
parameter corresponding to the value of the M, N and/or L may be
notified by the higher layer signalling.
[0301] The parameter corresponding to M may represent a subframe
offset (or a starting subframe) in addition to the cycle. That is,
the parameter corresponding to M may be an index correlated with
the cycle and/or the subframe offset.
[0302] The parameter corresponding to N may be managed as a table.
A value of the parameter corresponding to N may not directly
represent the number of subframes. The parameter corresponding to N
may be represented by including the starting subframe in addition
to the number of subframes.
[0303] The parameter corresponding to L may be managed as a table.
The parameter corresponding to L may be correlated with the cycle.
A value of the parameter corresponding to L may not directly
represent the offset of the subframe.
[0304] In the subframe in which it is likely to transmit the DRS or
a measurement subframe of the DRS, the terminal device 1 may
monitor the PDCCH in addition to the measurement of the DRS. For
example, the terminal device 1 may monitor the PDCCH in the
parameter corresponding to the N. In this case, there is a
condition in which the terminal device 1 supports a function of
monitoring the PDCCH for the small cell in the deactivated
state.
[0305] The DRS may be transmitted by including the information of
the transmission point ID. Here, the information of the
transmission point ID is information for identifying the
transmission point (cell) which transmits the DRS. For example, the
transmission point ID is a physical cell identity (physical cell
ID, physCellID, or physical layer cell ID), a Cell Global Identity
(CGI), a new cell identity (small cell ID), a discovery ID, or an
extended cell ID. The transmission point ID may be an ID different
from the physical cell identity identified by the PSS and the SSS
included in the DRS. The transmission point ID may be an ID
associated with the physical cell identity identified by the PSS
and the SSS included in the DRS. For example, a certain
transmission point ID may be associated with any one of the
physical cell identities identified by the PSS and the SSS included
in the DRS. A plurality of IDs related to the cell may be
transmitted by the DRS. For example, in an environment in which
cells of an insufficient number are arranged with the physical cell
identity, the combination of the physical cell identity and the new
cell identity is transmitted by the DRS, and thus, the physical
cell identity may be practically extended.
[0306] The DRS is transmitted through antenna ports p, . . . , and
p+n-1. Here, n represents the total number of antenna ports through
which the DRS is transmitted. As the values of p, . . . , and
p+n-1, values other than 0 to 22, and 107 to 110 may be applied.
That is, the DRS may be transmitted using antenna ports different
from the antenna ports used for other reference signals.
[0307] Hereinafter, an example of the structure (or configuration)
of the DRS will be described.
[0308] A plurality of structures and/or configurations may be
applied to the DRS. Here, the plurality of structures may be
structures or configurations of a plurality of signals. The
plurality of structures may be signals having the plurality of
structures. In other words, the DRS may include a plurality of
signals. For example, the same structure (or configuration) as that
of the PSS may be applied to the DRS. The same structure (or
configuration) as that of the SSS may be applied to the DRS. The
same structure (or configuration) as that of the CRS may be applied
to the DRS. The same structure (or configuration) as that of the
CSI-RS may be applied to the DRS. That is, the DRS may be based on
the structures (or configurations) of a first signal to an n-th
signal (n is a natural number). In other words, the DRS may be
based on a signal having a first structure to a signal having an
n-th structure. The structure of the signal may include a radio
resource arrangement (resource configuration) and a subframe
configuration.
[0309] The DRS may distinguishably use the signals (radio
resources) having the respective structures. For example, as the
signals used for the synchronization in the time domain or the
frequency domain, the cell identification, the RSRP/RSRQ/RSSI
measurement (RRM measurement), signals having different structures
may be used. That is, the terminal device 1 may perform the
synchronization in the time domain or the frequency domain by using
a first signal, may perform the cell identification by using a
second signal, and may perform the RSRP/RSRQ measurement by using a
third signal. The terminal device may perform the synchronization
in the time domain or the frequency domain and the cell
identification by using the first signal and the second signal, and
may perform the RSRP/RSRQ/RSSI measurement (RRM measurement) by
using the third signal.
[0310] In a case where the DRS is generated from the signals based
on the plurality of structures, a signal having a specific
structure is transmitted, and thus, the activated/deactivated state
of the small cell may be represented. For example, in a case where
a fourth signal (a signal having a fourth structure) is
transmitted, the terminal device 1 may recognize that the small
cell is in the activated state, and may perform the process. That
is, the terminal device 1 may recognize that the small cell is in
the activated state by detecting the fourth signal (the signal
having the fourth structure).
[0311] The CSI measurement may be performed using a fifth signal (a
signal having a fifth structure). In a case where the CSI
measurement is performed, the terminal device 1 may perform the CSI
reporting in a first uplink subframe which is positioned after a
prescribed subframe from a subframe on which the CSI measurement is
performed. The CSI measurement may be performed using another
signal instead of the fifth signal. In a case where the CSI
measurement is performed in the deactivated state, configuration
information for performing the CSI measurement/CSI reporting in the
deactivated state is notified to the terminal device 1 from the
base station apparatus 3 using the higher layer signalling.
[0312] The structure of the DRS transmitted from the small cell
(base station apparatus 3 constituting the small cell) may be
different between the activated state and the deactivated state of
the small cell. For example, the signals having the first structure
to the third structure may be transmitted in the deactivated state,
and the signals having the first structure to the fourth structure
may be transmitted in the activated state. In the activated state,
the signal having the fourth structure instead of the signal having
the third structure may be transmitted. In a case where the
plurality of signals having the same structure as that of the SSS
are configured, the plurality of signals may be transmitted in the
deactivated state of the small cell, but only one signal may be
transmitted in the activated state of the small cell. That is, the
structure of the DRS may be switched depending on the state of the
small cell.
[0313] In order to transmit an extended physical layer cell
identity (PCI), the DRS may include a plurality of signals. The
physical layer cell identity and the transmission point identity
(TPID) may be transmitted using the plurality of signals. Here, the
plurality of signals may be a plurality of SSSs or signals having
the same structure as that of the SSS. Here, the plurality of
signals may be signals having the same structure as that of the PSS
and the SSS. The plurality of signals may be signals having the
same structure as that of the PSS and the plurality of SSSs. The
TPID may be a virtual cell identity (VCID). The TPID may be a
transmission point, that is, an ID for identifying the base station
apparatus 3. The VCID may be identity used for a signal sequence.
In other words, due to the use of the DRS, the cell ID group is
identified by the signal having the first structure, the cell ID is
identified by the signal having the first structure and the signal
having the second structure, and the TPID is identified by the
signal having the first structure, the signal having the second
structure and the signal having the third structure. The TPID may
be extended by the signal having the fourth structure.
[0314] The DRS may be individually configured from the PSS, the
SSS, the CRS, and the CSI-RS. That is, the subframe configuration
or resource configuration of the DRS, the antenna port index, the
number of antenna ports, and the ID for sequence generation may be
independently (individually) configured from the PSS, the SSS, the
CRS, and the CSI-RS.
[0315] FIG. 9 is a diagram showing an example of the structure of
the DRS. Here, the sequence (signal sequence or reference signal
sequence) used for the DRS may be generated by a Zadoff-Chu
sequence on the frequency axis. The DRSs may be continuously
allocated to the frequency axis. The DRSs may be transmitted using
6 resource blocks and using 62 subcarriers of these resource
blocks. The DRSs may be transmitted at zero power by using 10
subcarriers of the 6 resource blocks. In other words, the DRSs may
reserve 10 subcarriers of the 6 resource blocks, and the signal may
not be transmitted. The DRSs are allocated to the last OFDM symbols
of the slot number 0 and the slot number 10 in the case of the FDD
(frame structure type 1), and are mapped to the third OFDM symbols
of the subframe 1 and the subframe 6 in the case of the TDD (frame
structure type 2). The DRSs may be transmitted by including a part
of information for identifying the cell ID.
[0316] The DRSs may be allocated to resource blocks (different
frequency positions) different from that of the PSS. The DRSs may
be transmitted using the number of resource blocks different from
that of the PSS. The DRSs may be transmitted using the number of
subcarriers different from that of the PSS. The DRSs may be
allocated to OFDM symbols different from those of the PSS. The DRSs
may be transmitted by including information different from the cell
ID (PCI or VCID).
[0317] Another example of the structure of the DRS will be
described.
[0318] FIG. 9 shows another example of the structure of the DRS.
The sequence (signal sequence or reference signal sequence) used
for the DRS may be interleaved by connecting two binary sequences
having a length of 31. The sequence of the DRS may be generated
based on an M sequence. The DRSs are different from the signals
allocated to the subframe 0 and the signals allocated to the
subframe 5. The DRSs are allocated to the sixth OFDM symbols of the
slot number 0 and the slot number 10 in the case of the FDD, and
are allocated to the seventh OFDM symbols of the slot number 1 and
the slot number 11 in the case of the TDD. In other words, the DRSs
are allocated to the second OFDM symbols from the last of the slot
number 0 and the slot number 10 in the case of the FDD, and are
allocated to the last OFDM symbols of the slot number 1 and the
slot number 11 in the case of the TDD. In this case, the DRSs may
be transmitted by including a part of the information for
identifying the cell ID.
[0319] The DRSs may be allocated to the resource blocks (frequency
positions) different from that of the SSS. The DRSs may be
transmitted using the number of resource blocks different from that
of the SSS. The DRSs may be transmitted using the number of
subcarriers different from that of the SSS. The DRSs may be
allocated to the OFDM symbols different from that of the SSS. The
DRSs may be transmitted by including the information different from
the cell ID.
[0320] The number of subframes in which the DRS is transmitted is
not limited. For example, the DRS may be transmitted in the
subframes 0, 1, 5, and 6. That is, a plurality of DRSs based on the
structure of the SSS may be transmitted. In this case, many
information items may be transmitted by adding the information
items to the DRS. In this case, since the number of orthogonal
sequences is increased, an effect of suppressing the inter-cell
interference is obtained.
[0321] FIG. 10 shows another example of the structure of the DRS.
The signal of the DRS is generated using a pseudo-random sequence.
The pseudo-random sequence is, for example, a Gold sequence. The
pseudo-random sequence is calculated based on the cell ID (PCI,
VCID, scramble identity (ID), scrambling identity, or scrambling
initialization identity (ID)). The pseudo-random sequence is
calculated based on the type of the CP. The pseudo-random sequence
is calculated based on the slot number and the OFDM symbol number
within the slot. The resource elements of the DRSs transmitted
through one antenna port are allocated to the frequency axis at
intervals of 6 subcarriers. The resource elements of the DRSs
transmitted through the antenna port p and the DRSs transmitted
through the antenna port p+l are allocated at intervals of 3
subcarriers. The DRS is shifted on the frequency so as to be
specific to the cell based on the cell ID. The resource elements of
the DRSs transmitted through the antenna port p and the DRSs
transmitted through the antenna port p+l are allocated to the OFDM
symbols 0 and 4 in the case of the normal CP, and are allocated to
the OFDM symbols 0 and 3 in the case of the extended CP. The
resource elements of the DRSs transmitted through the antenna port
p+2 and the DRSs transmitted through the antenna port p+3 are
allocated to the OFDM symbols 1. The DRSs are transmitted in a
broadband with a bandwidth configured for the downlink. The
transmission bandwidth of the DRS may be configured using the
higher layer signalling. The transmission bandwidth of the DRS may
be regarded as being the same as the measurement bandwidth.
[0322] The DRSs may be transmitted using a pseudo-random sequence
different from that of the CRS. The DRSs may use a sequence
calculation method different from that of the CRS. The DRSs may be
allocated to the frequency at a cycle of subcarriers different from
that of the CRS. The arrangement relationship of the resource
elements between the antenna port p through which the DRS is
transmitted and the antenna port p+1 through which the DRS is
transmitted may be different from the arrangement relationship
between the antenna port 0 and the antenna port 1. The arrangement
of the DRSs may be shifted on the frequency based on information
different from that of the CRS. The DRSs may be allocated to OFDM
symbols different from those of the CRS. The DRSs may be allocated
to a bandwidth different from that of the CRS, or may be allocated
to the bandwidth configured in the higher layer, and may be
transmitted in a narrowband.
[0323] FIG. 10 shows another example of the structure of the DRS.
The sequences (signal sequence and reference signal sequence) of
the DRSs (D1 and D2 of FIG. 10) are generated using the
pseudo-random sequence. The pseudo-random sequence is, for example,
a Gold sequence. The pseudo-random sequence is calculated based on
the information from the higher layer. The pseudo-random sequence
is calculated based on the cell ID in a case where the information
from the higher layer is not configured. The pseudo-random sequence
is calculated based on the type of the CP. The pseudo-random
sequence is calculated based on the slot number and the OFDM symbol
number within the slot. The resource elements to which the DRSs are
allocated may be determined by resource configuration numbers (DRS
resource configuration index), and may be calculated using the
table of FIG. 12. Here, k' represents a subcarrier number, 1'
represents an OFDM symbol number, n.sub.s represents a slot number,
and n.sub.s mod 2 represents a slot number within a subframe. For
example, in the case of the configuration number 0, the DRSs are
allocated to the resource elements of the slot number 0, the
subcarrier number 9, and the OFDM symbol numbers 5 and 6. The DRSs
are transmitted in a broadband with a bandwidth configured for the
downlink.
[0324] The sequence of the DRS may use a pseudo-random sequence
different from that of the CSI-RS. The sequence of the DRS may be
generated based on a sequence calculation method different from
that of the CSI-RS. The DRSs are not limited to the table of FIG.
12, and may be resource elements different from those of the
CSI-RS. The DRSs may be allocated to a bandwidth different from
that of the CSI-RS, or may be allocated to the bandwidth configured
in the higher layer and may be transmitted in a narrowband.
[0325] FIG. 10 shows another example of the structure of the DRS.
The resource elements to which the DRSs are allocated are
determined by resource configuration numbers (DRS resource
configuration index), and are calculated using the table of FIG.
12. Here, k' represents a subcarrier number, 1' represents an OFDM
symbol number, ns represents a slot number, and ns mod 2 represents
a slot number within a subframe. For example, in the case of the
configuration number 0, the DRSs are allocated to the resource
elements of the slot number 0, the subcarrier number 9, and the
OFDM symbol numbers 5 and 6. The DRSs are transmitted in a
broadband with a bandwidth configured for the downlink. The DRSs
may be transmitted in the configured resource elements at zero
power. In other words, the base station apparatus 3 may not
transmit the DRSs in the configured resource elements. From a
viewpoint of the terminal device 1, the resource elements in which
the DRSs are not transmitted from the base station apparatus 3 may
use interference measurement from the neighbour cell (or neighbour
base station apparatus). The DRSs may have the same structure as
that of R6 of FIG. 11.
[0326] FIG. 11 shows an example of the structure of the DRS. The
sequence of the DRS is generated using a pseudo-random sequence.
The pseudo-random sequence is, for example, a Gold sequence. The
pseudo-random sequence is calculated based on the cell ID. The
pseudo-random sequence is calculated based on the type of the CP.
The pseudo-random sequence is calculated based on the slot number
and the OFDM symbol number within the slot. The DRSs transmitted
through one antenna port are allocated to the frequency axis at a
cycle of 6 subcarriers. The DRS is shifted on the frequency so as
to be specific to the cell based on the cell ID. The DRSs are
allocated to the OFDM symbols 3, 5 and 6 of the slot 0 and the OFD
symbols 1, 2, 3, 5 and 6 of the slot 1 in the case of the normal
CP, and are allocated to the OFDM symbols 4 and 5 of the slot 0 and
the OFDM symbols 1, 2, 4 and 5 of the slot 1 in the case of the
extended CP. The resource elements of the DRSs are allocated to a
first OFDM symbol and an (1+L)-th OFDM symbol so as to be shifted
on the frequency by L. The DRSs are transmitted in a broadband with
a bandwidth configured for the downlink.
[0327] The sequence of the DRS may use a pseudo-random sequence
different from that of PRS. The sequence of the DRS may use a
sequence calculation method different from that of the PRS. The
DRSs may be allocated to the frequency at a cycle of subcarriers
different from that of the PRS. The DRSs may be allocated to OFDM
symbols different from those of the PRS. The DRSs may be allocated
to a bandwidth different from that of the PRS, and may be allocated
to the bandwidth configured in the higher layer and may be
transmitted in a narrowband. That is, the transmission bandwidth or
the measurement bandwidth of the DRS may be configured in the
higher layer.
[0328] The DRS may include a CSI-IM resource. The CSI-IM resource
is a resource used by the terminal device 1 to measure
interference. For example, the terminal device 1 uses the CSI-IM
resource as a resource for measuring interference in the CSI
measurement or a resource for measuring interference in the RSRQ
measurement. The CSI-IM resource is configured using the same
method as the CSI-RS configuration method. The CSI-IM resource may
be a resource configured as a zero power CSI-RS.
[0329] The structure of the DRS has been described above, but is
not limited to only the above-described examples, and the structure
of the DRS may be achieved by combining the plurality of
above-described examples.
[0330] A specific example of a preferred combination will be
described. The DRS may be generated by combining the signal
generated based on the Zadoff-Chu sequence, the signal generated
based on the M sequence and the signal generated based on the Gold
sequence. The signal generated based on the Gold sequence may be
generated in a band broader than that of the signal generated based
on the Zadoff-Chu sequence, and the signal generated based on the
Zadoff-Chu sequence may be transmitted using 6 resource blocks, and
the signal generated based on the Gold sequence may be transmitted
in the entire band of the subframe. That is, the bandwidth in which
the DRS is transmitted may be configurable by the higher layer.
That is, it is preferable that the DRS includes signals having
different structures in different sequences.
[0331] The DRS may include combinations of the signal generated
based on the Zadoff-Chu sequence, the signal generated based on the
M sequence, the signal generated based on the Gold sequence and the
signal transmitted at zero power. The signal generated based on the
Gold sequence and the signal transmitted at zero power may be
designated the resource elements by the configuration information
of the DRS. The signal generated based on the Gold sequence may be
generated in a band broader than that of the signal generated based
on the Zadoff-Chu sequence, the signal generated based on the
Zadoff-Chu sequence may be transmitted using 6 resource blocks, and
the signal based on the Gold sequence may be transmitted in the
entire band of the subframe.
[0332] The DRS configuration is notified to the terminal device 1
through the dedicated RRC signaling. The configuration of the DRS
includes information common to the cells that transmit the RS and
information of individual information that transmits the DRS. The
configuration of the DRS may be notified by being added to
configuration information of a measurement object to be described
below.
[0333] The information common to the cells that transmit the DRS
includes information of a center frequency of a band, information
of a bandwidth, and information of a subframe.
[0334] The information of the individual cell that transmits the
DRS includes information of a center frequency of a band,
information of a bandwidth, information of a subframe, information
for designating the resource element, information (cell ID, PCI, or
VCID) for identifying the cell.
[0335] Since the terminal device 1 can recognize the subframe that
includes the DRS by the configuration of the DRS, a DRS detection
process may not be performed in the subframe that does not include
the DRS. Accordingly, the power consumption of the terminal device
1 can be reduced.
[0336] The configuration of the DRS may include a configuration of
a signal having a first structure to a configuration of a signal
having an n-th structure. For example, the resource configurations
of the signals having the respective structures may be individually
set. The subframe configurations or transmit powers of the signals
having the respective structures may be common (or may have a
common value). The cell ID, the antenna port index, or the number
of antenna ports may be set to only a signal having a certain
structure. As the configuration of the DRS, a plurality of resource
configurations or subframe configurations may be set to a signal
having a certain structure.
[0337] The configuration of the DRS may include information
(parameter) indicating the frequency in which the DRS is
transmitted.
[0338] The configuration of the DRS may include information
indicating an offset (offset value) of a subframe in which the DRS
is likely to be transmitted.
[0339] The configuration of the DRS may include information
indicating a subframe cycle at which the DRS is likely to be
transmitted.
[0340] The configuration of the DRS may include an identifier for
generating the sequence of the DRS.
[0341] The configuration of the DRS may include information
indicating an antenna port through which the DRS is
transmitted.
[0342] The configuration of the DRS may include information
indicating a burst transmission period of the DRS.
[0343] The configuration of the DRS may include information
indicating a subframe cycle during which the DRS is measured once
during the subframe cycle.
[0344] That is, the configuration of the DRS may include
information required to transmit the DRS, and/or information
required to receive the DRS, and/or information required to measure
the DRS.
[0345] The information included in the configuration of the DRS may
be set for each signal having each structure. That is, the
above-described information may be set to the signals having
different structures.
[0346] The configuration of the DRS may be notified using the
higher layer signalling. The configuration of the DRS may be
notified using the system information. Partial information of the
configuration of the DRS may be notified using the L1 signalling
(DCI format) or L2 signalling (MAC CE).
[0347] The DRS may be used for a reference signal (listening RS)
for inter-base-station-apparatus synchronization (network
listening) through a wireless interface in the same frequency.
[0348] Hereinafter, the inter-base-station-apparatus
synchronization through the wireless interface using the DRS will
be described.
[0349] The transmission timing is synchronized between the base
station apparatuses, and thus, the application of the TDD system,
the application of an inter-cell interference suppression
technology such as eICIC or CoMP, and the application of carrier
aggregation between the base station apparatuses of which the
transmission points are different are possible. However, in a case
where the small cells are arranged in a building and an environment
in which the delay of the backhaul is large, it is difficult to
perform the time synchronization by the backhaul or a global
navigation satellite system (GNSS). Thus, a wireless interface is
used to perform the synchronization of the transmission timing of
the downlink.
[0350] A procedure of the inter-base-station-apparatus
synchronization through the wireless interface will be described.
Initially, the determination of the base station apparatus 3 as a
reference of the transmission timing and the designation of the
transmission timing of the listening RS are performed through the
backhaul. The determination of the base station apparatus 3 that
performs the synchronization of the transmission timing and the
designation of the reception timing of the listening RS are
performed through the backhaul. The determination of the base
station apparatus 3 as the reference of the transmission timing,
the base station apparatus 3 that performs the synchronization of
the transmission timing, and the transmission/reception timing of
the listening RS may be performed by the base station apparatus,
the MME or the S-GW. The base station apparatus 3 as the reference
of the transmission timing transmits the listening RS in the
downlink component carrier or the downlink subframe based on the
transmission timing notified through the backhaul. The base station
apparatus 3 that performs the synchronization of the transmission
timing receives the listening RS at the notified reception timing,
and performs the synchronization of the transmission timing. The
listening RS may be transmitted even in the deactivated state of
the base station apparatus 3 as the reference of the transmission
timing. The listening RS may be received even in the
activated/deactivated state of the base station apparatus 3 that
performs the synchronization of the transmission timing.
[0351] In the TDD, the base station apparatus 3 that performs the
synchronization of the transmission timing stops transmitting the
downlink signal during which the listening RS is received, and
performs the reception process of the radio signal. In other words,
the base station apparatus 3 that performs the synchronization of
the transmission timing is configured in the uplink subframe during
which the listening RS is received. Here, the terminal device 1
connected to the base station apparatus 3 that performs the
synchronization of the transmission timing recognizes that the base
station apparatus 3 that performs the synchronization of the
transmission timing is in the deactivated state during which the
listening RS is received. That is, the terminal device 1 recognizes
that the PSS/SSS, the PBCH, the CRS, the PCFICH, the PHICH and the
PDCCH are not transmitted from the base station apparatus 3 that
performs the synchronization of the transmission timing. The
terminal device 1 is notified of the timing when the listening RS
is received from the base station apparatus 3. In other words, the
terminal device 1 is notified of the deactivated state from the
base station apparatus 3. The terminal device 1 does not perform
the measurement on the base station apparatus 3 at the timing when
the listening RS is received. The terminal device 1 connected to
the base station apparatus 3 that performs the synchronization of
the transmission timing may recognize that a period during which
the base station apparatus 3 that performs the synchronization of
the transmission timing receives the listening RS is the uplink
subframe.
[0352] In the FDD, the base station apparatus 3 that performs the
synchronization of the transmission timing stops transmitting the
downlink signal during which the listening RS is received, and
performs the reception process using the downlink component
carrier. Here, the terminal device 1 connected to the base station
apparatus 3 that performs the synchronization of the transmission
timing recognizes that the base station apparatus 3 that performs
the synchronization of the transmission timing is in the
deactivated state during which the listening RS is received. That
is, the terminal device 1 recognizes that the PSS/SSS, the PBCH,
the CRS, the PCFICH, the PHICH and the PDCCH are not transmitted
from the base station apparatus 3 that performs the synchronization
of the transmission timing. The terminal device 1 is notified of
the timing when the listening RS is received from the base station
apparatus 3. In other words, the terminal device 1 is notified of
the deactivated state from the base station apparatus 3. The
terminal device 1 does not perform the measurement on the base
station apparatus 3 at the timing when the listening RS is
received.
[0353] The terminal device 1 may detect the cell by using the
listening RS transmitted from the base station apparatus 3 as the
reference of the transmission timing.
[0354] Hereinafter, the details of the measurement of the physical
layer will be described. The terminal device 1 performs the
measurement of the physical layer to be reported to the higher
layer. As the measurement of the physical layer, there are
reference signal received power (RSRP), received signal strength
indicator (RSSI), and reference signal received quality (RSRQ).
[0355] Hereinafter, the details of the RSRP will be described. The
RSRP is defined as the received power of the reference signal. The
RSRQ is defined as the reception quality of the reference
signal.
[0356] An example of the RSRP will be described.
[0357] The RSRP is defined as a value acquired by performing linear
mean on power of the resource element to which the CRS included in
a measurement frequency bandwidth to be considered is transmitted.
In the determination of the RSRP, the resource element to which the
CRS of the antenna port 0 is mapped is used. If the terminal device
can detect the CRS of the antenna port 1, it is possible to use the
resource element (the radio resource mapped to the resource element
assigned to the antenna port 1) to which the CRS of the antenna
port 1 is mapped in addition to the resource element (the radio
resource mapped to the resource element assigned to the antenna
port 0) to which the CRS of the antenna port 0 is mapped in order
to determine the RSRP. Hereinafter, the RSRP calculated using the
resource element to which the CRS of the antenna port 0 is mapped
is referred to as a CRS base RSRP or a first RSRP.
[0358] The terminal device 1 measures the RSRP of the cell having
an intra-frequency and/or the cell having an inter-frequency in an
RRC idle (RRC_IDLE). Here, the cell having the inter-frequency in
the RRC idle state is a cell having the same frequency band as that
of the cell from which the terminal device receives the system
information through the broadcasting. Here, the cell having the
inter-frequency in the RRC idle state is a cell having a frequency
band different from that of the cell from which the terminal device
1 receives the system information through the broadcasting. The
terminal device 1 measures the RSRP of the cell having the
intra-frequency and/or the cell having the inter-frequency in the
RRC connected (RRC_CONNECTED) state. Here, the cell having the
intra-frequency in the RRC connected state is a cell having the
same frequency band as that of the cell from which the terminal
device 1 receives the system information through the RRC signaling
or the broadcasting. Here, the cell having the inter-frequency in
the RRC connected state is a cell having a frequency band different
from that of the cell from which the terminal device 1 receives the
system information through the RRC signaling or the
broadcasting.
[0359] An example of the RSRP will be described.
[0360] The RSRP is defined as a value acquired by performing linear
mean on power of the resource element to which the DRS included in
a measurement frequency bandwidth to be considered is transmitted.
In the determination of the RSRP, the resource element to which the
DRS is mapped is used. The resource element and the antenna port to
which the DRS is transmitted is notified in the higher layer are
used.
[0361] The terminal device 1 measures the RSRP of the cell having
the intra-frequency and/or the cell having the inter-frequency in
the RRC connected (RRC_CONNECTED) state.
[0362] The details of the RSSI will be described. The RSSI is
defined by total received power observed using a receive
antenna.
[0363] An example of the RSSI will be described.
[0364] The RSSI (E-UTRA carrier RSSI) includes a value acquired by
performing linear mean on total received power acquired by
observing only the OFDM symbols including the reference signal of
the antenna port 0. In other words, the RSSI includes a value
acquired by performing linear mean on total received power acquired
by observing only the OFDM symbols that include the CRS of the
antenna port 0. The RSSI is observed in a bandwidth of the number
of resource blocks N. The total received power of the RSSI includes
power from the serving cell or the non-serving cell on the same
channel, interference power from the neighbour channel, and thermal
noise power.
[0365] An example of the RSSI will be described.
[0366] The RSSI (E-UTRA carrier RSSI) includes a value acquired by
performing linear mean on total received power acquired by
observing all the OFDM symbols. The total received power of the
RSSI includes power from the serving cell or the non-serving cell
on the same channel, interference power from the neighbour channel,
and thermal noise power.
[0367] An example of the RSSI will be described.
[0368] The RSSI (E-UTRA carrier RSSI) includes a value acquired by
performing linear mean on total received power acquired by
observing the OFDM symbols that do not include the DRS. The RSSI is
observed in a bandwidth of the number of resource blocks N. The
total received power of the RSSI includes power from the serving
cell or the non-serving cell on the same channel, interference
power from the neighbour channel, and thermal noise power. The
resource element and/or the antenna port to which the DRS is
transmitted are notified in the higher layer.
[0369] An example of the RSSI will be described.
[0370] The RSSI (E-UTRA carrier RSSI) includes a value acquired by
performing linear mean on total received power acquired by
observing only the OFDM symbols that do not include the DRS (CRS
and/or CSI-RS). In other words, the RSSI includes a value acquired
by performing linear mean on total received power acquired by
observing the OFDM symbols that do not include the DRS (CRS and/or
CSI-RS). The RSSI is observed in a bandwidth of the number of
resource blocks N. The total received power of the RSSI includes
power from the serving cell or the non-serving cell on the same
channel, interference power from the neighbour channel, and thermal
noise power.
[0371] An example of the RSSI will be described.
[0372] The RSSI (E-UTRA carrier RSSI) includes a total value of a
value acquired by performing linear mean on total received power
acquired by observing only the OFDM symbols that do not include the
DRS (CRS and/or CSI-RS) and a value of the RSRP. In other words,
the RSSI includes a total value of a value acquired by performing
linear mean on total received power acquired by observing only the
OFDM symbols that do not include the DRS (CRS and/or CSI-RS) and a
value of the RSRP. The RSSI is observed in a bandwidth of the
number of resource blocks N. The total received power of the RSSI
includes power from the serving cell or the non-serving cell on the
same channel, interference power from the neighbour channel, and
thermal noise power.
[0373] Hereinafter, the details of the RSRQ will be described. The
RSRQ is defined as a ratio between the RSRP and the RSSI, and is
used for the same purpose as that of a
signal-to-interference-plus-noise ratio (SINR) of a measuring
target cell which is an index of communication quality. The
combination of the RSRP and the RSSI in the RSRQ is not limited to
the following combination. However, in the present embodiment, a
preferred combination of the RSRP and the RSSI in the RSRQ is
described.
[0374] An example of the RSRQ will be described.
[0375] The RSRQ is defined as a ratio calculated by the expression
of N.times.RSRP/RSSI. Here, N is the number of resource blocks
equivalent to the measurement bandwidth of the RSSI, and the
numerator and denominator of the RSRQ include the set of the same
resource block. Here, the RSRP is a first RSRP. Hereinafter, the
RSRQ calculated using the RSRQ calculated using the first RSRP is
referred to as a CRS base RSRQ or a first RSRQ.
[0376] The RSSI (E-UTRA carrier RSSI) includes a value acquired by
performing linear mean on total received power acquired by
observing only the OFDM symbols that include the reference signal
of the antenna port 0. In other words, the RSSI includes a value
acquired by performing linear mean on total received power acquired
by observing only the OFDM symbols that include the CRS (the radio
resource mapped to the antenna port 0) of the antenna port 0. The
RSSI is observed in a bandwidth of the number of resource blocks N.
The total received power of the RSSI includes power from the
serving cell or the non-serving cell on the same channel,
interference power from the neighbour channel, and thermal noise
power. In a case where a prescribed subframe for measuring the RSRQ
is designated from the signalling of the higher layer, the RSSI is
measured from all the OFDM symbols in the designated subframe.
[0377] The terminal device 1 measures the RSRQ of the cell having
the intra-frequency and/or the cell having the inter-frequency in
the RRC idle state. The terminal device 1 measures the RSRQ of the
cell having the intra-frequency and/or the cell having the
inter-frequency in the RRC connected state.
[0378] An example of the RSRQ will be described.
[0379] The RSRQ is defined as a ratio calculated by the expression
of N.times.RSRP/RSSI. Here, N is the number of resource blocks of
the measurement bandwidth of the RSSI, and the numerator and
denominator of the RSRQ need to include the set of the same
resource block. Here, the RSRP is a second RSRP. Hereinafter, the
RSRQ calculated using the RSRQ calculated using the second RSRP is
referred to as a second RSRQ.
[0380] The RSSI (E-UTRA carrier RSSI) includes a value acquired by
performing linear mean on total received power acquired by
observing only the OFDM symbols including the reference signal of
the antenna port 0. In other words, the RSSI includes a value
acquired by performing linear mean on total received power acquired
by observing only the OFDM symbols that include the CRS of the
antenna port 0. The RSSI is observed in a bandwidth of the number
of resource blocks N. The total received power of the RSSI includes
power from the serving cell or the non-serving cell on the same
channel, interference power from the neighbour channel, and thermal
noise power. In a case where a prescribed subframe for measuring
the RSRQ is designated from the signalling of the higher layer, the
RSSI is measured from all the OFDM symbols in the designated
subframe.
[0381] An example of the RSRQ will be described.
[0382] The RSRQ is defined as a ratio calculated by the expression
of N.times.RSRP/RSSI. Here, N is the number of resource blocks
equivalent to the measurement bandwidth of the RSSI, and the
numerator and denominator of the RSRQ include the set of the same
resource block. Here, the RSRP is measured based on the DRS (CRS
and/or CSI-RS).
[0383] The RSSI (E-UTRA carrier RSSI) includes a total value of a
value acquired by performing linear mean on total received power
acquired by observing only the OFDM symbols that do not include the
DRS (CRS and/or CSI-RS) and a value of the RSRP. In other words,
the RSSI includes a total value of a value acquired by performing
linear mean on total received power acquired by observing only the
OFDM symbols that do not include the DRS (CRS and/or CSI-RS) and a
value of the RSRP. The RSSI is observed in a bandwidth of the
number of resource blocks N. The total received power of the RSSI
includes power from the serving cell or the non-serving cell on the
same channel, interference power from the neighbour channel, and
thermal noise power.
[0384] The RSSI used for the RSRQ may be acquired based on the RSRP
and the linear mean value of the total received power acquired by
the OFDM symbols that do not include the DRS within the measurement
bandwidth.
[0385] The RSSI used for the RSRQ may be acquired from the linear
mean value of the total received power acquired by all the OFDM
symbols of the measurement bandwidth.
[0386] The RSSI used for the RSRQ may be acquired from the linear
mean value of the total received power acquired by the OFDM symbols
that do not include the DRS within the measurement bandwidth.
[0387] The RSSI used for the RSRQ may be acquired from the RSSI
measurement on the CRS constituting the DRS.
[0388] In a case where the DRS has the same structure as that of
the CSI-RS, 5 MHz or more may be configured as the measurement
bandwidth.
[0389] In a case where the DRS has the same structure as that of
the CSI-RS, 6 RBs and/or 15 RBs may be configured for the
measurement bandwidth.
[0390] The measurement bandwidth of the DRS may be configured using
the higher layer signalling.
[0391] The terminal device 1 measures the RSRQ of the cell having
the intra-frequency and/or the cell having the inter-frequency in
the RRC connected state.
[0392] A first measurement procedure will be described. First
measurement is to measure the first RSRP or the first RSRQ. The
first measurement may be the measurement (RRM measurement, RSRP
measurement, RSRQ measurement or RSSI measurement) of the first
signal (the signal having the first structure).
[0393] The terminal device 1 recognizes the resource elements to
which the CRSs transmitted through the antenna port 0 from the
physical cell identity (PCI) are allocated. The terminal device
measures the first RSRP from the resource elements to which the
CRSs transmitted through the antenna port 0 are allocated. The
number of subframes used in the measurement is not limited, and the
measurement may be performed over a plurality of subframes, and the
average value may be reported. Subsequently, the terminal device
recognizes the OFDM symbols including the antenna port 0, and
measures the RSSI. The first RSRQ is calculated from the first RSRP
and RSSI. The measurement subframes of the first RSRP and RSSI may
be different.
[0394] The result (the first RSRP or the first RSRQ) acquired based
on the first measurement procedure is referred to as a first
measurement result.
[0395] A second measurement procedure will be described. Second
measurement is to measure the second RSRP or the second RSRQ.
[0396] The terminal device 1 recognizes the resource elements to
which the DRSs are allocated from the configuration information of
the DRS. The terminal device measures the second RSRP from the
resource elements to which the DRSs are allocated. The number of
subframes used in the measurement is not limited, and the
measurement may be performed on the plurality of subframes, and the
average value thereof may be reported. Subsequently, the RSSI is
measured. The second RSRQ is calculated from the second RSRP and
RSSI.
[0397] The result (the second RSRP, the second RSRQ, the second
RSSI or the second RRM) acquired based on the second measurement
procedure is referred to a second measurement result. The second
measurement may be the measurement (the RRM measurement, the RSRP
measurement, the RSRQ measurement or the RSSI measurement) of the
second signal (the signal having the second structure).
[0398] Hereinafter, the mechanism for reporting the measurement
value measured by the terminal device 1 to the higher layer will be
described.
[0399] A measurement model will be described. FIG. 13 is a diagram
showing an example of the measurement model.
[0400] A measurement unit 1301 may include a Layer 1 filtering unit
13011, a Layer 3 filtering unit 13012, and a report criteria
evaluation unit 13013. The measurement unit 1301 may have a partial
function of the reception unit 105 and the higher layer processing
unit 101. Specifically, the Layer 1 filtering unit 13011 may be
included in the reception unit 105, and the Layer 3 filtering unit
13012 and the report criteria evaluation 13013 may be included in
the higher layer processing unit 101.
[0401] A filter is applied to the measurement value (sample) input
from the physical layer by the Layer 1 filtering unit 13011. For
example, the Layer 1 filtering unit 13011 may apply the mean of a
plurality of input values, the weighted mean, the mean according to
the channel characteristics, or may apply other filtering methods.
Measurement value reported from the first layer is input to the
third layer after the Layer 1 filtering unit 13011. The filter is
applied to the measurement value input to the Layer 3 filtering
unit 13012. The configuration of the Layer 3 filtering is provided
from the RRC signaling. An interval at which the measurement value
is filtered by the Layer 3 filtering unit 13012 and is reported is
the same as that of the input measurement gap. The report criteria
evaluation unit 13013 checks whether or not the reporting of the
measurement value is actually required. The evaluation is based on
one or more measurement flows. For example, the evaluation is the
comparison of different measurement values. The terminal device 1
evaluates the report criteria at least whenever a new measurement
result is reported. The configuration of the report criteria is
provided through the RRC signaling. After it is determined that the
reporting of the measurement value is required in the evaluation of
the report criteria, the terminal device 1 sends measurement report
information (measurement report message) through the wireless
interface.
[0402] Hereinafter, the measurement will be described. The base
station apparatus 3 transmits a measurement configuration message
to the terminal device 1 by using an RRC connection reconfiguration
message of the RRC signaling (radio resource control signal). The
terminal device 1 configures the system information included in the
measurement configuration message, and performs measurement, event
evaluation and measurement reporting on the serving cell and the
neighbour cell (including a listed cell and/or a detected cell)
according to the notified system information. The listed cell is a
cell (a cell notified as a neighbour cell list of the terminal
device 1 from the base station apparatus 3) listed as a measurement
object, and the detected cell is a cell (a cell which is not
notified as the neighbour cell list and is detected by the terminal
device 1) which is detected by the terminal device 1 in the
frequency indicated by the measurement object but is not listed as
the measurement object.
[0403] As the measurement, there are three types (intra-frequency
measurements, inter-frequency measurements, and inter-RAT
measurements). The intra-frequency measurements are measurements in
the downlink frequency of the serving cell. The inter-frequency
measurements are measurements in a frequency different from the
downlink frequency of the serving cell. The inter-RAT measurements
are measurements in the radio technology (for example, UTRA, GERAN
or CDMA2000) different from the radio technology (for example,
EUTRA) of the serving cell.
[0404] The measurement configuration message includes a measurement
identity (measId), measurement objects, and the addition and/or the
modification and/or the removing of the configurations of the
reporting configurations, physical quantity configuration
(quantityConfig), measurement gap configuration (measGapConfig),
and serving cell quality threshold (s-Measure).
[0405] The physical quantity configuration (quantityConfig)
designates an L3 filtering coefficient in a case where the
measurement objects are EUTRA. The L3 filtering coefficient defines
a ratio between the latest measurement result and the past
filtering measurement result. The filtering result is used in the
event evaluation by the terminal device 1.
[0406] The measurement gap configuration (measGapConfig) is used
for the configuration of a measurement gap pattern or the
activation/deactivation of a measurement gap. In the measurement
cap configuration (measGapConfig), a gap pattern, a start system
frame number (startSFN), or a start subframe number
(startSubframeNumber) is notified as information in a case where
the measurement gap is activated. The gap pattern defines a pattern
to be used as the measurement gap. The start system frame number
(startSFN) defines a system frame number (SFN) in which the
measurement gap is started. The start subframe number
(startSubframeNumber) defines a subframe number in which the
measurement gap is started.
[0407] In a case where the uplink/downlink transmission is not
scheduled, the measurement gap is a period (time or subframe) that
is likely to be used by the terminal device 1 to perform the
measurement.
[0408] In a case where the measurement gap is configured for the
terminal device 1 (or to which the DRS configuration is set) that
supports the measurement of the DRS, the measurement of the DRS may
be performed in the subframe (that is, on the measurement gap)
defined based on the measurement gap configuration.
[0409] In a case where the measurement gap is configured for the
terminal device 1 (or to which the DRS configuration is set) that
supports the measurement of the DRS, the DRS may be measured on the
measurement gap if the DRS transmission subframe based on the
subframe configuration included in the DRS configuration overlaps
with the subframe defined based on the measurement gap
configuration. If the DRS transmission subframe is present on the
measurement gap, the terminal device 1 may measure the DRS on the
measurement gap.
[0410] In a case where the measurement gap is configured for the
terminal device 1 (or to which the DRS configuration is set) that
supports the measurement of the DRS, the DRS may be measured for
only the cell in the deactivated state on the measurement gap in
the DCI format or the MAC CE. That is, the terminal device 1 may
not perform the measurement of the DRS on the cell in the activated
state on the measurement gap. The base station apparatus 3 may not
transmit the DRS in the cell in the activated state.
[0411] The measurement gap may be configured for each DRS or each
cell in the activated/deactivated state.
[0412] The serving cell quality threshold (s-Measure) represents a
threshold related to the quality of the serving cell, and is used
by the terminal device 1 to control whether or not it is necessary
to perform the measurement. The serving cell quality threshold
(s-Measure) is configured as a value of the RSRP.
[0413] Here, the measurement identity (measId) is used to link the
measurement objects and the reporting configurations, and
specifically, to link the measurement object identity
(measObjectId) and the reporting configuration identity
(reportConfigId). One measurement object identity (measObjectId)
and one reporting configuration identity (reportConfigId) are
correlated with the measurement identity (measId). The measurement
configuration message may be added, modified and removed with
respect to the relationship between the measurement identity
(measId), the measurement objects and the reporting
configurations.
[0414] measObjectToRemoveList is a command for removing the
measurement objects corresponding to the designated measurement
object identity (measObjectId) and the designated measurement
object identity (measObjectId). In this case, all the measurement
identity (measId) correlated with the designated measurement object
identity (measObjectId) are removed. This command can
simultaneously designate a plurality of measurement object
identities (measObjectIds).
[0415] measObjectToAddModifyList is a command for modifying the
designated measurement object identities (measObjectIds) to the
designated measurement objects or adding the designated measurement
object identities (measObjectIds) and the designated measurement
objects (measurement objects). This command can simultaneously
designate a plurality of measurement object identities
(measObjectIds).
[0416] reportConfigToRemoveList is a command for removing the
reporting configurations corresponding to the designated reporting
configuration identity (reportConfigId) and the designated
reporting configuration identity (reportConfigId). In this case,
all the measurement identities (measIds) correlated with the
designated reporting configuration identity (reportConfigId) are
removed. This command can simultaneously designate a plurality of
reporting configuration identities (reportConfigIds).
[0417] measIdToRemoveList is a command for removing the designated
measurement identity (measId). In this case, the measurement object
identity (measObjectId) and the reporting configuration identity
(reportConfigId) correlated with the designated measurement
identity (measId) are maintained without being removed. This
command can simultaneously designate a plurality of measurement
identities (measIds).
[0418] measIdToAddModifyList is a command for modifying the
designated measurement identity (measId) such that the measurement
identity is correlated with the designated measurement object
identity (measObjectId) and the designated reporting configuration
identity (reportConfigId) or adding the designated measurement
identity (measId) by correlating the designated measurement object
identity (measObjectId) and the designated reporting configuration
identity (reportConfigId) with the designated measurement identity
(measId). This command can simultaneously designate a plurality of
measurement identities (measIds).
[0419] The measurement objects are defined for each radio access
technology (RAT) and frequency. As the reporting configurations,
there are the definition of the EUTRA and the definition of the RAT
other than the EUTRA.
[0420] The measurement object includes measurement object EUTRA
(measObjectEUTRA) correlated with the measurement object identity
(measObjectId).
[0421] The measurement object identity (measObjectId) is identity
used to identify the configuration of the measurement object. As
described above, the configuration of the measurement object is
defined for each radio access technology (RAT) and frequency. The
measurement object is separately specified for the EUTRA, the UTRA,
the GERAN or the CDMA2000. The measurement object EUTRA
(measObjectEUTRA) which is the measurement object of the EUTRA
defines information applied to the neighbour cell of the EUTRA. The
measurement object EUTRA (measObjectEUTRA) having a different
frequency is treated as a different measurement object, and is
separately assigned the measurement object identity
(measObjectId).
[0422] An example of the information of the measurement object will
be described.
[0423] The measurement object EUTRA (measObjectEUTRA) includes
EUTRA carrier frequency information (eutra-CarrierInfo), a
measurement bandwidth (measurementBandwidth), antenna port 1
presence information (presenceAntennaPort1), an offset frequency
(offsetFreq), information related to a neighbour cell list, and
information related to a blacklist.
[0424] Hereinafter, information included in the measurement object
EUTRA (measObjectEUTRA) will be described. The EUTRA carrier
frequency information (eutra-CarrierInfo) designates a carrier
frequency as the measurement object. The measurement bandwidth
(measurementBandwidth) indicates a measurement bandwidth common to
all the neighbour cells operated in the carrier frequency as the
measurement object. The antenna port 1 presence information
(presenceAntennaPort1) indicates whether or not the antenna port 1
is used in the cell as the measurement object. The offset frequency
(offsetFreq) indicates a measurement offset value applied in the
frequency as the measurement target.
[0425] An example of the information of the measurement object will
be described.
[0426] The base station apparatus 3 performs a configuration
different from that in the first measurement for the terminal
device 1 in order to perform the second measurement. For example, a
signal (or the structure of the signal, or the configuration of the
signal) as the measurement object may be different between the
first measurement and the second measurement. A cell ID set to the
signal as the measurement object may be different between the first
measurement and the second measurement. An antenna port of the
signal as the measurement object may be different between the first
measurement and the second measurement. A measurement cycle (or
measurement subframe pattern) of the signal as the measurement
object may be different between the first measurement and the
second measurement. That is, the first measurement and the second
measurement may be individually configured.
[0427] The measurement object EUTRA (measObjectEUTRA) includes
EUTRA carrier frequency information (eutra-CarrierInfo), a
measurement bandwidth (measurementBandwidth), DRS configuration
information, an offset frequency (offsetFreq), information related
to a neighbour cell list, and information related to a
blacklist.
[0428] Hereinafter, information included in the measurement object
EUTRA (measObjectEUTRA) will be described. The EUTRA carrier
frequency information (eutra-CarrierInfo) designates a carrier
frequency as the measurement object. The measurement bandwidth
(measurementBandwidth) indicates a measurement bandwidth common to
all the neighbour cells operated in the carrier frequency as the
measurement object. The DRS configuration information is used to
notify the terminal device 1 of the common configuration
information in the frequency band required to detect the DRS
configuration, and indicates, for example, a subframe number or a
subframe cycle transmitted in the cell as the measurement target.
The offset frequency (offsetFreq) indicates a measurement offset
value applied in the frequency as the measurement target.
[0429] An example of the information related to the neighbour cell
list and the blacklist will be described.
[0430] The information related to the neighbour cell list includes
information related to the neighbour cell as an object of the event
evaluation or the measurement reporting. The information related to
the neighbour cell list includes a physical cell identity (physical
cell ID), and a cell specific offset (cellIndividualOffset)
(indicating the measurement offset value applied to the neighbour
cell). In the case of the EUTRA, this information is used as
information for performing the adding, modifying or removing of the
neighbour cell list already acquired from broadcast information
(broadcasted system information) by the terminal device 1.
[0431] The information related to the blacklist includes
information related to the neighbour cell which is not the object
of the event evaluation or the measurement reporting. The
information related to the blacklist includes the physical cell
identity (physical cell ID). In the case of the EUTRA, this
information is used as information for performing the adding,
modifying or removing of the blacklisted cell list already acquired
from the broadcast information by the terminal device 1.
[0432] An example of the information related to the neighbour cell
list and the blacklist will be described.
[0433] In a case where the second measurement is performed, it is
assumed that a case where it is insufficient with the physical cell
identity (PCI) is used. Thus, a new neighbour cell list and a new
blacklist acquired by extending the physical cell identity are
required.
[0434] Information related to the new neighbour cell list
(neighbour small cell list) may include information related to the
neighbour cell as the object of the event evaluation or the
measurement report. The information related to the new neighbour
cell list may include a cell ID, a cell-specific offset
(cellIndividualOffset) (indicating the measurement offset applied
to the neighbour cell), and cell-specific DRS configuration
information. Here, the cell-specific DRS configuration information
is information of the DRS configured so as to be specific to the
cell, and is, for example, information indicating the resource
element of the used DRS. In the case of the EUTRA, this information
is used as information for performing the adding, modifying or
removing of the new neighbour cell list already acquired from the
broadcast information (broadcasted system information) by the
terminal device 1.
[0435] The information related to the new blacklist may include
information related to the neighbour cell that is not the object of
the event evaluation or the measurement report. The information
related to the new blacklist may include the cell ID. In the case
of the EUTRA, this information is used as information for
performing the adding, modifying or removing of a new blacklisted
cell list (blacklisted small cell list) already acquired from the
broadcast information by the terminal device 1.
[0436] Here, the cell ID is, for example, a physical cell ID
(physical layer cell ID), a cell global identity/identifier (CGI),
an E-UTRAN cell global identifier/identity (ECGI), a discovery ID,
a virtual cell ID, or a transmission point ID, and is constituted
based on information of the cell (transmission point) ID
transmitted by the DRS. A parameter related to a sequence generator
(a scrambling sequence generator or a pseudo-random sequence
generator) may be used instead of the cell ID.
[0437] In a case where the cell ID (or the parameter (for example,
the scrambling ID) associated with the pseudo-random sequence
generator) is included in the configuration of the DRS, the
neighbour cell list may indicate the list of the DRS. That is, the
terminal device 1 may perform the measurement of the DRS of the
cell ID set to the neighbour cell list.
[0438] In the cell ID is included in the configuration of the DRS,
the blacklist may indicate the blacklist of the DRS. That is, the
terminal device 1 may not perform the measurement of the DRS of the
cell ID set to the blacklist.
[0439] Hereinafter, the details of the reporting configurations
will be described.
[0440] The reporting configurations include reporting configuration
EUTRA (reportConfigEUTRA) correlated with the reporting
configuration identity (reportConfigId).
[0441] The reporting configuration identity (reportConfigId) is
identity used to identify the reporting configurations related to
the measurement. As stated above, as the reporting configurations
related to the measurement, there are the definition for the EUTRA
and the definition for the RAT (UTRA, GERAN, or CDMA2000) other
than the EUTRA. The reporting configuration EUTRA
(reportConfigEUTRA) which is the reporting configurations for the
EUTRA defines triggering criteria of the event used to report the
measurement in the EUTRA.
[0442] The reporting configuration EUTRA (reportConfigEUTRA)
includes an event identity (eventId), triggering quantity
(triggerQuantity), hysteresis, trigger time (timeToTrigger),
reporting quantity (reportQuantity), the maximum number of reported
cells (maxReportCells), reporting interval (reportInterval) and
reporting amount (reportAmount).
[0443] The event identity (eventId) is used to select criteria
related to the event triggered reporting. Here, in a case where the
triggering criteria are satisfied, the event triggered reporting is
a method of reporting the measurement. In addition, in a case where
the triggering criteria are satisfied, there is event triggered
periodic reporting for reporting the measurement a certain number
of times at regular intervals.
[0444] In a case where the event triggered criteria designated by
the event identity (eventId) are satisfied, the terminal device 1
reports the measurement to the base station apparatus 3. The
triggering quantity (triggerQuantity) is a quantity used to
evaluate the event triggered criteria. That is, the RSRP or the
RSRQ is designated. That is, the terminal device 1 measures the
downlink reference signal by using the quantity designated by the
triggering quantity (triggerQuantity), and determines whether or
not the event triggered criteria designated by the event identity
(eventId) are satisfied.
[0445] The hysteresis is a parameter used in the event triggered
criteria. The triggering time (timeToTrigger) indicates a period
during which the event triggered criteria are satisfied. The
reporting quantity (reportQuantity) indicates a quantity reported
by the measurement report. Here, the quantity designated by the
triggering quantity (triggerQuantity), or the RSRP and RSRQ is
designated.
[0446] The maximum number of reported cells (maxReportCells)
indicates the maximum number of cells included in the measurement
report. The reporting interval (reportInterval) is used in periodic
reporting or event triggered periodic reporting, and the periodical
reporting is performed every interval indicated by the reporting
interval (reportInterval). The reporting amount (reportAmount) is
defined by the number of times the periodical reporting is
performed if necessary.
[0447] A threshold parameter or an offset parameter used in the
event triggered criteria to be described below together with the
event identity (eventId) is notified to the terminal device 1 in
the reporting configurations.
[0448] The base station apparatus 3 may or may not notify of a
serving cell quality threshold (s-Measure) in some cases. In a case
where the base station apparatus 3 notifies the serving cell
quality threshold (s-Measure), when the RSRP of the serving cell is
lower than the serving cell quality threshold (s-Measure), the
terminal device 1 performs the event evaluation (referred to as
evaluation of reporting criteria of whether or not the event
triggered criteria are satisfied). Meanwhile, in a case where the
base station apparatus 3 does not notify of the serving cell
quality threshold (s-Measure), the terminal device 1 performs the
measurement of the neighbour cell and the event evaluation
irrespective of the RSRP of the serving cell.
[0449] Hereinafter, the details of the event and the event
triggered criteria will be described.
[0450] The terminal device 1 that satisfies the event triggered
criteria transmits the measurement report to the base station
apparatus 3. The measurement report includes a measurement
result.
[0451] A plurality of event triggered criteria for performing the
measurement report is defined, and there are a subscription
criterion and a separation criterion. That is, the terminal device
1 that satisfies the subscription criterion to the event designated
from the base station apparatus 3 transmits the measurement report
to the base station apparatus 3. In a case where the event
separation criterion is satisfied, the terminal device 1 which
satisfies the event subscription criterion and transmits the
measurement report stops transmitting the measurement report.
[0452] An example of the event and the event triggered criterion to
be described below is used by any one of a first measurement result
or a second measurement result.
[0453] Hereinafter, an example of the method of designating the
type of the measurement result used to evaluate the event triggered
criteria will be described.
[0454] The type of measurement result used to evaluate the event
triggered criteria is designated by the reporting configurations.
The event triggered criteria is evaluated using any one of the
first measurement result or the second measurement result by the
parameter.
[0455] As a specific example, whether the first measurement result
or the second measurement result is used is designated by the
triggering physical quantity (triggerQuantity). As the triggering
physical quantity, four selection fields of {first RSRP, first
RSRQ, second RSRP and second RSRQ} may be designated. The terminal
device 1 measures the downlink reference signal by using the
physical layer designated by the triggering quantity
(triggerQuantity), and determines whether or not the event
triggered criteria designated by the event identity (eventId) are
satisfied.
[0456] As a specific example, whether the first measurement result
or the second measurement result is used may be defined by a new
parameter (triggerMeasType) for designating the type of measurement
result used to evaluate the event triggered criteria in addition to
the triggering physical quantity. Information indicating that the
event triggered criteria are evaluated using the first measurement
result or information indicating that the event triggered criteria
are evaluated using the second measurement result is set to the new
parameter. For example, in a case where the information indicating
that the event triggered criteria are evaluated using the second
measurement result is set to the new parameter, the terminal device
1 performs the second measurement, and evaluates the event
triggered criteria by using the second measurement result. The
parameter may be shared with a parameter (reportMeasType) for
designating the type of reported measurement result.
[0457] In the event triggered criteria in which two or more
measurement results are used in one conditional expression such as
comparison of the measurement result of the serving cell and the
measurement result of the neighboring cell, the type of measurement
result used to evaluate the event triggered criteria may be
designated. For example, a new parameter (triggerMeasTypeServ) for
the measurement result of the serving cell and a new parameter
(triggerMeasTypeNeigh) for the measurement result of the
neighboring cell may be defined.
[0458] Hereinafter, an example of the method of designating the
type of the measurement result used to evaluate the event triggered
criteria will be described.
[0459] The type of measurement result used to evaluate the event
triggered criteria is determined depending on criteria for
designating the measurement by the reporting configurations.
[0460] As a specific example, the type of measurement result used
to evaluate the event triggered criteria is determined depending on
the activated/deactivated state of the target cell. For example, if
the target cell is in the activated state, the event triggered
criteria are evaluated using the first measurement result, and if
the target cell is in the deactivated state, the event triggered
criteria are evaluated using the second measurement result.
[0461] As a specific example, the type of measurement result used
to evaluate the event triggered criteria is determined depending on
the detection of the reference signal. For example, in a case where
the CRS is detected and the DRS is not detected, the event
triggered criteria may be evaluated using the first measurement
result, and in a case where the CRS is not detected and the DRS is
detected, the event triggered criteria may be evaluated using the
second measurement result. In a case where both the CRS and the DRS
are detected, the event triggered criteria may be evaluated using
the measurement result of which the received power is higher. In a
case where both the CRS and the DRS area detected, the event
triggered criteria may be evaluated using the measurement result
acquired by averaging both the received powers. In a case where
both the CRS and the DRS are not detected, the event triggered
criteria may not be evaluated.
[0462] Hereinafter, the details of the measurement result will be
described.
[0463] The measurement result includes a measurement identity
(measId), a serving cell measurement result (measResultServing),
and an EUTRA measurement result list (measResultListEUTRA). Here,
the EUTRA measurement result list (measResultListEUTRA) includes a
physical cell identity (physicalCellIdentity) and an EUTRA cell
measurement result (measResultEUTRA). Here, as mentioned above, the
measurement identity (measId) is identity used to link measurement
object identity (measObjectId) and reporting configuration identity
(reportConfigId). The physical cell identity (physicalCellIdentity)
is used to identify the cell. EUTRA cell measurement result
(measResultEUTRA) is a measurement result for the EUTRA cell. The
measurement result of the neighbour cell is included only when the
associated event occurs.
[0464] An example of the measurement result will be described.
[0465] The terminal device 1 may report the measurement result by
adding the results of the RSRP and the RSRQ for the target cell to
the measurement result. The RSRP and the RSRQ reported once may be
one of the first measurement result and the second measurement
result. The first measurement result may be a measurement result
acquired from the first measurement. The second measurement result
may be a measurement result acquired from the second measurement.
In other words, the first measurement result is a measurement
result acquired based on configuration information related to the
first measurement, and the second measurement result is a
measurement result acquired based on configuration information
related to the second measurement.
[0466] As a specific example, the measurement result is reported
based on the parameter for determining the first measurement result
or the second measurement result. A reference for determining the
first measurement result or the second measurement result is, for
example, a new parameter (reportMeasType). Information indicating
that the first measurement result is reported or information
indicating that the second measurement result is reported may be
set to the new parameter. For example, in a case where the
information indicating that the second measurement result is
reported is set to the new parameter, the terminal device 1
recognizes the new parameter, performs the second measurement,
transmits the second measurement result by adding the second
measurement result to the measurement reporting message, and does
not transmit the first measurement result. Information indicating
that the first measurement result and the second measurement result
are reported may be set to the new parameter.
[0467] The new parameter may be shared with a parameter
(triggerMeasType) for designating the type of measurement result
used to evaluate the event triggered criteria. The parameter may be
shared with a higher layer parameter for designating the
measurement method.
[0468] The parameter (reportQuantity) indicating the reporting
physical quantity may be configured as a parameter
(reportQuantityRSRP) for the RSRP and a parameter
(reportQuantityRSRQ) for the RSRQ for each measured type. For
example, the reportQuantityRSRP is configured as the first RSRP and
the reportQuantityRSRQ is configured as the second RSRQ, the
terminal device 1 transmits the first RSRP and the second RSRQ, and
does not transmit the second RSRP and the first RSRQ.
[0469] As a specific example, the measurement result may be
reported depending on the criteria for designating the
measurement.
[0470] For example, the type of reported measurement result may be
determined depending on the activated/deactivated state of the
target cell.
[0471] For example, the type of reported measurement result is
determined depending on the detection of the reference signal. For
example, in a case where the CRS is detected and the DRS is not
detected, the first measurement result is reported, and if the CRS
is not detected and the DRS is detected, the second measurement
result is reported. In a case where both the CRS and the DRS are
detected, the measurement result of which the received power is
higher is reported. In a case where both the CRS and the DRS are
not detected, the measurement result is not reported, or the
minimum value is reported.
[0472] In order for the base station apparatus 3 to recognize
whether the reported measurement result is the result calculated by
the first measurement or the measurement calculated by the second
measurement, the terminal device 1 may add a parameter indicating
the type of measurement to which the measurement result is set.
[0473] The example of the event triggered criteria and the
reporting of the measurement result has been described. The
terminal device 1 reports the first measurement result and/or the
second measurement result to the base station apparatus 3 by the
combination thereof. In the present embodiment, the combination of
the event, the event triggered criteria and the reporting of the
measurement result is not limited, and an example of a preferred
combination will be described below.
[0474] An example of the combination of the event, the event
triggered criteria and the reporting of the measurement result will
be described.
[0475] In a case where the first measurement is performed, the
measurement object (measObject) including the neighbour cell list
or the blacklist for the physical cell identity is configured is
configured, the reporting configuration (reportConfig) for which
the event and the event triggered criteria triggered by the first
measurement are configured is configured, and the measurement
reporting message including the first measurement result
(measResults) is transmitted in association with these parameters
by the ID. In a case where the second measurement is performed, the
measurement object (measObject) including the new neighbour cell
list or the new blacklist for which the extended cell ID is
configured is configured, the reporting configuration
(reportConfig) for which the event and the event triggered criteria
triggered by the second measurement are configured is configured,
and the measurement reporting message including the second
measurement result (measResults) is transmitted in association with
these parameters by the ID.
[0476] That is, the measurement object, reporting configuration and
measurement result for the first measurement and the measurement
object, measurement configuration and measurement result for the
second measurement are configured for the terminal device 1. That
is, the reporting configuration for the first measurement result
and the reporting configuration for the second measurement result
are respectively configured.
[0477] An example of the combination of the event, the event
triggered criteria and the reporting of the measurement result will
be described.
[0478] In a case where the first measurement is performed, the
measurement object (measObject) including the neighbour cell list
or the blacklist for which the physical cell identity is configured
is configured, the reporting configuration (reportConfig) for which
the event and the event triggered criteria triggered by the first
measurement are configured is configured, and these parameters are
associated with the measurement results (measResults) by the ID. In
a case where the second measurement is performed, the measurement
object (measObject) including the new neighbour cell list or the
new blacklist for which the extended cell ID is configured is
configured, the reporting configuration (reportConfig) for which
the event and the event triggered criteria triggered by the second
measurement are configured is configured, and these parameters are
associated with the measurement results (measResults) by the ID. In
a case where the event triggered by the first measurement occurs,
the first measurement result is substituted for the measurement
result, and is transmitted by the measurement reporting message. In
a case where the event triggered by the second measurement occurs,
the second measurement result is substituted for the measurement
result, and is transmitted by the measurement reporting
message.
[0479] That is, the measurement object and reporting configuration
for the first measurement and the measurement object and reporting
configuration for the second measurement are configured, and the
field of the measurement result is shared between the first
measurement and the second measurement. The first measurement
result or the second measurement result is transmitted by the
event.
[0480] Accordingly, the terminal device 1 may report the first
measurement result and the second measurement result to the base
station apparatus 3.
[0481] The terminal device 1 according to the present embodiment is
the terminal device 1 that communicates with the base station
apparatus 3, and includes a reception unit 105 which performs first
measurement based on a first RS (CRS), and performs second
measurement based on a second RS (DRS), and a higher layer
processing unit 101 that reports the first measurement result and
the second measurement result to the base station apparatus 3. The
terminal device reports the first measurement result to the base
station apparatus 3 in a first state, and reports the first
measurement result or the second measurement result to the base
station apparatus 3 in a second state.
[0482] As an example, in the second state, an event in which the
first measurement result is reported an event in which the second
measurement result is reported are configured by the base station
apparatus 3. As an example, in the second state, only the event in
which the second measurement is reported is configured by the base
station apparatus 3. An event triggered criteria in which the
second measurement result is reported is defined using the second
measurement result.
[0483] As an example, the first state is a state in which
configuration information of the second RS is not notified, and the
second state is a state in which configuration information of the
second RS is notified from the base station apparatus 3. As an
example, the first state is a state in which the second measurement
information is not configured, and the second state is a state in
which the second measurement information is configured from the
base station apparatus 3. As an example, the second state is a
state in which the first RS is not transmitted.
[0484] Reporting configuration for the DRS may be individually set
from reporting configuration for the CRS or CSI-RS.
[0485] A value is determined depending on a path loss in transmit
power or power headroom (PHR). Hereinafter, an example of a method
of estimating the path loss (channel attenuation value) will be
described.
[0486] A downlink path loss estimation value of a serving cell c is
calculated by the terminal device 1 using the expression of
PLc=referenceSignalPower-higher layer filtered RSRP. Here, the
referenceSignalPower is obtained in the higher layer. The
referenceSignalPower is information based on the transmit power of
the CRS. Here, the higher layer filtered RSRP is a first RSRP of a
reference serving cell filtered in the higher layer.
[0487] In a case where the serving cell c belongs to TAG (pTAG)
including the primary cell, the primary cell is used as the
reference serving cell of the referenceSignalPower and the higher
layer filtered RSRP for the uplink primary cell. The serving cell
configured by a parameter of pathlossReference linking of the
higher layer is used as the reference serving cell of the
referenceSignalPower and the higher layer filtered RSRP for the
uplink secondary cell. In a case where the serving cell c belongs
to TAG (for example, sTAG) that does not include the primary cell,
the serving cell c is used as the reference serving cell of the
referenceSignalPower and the higher layer filtered RSRP.
[0488] An example of the method of estimating the path loss will be
described.
[0489] The downlink path loss estimation value of the serving cell
c is calculated by the terminal device 1 by using the expression of
PLc=discoveryReferenceSignalPower-higher layer filtered RSRP2 in a
case where the parameter is configured by the higher layer or by
using the expression of PLc=referenceSignalPower-higher layer
filtered RSRP in a case where the parameter is not configured by
the higher layer. Here, the referenceSignalPower is obtained in the
higher layer. The referenceSignalPower is information based on the
transmit power of the CRS. Here, the higher layer filtered RSRP is
a first RSRP of the reference serving cell filtered in the higher
layer. Here, the discoveryReferenceSignalPower is a parameter
associated with the transmit power of the DRS, and is obtained in
the higher layer. The higher layer filtered RSRP2 is a second RSRP
of the reference serving cell filtered in the higher layer.
[0490] Here, the case where the parameter is configured by the
higher layer may be, for example, a case where the parameter is
based on the configuration of the DRS notified using the higher
layer signalling. The case where the parameter is configured by the
higher layer may be, for example, a case where the parameter is
based on the configuration of the measurement notified using the
higher layer signalling. The case where the parameter is configured
by the higher layer may be, for example, a case where the parameter
is based on the configuration of the uplink power control notified
using the higher layer signalling. That is, the case where the
parameter is configured by the higher layer may include a case
where the parameter or the information is notified using the higher
layer signalling and is configured for the terminal device 1.
[0491] In a case where the serving cell c belongs to the TAG
including the primary cell, the primary cell is used as the
reference serving cell of the discoveryReferenceSignalPower and the
higher layer filtered RSRP2 for the uplink primary cell. The
serving cell configured by a parameter of pathlossReferenceLinking
of the higher layer is used as the reference serving cell of the
discoveryReferenceSignalPower and the higher layer filtered RSRP2
for the uplink secondary cell. In a case where the serving cell c
belongs to the TAG that does not include the primary cell, the
serving cell c is used as the reference serving cell of the
discoveryReferenceSignalPower and the higher layer filtered
RSRP2.
[0492] In a case where the secondary cell is in the deactivated
state, the terminal device 1 may not perform the following process.
The process includes the transmission of the SRS in the secondary
cell, the reporting of the channel quality indicator
(CQI)/precoding matrix indicator (PMI)/rank indicator
(RI)/precoding type indicator (PTI) for the secondary cell, the
transmission of the uplink data (UL-SCH) in the secondary cell, the
transmission of the RACH in the secondary cell, the monitoring of
the PDCCH in the secondary cell, and the monitoring of the PDCCH
for the secondary cell.
[0493] In a case where the secondary cell is the small cell, even
in a case where the secondary cell is in the deactivated state, the
terminal device 1 may perform the following process. The process
includes the transmission of the SRS in the secondary cell, the
reporting of the CQI/PMI/RI/PTI for the secondary cell, (the
transmission of the uplink data (UL-SCH) in the secondary cell),
the transmission of the RACH in the secondary cell, the monitoring
of the PDCCH in the secondary cell, and the monitoring of the PDCCH
for the secondary cell.
[0494] In a case where the secondary cell in the deactivated state
is the small cell, if there is a request for the SRS transmission
to the secondary cell from the primary cell (PDCCH/EPDCCH (DCI
format) transmitted in the primary cell) (an SRS request is
transmitted) through cross-carrier scheduling, the terminal device
1 may transmit the SRS in the secondary cell. That is, in this
case, the base station apparatus 3 expects to receive the SRS.
[0495] In a case where the secondary cell in the deactivated state
is the small cell, if there is a request for the CSI reporting to
the secondary cell from the primary cell (PDCCH/EPDCCH (DCI format)
transmitted in the primary cell) (a CSI request is transmitted)
through cross-carrier scheduling, the terminal device 1 may
transmit the CQI/PMI/RI/PTI for the secondary cell by using the
PUSCH of the primary cell. That is, in this case, the base station
apparatus 3 expects to receive the CQI/PMI/RI/PTI for the secondary
cell by using the PUSCH of the primary cell.
[0496] In a case where the secondary cell in the deactivated state
is the small cell, if a random access response grant (RAR grant)
through a PDCCH order is transmitted from the primary cell
(PDCCH/EPDCCH (DCI format) transmitted in the primary cell) through
cross-carrier scheduling, the terminal device 1 may perform the
RACH transmission in the secondary cell. That is, in this case, the
base station apparatus 3 expects to receive the RACH in the
secondary cell.
[0497] In a case where the secondary cell in the deactivated state
is the small cell, if the DCI format accompanying by the CRC
scrambled with the RA-RNTI can be detected for the secondary cell
from the primary cell (PDCCH/EPDCCH (DCI format) transmitted in the
primary cell) through cross-carrier scheduling, the terminal device
1 may perform the RACH transmission in the secondary cell. That is,
in this case, the base station apparatus 3 expects to receive the
RACH in the secondary cell.
[0498] In a case where the secondary cell in the deactivated state
is the small cell, if the configuration (or EPDCCH configuration)
of the EPDCCH set is not set to the secondary cell, the terminal
device 1 may monitor the PDCCH in the secondary cell. That is, in
this case, the base station apparatus 3 may transmit the PDCCH in
the small cell in the deactivated state.
[0499] In a case where the secondary cell in the deactivated state
is the small cell, if the downlink grant or the uplink grant, the
CSI request or the SRS request, or the random access response grant
are transmitted to the secondary cell from the primary cell
(PDCCH/EPDCCH (DCI format) transmitted in the primary cell) through
cross-carrier scheduling, the terminal device 1 may monitor the
PDCCH for the secondary cell. In this case, only in a case where
the EPDCCH set (or EPDCCH configuration) is not configured for the
terminal device 1 or the terminal device 1 does not support a
function of receiving the DCI by using the EPDCCH, the terminal
device 1 may monitor the PDCCH for the secondary cell. That is, in
this case, the base station apparatus 3 may transmit the PDCCH in
the small cell in the deactivated state.
[0500] In a case where the secondary cell in the deactivated state
is the small cell, even though information related to the uplink
scheduling is transmitted to the secondary cell, the terminal
device 1 may not perform the uplink transmission based on the
information related to the uplink scheduling. That is, in this
case, the base station apparatus 3 does not expect that the uplink
transmission is performed in the small cell in the deactivated
state.
[0501] In a case where the secondary cell in the deactivated state
is the primary secondary cell (special secondary cell), if there is
a request for the SRS transmission to the secondary cell (an SRS
request is transmitted) through self-scheduling, the terminal
device 1 may transmit the SRS in the secondary cell. That is, in
this case, the base station apparatus 3 expects to receive the
SRS.
[0502] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if there is a request for the CSI
reporting for the secondary cell (a CSI request is transmitted)
through self-scheduling, the terminal device 1 may transmit the
CQI/PMI/RI/PTI for the secondary cell by using the PUSCH of the
secondary cell.
[0503] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the random access response grant
(RAR grant) through the PDCCH order is transmitted through
self-scheduling, the terminal device 1 may perform the RACH
transmission in the secondary cell.
[0504] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the DCI format accompanying by
the CRC scrambled with the RA-RNTI can be detected for the
secondary cell through self-scheduling, the terminal device 1 may
perform the RACH transmission in the secondary cell.
[0505] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the EPDCCH set is not configured
for the secondary cell, the terminal device 1 may monitor the PDCCH
in the secondary cell. That is, if the configuration of the EPDCCH
set is not received for the primary secondary cell, the terminal
device 1 may monitor the PDCCH in the secondary cell. If the
configuration of the EPDCCH set is not set to the primary secondary
cell, the base station apparatus 3 may transmit the PDCCH for the
terminal device 1 in the secondary cell.
[0506] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the downlink grant or the uplink
grant, the CSI request or the SRS request, or the random access
response grant is transmitted for the secondary cell through
self-scheduling, the terminal device 1 may monitor the PDCCH for
the secondary cell. In this case, only in a case where the EPDCCH
set is not configured for the terminal device 1 or the terminal
device 1 does not support a function of receiving the DCI by using
the EPDCCH, the terminal device 1 may monitor the PDCCH for the
secondary cell.
[0507] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if information (PUSCH grant, CSI
request or SRS request) related to the uplink scheduling is
transmitted for the secondary cell through self-scheduling, the
terminal device 1 may perform the uplink transmission based on the
information related to the uplink scheduling in the secondary cell.
For example, in a case where the DCI format 0 is detected for the
secondary cell, the terminal device 1 may perform the PUSCH
transmission in the secondary cell.
[0508] In a case where the secondary cell in the deactivated state
is the primary secondary cell (special secondary cell), if there is
a request for the SRS transmission to the secondary cell from the
primary cell (PDCCH/EPDCCH (DCI format) transmitted in the primary
cell) (an SRS request is transmitted) through cross-carrier
scheduling, the terminal device 1 may transmit the SRS in the
secondary cell. In this case, the terminal device 1 may support a
function of performing the cross-carrier scheduling of the primary
cell and the primary secondary cell.
[0509] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if there is a request for the CSI
reporting for the secondary cell from the primary cell
(PDCCH/EPDCCH (DCI format) transmitted in the primary cell) (a CSI
request is transmitted) through cross-carrier scheduling, the
terminal device 1 may transmit the CQI/PMI/RI/PTI for the secondary
cell by using the PUSCH of the primary cell. In this case, the
terminal device 1 may support a function of performing the
cross-carrier scheduling of the primary cell and the primary
secondary cell.
[0510] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the random access response grant
(RAR grant) through a PDCCH order is transmitted from the primary
cell (PDCCH/EPDCCH (DCI format) transmitted in the primary cell)
through cross-carrier scheduling, the terminal device 1 may perform
the RACH transmission in the secondary cell. In this case, the
terminal device 1 may support a function of performing the
cross-carrier scheduling of the primary cell and the primary
secondary cell. In this case, the base station apparatus 3 may
transmit the random access response grant (RAR grant) through the
PDCCH order to the secondary cell in the deactivated state through
cross-carrier scheduling.
[0511] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the DCI format accompanying by
the CRC scrambled with RA-RNTI can be detected for the secondary
cell from the primary cell (PDCCH/EPDCCH (DCI format) transmitted
in the primary cell), the terminal device 1 may perform the RACH
transmission in the secondary cell. In this case, the terminal
device 1 may support a function of performing the cross-carrier
scheduling of the primary cell and the primary secondary cell.
[0512] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the EPDCCH set is not configured
for the secondary cell, the terminal device 1 may monitor the PDCCH
in the secondary cell.
[0513] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the downlink grant or the uplink
grant, the CSI request or the SRS request, or the random access
response grant is transmitted to the secondary cell from the
primary cell (PDCCH/EPDCCH (DCI format) transmitted in the primary
cell) through cross-carrier scheduling, the terminal device 1 may
monitor the PDCCH for the secondary cell. In this case, only in a
case where the EPDCCH set is not configured for the terminal device
1 or the terminal device 1 does not support a function of receiving
the DCI by using the EPDCCH, the terminal device 1 may monitor the
PDCCH for the secondary cell.
[0514] In a case where the cross-carrier scheduling is invalid for
the secondary cell in the deactivated state, the terminal device 1
may monitor the PDCCH in the secondary cell in the deactivated
state.
[0515] In a case where the cross-carrier scheduling is invalid for
the secondary cell in the deactivated state and various
configurations related to the EPDCCH are not received, the terminal
device 1 may monitor the PDCCH in the secondary cell in the
deactivated state.
[0516] If the EPDCCH configuration and/or the configuration of the
EPDCCH set are not performed for the secondary cell in the
deactivated state, the terminal device 1 may monitor the PDCCH in
the secondary cell in the deactivated state. The base station
apparatus 3 may determine whether or not the PDCCH is transmitted
in the secondary cell in the deactivated state to the terminal
device 1 depending on whether or not the EPDCCH configuration
and/or the configuration of the EPDCCH set for the secondary cell
in the deactivated state is set.
[0517] In a case where the secondary cell in the deactivated state
is the primary secondary cell, if the information related to the
uplink scheduling is transmitted to the secondary cell from the
primary cell through the cross-carrier scheduling, the terminal
device 1 may perform the uplink transmission based on the
information related to the uplink scheduling. In this case, the
terminal device 1 may support a function of performing the
cross-carrier scheduling of the primary cell and the primary
secondary cell.
[0518] If a certain serving cell is configured such that the
terminal device 1 receives PDSCH data transmission according to
Transmission Modes 1 to 9 through the higher layer signalling and
is configured such that the terminal device 1 monitors the EPDCCH,
the terminal device 1 assumes that the antenna ports 0 to 3 and 107
to 110 of the serving cell are quasi co-located for the Doppler
shift, Doppler spread, average delay and delay spread.
[0519] In a case where a certain serving cell is configured such
that the terminal device 1 receives the PDSCH data transmission
according to Transmission Mode 10 through higher layer signalling
and is configured such that the terminal device 1 monitors the
EPDCCH for each EPDCCH-PRB set, and if the certain cell is
configured by the higher layer such that the terminal device 1
decodes the PDSCH according to quasi-co-location (QCL) type A, the
terminal device 1 assumes that the antenna ports 0 to 3 and the
antenna ports 107 to 110 of the serving cell are quasi co-located
for the Doppler shift, Doppler spread, average delay, and delay
spread. Meanwhile, if the certain cell is configured by the higher
layer that the terminal device 1 decodes the PDSCH according to
quasi-co-location type B, the terminal device 1 assumes that the
antenna ports 15 to 22 and the antenna ports 107 to 110
corresponding to a higher layer parameter (qcl-CSI-RS-ConfigNZPId)
for the Doppler shift, Doppler spread, average delay, and delay
spread.
[0520] According to the QCL type A, it may be assumed in the
terminal device 1 that the antenna ports 0 to 3 and the antenna
ports 107 to 110 of the serving cell are quasi co-located for the
Doppler shift, Doppler spread, average delay, and delay spread.
[0521] According to the QCL type B, it may be assumed in the
terminal device 1 that the antenna ports 107 to 110 and the antenna
ports 15 to 22 corresponding to the higher layer parameter
(qcl-CSI-RSConfigNZPId) are quasi co-located for the Doppler shift,
Doppler spread, average delay, and delay spread.
[0522] That is, in a case where the type A is set to the terminal
device 1 based on the higher layer parameter QCL operation, it is
assumed that the antenna ports 0 to 3 and the antenna ports 107 to
110 of the serving cell are quasi co-located, and in a case where
the type B is set, it is assumed that the antenna ports 107 to 110
and the antenna ports 15 to 22 corresponding to the higher layer
parameter (qcl-CSI-RSConfigNZPId) are quasi co-located. In other
words, in a case where the type A is set to the terminal device 1
configured so as to monitor the EPDCCH based on the higher layer
parameter QCL operation, it is assumed that the CRS and the EPDCCH
are quasi co-located, and in a case where the type B is set, it is
assumed that the CSI-RS and the EPDCCH are quasi co-located.
[0523] In a case where a certain serving cell is configured such
that the terminal device 1 receives PDSCH data transmission
corresponding to Transmission Mode 10 through the higher layer
signalling and each EPDCCH-PRB set is configured that the terminal
device 1 monitors the EPDCCH, a parameter set
(PDSCH-RE-MappingQCL-Config) indicated by the higher layer
parameter (re-MappingQCL-ConfigId or PDSCH-RE-MappingQCL-ConfigId)
is used in order to determine the quasi-co-location of the EPDCCH
antenna ports and the mapping of the EPDCCH resource elements. In
order to determine the mapping of the EPDCCH resource elements and
the quasi-co-location of the EPDCCH antenna ports, various
parameters (crs-PortsCount, crs-FreqShift,
mbsfn-SubframeConfigList, csi-RS-ConfigZPId, pdsch-Start, and
qcl-CSI-RS-ConfigNZPId) are included in the parameter set.
[0524] In a case where a certain serving cell (secondary cell) is
configured such that the terminal device 1 receives the DRS through
the higher layer signalling and is configured such that the
terminal device 1 monitors the EPDCCH, the higher layer parameter
(qcl-DRS-ConfigId) for determining the mapping of the DRS and
EPDCCH resource elements and the quasi-co-location of the EPDCCH
antenna ports may be configured.
[0525] In a case where a certain serving cell (secondary cell) is
configured such that the terminal device 1 receives the DRS through
the higher layer signalling and is configured such that the
terminal device 1 monitors the EPDCCH, the terminal device 1
assumes that the antenna ports 107 to 110 and one or more antenna
ports corresponding to the higher layer parameter
(qcl-DRS-ConfigId) are quasi co-located.
[0526] In order to determine the mapping of the EPDCCH resource
elements and the quasi-co-location of the EPDCCH antenna ports with
respect to the DRS, various parameters (drs-PortsCount,
drs-FreqShift, drs-ConfigZPId, qcl-DRS-ConfigNZPId, and
qcl-DRS-ConfigId) may be set. That is, the number of DRS antenna
ports (drs-PortsCount) may be included in the configuration of the
quasi-co-location of the EPDCCH and the DRS. The DRS frequency
shift (drs-FreqShift) may be included in the configuration of the
quasi-co-location of the EPDCCH and the DRS. A zero power DRS-ID
(drs-ConfigZPId) may be included in the configuration of the
quasi-co-location of the EPDCCH and the DRS. Non-zero power DRS ID
(qcl-DRS-ConfigNZPId) that is quasi co-located may be included in
the configuration of the quasi-co-location of the EPDCCH and the
DRS.
[0527] A signal as a target which is quasi co-located with the
EPDCCH may be changed depending on the activated/deactivated state
of the serving cell (secondary cell). For example, the terminal
device 1 may assume that the DRS and the EPDCCH are quasi
co-located in the deactivated state of the serving cell and may
assume that the CRS and the EPDCCH are quasi co-located in the
activated state of the serving cell. The terminal device 1 may
assume that the CSI-RS and the EPDCCH are quasi co-located in the
deactivated state of the serving cell and may assume that the CRS
and the EPDCCH are quasi co-located in the activated state of the
serving cell. The terminal device 1 may assume that the CSI-RS, the
CRS, and the EPDCCH are quasi co-located in the activated state of
the serving cell and may assume that the CSI-RS and the EPDCCH are
quasi co-located in the deactivated state of the serving cell. That
is, the terminal device 1 determines that the quasi-co-location of
the EPDCCH (the mapping of the resource elements and the antenna
ports) based on the set configuration information. In a case where
the quasi-co-location of the EPDCCH is changed in the activated
state and deactivated state, the base station apparatus 3 may
transmit the information related to the plurality of QCL
configurations.
[0528] Hereinafter, the discontinuous reception (DRX) will be
described.
[0529] The terminal device 1 may configure the DRX by the RRC
accompanying by the DRX function in order to control the activation
(whether or not to perform the PDCCH monitoring) of the PDCCH
monitoring of the terminal device 1 for the C-RNTI, TPC-PUCCH-RNTI,
TPC-PUSCH-RNTI, and SPS-RNTI of the terminal device 1. If the DRX
is not configured, the terminal device 1 continues to continuously
monitor the PDCCH. In order to perform the DRX, a plurality of
timers (onDurationTimer, drx-InactivityTimer, and
drx-RetransmissionTimer) is configured for the terminal device 1. A
cycle (longDRX-Cycle or shortDRX-Cycle) and a start offset
(drxStartOffset) are configured, and thus, a subframe in which the
PDCCH is monitored during the DRX is configured. Parameters
(drxShortCycleTimer and shortDRX-Cycle) related to short DRX may be
configured as options. An HARQ RTT timer is defined for each DL
HARQ process (except for a broadcast process). A period during
which the PDCCH can be monitored during the DRX is referred to as
an active time.
[0530] The active time may be a time during which at least one
timer of a plurality of timers (onDurationTimer,
drx-InactivityTimer, drx-RetransmissionTimer, and
mac-ContentionResolutionTimer) is started. The active timer is a
time during which a scheduling request is transmitted through the
PUCCH and is pending. The active time may be a timer during which
there is an uplink grant for the HARQ transmission being pending
and data is present in corresponding HARQ buffer. The active time
may be a time during which the PDCCH indicating new transmission
related to the C-RNTI of the terminal device 1 is not received
after the reception of the random access response for a preamble
which is not selected by the terminal device 1 succeeds. The active
time may be the number of subframes configured as a DRX active time
(drx-Activetime).
[0531] If the DRX is configured, the terminal device 1 starts a DRX
retransmission timer (drx-RetransmissionTimer) of the corresponding
HARQ process for each subframe if the HARQ RTT timer expires in
each subframe and the decoding of the data of the corresponding
HARQ process does not succeed.
[0532] If the DRX is configured, the terminal device 1 stops the
duration timer (onDurationTimer) and the DRX inactivity timer
(drx-InactivityTimer) for each subframe if the DRX command MAC
control element (MAC CE) is received.
[0533] The duration timer (onDurationTimer) is used to define the
continuous PDCCH subframe at the inception of the DRX cycle.
[0534] The DRX inactivity timer (drx-InactivityTimer) is used to
define the number of continuous PDCCH subframes after the subframe
in which the PDCCH indicating the transmission of initial
uplink/downlink user data to a certain terminal device 1 is
transmitted.
[0535] The DRX retransmission timer (drx-RetransmissionTimer) is
used to define the maximum number of continuous PDCCH subframes
until the downlink transmission is received.
[0536] The HARQ RTT timer is used to define the minimum number
(minimum amount) of subframes before the downlink HARQ transmission
is expected by the terminal device 1.
[0537] A MAC contention resolution timer
(mac-ContentionResolutionTimer) is used to define the number of
continuous subframes in which the terminal device 1 after Message 3
(PUSCH corresponding to the random access response grant) is
transmitted monitors the PDCCH.
[0538] A DRX short cycle timer (drxShortCycleTimer) is used to
define the number of continuous subframes in which the terminal
device 1 follows a short DRX cycle.
[0539] A DRX start offset (drxStartOffset) is used to define the
subframe in which the DRX cycle is started.
[0540] The active timer defines a time associated to the DRX
operation and a period (time) during which the terminal device 1
monitors the PDCCH in a PDCCH monitoring subframe.
[0541] The PDCCH monitoring subframe is basically the same as the
PDCCH subframe. However, in a case where the terminal device 1 can
perform the eIMTA in a certain serving cell, the PDCCH monitoring
subframe is the determined downlink subframe and a subframe
including the DwPTS depending on the TDD UL-DL configuration
indicated by the L1 signalling (for example, the DCI format with
which the eIMTA-RNTI is scrambled) related to the eIMTA.
[0542] If the DRX is configured, if the DRX inactivity timer
expires or the DRX command MAC CE is received in each subframe and
the short DRX cycle is configured, the terminal device 1 starts
(restarts) the DRX short cycle timer (drxShortCycleTimer) for each
subframe, and uses the DRX cycle. Otherwise, the terminal device
uses a log DRX cycle.
[0543] If the DRX is configured, if the DRX short cycle timer
expires, the terminal device 1 uses the log DRX cycle for each
subframe.
[0544] If the DRX is configured, in a case where an expression
satisfies a prescribed condition based on a system frame number, a
subframe number, a short DRX cycle (and/or log DRX cycle), and a
DRX start offset (drxStartOffset), the terminal device 1 starts the
duration timer for each subframe.
[0545] If the DRX is configured, if the PDCCH subframe is not
necessary for the uplink transmission for half-duplex FDD terminal
device operation during the active time or this subframe is not a
part of a measurement gap for this subframe is configured, the
terminal device 1 monitors the PDCCH for each subframe. If the
PDCCH indicates the downlink transmission or if the downlink
assignment is configured for the subframe, the HARQ RTT timer for
the corresponding HARQ process is started, and the DRX
retransmission timer for the corresponding HARQ process is stopped.
In a case where the PDCCH indicates the new transmission (downlink
or uplink), the DRX inactivity timer is started (or restarted).
[0546] If the DRX is configured, if the timer is not in the active
time in consideration of the scheduling request transmitted and the
grant/assignment/DRX command MAC CE received until the subframe n-5
(including the subframe n-5) in which all the DRX active time
conditions are evaluated by the terminal device 1 in the latest
subframe n, the terminal device 1 does not transmit a trigger type
0 SRS to each subframe.
[0547] If the DRX is configured, if CQI masking (cqi-Mask) is set
up by the higher layer, the terminal device 1 does not report the
CQI/PMI/RI/PTI in the PUCCH for each subframe if the duration timer
is not in the active time in consideration of the
grant/assignment/DRX command MAC CE received until the subframe n-5
(including the subframe n-5) in which all the DRX active time
conditions are evaluated in the latest subframe n. Otherwise, if
the terminal device 1 is not in the active time in consideration of
the grant/assignment/DRX command MAC CE received until the subframe
n-5 (including the subframe n-5) in which all the DRX active time
conditions are evaluated in the latest subframe n, the
CQI/PMI/RI/PTI (that is, CSI) is not reported in the PUCCH.
[0548] If there is an occurrence possibility irrespective of
whether or not the terminal device 1 monitors the PDCCH, the
terminal device 1 may receive/transmit the HARQ feedback, and may
transmit the trigger type 1 SRS.
[0549] The same active time may be applied to all activated serving
cells.
[0550] In the case of the spatial multiplexing of the downlink, if
the transport block is received during which the HARQ RTT timer is
being started and during which the transmission before the same
transport block is received in a subframe which is positioned
before at least N subframes from the latest subframe, the terminal
device 1 may process the transport block, and may restart the HARQ
RTT timer. Here, N equivalent to a value set to the HARQ RTT timer
or the HARQ RTT timer.
[0551] In a case where the DRX is configured in the primary cell
and the configuration of the DRS for the secondary cell is set, and
in a case where the measurement subframe set based on the
configuration of the DRS and the PDCCH subframe set based on the
configuration of the DRX overlap, the terminal device 1 may perform
the DRS measurement and the PDCCH monitoring in the secondary cell
in the deactivated state in the overlapped subframe. The DRX active
timer is applied to the activation serving cell, that is, all the
serving cell in the activated state, but is not applied to the
deactivation serving cell, that is, the serving cells in the
deactivated state. In a case where the DRS configuration is set,
the DRX active timer may be applied in the serving cell (or
secondary cell) even in the deactivation state (off state,
deactivation, or dormant mode). In this case, the DRS configuration
may not include the subframe configuration. That is, the base
station apparatus 3 may transmit the DRS based on the DRX active
time.
[0552] In a case where the DRX is configured in all the activation
serving cells, the terminal device 1 may measure the DRS in the
subframe of which the timer becomes the active time by the DRX in
the small cell in the deactivated state to which the configuration
of the DRS is set.
[0553] In a case where the DRX deactivation timer or the duration
timer expires, the terminal device 1 may not perform the
measurement of the DRS even though the expired subframe can be
measured based on the DRS measurement subframe. That is, in a case
where the DRX deactivation timer or the duration timer expires, the
terminal device 1 does not expect that the DRS is transmitted in
the subsequent DRS measurement subframes.
[0554] In a case where the DRS configuration for the secondary cell
in the deactivated state (as the small cell) is notified (provided
or obtained) using the higher layer signalling in the terminal
device 1 for which the DRX is configured, the terminal device 1 may
perform the RRM (RSRP/RSRQ/RSSI) measurement of the DRS in the DRS
transmission subframe of the secondary cell overlapping with the
active time of the DRX.
[0555] The configuration of the DRX (drx-Config) may be
individually set to the MCG and the SCG, or the primary cell and
the primary secondary cell, or the MeNB and the SeNB. The DRX in
the SCG may indicate the activated/deactivated state of the primary
secondary cell. In a case where the DRX is configured for the SCG,
the DRS and the PDCCH may be transmitted in the DRX subframe.
[0556] Here, although the configuration of the DRX has been
performed, various parameters set to the configuration of the DRX
may be set as the configuration of discontinuous transmission
(DTX).
[0557] Hereinafter, radio link monitoring will be described. The
radio link monitoring means that the downlink radio link quality of
the primary cell is monitored by the terminal device 1 in order to
indicate to the higher layer that the radio link quality is in-sync
or out-of-sync.
[0558] In the non-DRX operation, the physical layer of the terminal
device 1 evaluates the radio link quality evaluated over the past
(previous) time period using thresholds (Q.sub.in and Q.sub.out)
defined based on the test associated with the radio link monitoring
for each radio frame (the number of subframes constituting the
radio frame).
[0559] In the DRX operation, the physical layer of the terminal
device 1 evaluates the radio link quality evaluated over the past
(previous) time period using thresholds (Q.sub.in and Q.sub.out)
defined based on the test associated with the radio link monitoring
for each at least one DRX (the number of subframes constituting the
DRX cycle).
[0560] If the higher layer signalling indicates a certain subframe
in order to limit the radio link monitoring, the radio link quality
is not monitored in the subframe other than the subframe indicated
by the higher layer signalling. That is, in a case where the
subframe in which the radio link monitoring is performed is limited
by the higher layer signalling, the terminal device 1 performs the
radio link monitoring only in the limited subframe.
[0561] In a case where the radio link quality is worse than the
threshold Q.sub.out in the radio frame in which the radio link
quality is evaluated, the physical layer of the terminal device 1
indicates to the higher layer that the radio link quality is the
out-of-sync. In a case where the radio link quality is better than
the threshold Q.sub.in, the physical layer of the terminal device 1
indicates to the higher layer that the radio link quality is the
in-sync in the radio frame in which the radio link quality is
evaluated.
[0562] The physical layer of the terminal device 1 that supports
the dual connectivity may perform the radio link monitoring on the
primary cell and the primary secondary cell. The thresholds related
to the radio link quality may be defined for the primary cell and
the primary secondary cell.
[0563] The physical layer of the terminal device 1 that supports
the dual connectivity may individually evaluate the radio link
quality (out-of-sync or in-sync) on the primary cell and the
primary secondary cell.
[0564] When the radio link quality is evaluated, in a case where
the out-of-sync is continued a prescribed number of times, the
physical layer of the terminal device 1 that supports the dual
connectivity starts a protection timer. In a case where the
protection timer expires, the physical layer of the terminal device
1 notifies the higher layer that the out-of-sync occurs in this
cell (in other words, a physical layer problem is detected). The
higher layer of the terminal device 1 recognizes that a radio link
failure (RLF) is detected in a case where the cell in which the
physical layer problem is detected is the primary cell. In this
case, the higher layer of the terminal device 1 may notify the base
station apparatus 3 that the RLF is detected in the primary cell.
The higher layer of the terminal device 1 may not recognize the RLF
in a case where the cell in which the physical layer problem is
detected is the primary secondary cell. The higher layer of the
terminal device 1 may perform the same process as that of the
primary cell in a case where the cell in which the physical layer
problem is detected is the primary secondary cell.
[0565] Hereinafter, the semi-persistent scheduling (SPS) will be
described. In a case where the semi-persistent scheduling is
configured to be valid by the RRC layer (higher layer signalling,
or the higher layer), the terminal device 1 receives the following
information. This information includes the uplink semi-persistent
scheduling interval (semiPersistSchedIntervalUL) and the number of
times blank transmission is performed before being implicitly
released (implicitReleaseAfter) in a case where the semi-persistent
scheduling C-RNTI and the semi-persistent scheduling are effective
for the uplink, and the downlink semi-persistent scheduling
interval (semiPersistSchedIntervalDL) and the number of HARQ
processes (numberOfConfSPS-Processes) configured for the
semi-persistent scheduling in a case where two parameter
configurations (twoIntervalsConfig) are effective for the uplink or
the semi-persistent scheduling is effective for the downlink only
in the TDD.
[0566] In a case where the semi-persistent scheduling for the
uplink or downlink is configured to be invalid by the RRC layer
(higher layer signalling or the higher layer), the corresponding
configured grant or configured assignment is ignored.
[0567] The semi-persistent scheduling is supported only by the
primary cell.
[0568] The semi-persistent scheduling is not supported for RN
communication of the E-UTRAN of the connection accompanying by the
RN subframe configuration.
[0569] After the semi-persistent downlink assignment is configured,
if N-th assignment occurs in the subframe and system frame number
that satisfies a certain condition, the terminal device 1 regards
these frames to be continued. Here, the certain condition may be
determined based on the system number (SFN.sub.start_time) and the
subframe (subframe.sub.start_time) when the downlink assignment
configured for the terminal device 1 is initialized (or
reinitialized).
[0570] After the semi-persistent uplink grant is configured, the
terminal device 1 sets a subframe offset (Subframe_Offset) based on
a certain table if two interval configurations are configured to be
valid in the higher layer, and sets the subframe offset to be 0 if
not.
[0571] After the semi-persistent uplink grant is configured, if the
N-th grant occurs in the subframe and the system number that
satisfies a certain condition, the terminal device 1 regards these
frames to be continued. Here, the certain condition may be
determined based on the system frame number (SFN.sub.start_time)
and the subframe (subframe.sub.start_time) when the uplink grant
configured for the terminal device 1 is initialized (or
reinitialized).
[0572] The terminal device 1 clears the configured uplink grant
immediately after the number of times blank transmission is
performed before continuous MAC protocol data units (PDUs)
including a zero MAC service data unit (SDU) are implicitly
released is obtained by multiplexing and constructing entities.
[0573] In a case where the terminal device 1 supports a function of
performing the dual connectivity, the SPS may be performed in the
primary secondary cell in addition to the primary cell. That is,
the SPS configuration may be set to the primary secondary cell in
addition to the primary cell.
[0574] In the terminal device 1 that supports the function of
performing the dual connectivity, in a case where only one SPS
configuration is set, the SPS may be applied to only the primary
cell.
[0575] In the terminal device 1 that supports the function of
performing the dual connectivity, in a case where only one SPS
configuration is set, the same configuration may be applied to the
primary cell and the primary secondary cell.
[0576] In the terminal device 1 that supports the function of
performing the dual connectivity, the downlink SPS configuration
and/or the uplink SPS configuration may be individually set to the
primary cell and the primary secondary cell. That is, the downlink
SPS configuration and/or the uplink SPS configuration may be common
to or may be individually configured for the primary cell and the
primary secondary cell. Whether or not the SPS is individually
performed in the primary cell and the primary secondary cell in the
downlink and/or the uplink may be determined based on function
information transmitted from the terminal device 1.
[0577] Hereinafter, the PDCCH and the EPDCCH transmitted in the
primary secondary cell will be described.
[0578] The PDCCH transmitted in the primary secondary cell may be
scrambled using the parameter common to the plurality of terminal
devices and/or the previously defined parameter. In a case where
the parameter common to the plurality of terminal devices is not
configured, the PDCCH is scrambled using the physical cell
identity.
[0579] The PDCCH transmitted in the primary secondary cell may be
cyclic-shifted on a per REG basis based on the parameter common to
the plurality of terminal devices and/or the previously defined
parameter. In a case where the parameter common to the plurality of
terminal devices is not configured, the PDCCH is cyclic-shifted
based on a value of the physical cell identity.
[0580] The USS and the search space different from the USS are
allocated to the primary secondary cell. The search space different
from the USS is a search space which monitors a region common to
the plurality of terminal devices. The CSS allocated to the primary
cell is referred to as a first CSS, and the search space different
from the USS allocated to the primary secondary cell is referred to
as a second CSS.
[0581] The second CSS is a search space configured using the
parameter common to the plurality of terminal devices and/or the
previously defined parameter. The parameter common to the plurality
of terminal device is notified from the higher layer. As an example
of the parameter common to the plurality of terminal devices, the
parameter specific to the base station apparatus 3 (cell or
transmission point) is used. For example, as the parameter specific
to the transmission point, the virtual cell identity or TPID is
used. As an example of the parameter common to the plurality of
terminal devices, a parameter capable of being individually
configured for the terminal device, or a parameter for which a
value common to the plurality of terminals is configured is used.
For example, as the parameter for which the value common to the
plurality of terminal devices is configured, the RNTI is used.
[0582] The PDCCH may be allocated to the second CSS. In this case,
in the second CSS, the CCE in which the search space is started is
determined by using the parameter common to the plurality of
terminals and/or the previously defined parameter. Specifically,
the RNTI (for example, UE-group-RNTI or CSS-RNTI) common to the
plurality of terminals is configured as an initial value of Y.sub.k
used in the expression (1) of FIG. 14. The CCE in which the search
space of the second CSS is started may be designated in common to
the terminals by the higher layer parameter. Specifically, the
Y.sub.k used in the expression (1) of FIG. 14 is constantly a fixed
value, and the higher layer parameter (for example, the parameter
for designating the CCE index) is set. Zero may be constantly set
to the Y.sub.k.
[0583] The aggregation levels 4 and 8 of the second CSS allocated
to the PDCCH are supported. Four PDCCH candidates are defined in
the aggregation level 4, and two PDCCH candidates are defined in
the aggregation level 8. The aggregation levels 1, 2, 16 and 32 may
be supported. In this case, the number of times blind decoding is
performed is not increased in the second CSS by limiting the number
of PDCCH candidates. For example, in a case where the aggregation
levels 2, 4 and 8 of the second CSS are supported, two PDCCH
candidates are defined in each aggregation level.
[0584] The EPDCCH may be allocated to the second CSS. In this case,
in the second CSS, the ECCE in which the search space is started is
determined using the parameter common to the plurality of terminals
and/or the previously defined parameter. Specifically, the RNTI
(for example, UE-group-RNTI or CSS-RNTI) common to the plurality of
terminals is configured for an initial value of Y.sub.p,k used in
the expression (2) of FIG. 14. The ECCE in which the search space
of the second CSS is started may be designated in common to the
terminals by the higher layer parameter. Specifically, the
Y.sub.p,k used in the expression (2) of FIG. 14 is constantly a
fixed value, and the higher layer parameter (for example, the
parameter for designating the ECCE index) is set. Zero may be
constantly set to the Y.sub.p,k.
[0585] In a case where the EPDCCH is allocated to the second CSS,
the EPDCCH set allocated to the second CSS may be configured. For
example, the EPDCCH set 0 may be allocated to the USS, and the
EPDCCH set 1 may be allocated to the second CSS. The USS and the
second CSS may be allocated within one EPDCCH set. For example, the
EPDCCH set 0 may be allocated to the USS and the second CSS.
[0586] The aggregation levels 4 and 8 of the second CSS to which
the EPDCCH is allocated are supported. Four EPDCCH candidates are
defined in the aggregation level 4, and two EPDCCH candidates are
defined in the aggregation level 8. The aggregation levels 1, 2, 16
and 32 may be supported. In this case, the number of times blind
decoding is performed is not increased in the second CSS by
limiting the number of PDCCH candidates. For example, in a case
where the aggregation levels 2, 4 and 8 of the second CSS are
supported, two PDCCH candidates are defined in each aggregation
level.
[0587] An example of the type of RNTI used in the PDCCH monitoring
in the second CSS will be described.
[0588] The PDCCH for notifying of at least random access response,
the PDCCH for indicating the TPC command to a specific terminal
device 1, or the PDCCH for notifying of the TDD UL/DL configuration
may be allocated to the second CSS. In a case where backhaul delay
between the MeNB and SeNB is large, it is necessary to perform the
transmission from the SeNB even at the time of the RRC
reconfiguration. That is, the terminal device 1 monitors the PDCCH
allocated to the second CSS by using the RA-RNTI, TPC-PUCCH-RNTI,
TPC-PUSCH-RNTI, TDD-ModeA-RNTI, C-RNTI, SPS C-RNTI, and temporary
C-RNTI.
[0589] Meanwhile, it is not necessary to arrange the PDCCH to which
the system information or information related to paging is assigned
in the second CSS. Since the primary secondary cell is used in the
RRC connected mode, it is not necessary to arrange the PDCCH to
which the downlink/uplink grant for transmission by a subordinate
transmission scheme required at the time of the RRC reconfiguration
is assigned. That is, the terminal device 1 may not monitor the
PDCCH allocated to the second CSS by using the SI-RNTI or the
P-RNTI.
[0590] An example of the type of RNTI used in the PDCCH monitoring
in the second CSS will be described.
[0591] The PDCCH for notifying of at least random access response,
the PDCCH for indicating the TPC command to a specific terminal
device 1, or the PDCCH for notifying of the TDD UL/DL configuration
may be allocated to the second CSS. That is, the terminal device 1
monitors the PDCCH allocated to the second CSS by using at least
RA-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, and TDD-ModeA-RNTI.
[0592] Meanwhile, it is not necessary to arrange the PDCCH to which
the system information or information related to paging is assigned
in the second CSS. Since the primary secondary cell is used in the
RRC connected mode, it is not necessary to arrange the PDCCH to
which the downlink/uplink grant for transmission by a subordinate
transmission scheme required at the time of the RRC reconfiguration
is assigned. That is, the terminal device 1 may not monitor the
PDCCH allocated to the second CSS by using the SI-RNTI, P-RNTI,
C-RNTI, SPS C-RNTI or temporary C-RNTI.
[0593] The PDCCH including the information indicating the
activated/deactivated state of the cell may be allocated to the
second CSS. That is, the terminal device 1 monitors the PDCCH
allocated to the second CSS by using the RNTI (SCE-RNTI) associated
with the small cell ON/OFF.
[0594] The terminal device 1 increases the number of times the
blind decoding is performed in the primary secondary cell by the
second CSS. Specifically, only the USS is allocated to the
secondary cell, and both the USS and the second CSS are allocated
to the primary secondary cell. If the number of times the blind
decoding is performed in the second CSS is the same as the number
of times the blind decoding is performed in the first CSS, the
number of times the blind decoding is performed is increased to
twelve, and the load of the terminal device 1 is increased.
[0595] An example in which the number of times the blind decoding
is performed in the second CSS is reduced will be described.
[0596] In a case where the PDCCH allocated to the second CSS is not
monitored using the C-RNTI, SPS C-RNTI or Temporary C-RNTI, the DCI
format 0/1A is not allocated to the second CSS, and thus, it is
possible to reduce the number of times the blind decoding is
performed in the second CSS.
[0597] In this case, the DCI format 3/3A is padded so as to be
adjusted for a payload size of the DCI format 1C. Alternatively, a
new DCI format (DCI format 3B) in which the TPC command is
transmitted is configured.
[0598] The DCI format 3B is used to transmit the TPC command for
the PUCCH and PUSCH through 1-bit power adjustment. The terminal
device 1 may detect the value of the transmission power control
command corresponding to the PUSCH or the PUCCH by detecting bit
information corresponding to the index (TPC-index) assigned to the
terminal device. It is determined whether the DCI format 3B
indicates the transmission power control command for the PUSCH or
the transmission power control command for the PUCCH depending on
the type of the RNTI to be scrambled. The DCI format 3B is padded
so as to be adjusted for a payload size of the DCI format 1C.
[0599] Accordingly, since only control information having the same
payload size as that of the DCI format 1C is allocated to the
second CSS, it is possible to reduce the number of times the blind
decoding is performed. Specifically, in the second CSS, the
decoding of six PDCCH candidates and the DCI format having one type
of bit size is tried in the aggregation 4, or the decoding of two
PDCCH candidates and the DCI format having one type of bit size is
tried in the aggregation 8. That is, the terminal device 1 tries to
decode in the second CSS six times. Accordingly, it is possible to
halve the number of times the blind decoding is performed in the
CSS.
[0600] An example in which the number of times the blind decoding
is performed in the second CSS is reduced will be described.
[0601] In the second CSS, the parity bit is inserted until the
payload size of the DCI format 1C becomes the same as that of the
DCI format 0. Accordingly, since only the control information
having the same payload size as that of the DCI format 0 is
allocated to the second CSS, it is possible to reduce the number of
times the blind decoding is performed. Specifically, in the second
CSS, the decoding of six PDCCH candidates and the DCI format having
one type of bit size is tried in the aggregation 4, or the decoding
of two PDCCH candidates and the DCI format having one type of bit
size is tried in the aggregation 8. That is, the terminal device 1
tries to decode in the second CSS six times. Accordingly, it is
possible to halve the number of times the blind decoding is
performed in the CSS.
[0602] All the terminal devices 1 do not support the monitoring of
the second CSS in terms of the increase in the number of times the
blind decoding is performed. Thus, information (capability)
indicating ability of whether or not the terminal device 1 can
monitor the second CSS may be notified to the base station
apparatus 3.
[0603] The terminal device 1 having high processibility notifies
the base station apparatus 3 of information indicating that the
terminal device can monitor the second CSS. Meanwhile, the terminal
device 1 having low processibility notifies the base station
apparatus 3 of information indicating that the terminal device is
not able to monitor the second CSS. The base station apparatus 3
acquires the information indicating the ability of whether or not
the terminal device can monitor the second CSS from each terminal
device 1, and performs the configuration of the second CSS for only
the terminal device 1 capable of monitoring the second CSS. Here,
the base station apparatus 3 may configure the terminal device 1
capable of monitoring the second CSS as the UE group.
[0604] The base station apparatus 3 arranges the PDCCH in the
second CSS, and performs the notification of the random access
response or the notification of the TDD UL/DL configuration to the
terminal device 1 capable of monitoring the second CSS.
[0605] The base station apparatus 3 arranges the PDCCH in the USS,
and performs the notification of the random access response or the
notification of the TDD UL/DL configuration to the terminal device
1 which is not capable of monitoring the second CSS. In this case,
in terms of the number of times the blind decoding is performed,
the DCI format 1A is used in the notification of the random access
response, and the DCI format 1C used in the notification of the TDD
UL/DL configuration is fed back until the payload size of the DCI
format 1C becomes the same as that of the DCI format 0.
[0606] Accordingly, the notification of the random access response
or the notification of the TDD UL/DL configuration may also be
performed to the terminal device 1 having low processibility, which
is not able to monitor the second CSS.
[0607] The information indicating the ability of whether or not the
terminal device is not able to monitor the second CSS may be
notified in association with information indicating that the
terminal device can be operated in the dual connectivity mode. That
is, if the terminal device can be operated in the dual connectivity
mode, the terminal device may monitor the second CSS.
[0608] The processes of the terminal device 1 and the base station
apparatus 3 in a case where the information indicating the
activated/deactivated state of the secondary cell as the small cell
is transmitted using the DCI format (PDCCH/EPDCCH accompanying by
the DCI format) will be described.
[0609] One bit indicating the activated/deactivated state of each
of the plurality of cells (small cell, secondary cell, and serving
cell) may be set to a certain DCI format. For example, a case where
the DCI format including the information indicating the
activated/deactivated state is constituted by 15 bits may mean that
as much information indicating the activated/deactivated state as
15 cells is included. That is, the activated/deactivated state is
represented by one bit. The activated state being represented by
one bit may be simultaneously recognized as the CSI request for the
cell corresponding to one bit. When the activated state is
represented by one bit, the CSI corresponding to one bit is
transmitted in the first uplink subframe after a prescribed
subframe after the CSI is received. Positions of the bits
constituting the DCI format and a cell index (for example, serving
cell index, small cell index, or ON/OFF cell index) may be
previously correlated.
[0610] The DCI format may indicate only the activated state. For
example, "1" in one bit indicates activation, and "0" indicates
that the current state is the same as the previous state. In this
case, it is preferable that another method of indicating the
deactivated state such as the deactivation timer is also used.
[0611] The DCI format may indicate only the deactivated state. For
example, "1" in one bit indicates deactivation, and "0" indicates
that the current state is the same as the previous state. In this
case, it is preferable that another method of indicating the
activated state such as activation notification through the MAC CE
is also used.
[0612] n bits indicating the activated/deactivated state of each of
the plurality of cells (small cell, secondary cell, and serving
cell) may be set to a certain DCI format. For example, a case where
the DCI format including the information indicating the
activated/deactivated state is constituted by 15 bits may mean that
as much information indicating the activated/deactivated state as
15/n cells is included. That is, the activated/deactivated state
may be represented by n bits. For example, information notified in
n bits is information of the activated/deactivated states of the
cells of n subframes. Each bit of n bits corresponds to the
subframe. Specifically, information notified in 8 bits is
information indicating the activated/deactivated states of 8
subframes. For example, the information notified in n bits is
information indicating subframe patterns in the
activated/deactivated state. The subframe pattern in the
activated/deactivated state may be previously determined. The
subframe pattern in the activated/deactivated state may be notified
in the higher layer. Specifically, information notified in 2 bits
indicates four subframe patterns. A length of the bit indicating
the activated/deactivated state is determined depending on the
maximum number of the types of subframe patterns. The maximum
number of the types of subframe patterns may be configured in the
higher layer.
[0613] The PDCCH/EPDCCH including the information indicating the
activated/deactivated state is scrambled by the RNTI (for example,
SCE-RNTI) for indicating the activated/deactivated state. In a case
where the decoding of a certain PDCCH/EPDCCH by the SCE-RNTI
succeeds, the terminal device 1 recognizes that the information
indicating the activated/deactivated state is included in the
PDCCH/EPDCCH. Accordingly, even though the information indicating
the activated/deactivated state is included in the same DCI format
as that of another control information, the terminal device 1 can
recognize that the information for indicating the
activated/deactivated state is included.
[0614] The information indicating the activated/deactivated state
of the secondary cell as the small cell may be combined with the
DCI including another control information scrambled with another
RNTI. For example, the deactivated state of the cell may be
indicated using the state of UL/DL configuration 7 in the dynamic
TDD. In other words, UL/DL configurations 1 to 6 may indicate the
activated state of the cell. For example, the activated/deactivated
state of the cell may be indicated using extra bits other than the
information indicating the UL/DL configuration in the dynamic TDD.
For example, the activated/deactivated state of the cell may be
indicated using the extra bits other than the information for
notifying of the TPC command.
[0615] A field may be configured for the DCI format indicating the
downlink grant/uplink grant, and information indicating the
activated state of the secondary cell may be notified. For example,
a 3-bit field indicating the serving cell is configured for the DCI
format 4 or the DCI format 2D. The terminal device 1 recognizes
that the serving cell indicated by the DCI format of the downlink
grant/uplink grant is in the activated state.
[0616] The field may be configured for the DCI format indicating
the downlink grant/uplink grant, and information indicating the
deactivated state of the secondary cell may be notified. For
example, a 3-bit field indicating the serving cell is configured
for the DCI format 4 or the DCI format 2D. The terminal device 1
recognizes that the serving cell indicated by the DCI format of the
downlink grant/uplink grant is in the deactivated state.
[0617] It is preferable that the activated/deactivated state is not
indicated by the DCI format including the information indicating
the activated/deactivated state over the plurality of cell groups.
For example, the information indicating the activated/deactivated
state corresponding to the secondary cell belonging to the master
cell group and the information indicating the activated/deactivated
state corresponding to the secondary cell belonging to the
secondary cell group are not included in one DCI format. In other
words, the information indicating the activated/deactivated state
included in one DCI format corresponds to only the serving cell
belonging to one cell group.
[0618] The DCI format including the information indicating the
activated/deactivated state of the cell belonging to the master
cell group is allocated to the first CSS of the primary cell. In
terms of the processing load of the blind decoding, it is
preferable that the DCI format including the information indicating
the activated/deactivated state has the same number of bits as that
of another DCI format allocated to the first CSS. Specifically, the
bits of the DCI format including the information indicating the
activated/deactivated state are padded such that the payload size
of this DCI format becomes the same as that of the DCI format
0/1A/3/3A or the DCI format 1C, and this DCI format is allocated to
the first CSS. The terminal device 1 monitors the CSS of the
primary cell, and acquires the activated/deactivated states of the
plurality of secondary cells (small cells) of the cell group to
which the primary cell belongs by using the DCI format.
Accordingly, it is easy to notify the plurality of terminal devices
by using one PDCCH, and thus, overhead is reduced.
[0619] The DCI format including the information indicating the
activated/deactivated state of the cell belonging to the secondary
cell group is allocated to the SS of the primary secondary cell. It
is preferable that the DCI format including the information
indicating the activated/deactivated state of the cell belonging to
the secondary cell group is allocated to the SS capable of being
monitored by the plurality of terminal devices as the primary
secondary cells. For example, the DCI format including the
information indicating the activated/deactivated state of the cell
belonging to the secondary cell group is allocated to the second
CSS. In terms of the processing load of the blind decoding, it is
preferable that the DCI format including the information indicating
the activated/deactivated state has the same number of bits as that
of another DCI format allocated to the second CSS. Specifically,
the bits of the DCI format including the information indicating the
activated/deactivated state are padded such that the payload size
of this DCI format becomes the same as that of the DCI format
0/1A/3/3A or the DCI format 1C, and this DCI format is allocated to
the CSS. The terminal device 1 monitors the second CSS of the
primary secondary cell, and acquires the activated/deactivated
states of the plurality of secondary cells (small cells) of the
cell group to which the primary secondary cell belongs to by using
the DCI format. Accordingly, it is easy to notify the plurality of
terminal devices by using one PDCCH/EPDCCH, and thus, overhead is
reduced.
[0620] The DCI format including the information indicating the
activated/deactivated state of the cell may be allocated to the USS
in the cell. In this case, the notification may be performed using
1-bit information indicating the activated/deactivated state.
[0621] The terminal device 1 may continue to recognize the
activated/deactivated state indicated by the transmitted DCI format
until the activated/deactivated state is indicated by the next DCI
format indicating the activated/deactivated state of the cell. In
this case, t is preferable that the DCI format indicating the
activated/deactivated state of the cell is periodically
transmitted. The cycle and timing (subframe) in which the DCI
format indicating the activated/deactivated state is transmitted is
notified to the terminal device 1. The cycle in which the DCI
format indicating the activated/deactivated state is transmitted is
for example, one radio frame (10 subframes) or one half frame (5
subframes). The timing in which the DCI format indicating the
activated/deactivated state is transmitted is, for example, the
subframe 0 or the subframe 5. The terminal device 1 can explicitly
recognize the period during which the activated/deactivated state
is recognized by periodically transmitting the DCI format.
[0622] The terminal device 1 may change the state such that the
state is recognized as the deactivated state before the
activated/deactivated state is indicated by the next DCI format
indicating the activated/deactivated state of the cell. In this
case, for example, a timer (small cell deactivation timer) for
performing transition to the deactivated state is set, and the
terminal device 1 recognizes the state as the deactivated state
before the indication from the base station apparatus 3 is received
in a case where the timer exceeds.
[0623] The activated/deactivated state of each cell (neighbour cell
or transmission point) having a transmission point different that
of the serving cell may be indicated by the DCI format. In this
case, it is preferable that the cell having a transmission point
different from that of the serving cell is connected through
low-delay backhaul such as an optical cable.
[0624] The ON/OFF cell PDCCH configuration is used to define the
RNTI and index for indicating the activated/deactivated state of
the small cell (or the secondary cell/serving cell equivalent to
the small cell). The ON/OFF function of the small cell together
with this configuration may be set up or released.
[0625] The ON/OFF cell PDCCH configuration may include the RNTI
(for example, SCE-RNTI) indicating that the DCI format is the DCI
format indicating the activated/deactivated state of the small cell
(serving cell). The ON/OFF cell PDCCH configuration may include the
list of the index of the small cell of which the
activated/deactivated state is indicated by the DCI format. The
activated/deactivated state may be notified to a specific small
cell by this list. For example, in a case where a certain DCI
format is constituted by 15 bits, the terminal device 1 may check
the activated/deactivated state of only the bit corresponding to
the index indicated by the list without checking the
activated/deactivated states for all the bits. The terminal device
may recognize that other bits are all in the deactivated state.
[0626] In a case where the DCI format including the information
indicating the activated state of a certain cell is detected in a
certain subframe (i=0, 1, 2, . . . ), the terminal device 1
recognizes that this cell is in the activated state in a subframe
i+k (k is a prescribed value). The same process may be performed in
the deactivated state. The value of k may be different between the
activated state and the deactivated state.
[0627] In a case where the information indicating the
activated/deactivated state is included in the first DCI format,
the size of the first DCI format may be the same as the size of
another DCI format. The sizes of the DCI formats are equal, and
thus, new indication information can be configured without
increasing the number of times the blind decoding is performed. In
a case where the number (type) of transmitted control information
items or the number of required bits are different between the
first DCI format and the second DCI format, the bits that are not
used as the control information may be padded.
[0628] In a case where the information indicating the
activated/deactivated state us included in the first DCI format,
bits other than the bits required for the information indicating
the activated/deactivated state may be removed. That is, the size
of the first DCI format may be increased or decreased if
necessary.
[0629] In a case where the activated state is indicated by the
information indicating the activated/deactivated state, the
terminal device 1 may perform the CSI measurement on the cell of
which the activated state is indicated, and may perform the CSI
report in the first uplink subframe after a prescribed
subframe.
[0630] In a case where the PDCCH/EPDCCH and the DRS are transmitted
in the same subframe, the URS (or DMRS) may be transmitted in the
same subframe in order to demodulate and decode the
PDCCH/EPDCCH.
[0631] In a case where the PDCCH/EPDCCH and the DRS are transmitted
in the same subframe, the terminal device 1 may demodulate and
decode the PDCCH/EPDCCH by using the DRS (one of the plurality of
signals constituting the DRS).
[0632] In a case where the configuration of the DRS is set to a
certain cell through the higher layer signalling, if the
measurement result does not satisfy a threshold in the measurement
subframe of the DRS on a certain cell a prescribed number of times,
the terminal device 1 may request the reconfiguration of the DRS by
using the primary cell.
[0633] Hereinafter, the implicit OFF state (implicit deactivation)
of the ON/OFF cell will be described.
[0634] The ON/OFF cell may be the same as the small cell.
[0635] In a case where the inter-cell interference is suppressed by
performing the transition of the base station apparatus 3 from the
ON state (operating state or activated state) to the OFF state
(deactivated state) (referred to as a case where the base station
apparatus 3 uses the ON/OFF cell for the sake of convenience in the
description), it is assumed that the ON/OFF cell is in the OFF
state before the OFF state timer associated with the ON/OFF state
configured for the terminal device 1 expires.
[0636] The OFF state of the ON/OFF cell may be a state in which the
terminal device 1 does not expect the downlink transmission from
the base station apparatus 3. That is, the OFF state may be a state
in which at least one of the PSS/SSS, the CRS, the CSI-RS, the
PBCH, the PDCCH, the EPDCCH, and the PDSCH is not transmitted. For
example, the OFF state may be a state in which the PSS/SSS is not
transmitted over one or more half frame (5 or more subframes). For
example, the OFF state of the base station apparatus 3 is a state
in which only the DRS is transmitted.
[0637] The OFF state of the ON/OFF cell may be a state in which the
terminal device 1 performs a process different from that in the
terminal device of the related art, and the ON state of the ON/OFF
cell may be a state in which the terminal device 1 can perform the
same process as that in the terminal device of the related art.
[0638] In the OFF state of the ON/OFF cell, the terminal device 1
may perform the uplink transmission of the PUCCH or the PUSCH in
the ON/OFF cell. That is, the ON/OFF cell may also perform the
reception process in the OFF state.
[0639] In the OFF state of the ON/OFF cell, the terminal device 1
may not release (remove) the information associated with the ON/OFF
cell. For example, in the OFF state of the ON/OFF cell, the
terminal device 1 may retain the information associated with the
ON/OFF cell, and may reuse the information associated with the
ON/OFF cell when the ON/OFF cell is in the ON state.
[0640] The ON/OFF cell being in the OFF state and the ON/OFF cell
being deactivated may be the same, and the deactivation of the
ON/OFF cell may be the same as the deactivation (deactivation of
the non-ON/OFF cell) of the related art.
[0641] The OFF state of the ON/OFF cell and the deactivation of the
related art may be simultaneously performed.
[0642] If the base station apparatus 3 notifies the terminal device
1 of the OFF state of the ON/OFF cell by the L1 signalling (DCI
format) or the L2 signalling (MAC CE) whenever the ON/OFF cell
performs transition from the ON state to the OFF state (the base
station apparatus 3 performs transition from the activated state to
the deactivated state), the overhead of the control information is
increased.
[0643] However, if the ON state/OFF state of the ON/OFF cell is
notified to the terminal device 1 whenever the ON/OFF cell performs
transition from the ON state to the OFF state, the terminal device
1 excessively consumes the battery in order to perform the
operation such as the monitoring of the PDCCH in the ON/OFF cell in
the OFF state until the OFF state timer of the cell in the OFF
state expires.
[0644] Thus, in a case where the base station apparatus 3 uses the
ON/OFF cell, a case where the terminal device 1 implicitly
determines (assumes) the OFF state of the ON/OFF cell and the
terminal device 1 implicitly recognizes the ON/OFF cell determined
(assumed) to be in the OFF state as the OFF state (implicit
deactivation), or a case where the terminal device performs
transition to the operation in a case where the communication with
the ON/OFF cell in the OFF state is performed in the ON/OFF cell
determined (assumed) to be in the OFF state is effective. For
example, the operation in the case where the communication with the
ON/OFF state in the OFF state is performed is an operation assumed
that at least one of the PSS/SSS, the CRS, the CSI-RS, the PBCH,
the PDCCH, the EPDCCH and the PDSCH is not transmitted. For
example, the operation in the case where the communication with the
ON/OFF cell in the OFF state is performed may be a state in which
the terminal device 1 performs a process different from that of the
terminal device of the related art. For example, the operation in
the case where the communication with the ON/OFF cell in the OFF
state is performed may be an operation in which the terminal device
1 performs only the uplink transmission of the PUCCH or the
PUSCH.
[0645] The terminal device 1 may receive information indicating
whether or not the cell configured for the terminal device 1 is the
ON/OFF cell from the base station apparatus 3. That is, the base
station apparatus 3 may transmit the information indicating whether
or not the cell configured for the terminal device 1 is the ON/OFF
cell to the terminal device 1.
[0646] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0647] The terminal device 1 reports the channel quality indicator
(CQI)/precoding matrix indicator (PMI)/rank indicator
(RI)/precoding type indicator (PTI) for the ON/OFF cell for which
the ON state is configured. That is, in a case where the ON/OFF
cell performs transition from the ON state to the OFF state,
information associated with the calculation of the channel quality
indicator (CQI)/precoding matrix indicator (PMI)/rank indicator
(RI)/precoding type indicator (PTI) is measured until the OFF state
timer associated with the ON/OFF cell expires or the OFF state of
the ON/OFF cell is notified by the base station apparatus 3.
[0648] In the ON/OFF cell in the OFF state, the reference signal
(CRS, CSI-RS or DRS) used by the terminal device 1 to measure the
information associated with the calculation of the channel quality
indicator (CQI)/precoding matrix indicator (PMI)/rank indicator
(RI)/precoding type indicator (PTI) is not transmitted in some
cases. That is, if the terminal device 1 calculates the channel
quality indicator (CQI)/precoding matrix indicator (PMI)/rank
indicator (RI)/precoding type indicator (PTI) for the ON/OFF cell
in the OFF state, a possibility that a specific channel quality
indicator (CQI)/precoding matrix indicator (PMI)/rank indicator
(RI)/precoding type indicator (PTI) is calculated becomes high.
Thus, if the terminal device 1 calculates the specific channel
quality indicator (CQI)/precoding matrix indicator (PMI)/rank
indicator (RI)/precoding type indicator (PTI) a prescribed number
of times or more in the ON/OFF cell for which the ON state is
configured, the reference signal is not transmitted in the ON/OFF
cell, that is, it is determined (assumed) that the base station
apparatus 3 is in the OFF state and it is recognized that the
ON/OFF cell is in the OFF state (performs transition to an
operation in a case where the communication with the ON/OFF cell in
the OFF state is performed).
[0649] For example, in a case where "out of range (out of allowable
range)" is calculated a prescribed number of times, in a case where
"out of range (out of allowable range)" is calculated in subframes
in which a prescribed number of subframes are continued a
prescribed number of times, or in a case where "out of range (out
of allowable range)" is continuously calculated a prescribed number
of times, the ON/OFF cell may be recognized as the OFF state
(transition to the operation in which the communication with the
ON/OFF cell in the OFF state is performed in the ON/OFF cell may be
performed).
[0650] The prescribed number of subframes and/or the prescribed
number of times with which the terminal device 1 determines the OFF
state of the ON/OFF cell may be previously defined, or may be
notified from the base station apparatus 3.
[0651] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0652] The DRS is not transmitted in the ON/OFF cell in the OFF
state in some cases. In a case where the DRS is not detected in the
ON/OFF cell for which the ON state is configured, or in a case
where the received power of the resource assumed that the DRS is
transmitted does not a threshold, the terminal device 1 does not
transmit the DRS in the ON/OFF cell, that is, determines (assumes)
that the base station apparatus 3 is in the OFF state and
recognizes that the ON/OFF cell is in the OFF state (performs
transition to the operation in a case where the communication with
the ON/OFF cell in the OFF state is performed in the ON/OFF
cell).
[0653] For example, in a case where the DRS is not detected a
prescribed number of times, in a case where the DRS is not detected
in the subframes in which a prescribed number of subframes are
continued a prescribed number of times, in a case where the DRS is
not continuously detected a prescribed number of times, it may be
recognized that the ON/OFF cell is in the OFF state (transition to
the operation in which the communication with the ON/OFF cell in
the OFF state is performed in the ON/OFF cell may be
performed).
[0654] The case where the RS is not detected is a case where the
average power of the RE to which the RS is mapped does not exceed a
threshold. The RE of which the power is calculated may be averaged
over the plurality of subframes. The RE of which the power is
calculated may be averaged only in a specific subframe. The RE of
which the power is calculated may be averaged in a partial resource
block having the system bandwidth, and may not be averaged in a
partial resource block.
[0655] The subframe in which a part or all of the RSs is not
present is notified to the terminal device 1. The terminal device 1
does not add the average of the power calculated for the RE in
which the RS is not present in the subframe in which a part or all
of the RSs is not present.
[0656] The prescribed number of subframes and/or the prescribed
number of times with which the terminal device 1 determines the OFF
state of the ON/OFF cell may be previously defined, or may be
notified from the base station apparatus 3.
[0657] In a case where the DRS is not detected, the determination
may be performed based on the RSRP and/or the RSRQ.
[0658] In a case where the DRS is not detected, the determination
may be performed by comparing the average received power of the
subframes or the received power of the resource assumed that the
DRS is transmitted with a prescribed threshold. The prescribed
threshold may be previously defined, or may be notified from the
base station apparatus 3.
[0659] In a case where a DRS pattern indicating the ON state and a
DRS pattern indicating the OFF state are independently defined and
the DRS pattern indicating the OFF state is detected, it may be
recognized that the ON/OFF cell is in the OFF state (transition to
the operation in a case where the communication with the ON/OFF
cell in the OFF state is performed in the ON/OFF cell may be
performed). That is, the base station apparatus 3 may transmit the
DRS by using a different DRS pattern between the ON state and the
OFF state.
[0660] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0661] The CRS is not transmitted in the ON/OFF cell in the OFF
state in some cases. In a case where the CRS is not detected in the
ON/OFF cell for which the ON state is configured, or in a case
where the received power of the resource assumed that the CRS is
transmitted does not a threshold, the terminal device 1 does not
transmit the CRS in the ON/OFF cell, that is, determines (assumes)
that the base station apparatus 3 is in the OFF state and
recognizes that the ON/OFF cell is in the OFF state (performs
transition to the operation in a case where the communication with
the ON/OFF cell in the OFF state is performed in the ON/OFF
cell).
[0662] For example, in a case where the CRS is not detected a
prescribed number of times, in a case where the CRS is not detected
in the subframes in which a prescribed number of subframes are
continued a prescribed number of times, in a case where the CRS is
not continuously detected a prescribed number of times, it may be
recognized that the ON/OFF cell is in the OFF state (transition to
the operation in which the communication with the ON/OFF cell in
the OFF state is performed in the ON/OFF cell may be
performed).
[0663] The prescribed number of subframes and/or the prescribed
number of times with which the terminal device 1 determines the OFF
state of the ON/OFF cell may be previously defined, or may be
notified from the base station apparatus 3.
[0664] In a case where the CRS is not detected, the determination
may be performed based on the RSRP and/or the RSRQ.
[0665] In a case where the CRS is not detected, the determination
may be performed by comparing the average received power of the
subframes or the received power of the resource assumed that the
CRS is transmitted with a prescribed threshold. The prescribed
threshold may be previously defined, or may be notified from the
base station apparatus 3.
[0666] In a case where a CRS pattern indicating the ON state and a
CRS pattern indicating the OFF state are independently defined and
the CRS pattern indicating the OFF state is detected, it may be
recognized that the ON/OFF cell is in the OFF state (transition to
the operation in a case where the communication with the ON/OFF
cell in the OFF state is performed in the ON/OFF cell may be
performed). That is, the base station apparatus 3 may transmit the
CRS by using a different CRS pattern between the ON state and the
OFF state.
[0667] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0668] The terminal device 1 monitors the PDCCH/EPDCCH in the
ON/OFF cell for which the ON state is configured. In a case where
the PDCCH/EPDCCH is not continuously detected over a prescribed
number of subframes or more in the ON/OFF cell for which the ON
state is configured, the terminal device 1 determines (assumes)
that the base station apparatus 3 is in the OFF state, and
recognizes that the ON/OFF cell is in the OFF state (performs
transition to the operation in a case where the communication with
the ON/OFF cell in the OFF state is performed in the ON/OFF cell).
That is, in a case where the PDCCH/EPDCCH is not continuously
detected over a prescribed number of subframes or more in the
search space based on the value of the CIF associated with the
ON/OFF cell for which the ON state is configured, the terminal
device 1 determines (assumes) that the base station apparatus 3 is
in the OFF state, recognizes that the ON/OFF cell is in the OFF
state (performs transition to the operation in a case where the
communication with the ON/OFF cell in the OFF state is performed in
the ON/OFF cell). That is, the base station apparatus 3 does not
arrange the PDCCH/EPDCCH in the search space based on the value of
the CIF associated with the ON/OFF cell for which the OFF state is
configured.
[0669] The prescribed number of subframes with which the terminal
device 1 determines the OFF state of the ON/OFF cell may be
previously defined, or may be notified from the base station
apparatus 3.
[0670] In a case where the PDCCH/EPDCCH is not detected, an error
is not detected by a cyclic redundancy check (CRC) or the average
received power of the subframes is compared with a prescribed
threshold, and thus, the determination may be performed. The
prescribed threshold may be previously defined, or may be notified
from the base station apparatus 3.
[0671] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0672] In a case where the PDCCH/EPDCCH indicating the downlink
grant for the ON/OFF cell for which the ON state is configured or
the uplink grant for the ON/OFF cell for which the ON state is
configured in the ON/OFF cell for which the ON state is configured
is not continuously detected over a prescribed number of subframes
or, the terminal device 1 determines (assumes) that the base
station apparatus 3 is in the OFF state, and recognizes that the
ON/OFF cell in the OFF state (perform transition to the operation
in a case where the communication with the ON/OFF cell in the OFF
state is performed in the ON/OFF cell).
[0673] The prescribed number of subframes with which the terminal
device 1 determines the OFF state of the ON/OFF cell may be
previously defined, or may be notified from the base station
apparatus 3.
[0674] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0675] In a case where the PDCCH/EPDCCH indicating the downlink
grant for the ON/OFF cell for which the ON state is configured or
the uplink grant for the ON/OFF cell for which the ON state is
configured is not continuously detected over a prescribed number of
subframes or more in the serving cell that schedules the ON/OFF
cell for which the ON state is configured, the terminal device 1
determines (assumes) that the base station apparatus 3 is in the
OFF state, and recognizes that the ON/OFF cell is in the OFF state
(perform transition to the operation in a case where the
communication with the ON/OFF cell in the OFF state is performed in
the ON/OFF cell). That is, in a case where the PDCCH/EPDCCH
indicating the downlink grant for the ON/OFF cell for which the ON
state is configured or the uplink grant for the ON/OFF cell for
which the ON state is configured is not continuously detected over
a prescribed number of subframes or more in the search space based
on the value of the CIF associated with the ON/OFF cell for which
the ON state is configured, the terminal device 1 determines
(assumes) that the base station apparatus 3 is in the OFF state,
and recognizes that the ON/OFF cell is in the Off state (performs
transition to the operation in a case where the communication with
the ON/OFF cell in the OFF state is performed in the ON/OFF cell).
That is, the base station apparatus 3 does not arrange the
PDCCH/EPDCCH indicating the downlink grant for the ON/OFF cell for
which the ON state is configured or the uplink grant for the ON/OFF
cell for which the ON state is configured in the search space based
on the value of the CIF associated with the ON/OFF cell for which
the OFF state is configured.
[0676] The prescribed number of subframes with which the terminal
device 1 determines the OFF state of the ON/OFF cell may be
previously defined, or may be notified from the base station
apparatus 3.
[0677] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0678] In a case where discontinuous reception (DRX) is configured
for the ON/OFF cell for which the ON state is configured, the
terminal device 1 determines (assumes) that the base station
apparatus 3 is in the OFF state, and recognizes that the ON/OFF
cell is in the OFF state (performs transition to the operation in a
case where the communication with the ON/OFF cell in the OFF state
is performed in the ON/OFF cell).
[0679] In a case where a parameter related to short DRX is
configured, it is preferable that the terminal device 1 determines
(assumes) that the base station apparatus 3 is in the ON state and
does not recognize that the ON/OFF cell in the OFF state (it is
preferable that transition to the operation in a case where the
communication with the ON/OFF cell in the OFF state is performed in
the ON/OFF cell is not performed).
[0680] The discontinuous reception (DRX) for the ON/OFF cell may be
independently configured for each ON/OFF cell.
[0681] The timer associated with the duration of the discontinuous
reception (DRX) for the ON/OFF cell may be configured on a per
subframe basis.
[0682] An example of the implicit OFF state of the ON/OFF cell will
be described.
[0683] In the ON/OFF cell in the OFF state, the PHICH is not
transmitted (the HARQ indicator (HARQ feedback or response
information) indicating acknowledgement (ACK) or negative
acknowledgement (NACK) for the uplink data (uplink shared channel:
UL-SCH) transmitted by the terminal device 1 is not transmitted) in
some cases. In a case where the PHICH is not detected in the ON/OFF
cell for which the ON state is configured (the HARQ indicator (HARQ
feedback or response information) indicating the acknowledgement
(ACK) or negative acknowledgement (NACK) for the uplink data
(uplink shared channel: UL-SCH) transmitted by the terminal device
1 is not detected), the terminal device 1 determines (assumes) that
the base station apparatus 3 is in the OFF state, and recognizes
that the ON/OFF cell is in the OFF state (performs transition to
the operation in a case where the communication with the ON/OFF
cell in the OFF state is performed in the ON/OFF cell).
[0684] For example, in a case where the PHICH is not detected a
prescribed number of times, in a case where the PHICH is not
detected in the subframes in which a prescribed number of subframes
are continued a prescribed number of times, or in a case where the
PHICH is not continuously detected a prescribed number of times, it
may be recognized that the ON/OFF cell is in the OFF state
(transition to the operation in a case where the communication with
the ON/OFF cell in the OFF state is performed in the ON/OFF cell
may be performed).
[0685] The prescribed number of subframes and/or the prescribed
number of times with which the terminal device 1 determines the OFF
state of the ON/OFF cell may be previously defined, or may be
notified from the base station apparatus 3.
[0686] In a case where the PHICH is not detected, the determination
may be performed by comparing the average received power of the
subframes or the received power of the resource assumed that the
PHICH is transmitted with a prescribed threshold. The prescribed
threshold may be previously defined, or may be notified from the
base station apparatus 3.
[0687] The example of the implicit OFF state of the ON/OFF cell is
not limited to the case where the OFF state is individually
performed, and two or more OFF states may be simultaneously
performed, or may be simultaneously performed with another
deactivation defined by the specifications.
[0688] The OFF state of the ON/OFF cell determined (assumed) to be
in the OFF state (transition to the operation in a case where the
communication with the ON/OFF cell in the OFF state is performed)
may be applied to a radio frame and/or a subframe determined
(assumed) to be in the OFF state, or may be applied to a radio
frame and/or a subframe which is positioned after a prescribed
number of radio frames or a prescribed number of subframes from the
radio frame and/or the subframe determined (assumed) to be in the
OFF state.
[0689] The prescribed number of radio frames or the prescribed
number of subframes before the OFF state of the ON/OFF cell
determined (assumed) to be in the OFF state is applied (transition
to the operation in a case where the communication with the ON/OFF
cell in the OFF state is performed) may be previously defined, or
may be notified from the base station apparatus 3.
[0690] Hereinafter, the implicit ON state (implicit activation) of
the ON/OFF cell will be described.
[0691] The ON state of the base station apparatus 3 is a state in
which the terminal device 1 can perform the same process as that of
the terminal device of the related art. A specific example in the
ON state of the base station apparatus 3 is as follows. The
terminal device 1 expects to receive the PSS, the SSS and the PBCH.
The terminal device 1 monitors that the PDCCH and/or the EPDCCH in
a prescribed subframe. The terminal device 1 performs the CSI
reporting based on the configured CSI reporting mode. The terminal
device 1 expects that the CSI reference resource and the reference
signal (for example, CRS or CSI-RS) for the CSI reporting are
present.
[0692] In the ON state of the ON/OFF cell, the terminal device 1
may use information which is retained in the OFF state and is
associated with the ON/OFF cell again.
[0693] The ON/OFF cell being in the ON state and the ON/OFF cell
being activated may be the same, or the activation of the ON/OFF
cell may be the same as the activation (activation of the
non-ON/OFF cell) of the related art.
[0694] The ON state of the ON/OFF cell and the activation of the
related art may be simultaneously performed.
[0695] If the base station apparatus 3 notifies the terminal device
1 of the ON state of the ON/OFF cell by the L1 signalling (DCI
format) or the L2 signalling (MAC CE) whenever the ON/OFF cell
performs transition to the ON state from the OFF state (the base
station apparatus 3 performs transition to the activated state from
the deactivated state), the overhead of the control information is
increased.
[0696] Thus, in a case where the base station apparatus 3 uses the
ON/OFF cell, a case where the terminal device 1 implicitly
determines (assumes) the ON state of the ON/OFF cell and the
terminal device 1 implicitly changes the ON/OFF cell determined
(assumed) to be in the ON state to the ON state (implicit
activation) or a case where the terminal device performs transition
in a case where the communication with the ON/OFF cell in the ON
state is performed is effective. For example, the operation in the
case where the communication with the ON/OFF cell in the ON state
may be an operation in which the terminal device 1 uses information
which is retained in the OFF state of the ON/OFF cell and is
associated with the ON/OFF cell again. The operation in the case
where the communication with the ON/OFF cell in the ON state may be
an operation in which the terminal device 1 can perform the same
process as that in the terminal device of the related art.
[0697] The terminal device 1 may receive information indicating
whether or not the cell configured for the terminal device 1 is the
ON/OFF cell from the base station apparatus 3. That is, the base
station apparatus 3 may transmit the information indicating whether
or not the cell configured for the terminal device 1 is the ON/OFF
cell to the terminal device 1.
[0698] An example of the implicit ON state of the ON/OFF cell will
be described.
[0699] In the ON/OFF cell in the OFF state, the DRS is not
transmitted in some cases, that is, the DRS is transmitted only in
the ON state of the ON/OFF cell in some cases. In a case where the
DRS is detected in the ON/OFF cell for which the OFF state is
configured, or in a case where the received power of the resource
assumed that the DRS is transmitted exceeds a threshold, the
terminal device 1 transmits the DRS in the ON/OFF cell, that is,
determines (assumes) that the base station apparatus 3 is in the ON
state, and recognizes that the ON/OFF cell is in the ON state
(performs transition to the operation in a case where the
communication with the ON/OFF cell in the ON state is performed in
the ON/OFF cell).
[0700] In a case where the DRS is detected, the determination may
be performed based on the RSRP and/or the RSRQ.
[0701] In a case where the DRS is detected, the determination may
be performed by comparing the average received power of the
subframes or the received power of the resource assumed that the
DRS is transmitted with a prescribed threshold. The prescribed
threshold may be previously defined, or may be notified from the
base station apparatus 3.
[0702] A DRS pattern indicating the ON state and a DRS pattern
indicating the OFF state are independently defined, and in a case
where the DRS pattern indicating the ON state is detected, it may
be recognized that the ON/OFF cell is in the ON state (transition
to the operation in a case where the communication with the ON/OFF
cell in the ON state is performed in the ON/OFF cell may be
performed). That is, the base station apparatus 3 may transmit the
DRS by using a different DRS pattern between the ON state and the
OFF state.
[0703] An example of the implicit ON state of the ON/OFF cell will
be described.
[0704] In the ON/OFF cell in the ON state, the DRS is not
transmitted in some cases, that is, the DRS is transmitted only in
the OFF state of the ON/OFF cell in some cases. In a case where the
DRS is not detected in the ON/OFF cell for which the OFF state is
configured, or in a case where the received power of the resource
assumed that the DRS is transmitted does not exceed a threshold,
the terminal device 1 does not transmit the DRS in the ON/OFF cell,
that is, determines (assumes) that the base station apparatus 3 is
in the ON state, and recognizes that the ON/OFF cell is in the ON
state (performs transition to the operation in a case where the
communication with the ON/OFF cell in the ON state is performed in
the ON/OFF cell).
[0705] In a case where the DRS is not detected, the determination
may be performed based on the RSRP and/or the RSRQ.
[0706] In a case where the DRS is not detected, the determination
may be performed by comparing the average received power of the
subframes or the received power of the resource assumed that the
DRS is transmitted with a prescribed threshold. The prescribed
threshold may be previously defined, or may be notified from the
base station apparatus 3.
[0707] An example of the implicit ON state of the ON/OFF cell will
be described.
[0708] In the ON/OFF cell in the OFF state, the CRS is not
transmitted in some cases, that is, the CRS is transmitted only in
the ON state of the ON/OFF cell in some cases. In a case where the
CRS is detected in the ON/OFF cell for which the OFF state is
configured, or in a case where the received power of the resource
assumed that the CRS is transmitted exceeds a threshold, the
terminal device 1 transmits the CRS in the ON/OFF cell, that is,
determines (assumes) that the base station apparatus 3 is in the ON
state, and recognizes that the ON/OFF cell is in the ON state
(performs transition to the operation in a case where the
communication with the ON/OFF cell in the ON state is performed in
the ON/OFF cell).
[0709] In a case where the CRS is detected, the determination may
be performed based on the RSRP and/or the RSRQ.
[0710] In a case where the CRS is detected, the determination may
be performed by comparing the average received power of the
subframes or the received power of the resource assumed that the
CRS is transmitted with a prescribed threshold. The prescribed
threshold may be previously defined, or may be notified from the
base station apparatus 3.
[0711] A CRS pattern indicating the ON state and a CRS pattern
indicating the OFF state are independently defined, and in a case
where the CRS pattern indicating the ON state is detected, it may
be recognized that the ON/OFF cell is in the ON state (transition
to the operation in a case where the communication with the ON/OFF
cell in the ON state is performed in the ON/OFF cell may be
performed). That is, the base station apparatus 3 may transmit the
CRS by using a different CRS pattern between the ON state and the
OFF state.
[0712] An example of the implicit ON state of the ON/OFF cell will
be described.
[0713] In a case where the PDCCH/EPDCCH indicating the downlink
grant for the ON/OFF cell for which the OFF state is configured or
the uplink grant for the ON/OFF cell for which the OFF state is
configured in the serving cell that schedules the ON/Off cell for
which the OFF state is configured is detected, the terminal device
1 determines (assumes) that the base station apparatus 3 is in the
ON state, and recognizes that the ON/OFF cell is in the ON state
(performs transition to the operation in a case where the
communication with the ON/OFF cell in the ON state is performed in
the ON/OFF cell).
[0714] It is preferable that the PDCCH/EPDCCH indicating the
downlink grant for the ON/OFF cell for which the OFF state is
configured or the uplink grant for the ON/OFF cell for which the
OFF state is configured in the serving cell that schedules the
ON/OFF cell for which the OFF state is configured is not allocated
to the search space based on the carrier indicator field (CIF)
associated with the ON/OFF cell for which the OFF state is
configured (it is preferable that the PDCCH/EPDCCH is allocated to
the search space based on the carrier indicator field (CIF)
associated with the cell for which the ON state is configured).
[0715] It is preferable that the PDCCH/EPDCCH indicating the
downlink grant for the ON/OFF cell for which the OFF state is
configured or the uplink grant for the ON/OFF cell for which the
OFF state is configured in the serving cell that schedules the
ON/OFF cell for which the OFF state is configured is CRC-masked
with the RNTI associated with the ON/OFF cell for which the OFF
state is configured.
[0716] It is preferable that the PDCCH/EPDCCH indicating the
downlink grant for the ON/OFF cell for which the OFF state is
configured or the uplink grant for the ON/OFF cell for which the
OFF state is configured in the serving cell that schedules the
ON/OFF cell for which the OFF state is configured is a payload size
including bit information associated with the carrier indicator
field (CIF) associated with the ON/OFF cell for which the OFF state
is configured.
[0717] An example of the implicit ON state of the ON/OFF cell will
be described.
[0718] In a case where the timer associated with the discontinuous
reception (DRX) for the ON/OFF cell for which the OFF state is
configured expires, the terminal device 1 determines (assumes) that
the base station apparatus 3 is in the ON state, and recognizes
that the ON/OFF cell is in the ON state (performs transition to the
operation in a case where the communication with the ON/OFF cell in
the ON state is performed in the ON/OFF cell).
[0719] The discontinuous reception (DRX) for the ON/OFF cell may be
independently configured for each ON/OFF cell.
[0720] The timer associated with the duration of the discontinuous
reception (DRX) for the ON/OFF cell may be configured on a per
subframe basis.
[0721] An example of the implicit ON state of the ON/OFF cell will
be described.
[0722] In a case where the timer associated with the short DRX for
the ON/OFF cell for which the OFF state is configured expires, the
terminal device 1 determines (assumes) that the base station
apparatus 3 is in the ON state, and recognizes that the ON/OFF cell
is in the ON state (performs transition to the operation in a case
where the communication with the ON/OFF cell in the ON state is
performed in the ON/OFF cell).
[0723] The short DRX for the ON/OFF cell may be independently
configured for each ON/OFF cell.
[0724] The timer associated with the duration of the short DRX for
the ON/OFF cell may be configured on a per subframe basis.
[0725] The example of the implicit ON state of the ON/OFF cell is
not limited to the case where the ON state is individually
performed, and two or more ON states may be simultaneously
performed, or may be simultaneously performed with another
activation defined by the specifications.
[0726] The ON state of the ON/OFF cell determined (assumed) to be
in the ON state (transition to the operation in a case where the
communication with the ON/OFF cell in the ON state is performed)
may be applied to a radio frame and/or a subframe determined
(assumed) to be in the ON state, or may be applied to a radio frame
and/or a subframe which is positioned after a prescribed number of
radio frames or a prescribed number of subframes from the radio
frame and/or the subframe determined (assumed) to be in the ON
state.
[0727] The prescribed number of radio frames or the prescribed
number of subframes before the ON state of the ON/OFF cell
determined (assumed) to be in the ON state is applied (transition
to the operation in a case where the communication with the ON/OFF
cell in the ON state is performed) may be previously defined, or
may be notified from the base station apparatus 3.
[0728] The implicit ON state and/or implicit OFF state of the
ON/OFF cell may be performed in a case where the terminal device 1
waits for a prescribed function (capability or UE capability).
[0729] The implicit ON state and/or implicit OFF state of the
ON/OFF cell may be performed by the terminal device 1 in a
prescribed mode. For example, in a case where an implicit/explicit
activation mode is defined, the implicit ON state and/or implicit
OFF state of the ON/OFF cell may be performed in a case where the
terminal device 1 is in the implicit mode. It is preferable that
the switching of the implicit/explicit activation mode is notified
using a R field reserved in the MAC CE, and it is preferable that a
case where the R field is set to be "0" indicates the explicit
activation mode and a case where the R field is set to be "1"
indicates the implicit activation mode.
[0730] Hereinafter, the OFF state timer (OFF timer or small cell
deactivation timer) of the ON/OFF cell will be described.
[0731] In a case where the indication of the ON state of the ON/OFF
cell is received, the terminal device 1 starts or restarts the OFF
state timer associated with the ON/OFF cell.
[0732] In a case where the PDCCH of the ON/OFF cell does not
indicate the downlink grant or the uplink grant, in a case where
the PDCCH of the serving cell that schedules the ON/OFF cell does
not indicate the downlink grant for the ON/OFF cell or the uplink
grant for the ON/OFF cell, or in a case where there is no
indication of the PDCCH for the ON/OFF cell, the terminal device 1
counts up the OFF state timer associated with the ON/OFF cell
(increases 1 or adds 1). In a case where the OFF state timer is
present on a per radio frame basis, the timer counts up in all
prescribed radio frames in a case where there is no indication of
the PDCCH. In a case where the OFF state timer is present for a
plurality of subframes, the timer counts up in all the plurality of
subframes in a case where there is no indication of the PDCCH.
[0733] The OFF state timer may count up only in a specific
subframe. In other words, the OFF state timer does not count up in
the subframes other than the specific subframe. For example, the
OFF state timer does not count up in the uplink subframe even
though the timer satisfies the above-described condition. For
example, the OFF state timer does not count in the MBSFN subframe
even though the timer satisfies the above-described condition. For
example, the OFF state timer does not count up in the subframe
indicated in the higher layer even though the timer satisfies the
above-described condition.
[0734] In a case where the OFF state timer associated with the
ON/OFF cell expires, the terminal device 1 recognizes that the
ON/OFF cell is in the OFF state.
[0735] In a case where the PDCCH of the ON/OFF cell indicates the
downlink grant or the uplink grant, or in a case where the PDCCH of
the serving cell that schedules the ON/OFF cell indicates the
downlink grant for the ON/OFF cell or the uplink grant for the
ON/OFF cell, the terminal device 1 starts or restarts the OFF state
timer associated with the ON/OFF cell.
[0736] In a case where the indication of the OFF state of the
ON/OFF cell is received, or in a case where the OFF state timer
associated with the ON/OFF cell expires, the terminal device 1
stops the OFF timer associated with the ON/OFF cell.
[0737] The OFF state timer of the ON/OFF cell may be the same as
the deactivation timer (timer associated with the duration of the
cell). The OFF state timer of the ON/OFF cell may be a timer
associated with the duration of the ON/OFF cell.
[0738] In a case where the inter-cell interference is suppressed
using the ON/OFF cell, the ON state and the OFF state of the ON/OFF
cell are dynamically switched depending on the position or traffic
amount of the terminal device 1. As the switching speed between the
ON state and the OFF state of the ON/OFF cell becomes higher, the
adaptability for the position or traffic amount of the terminal
device 1 becomes high.
[0739] The ON/OFF cell and/or the non-ON/OFF cell may be configured
for the primary cell, may be configured for the secondary cell, or
may be configured for the secondary cell (primary secondary cell or
special cell) having a special function (for example, a function of
the primary cell) among the secondary cells.
[0740] The ON state may be constantly configured for the ON/OFF
cell and/or the non-ON/OFF cell.
[0741] That is, it is preferable that the ON/OFF cell and the
non-ON/OFF cell are independently maintained in the terminal device
1. That is, an initial value of the OFF state timer associated with
the ON/OFF cell and an initial value of the deactivation timer
associated with the non-ON/OFF cell are independently
configured.
[0742] An example of the configuration of the initial value of the
OFF state timer will be described.
[0743] The initial value of the OFF state timer associated with the
ON/OFF cell may be configured using a parameter of
sCellDeactivationTimer-r12 from the higher layer (RRC layer), and
the initial value of the deactivation timer associated with the
non-ON/OFF cell may be configured using a parameter of
sCellDeactivationTimer-r10 from the higher layer (RRC layer).
[0744] An example of the configuration of the initial value of the
OFF state timer will be described.
[0745] The initial value of the OFF state timer associated with the
ON/OFF cell and the initial value of the deactivation timer
associated with the non-ON/OFF cell may be configured using two or
more same parameters. For example, the initial value of the OFF
state timer associated with the ON/OFF cell and the initial value
of the deactivation timer associated with the non-ON/OFF cell may
be configured using two or more parameters of
sCellDeactivationTimer-r10.
[0746] An example of the configuration of the initial value of the
OFF state timer will be described.
[0747] The initial value of the OFF state timer associated with the
ON/OFF cell may be configured by replacing the initial value of the
OFF state timer associated with the ON/OFF cell with the parameter
of sCellDeactivationTimer-r10 associated with the initial value of
the deactivation timer associated with the non-ON/OFF cell. For
example, in a case where rf2 which is a value associated with the
number of radio frames is configured for the parameter of
sCellDeactivationTimer-r10, the initial value of the OFF state
timer associated with the ON/OFF cell may be configured by being
replaced with rf1.
[0748] The parameter of sCellDeactivationTimer-r10 associated with
the initial value of the deactivation timer associated with the
non-ON/OFF cell may be configured as the initial value of the OFF
state timer associated with the ON/OFF cell.
[0749] It is preferable that at least one of rf2, rf4, rf8, rf16,
rf32, rf64 and rf128 which are values associated with the number of
radio frames is configured for the parameter of
sCellDeactivationTimer-r12 and the parameter of
sCellDeactivationTimer-r10. Here, rf2 corresponds to 2 radio
frames, rf4 corresponds to 4 radio frames, rf8 corresponds to 8
radio frames, rf16 corresponds to 16 radio frames, rf32 corresponds
to 32 radio frames, rf64 corresponds to 64 radio frames, and rf128
corresponds to 128 radio frames.
[0750] The values associated with the number of radio frames
configured for the parameter of sCellDeactivationTimer-r12 and the
parameter of sCellDeactivationTimer-r10 may be selected from
different values. For example, it is preferable that at least one
of rf2, rf4, rf8, rf16, rf32, rf64 and rf128 which are values
associated with the number of radio frames is configured for the
parameter of sCellDeactivationTimer-r10 and at least one of rf1,
rf2, rf4, rf8, rf16, rf32 and rf64 which are values associated with
the number of radio frames is configured for the parameter of
sCellDeactivationTimer-r12. Here, rf1 corresponds to 1 radio frame,
rf2 corresponds to 2 radio frames, rf4 corresponds to 4 radio
frames, rf8 corresponds to 8 radio frames, rf16 corresponds to 16
radio frames, rf32 corresponds to 32 radio frames, rf64 corresponds
to 64 radio frames, and rf128 corresponds to 128 radio frames.
[0751] The values configured for the parameter of
sCellDeactivationTimer-r12 and the parameter of
sCellDeactivationTimer-r10 may be selected from values associated
with the number of subframes.
[0752] The initial value of the OFF state timer may be applied to a
radio frame and/or a subframe in which the configuration is
received, or may be applied to a radio frame and/or a subframe
which is positioned after a prescribed number of radio frames or a
prescribed number of subframes from the radio frame and/or the
subframe in which the configuration is received.
[0753] In a case where an initial value of a second OFF state timer
is configured for the terminal device 1 for which an initial value
of a first OFF state timer is configured, the initial value may be
applied to a radio frame and/or a subframe in which the
configuration of the initial value of the second OFF state timer is
received, or may be applied to a radio frame or a subframe which is
positioned after a prescribed number of radio frames or a
prescribed number of subframes from the radio frame and/or the
subframe in which the configuration of the initial value of the
second OFF state timer is received, or the initial value of the
second OFF state timer may be ignored.
[0754] The prescribed number of radio frames or the prescribed
number of subframes to which the initial value of the OFF state
timer is applied may be previously defined, or may be notified from
the base station apparatus 3.
[0755] The initial value of the OFF state timer associated with the
ON/OFF cell may be configured using the higher layer (RRC
layer).
[0756] The initial value of the OFF state timer associated with the
ON/OFF cell may be configured using the L1 signalling (for example,
DCI format). For example, the initial value of the OFF state timer
associated with the ON/OFF cell may be configured using the L1
signalling (for example, DCI format), and the initial value of the
deactivation timer associated with the non-ON/OFF cell may be
configured using the higher layer (RRC layer).
[0757] In a case where a plurality of ON/OFF cells is configured
for the terminal device 1, as the initial value of the OFF state
timer associated with the ON/OFF cell, a value common to the
plurality of configured ON/OFF cells may be configured, individual
values for the plurality of configured ON/OFF cells may be
configured, or a value common to groups acquired by grouping the
plurality of configured ON/OFF cells may be configured.
[0758] Hereinafter, the details of the CSI measurement and CSI
reporting of the terminal device 1 will be described.
[0759] The CSI includes a channel quality indicator (CQI), a
precoding matrix indicator (PMI), a precoding type indicator (PTI)
and/or a rank indicator (RI). The RI indicates the number of
transmission layers (the number of ranks). The PMI is information
indicating a predefined precoding matrix. The PMI indicates one
precoding matrix by using one information item or two information
items. The PMI in a case where two information items are used is
referred to as a first PMI and a second PMI. The CQI is information
indicating the combination of a predefined modulation scheme and
coding rate. The terminal device reports a recommended CSI to the
base station apparatus 3. The terminal device 2 reports the CQI
that satisfies prescribed reception quality for each transport
block (code word).
[0760] The subframe (reporting instances) in which the CSI
reporting can be periodically performed is determined by a
reporting cycle and a subframe offset based on the information (CQI
PMI index or RI index) configured in the higher layer. The
information configured in the higher layer can be configured for
each subframe set configured in order to measure the CSI. In a case
where only one information item is configured for a plurality of
subframe sets, the information may be regarded as being common to
the subframe sets.
[0761] One P-CSI reporting event to each serving cell is configured
for the terminal device 2 configured in Transmission Modes 1 to 9
by the higher layer signalling.
[0762] One or more P-CSI reporting events to each serving cell are
configured for the terminal device 2 configured in Transmission
Mode 10 by higher layer signalling.
[0763] Eight CSI-RS ports (CSI-RSs of 8 antenna ports) are
configured for the terminal device 2 configured in Transmission
Mode 9 or 10, and a reporting mode (Mode 1-1) of a single PMI in a
feedback CQI is configured in Submode 1 or Submode 2 using a
certain parameter (PUCCH_format 1-1_CSI_reporting_mode) by the
higher layer signalling.
[0764] The CQI reporting in a certain subframe of a certain serving
cell for a UE-selected subband CQI is to report channel quality in
a specific portion (a part) of a bandwidth of the serving cell
indicated as a bandwidth part.
[0765] A CSI reporting type supports a PUCCH CSI reporting mode.
The CSI reporting type is referred to as a PUCCH reporting type in
some cases. Type 1 reporting supports CQI feedback for the
UE-selected subband. Type 1a reporting supports a subband CQI and
second PMI feedback. Type 2, type 2b and type 2c reporting events
support a feedback CQI and PMI feedback. Type 2a reporting supports
feedback PMI feedback. Type 3 reporting supports RI feedback. Type
4 reporting supports a feedback CQI. Type 5 reporting supports RI
and feedback PMI feedback. Type 6 reporting supports RI and PTI
feedback.
[0766] Hereinafter, the details of the CSI measurement and CSI
reporting of the terminal device 1 in the base station apparatus 3
that supports the ON state and the OFF state will be described.
[0767] Information related to the CSI measurement and CSI reporting
is configured for the terminal device 1 from the base station
apparatus 3. The CSI measurement is performed based on the
reference signal and/or the reference resource (for example, CRS,
CSI-RS, CSI-IM resource and/or DRS). The reference signal used in
the CSI measurement is determined based on the configuration of the
transmission mode. The CSI measurement is performed based on the
channel measurement and the interference measurement. For example,
the channel measurement is to measure the power of a desired cell.
The interference measurement is to measure the power and noise
power in cells other than the desired cell.
[0768] As an example, the terminal device 1 performs the channel
measurement and the interference measurement based on the CRS. As
another example, the terminal device 1 performs the channel
measurement based on the CSI-RS, and performs the interference
measurement based on the CRS. As another example, the terminal
device 1 performs the channel measurement based on the CSI-RS, and
performs the interference measurement based on the CSI-IM resource.
As another example, the terminal device 1 performs the channel
measurement and the interference measurement based on the DRS.
[0769] The terminal device 1 may perform the CSI measurement in
consideration of the ON state and the OFF state of the base station
apparatus 3. For example, the terminal device 1 may take account of
the ON state and the OFF state of the base station apparatus 3 for
the reference signal and/or the reference resource for performing
the CSI measurement. In the following description, the reference
signal in the CSI measurement also includes the reference resource.
Particularly, the reference signal for the interference measurement
may be replaced with the resource to be referred to in order to
perform the interference measurement. That is, a signal may not be
mapped to the resource for performing the interference measurement.
Thus, it is possible to determine whether the resource for
performing the interference measurement is valid or invalid
depending on the ON state and the OFF state of the base station
apparatus 3.
[0770] As an example, in the CSI measurement, the terminal device 1
assumes that the reference signal for the channel measurement is
transmitted only in the ON state of the base station apparatus 3
and the reference signal for the interference measurement is
transmitted only in the ON state of the base station apparatus 3.
That is, the terminal device 1 assumes that the reference signal
for the channel measurement is transmitted in the subframe in the
ON state of the base station apparatus 3 and the reference signal
for the channel measurement is not transmitted in the subframe in
the OFF state of the base station apparatus 3. The terminal device
1 assumes that the reference signal for the interference
measurement is transmitted in the subframe in the ON state of the
base station apparatus 3 and the reference signal for the
interference measurement is not transmitted in the subframe in the
OFF state of the base station apparatus 3. In other words, the
terminal device 1 performs the channel measurement based on the
reference signal transmitted in a prescribed subframe of the
subframes in the ON state of the base station apparatus 3, and
performs the interference measurement based on the reference signal
transmitted in a prescribed subframe of the subframes in the ON
state of the base station apparatus 3. Accordingly, in the OFF
state, the base station apparatus 3 may stop the reference signal
for the CSI measurement in the terminal device 1.
[0771] As another example, in the CSI measurement, the terminal
device 1 assumes that the reference signal for the channel
measurement is transmitted only in the ON state of the base station
apparatus 3 and the reference signal for the interference
measurement is transmitted in the ON state and the OFF state of the
base station apparatus 3. That is, the terminal device 1 assumes
that the reference signal for the channel measurement is
transmitted in the subframe in the ON state of the base station
apparatus 3 and the reference signal for the channel measurement is
not transmitted in the subframe in the OFF state of the base
station apparatus 3. The terminal device 1 assumes that the
reference signal for the interference measurement is transmitted in
the subframe of the ON state and the OFF state of the base station
apparatus 3. In other words, the terminal device 1 performs the
channel measurement based on the reference signal transmitted in a
prescribed subframe of the subframes in the ON state of the base
station apparatus 3, and performs the interference measurement
based on the reference signal transmitted in a prescribed subframe
of the subframes in the ON state and the OFF state of the base
station apparatus 3. Accordingly, in the OFF state, the base
station apparatus 3 may stop the reference signal for the channel
measurement in the terminal device 1. Since the terminal device 1
can perform the interference measurement irrespective of the ON
state or the OFF state of the base station apparatus 3, in a case
where the terminal device 1 performs a process such as averaging in
a time direction in the interference measurement, it is possible to
improve the accuracy of the process.
[0772] As another example, in the CSI measurement, the terminal
device 1 assumes that the reference signal for the channel
measurement is transmitted in the ON state and the OFF state of the
base station apparatus 3 and the reference signal the interference
measurement is transmitted only in the ON state of the base station
apparatus 3. That is, the terminal device 1 assumes that the
reference signal for the channel measurement is transmitted in the
subframe in the ON state and the OFF state of the base station
apparatus 3. The terminal device 1 assumes that the reference
signal for the interference measurement is transmitted in the
subframe in the ON state of the base station apparatus 3 and the
reference signal for the interference measurement is not
transmitted in the subframe in the OFF state of the base station
apparatus 3. In other words, the terminal device 1 performs the
channel measurement based on the reference signal transmitted in a
prescribed subframe of the subframes in the ON state and the OFF
state of the base station apparatus 3, and performs the
interference measurement based on the reference signal transmitted
in a prescribed subframe of the subframes in the ON state of the
base station apparatus 3. Accordingly, in the OFF state, the base
station apparatus 3 may stop the reference signal for the
interference measurement in the terminal device 1. Since the
terminal device 1 can perform the channel measurement irrespective
of the ON state or the OFF state of the base station apparatus 3,
in a case where the terminal device 1 performs a process such as
averaging in a time direction in the channel measurement, it is
possible to improve the accuracy of the process.
[0773] As another example, in the CSI measurement, the terminal
device 1 assumes that the reference signal for the channel
measurement is transmitted in the ON state and the OFF state of the
base station apparatus 3 and the reference signal for the
interference measurement is transmitted in the ON state and the OFF
state of the base station apparatus 3. That is, the terminal device
1 assumes that the reference signal for the channel measurement is
transmitted in the subframe in the ON state and the OFF state of
the base station apparatus 3. The terminal device 1 assumes that
the reference signal for the interference measurement is
transmitted in the subframe of the ON state and the OFF state of
the base station apparatus 3. In other words, the terminal device 1
performs the channel measurement based on the reference signal
transmitted in a prescribed subframe of the subframes in the ON
state and the OFF state of the base station apparatus 3, and
performs the interference measurement based on the reference signal
transmitted in a prescribed subframe of the subframes in the ON
state and the OFF state of the base station apparatus 3.
Accordingly, in the OFF state, the base station apparatus 3 can
perform the CSI measurement in the terminal device 1 even in a case
where the transmission of the signal and channel other than the
reference is stopped. Since the terminal device 1 can perform the
CSI measurement irrespective of the ON state or the OFF state of
the base station apparatus 3, in a case where the terminal device 1
performs a process such as averaging in a time direction in the
interference measurement, it is possible to improve the accuracy of
the process.
[0774] Hereinafter, a specific example of the reference signal for
the channel measurement and the interference measurement will be
described.
[0775] In the terminal device 1 for which a prescribed transmission
mode is configured, the terminal device 1 performs the channel
measurement for calculating the value of the CQI. The value of the
CQI is reported in a prescribed subframe, and corresponds to a
certain CSI process. The channel measurement is performed based on
only a non-zero power CSI-RS of the configuration of the CSI-RS
resource associated with the CSI process. In the CSI process, in a
case where the RRC parameter related to the ON state and the OFF
state is configured for the terminal device 1 for which a
prescribed transmission mode is configured by the higher layer, the
CSI-RS resource within the subframe in the ON state is used to
perform the channel measurement.
[0776] In the terminal device 1 for which a prescribed transmission
mode is configured, the terminal device 1 performs the channel
measurement for calculating the value of the CQI. The value of the
CQI is reported in a prescribed subframe, and corresponds to a
certain CSI process. The channel measurement is performed based on
only a non-zero power CSI-RS of the configuration of the CSI-RS
resource associated with the CSI process. In the CSI process, in a
case where the RRC parameter related to the ON state and the OFF
state is configured for the terminal device 1 for which a
prescribed transmission mode is configured by the higher layer, the
CSI-RS resource within the subframe in the ON state and the OFF
state is used to perform the channel measurement.
[0777] In the terminal device 1 for which a prescribed transmission
mode is configured, the terminal device 1 performs the interference
measurement for calculating the value of the CQI. The value of the
CQI is reported in a prescribed subframe, and corresponds to a
certain CSI process. The interference measurement is performed
based on only the zero power CSI-RS of the configuration of the
CSI-IM resource associated with the CSI process. In the CSI
process, in a case where the CSI subframe set is configured for the
terminal device 1 for which a prescribed transmission mode is
configured by the higher layer, the CSI-IM resource within a subset
of the subframe belonging to the CSI reference resource is used to
perform the interference measurement. In the CSI process, in a case
where the RRC parameter related to the ON state and the OFF state
is configured for the terminal device 1 for which a prescribed
transmission mode is configured by the higher layer, the CSI-RS
resource within the subframe in the ON state is used to perform the
interference measurement.
[0778] In the terminal device 1 for which a prescribed transmission
mode is configured, the terminal device 1 performs the interference
measurement for calculating the value of the CQI. The value of the
CQI is reported in a prescribed subframe, and corresponds to a
certain CSI process. The interference measurement is performed
based on only the zero power CSI-RS of the configuration of the
CSI-IM resource associated with the CSI process. In the CSI
process, in a case where the CSI subframe set is configured for the
terminal device 1 for which a prescribed transmission mode is
configured by the higher layer, the CSI-IM resource within a subset
of the subframe belonging to the CSI reference resource is used to
perform the interference measurement. In the CSI process, in a case
where the RRC parameter related to the ON state and the OFF state
is configured for the terminal device 1 for which a prescribed
transmission mode is configured by the higher layer, the CSI-RS
resource within the subframe in the ON state and the OFF state is
used to perform the interference measurement.
[0779] In the description of the present embodiment, the RRC
parameter related to the ON state and the OFF state is configured
in the higher layer. The configuration of the RRC parameter related
to the ON state and the OFF state is also referred to as a
configuration for the cell state information. The configuration for
the cell state information is used for the cell state information
which is explicitly or implicitly notified in the physical layer.
For example, the configuration for the cell state information
includes information required to receive the cell state information
which is explicitly or implicitly notified in the physical layer.
The configuration for the cell state information may be
individually performed for each CSI process. The configuration for
the cell state information may be individually configured for each
CSI subframe set.
[0780] The CSI process is configured as information specific to the
terminal device 1 in the higher layer. One or more CSI processes
are configured for the terminal device 1, and the terminal device 1
performs the CSI measurement and the CSI reporting based on the
configuration of the CSI process. For example, in a case where a
plurality of CSI processes is configured, the terminal device 1
independently reports a plurality of CSIs based on these CSI
processes. Each CSI process includes configuration for the cell
state information, identity of the CSI process, configuration
information related to the CSI-RS, configuration information
related to the CSI-IM, a subframe pattern configured in order to
perform the CSI reporting, configuration information related to
periodic CSI reporting, and/or configuration information related to
aperiodic CSI reporting. The configuration for the cell state
information may be common to the plurality of CSI processes.
[0781] Hereinafter, the details of the CSI reference resource in a
certain serving cell will be described.
[0782] The CSI reference resource is a resource used by the
terminal device 1 to perform the CSI measurement. For example, the
terminal device 1 measures the CSI in a case where the PDSCH is
transmitted by using the group of downlink physical resource blocks
indicated by the CSI reference resource. In a case where the CSI
subframe set is configured in the higher layer, the CSI reference
resource belongs to any one of the CSI subframe sets, and does not
belong to both the CSI subframe sets.
[0783] In a frequency direction, the CSI reference resource is
defined by the group of downlink resource blocks corresponding to
the band associated with the value of the required CQI.
[0784] In a layer direction (space direction), the CSI reference
resource is defined by the RI and the PMI of which conditions are
set by the required CQI. In other words, in the layer direction
(space direction), the CSI reference resource is defined by the RI
and the PMI assumed or generated when the CQI is required.
[0785] In a time direction, the CSI reference resource is defined
by one prescribed downlink subframe. Specifically, the CSI
reference resource is defined by a subframe which is positioned
before a prescribed number of subframes earlier from the subframe
in which the CSI is reported. The prescribed number of subframes
that defines the CSI reference resource is determined based on the
transmission mode, frame constituting type, the number of CSI
processes to be configured, and/or the CSI reporting mode. For
example, in a case where one CSI process and the periodic CSI
reporting mode are configured for the terminal device 1, the
prescribed number of subframes that defines the CSI reference
resource is a minimum value of 4 or more among effective downlink
subframes.
[0786] Hereinafter, the details of the effective downlink subframe
will be described.
[0787] In a case where a part or all of the following conditions is
satisfied, it is considered that the downlink subframe of a certain
serving cell is effective. As one condition, the effective downlink
subframe is the subframe in the ON state in the terminal device 1
for which the RRC parameter related to the ON state and the OFF
state is configured. As one condition, the effective downlink
subframe is configured as the downlink subframe in the terminal
device 1. As one condition, the effective downlink subframe is not
the multimedia broadcast multicast service single frequency network
(MBSFN) subframe in a prescribed transmission mode. As one
condition, the effective downlink subframe is not included in the
range of the measurement gap configured for the terminal device 1.
As one condition, the effective downlink subframe is an element or
a part of the CSI subframe set linked to the periodic CSI reporting
when the CSI subframe set is configured for the terminal device 1
in the periodic CSI reporting. As one condition, the effective
downlink subframe is an element or a part of the CSI subframe set
linked to the downlink subframe accompanying by the corresponding
CSI request within the DCI format of the uplink in the aperiodic
CSI reporting for the CSI process. In the condition, a prescribed
transmission mode, a plurality of CSI processes, and a CSI subframe
set for the CSI process are configured for the terminal device
1.
[0788] In a case where there is no effective downlink subframe for
the CSI reference resource within a certain serving cell, the CSI
reporting in the serving cell is excluded from the uplink subframe.
That is, in the condition in which the effective downlink subframe
is the subframe in the ON state, the terminal device 1 assumes that
the subframe in the OFF state is not the effective downlink
subframe.
[0789] In a case where the base station apparatus 3 (serving cell)
is in the OFF state, the terminal device 1 may assume that all the
subframes including the subframe in the previous ON state are not
the effective downlink subframes. That is, in a case where the base
station apparatus 3 (serving cell) is in the OFF state, the
terminal device 1 assumes that the effective downlink subframe is a
prescribed subframe after the subframe in the subsequent ON state
or the subframe notified as being in the ON state.
[0790] The terminal device 1 may have a condition in which even the
subframe in the OFF state is the effective downlink subframe. That
is, the terminal device 1 may determine whether or not the subframe
is the effective downlink subframe irrespective of the subframe in
the ON state or the OFF state.
[0791] The terminal device 1 may have a condition in which the
subframe in the ON state and a part of the subframes in the OFF
state are the effective downlink subframe. The part of the
subframes in the OFF state is a prescribed subframe that is
previously defined, a prescribed subframe configured so as to be
specific to the base station apparatus 3, or a subframe configured
so as to be specific to the terminal device 1. For example, the
part of the subframes in the subframes in the OFF state is a
subframe between a prescribed subframe and a subframe which is
positioned before a prescribed number of subframes from the
prescribed subframe. For example, the prescribed subframe is a
subframe in the ON state or a subframe notified as being in the ON
state. The prescribed subframe is a subframe in which the DCI
format including the CSI request is received. The prescribed
subframe is a subframe in which the CSI is reported.
[0792] Hereinafter, a specific example of the method of notifying
of the cell state (ON state or OFF state) of the base station
apparatus 3 will be described.
[0793] The base station apparatus 3 performs configuration related
to the cell state information for the terminal device 1 through the
RRC signaling. The base station apparatus 3 notifies of the cell
state by a prescribed method based on the configuration related to
the cell state information configured for the terminal device 1.
The cell state information is configured for the terminal device 1
from the base station apparatus 3 through the RRC signaling. The
terminal device 1 recognizes the cell state by a prescribed method
based on the configuration related to the cell state information
configured from the base station apparatus 3.
[0794] As the method of notifying of the cell state, there is an
explicit method or an implicit method. As an example, the cell
state is explicitly notified based on the cell state information
notified using the DCI transmitted by the PDCCH or the EPDCCH. For
example, the terminal device 1 recognizes that the cell is in the
ON state in a case where the cell state information indicates 1 and
the cell is in the OFF state in a case where the cell state
information indicates 0. As another example, the cell state is
implicitly notified based on the presence or absence of the
reference signal. The presence or absence of the reference signal
is determined by comparing the received power or the reception
level of the reference signal with a prescribed threshold. As
another example, the cell state is implicitly notified based on the
procedure or configuration of the DRX. For example, the terminal
device 1 recognizes that the cell is in the ON state in a non-DRX
period and the cell is in the OFF state in a DRX period. As another
example, the cell state is implicitly notified based on the
activation or deactivation of the cell notified by the MAC layer.
For example, the terminal device 1 recognizes that the cell is in
the ON state in an activation period of the cell and the cell is in
the OFF state in an activation period of the cell.
[0795] As the configuration related to the cell state, information
used by the terminal device 1 to recognize the cell state is
configured. For example, the configuration related to the cell
state information includes subframe information, information
related to the search space, and information related to the RNTI,
as information used to receive or monitor the PDCCH or the EPDCCH
in which the cell state information is notified. The configuration
related to the cell state information includes information related
to the reference signal, virtual cell identity, a prescribed
threshold, and subframe information, as information used to
recognize the presence or absence of the reference signal.
[0796] Hereinafter, the details of the recognition of the
notification of the cell state in the terminal device 1 will be
described.
[0797] As an example, the recognition of the notification of the
cell state in the terminal device 1 is performed based on the
cyclic redundancy check (CRC) added to the PDCCH or the EPDCCH
including the DCI for notifying of the cell state information. For
example, in a case where the value acquired by the cyclic
redundancy check is not correct, the terminal device 1 determines
that the notification of the cell state is not able to be
recognized (detected).
[0798] As another example, the recognition of the notification of
the cell state in the terminal device 1 is performed based on
whether or not the received power or reception level of the
reference signal is within a range of a prescribed threshold. For
example, if a first threshold and a second threshold greater than
the first threshold are defined or configured and the received
power or reception level of the reference signal is within a range
from the first threshold to the second threshold, the terminal
device 1 determines that the notification of the cell state is not
able to be recognized (detected). In a case where the received
power or reception level of the reference signal is less than the
first threshold, the terminal device 1 determines that the cell is
in the OFF state. In a case where the received power or reception
level of the reference signal is greater than the second threshold,
the terminal device 1 determines that the cell is in the ON
state.
[0799] A process (operation) in a case where the terminal device 1
is not able to recognize (detect) the notification of the cell
state will be described.
[0800] As an example, in a case where the terminal device 1 is not
able to recognize (detect) the notification of the cell state in a
certain subframe, the terminal device 1 assumes that the cell is in
the OFF state until the subframe in which the notification of the
next cell state is performed. That is, the terminal device 1
performs the same process in a case where the OFF state is notified
until the subframe in which the next cell state is notified.
[0801] As an example, in a case where the terminal device 1 is not
able to recognize (detect) the notification of the cell state in a
certain subframe, the terminal device 1 assumes that the cell is in
the ON state until a subframe in which the notification of the next
cell state is performed. That is, the terminal device 1 performs
the same process in a case where the ON state is notified until the
subframe in which the notification of the next cell state is
performed.
[0802] As an example, in a case where the terminal device 1 is not
able to recognize (detect) the detection of the cell state in a
certain subframe, the terminal device 1 assumes that the cell is in
a state different from the ON state or the OFF state until the
subframe in which the next cell state is notified. That is, the
terminal device 1 performs a process different from that in a case
where the ON state or the OFF state is notified until the subframe
in which the next cell state is notified.
[0803] For example, in a certain subframe in a state different from
the ON state or the OFF state, the terminal device 1 assumes that
the downlink subframe is in the ON state and the uplink subframe is
in the OFF state. That is, the terminal device 1 receives or
monitors a part or all of the downlink signals and/or channels, and
does not transmit a part or all the uplink signals and/or channels.
For example, the terminal device 1 receives the reference signal,
monitors the PDCCH and/or monitors the EPDCCH, and does not perform
the periodic CSI reporting and/or SRS transmission.
[0804] For example, in a subframe in a state different from the ON
state or the OFF state, the terminal device 1 assumes that the
downlink subframe is in the OFF state and the uplink subframe is in
the ON state. That is, the terminal device 1 does not receive or
monitor a part or all of the downlink signals and/or channels, and
transmits a part or all of the uplink signals and/or channels. For
example, the terminal device 1 does not receive the reference
signal, monitor the PDCCH and/or monitor the EPDCCH, and performs
the periodic CSI reporting and/or SRS transmission.
[0805] For example, in a subframe in a state different from the ON
state or the OFF state, the terminal device 1 monitors a prescribed
PDCCH and/or EPDCCH different from that in the ON state. The
prescribed PDCCH and/or EPDCCH are monitored in a prescribed search
space different from that in the ON state. The CRC scrambled with a
prescribed RNTI different that in the ON state is added to the
prescribed PDCCH and/or EPDCCH.
[0806] Although it has been described above that in a case where
the terminal device 1 is not able to recognize (detect) the
notification of the cell state in a certain subframe, the terminal
device 1 assumes that the cell is in a prescribed state until the
subframe in which the next cell state is notified, the present
invention is not limited thereto. For example, in a case where the
terminal device 1 is not able to recognize (detect) the detection
of the cell state in a certain subframe, the terminal device 1 may
assume that the cell is in a prescribed state until a subframe in
which a cell state indicated by the notification of the next cell
state is applied. Accordingly, the subframe in which the cell state
is notified and the subframe in which the cell state indicated by
this notification is applied may be independently defined or
configured.
[0807] Hereinafter, the uplink power control of the terminal device
1 in the dual connectivity will be described. Here, the uplink
power control includes power control for the uplink transmission.
The uplink transmission includes the transmission(s) of the uplink
signal(s) and/or uplink physical channel(s) such as PUSCH, PUCCH,
PRACH, or SRS.
[0808] The terminal device 1 may perform the uplink power control
for each of the MCG including the primary cell and the SCG
including the primary secondary cell. The uplink power control
includes transmission power control for uplink transmission. The
uplink power control includes the transmission power control of the
terminal device 1.
[0809] The MeNB (a first base station apparatus connected to the
terminal device 1) and the SeNB (a second base station apparatus
connected to the terminal device 1) may notify (configure) the
terminal device 1 of maximum allowed output power (maximum allowed
UE output power, P-Max, P.sub.EMAX, P.sub.EMAX,c) of the terminal
device 1 or a value (or index and/or parameter required to define
the value) of a power class of the terminal device 1 by using the
higher layer signalling or the system information block (SIB). The
maximum allowed UE output power may be referred to as maximum
output power of the higher layer. The P.sub.EMAX may be configured
for each serving cell (referred to as P.sub.EMAX,c).
[0810] In a case where the terminal device 1 receives the P-Max
from the MeNB (or PCell) and the SeNB (pSCell), the terminal device
1 sets the maximum output power (configured maximum UE output
power, P.sub.CMAX, P.sub.CMAX,c) (the configured maximum value of
the transmit power) to the MeNB and the SeNB. Here, the maximum
output power for the MeNB may be referred to as P.sub.MeNB_MAX, and
the maximum output power for the SeNB may be referred to as
P.sub.SeNB_MAX. The P.sub.MeNB_MAX and the P.sub.SeNB_MAX may be
set such that these values do not exceed the P.sub.CMAX or the
P.sub.CMAX,c. The maximum output power may be referred to as the
maximum output power of the physical layer. The MeNB may include
the MCG and/or the PCell. The SeNB may include the SCG and/or the
pSCell.
[0811] In a case where a scaling factor of a transmit power (output
power) is received from the MeNB (or PCell and/or MCG) and/or SeNB
(pSCell and/or SCG), the P.sub.CMAX (P.sub.MeNB_MAX) for the MeNB
and the P.sub.CMAX (P.sub.SeNB_MAX) for the SeNB may be set to the
terminal device 1 based on the scaling factor. In a certain timing,
in a case where a common scaling factor to the MeNB and the SeNB is
configured, the total of the P.sub.MeNB_MAX and the P.sub.SeNB_MAX
is set so as not to exceed the P.sub.CMAX or the P.sub.CMAX,c. The
P.sub.CMAX may be configured for each serving cell (referred to as
P.sub.CMAX,c).
[0812] In a case where scaling factors of transmit powers (output
powers) for the MeNB (or PCell and/or MCG) and the SeNB (pSCell
and/or SCG) are configured, the P.sub.MeNB_MAX and the
P.sub.SeNB_MAX are individually configured for the terminal device
1. That is, in a case where a scaling factor of a transmit power
(output power) corresponding to each base station apparatus
(serving cell and/or cell group) is configured, the maximum value
of the transmit power corresponding to each base station apparatus
may be set.
[0813] In a case where the P-Max is (a value) common to the MeNB
and the SeNB, the maximum output power (the maximum output power of
the physical layer or the maximum value of the output power) for
the SeNB (or PCell and/or MCG) may be set based on the P.sub.CMAX
or the P.sub.CMAX,c based on the P-Max and a transmit power
required in the MeNB.
[0814] The terminal device 1 may determine whether or not the
output power is shared between the transmission to the MeNB and the
transmission to the SeNB which occur in the same timing depending
on whether or not the maximum value of the transmit power for the
SeNB is set.
[0815] In a case where the maximum output power (P.sub.MeNB_MAX)
for the MeNB and the maximum output power (P.sub.SeNB_MAX) for the
SeNB are individually set, the maximum output power (P.sub.UE_MAX)
configured for the terminal device 1 may be individually set. The
total of the P.sub.MeNB_MAX and the P.sub.SeNB_MAX may be set so as
not to exceed the P.sub.UE_MAX. The P.sub.UE_MAX may be the
P.sub.CMAX. Each maximum output power may be set for each serving
cell or for each cell group. Each maximum output power may be set
for each subframe. Here, the P.sub.MeNB is a transmit power set to
the uplink transmission to the MeNB, and the P.sub.SeNB is a
transmit power set to the uplink transmission to the SeNB. These
transmit powers may be set so as not to exceed the maximum output
powers.
[0816] In a certain timing, in a case where the P.sub.MeNB_MAX and
the P.sub.SeNB_MAX are set, the total of the P.sub.MeNB_MAX and the
P.sub.SeNB_MAX may be set so as not to exceed the P.sub.UE_MAX. In
this case, in a case where the parameter such as the P-Max is
common to or a value common to the MeNB and the SeNB, for example,
in a case where the P.sub.MeNB_MAX and the P.sub.SeNB_MAX are set
to the P.sub.UE_MAX, the total of the P.sub.MeNB_MAX and the
P.sub.SeNB_MAX may be set so as not to exceed the P.sub.UE_MAX by
using the parameter for scaling the maximum output power such as
the scaling factor. As mentioned above, a case where the maximum
output power for the MeNB and the maximum output power for the SeNB
are individually configured in advance is referred to as hard
split.
[0817] Here, a case where the terminal device 1 and/or the base
station apparatus 3 previously set the values of the parameters
required to set the values of the P.sub.MeNB_MAX and the
P.sub.SeNB_MAX or the P.sub.MeNB_MAX and the P.sub.SeNB_MAX such
that the total of the P.sub.MeNB_MAX and the P.sub.SeNB_MAX does
not exceed the P.sub.UE_MAX is referred to as first hard split, and
a case where the transmit power of the terminal device 1 is
adjusted using the parameter such as the scaling factor such that
the total of the P.sub.MeNB_MAX and the P.sub.SeNB_MAX is equal to
or less than the P.sub.UE_MAX in a case where the total of the
P.sub.MeNB_MAX and the P.sub.SeNB_MAX exceeds the P.sub.UE_MAX is
referred to as second hard split.
[0818] In a certain timing, in a case where the P.sub.SeNB_MAX is
not set, a case where the P.sub.MeNB_MAX and the P.sub.SeNB_MAX are
not set, or a case where only the P.sub.UE_MAX is set, the transmit
power set to the uplink transmission to the MeNB and the transmit
power set to the uplink transmission to the SeNB may be shared. In
a certain timing, the total of the P.sub.MeNB and the P.sub.SeNB is
controlled so as not to exceed the P.sub.UE_MAX. In a certain
timing, in a case where the total of the P.sub.MeNB and the
P.sub.SeNB exceeds the P.sub.UE_MAX, the total may be controlled so
as not to exceed the P.sub.UE_MAX by using the scaling factor. The
P.sub.SeNB_MAX may be used as P.sub.UE_MAX-P.sub.MeNB such that the
total of the P.sub.MeNB and the P.sub.SeNB does not exceed the
P.sub.UE_MAX. That is, the P.sub.SeNB_MAX is set in consideration
of the P.sub.MeNB. In this case, the P.sub.MeNB may be the
P.sub.UE_MAX. As stated above, a case where the transmit power for
the MeNB and the transmit power for the SeNB are shared is referred
to as power sharing (first power sharing). Here, the timing may be
defined a subframe. The timing may be defined by a symbol. The
timing may be defined by a time or a period. The timing may be
defined by an instant.
[0819] In a certain timing, in a case where the P.sub.SeNB_MAX is
not set and a case where the P.sub.MeNB_MAX is set by the terminal
device 1 and the parameter (or the value of the parameter) set
through the higher layer signalling, that is, in a case where only
the P.sub.MeNB_MAX is configured by the terminal device 1 by using
the higher layer parameter, the transmit power set to the uplink
transmission to the MeNB and the transmit power set to the uplink
transmission to the SeNB may be shared. In a certain timing, in the
case of only the uplink transmission to the MeNB, the maximum value
of the transmit power set by the terminal device 1 is the
P.sub.MeNB_MAX. In this case, the P.sub.MeNB_MAX may be the
P.sub.UE_MAX. In a certain timing, in the case of only the uplink
transmission to the SeNB, the maximum value of the transmit power
set by the terminal device 1 may be the P.sub.MeNB_MAX. That is, in
a case where the uplink transmission to the MeNB and the uplink
transmission to the SeNB overlap, the terminal device 1 sets such
that the transmit power of the uplink transmission to the SeNB does
not exceed the P.sub.MeNB_MAX. In a certain timing, the total of
the transmit powers configured for one or more cells belonging to
the MCG is set so as not to exceed the P.sub.MeNB_MAX. In a certain
timing, in a case where the uplink transmission to the MeNB and the
uplink transmission to the SeNB overlap, the transmit power
P.sub.MeNB required in the uplink transmission to the MeNB is
initially determined, and then the maximum value of the transmit
power in the uplink transmission to the SeNB is determined. That
is, in a case where the P.sub.MeNB exceeds the P.sub.MeNB_MAX, the
terminal device 1 is not able to perform the uplink transmission to
the SeNB.
[0820] In a certain timing, in a case where the P.sub.SeNB_MAX is
not set and a case where the P.sub.UE_MAX and the P.sub.MeNB_MAX
are set using the higher layer parameter (however, the
P.sub.MeNB_MAX.ltoreq.P.sub.UE_MAX), the transmit power set to the
uplink transmission to the MeNB and the transmit power set to the
uplink transmission to the SeNB may be shared. In a certain timing,
in the case of only the uplink transmission to the MeNB, the
maximum value of the transmit power set by the terminal device 1
may be the P.sub.UE_MAX. In a certain timing, in the case of only
the uplink transmission to the MeNB, the maximum value of the
transmit power set by the terminal device 1 may be the
P.sub.MeNB_MAX. In a certain timing, in the case of only the uplink
transmission to the MeNB, the maximum value of the transmit power
set by the terminal device 1 may be less than the P.sub.UE_MAX and
the P.sub.MeNB_MAX. In a certain timing, in the case of only the
uplink transmission to the SeNB, the maximum value of the transmit
power set by the terminal device 1 is the P.sub.UE_MAX. In a
certain timing, in a case where the uplink transmission to the MeNB
and the uplink transmission to the SeNB overlap, the maximum value
of the transmit power in the uplink transmission to the SeNB is the
P.sub.UE_MAX-P.sub.MeNB_MAX. In this case, in a case where the
P.sub.MeNB_MAX is the P.sub.UE_MAX the same value as the
P.sub.UE_MAX, or a value which exceeds the P.sub.UE_MAX, the
terminal device 1 is not able to perform the uplink transmission to
the SeNB. The uplink transmission to the SeNB may be performed in a
case where P.sub.UE_MAX-P.sub.MeNB_MAX>0. That is, in a case
where P.sub.UE_MAX-P.sub.MeNB_MAX>0, the terminal device 1 sets
the transmit power in the uplink transmission to the SeNB. In a
certain timing, the total of the transmit powers configured for one
or more cells belonging to the MCG is set so as not to exceed the
P.sub.UE_MAX. In a certain timing, the total of the transmit powers
configured for one or more cells belonging to the MCG is set so as
not to exceed the P.sub.MeNB_MAX.
[0821] In other words, in a case where the serving cell group is
the MCG (serving cell group corresponding to the MeNB), the
terminal device 1 sets the threshold (maximum output power of each
serving cell group) to be P.sub.CMAX which is the maximum output
power (maximum value of the total output power for all the serving
cell groups) of the terminal device 1. Alternatively, the threshold
is set to be a value (maximum output power value of the MCG
configured by the higher layer) configured by the message of the
higher layer such as the RRC message. Meanwhile, in a case where
the serving cell group is the SCG (serving cell group corresponding
to the SeNB), the threshold (maximum output power of each serving
cell group) is set to be a value calculated by subtracting an
actual transmit power used in the uplink transmission in the MCG
from the P.sub.CMAX. Here, it is preferable that as the actual
transmit power used in the uplink transmission in the MCG, a
transmit power value in a subframe having a large transmit power
value, among two subframes overlapping with the subframes in the
SCG is used. The terminal device 1 scales the transmit power for
the PUSCH in each of the serving cells within the serving cell
group depending on whether or not the total transmit power value
exceeds these thresholds. More specifically, in a case where the
total transmit power value of the serving cell group exceeds the
threshold, the terminal device performs the scaling (negative
adjustment of power) by using the scaling factor that satisfies a
condition in which the total value of the values acquired by
multiplying the power of the PUSCH in each serving cell is equal to
or less than a value acquired by subtracting the power of the PUCCH
from the threshold. Meanwhile, in a case where the total transmit
power value does not exceed the threshold, the scaling may not be
performed.
[0822] The terminal device 1 may determine whether to perform the
uplink power control through the hard split (using the maximum
output power value configured instead of the P.sub.CMAX in each
serving cell group) or the power sharing (using the maximum output
power value calculated in consideration of the transmit power value
in another serving cell group instead of the P.sub.CMAX in each
serving cell group) in the uplink transmission to the MeNB and the
uplink transmission to the SeNB, in a certain timing, depending on
whether or not only the P.sub.UE_MAX, only the P.sub.MeNB_MAX the
P.sub.SeNB_MAX or the P.sub.MeNB MAX and the P.sub.SeNB_MAX is set
(or whether or not the base station apparatus 3 configures the
terminal device 1).
[0823] In a case where only the P.sub.UE_MAX is set, the
P.sub.SeNB_MAX is not set, or the P.sub.MeNB_MAX and the
P.sub.SeNB_MAX are not set, the terminal device 1 performs the
uplink power control through the power sharing in the uplink
transmission to the MeNB and the uplink transmission to the SeNB in
a certain timing.
[0824] In a case where the P.sub.SeNB_MAX is set or the
P.sub.MeNB_MAX and the P.sub.SeNB_MAX are set, the terminal device
1 performs the uplink power control through the hard split in the
uplink transmission to the MeNB and the uplink transmission to the
SeNB in a certain timing.
[0825] Here, a case where the P.sub.MeNB_MAX is not set includes a
case where the P.sub.MeNB_MAX is set using the higher layer
parameter (for example, P-Max or power class). A case where the
P.sub.MeNB_MAX is not set includes a case where the P.sub.MeNB_MAX
is not set as the higher layer parameter.
[0826] Here, a case where the P.sub.SeNB_MAX is not set includes a
case where the P.sub.SeNB_MAX is set using the higher layer
parameter (for example, P-Max or power class). A case where the
P.sub.SeNB_MAX is not set includes a case where the P.sub.SeNB_MAX
is not set as the higher layer parameter.
[0827] In a case where the uplink transmission to the SeNB or the
SCG in a subframe j occurs, if the subframe j for the SeNB or the
SCG overlaps with a subframe i-1 and a subframe i for the MeNB or
the MCG, a transmit power P.sub.SeNB(j) of the uplink transmission
in the subframe j of the SeNB or the SCG is set in consideration of
transmit powers P.sub.SeNB(i-1) and P.sub.SeNB(i) set to the uplink
transmission in any one of the subframe i-1 and the subframe i for
the MeNB or the MCG. In this case, the terminal device 1 may set
the P.sub.SeNB(j) in consideration of a higher one of the
P.sub.MeNB(i-1) and the P.sub.MeNB(i). In this case, the terminal
device 1 may set the P.sub.SeNB in consideration of only the
P.sub.MeNB(i-1). If the uplink transmission is not performed in the
subframe i-1 for the MeNB or the MCG, that is, if the
P.sub.MeNB(i-1)=0, the terminal device 1 may set the P.sub.SeNB(j)
in consideration of the P.sub.MeNB(i). Here, a case where a first
transmit power is set in consideration of a second transmit power
includes a case where the second transmit power is not reduced (in
other words, the second transmit power is previously obtained) and
the first transmit power is set.
[0828] In a case where the uplink transmission to the SeNB or the
SCG in the subframe j occurs, if the subframe j for the SeNB or the
SCG overlaps with the subframe i and the subframe i+1 for the MeNB
or the MCG, the transmit power P.sub.SeNB(j) of the uplink
transmission in the subframe j of the SeNB or the SCG is set in
consideration of transmit powers P.sub.MeNB(i) and P.sub.MeNB(i+1)
set to the uplink transmission in any one of the subframe i and the
subframe i+1 for the MeNB or the MCG. In this case, the terminal
device 1 may set the P.sub.SeNB in consideration of a higher one of
the P.sub.MeNB(i) and the P.sub.MeNB(i+1). The terminal device may
set the P.sub.SeNB(j) in consideration of at least the
P.sub.MeNB(i). If the uplink transmission is not performed in the
subframe i for the MeNB or the MCG, that is if the P.sub.MeNB(i)=0,
the terminal device 1 may set the P.sub.SeNB(j) in consideration of
the P.sub.MeNB(i+1).
[0829] In a case where the uplink transmission to the MeNB or the
MCG in the subframe i occurs, if the subframe i for the MeNB or the
MCG overlaps with the subframe j-1 and the subframe j for the SeNB
or the SCG, the transmit power P.sub.MeNB(i) of the uplink
transmission in the subframe i of the MeNB or the MCG may be set in
consideration of the transmit powers P.sub.SeNB(j-1) and
P.sub.SeNB(j) set to the uplink transmission in any one of the
subframe j-1 and the subframe j for the SeNB or the SCG. For
example, in a case where the transmission of the PRACH format 4
allocated to the UpPTS and/or the PUCCH and/or the PUSCH
accompanying by the UCI is included in the subframe j-1 for the
SeNB or the SCG, if the uplink transmission in the subframe j of
the MeNB or the MCG is the transmission of the PUSCH which does not
accompany by the SRS or the UCI, the terminal device 1 may
initially set the P.sub.MeNB(i) in consideration of the
P.sub.SeNB(j-1) and/or the P.sub.SeNB(j).
[0830] In a case where the uplink transmission to the MeNB or the
MCG in the subframe i occurs, if the subframe i for the MeNB or the
MCG overlaps with the subframe j and the subframe j+1 for the SeNB
or the SCG, the transmit power P.sub.MeNB(i) of the uplink
transmission in the subframe i of the MeNB or the MCG may be set in
consideration of the transmit powers P.sub.SeNB(j) and
P.sub.SeNB(j+1) set to the uplink transmission in any one of the
subframe j and the subframe j+1 for the SeNB or the SCG. For
example, in a case where the transmission of the PRACH format 4
allocated to the UpPTS and/or the PUCCH and/or the PRACH and/or the
PUSCH accompanying by the UCI is included in the subframe j or the
subframe j+1 for the SeNB or the SCG, if the uplink transmission in
the subframe i of the MeNB or the MCG is the transmission of only
the SRS, only the PUSCH which does not accompany by the UCI, or the
PUSCH which does not accompany by the UCI, and the SRS, the
terminal device 1 may initially set the P.sub.MeNB(i) in
consideration of the P.sub.SeNB(j) and/or the P.sub.SeNB(j+l).
Here, in a case where the minimum output value (lowest output
value) of the P.sub.MeNB(i) is not satisfied in consideration of
the P.sub.SeNB(j) and/or the P.sub.SeNB(j+1), the terminal device 1
may not perform the uplink transmission for the MeNB or the
MCG.
[0831] The transmit powers set to the uplink transmission in
subframes (subframes i-1, i and i+1) of another serving cell may be
set in consideration of the type of uplink signal transmission in a
subframe i of a certain serving cell.
[0832] In a case where the frame structure type (FDD or TDD) is
configured using the system information (for example, SIB1) or the
higher layer signalling in the first cell group (first CG) or all
the cells belonging to the first cell group, whereas the TDD UL-DL
configuration is set using the L1 signalling (DCI format, or
PDCCH/EPDCCH) and the system information (or higher layer
signalling) in the second cell group (second CG) or at least one
cell belonging to the second cell group, the set of subframes in
which the uplink power control is performed through the hard split
and the set of subframes in which the uplink power control is
performed through t the power sharing may be defined depending on
the condition (status or state). The set of subframes may be
referred to as a subframe set, or may be referred to as a subframe
subset. The set of subframes may include one subframe. The set of
subframes may include a plurality of subframes.
[0833] If the uplink subframe for the first CG and the uplink
subframe for the second CG are the uplink subframes indicated by
the TDD UL-DL configuration and the frame structure type configured
using the system information, in the subframe i, the subframe i
belongs to a first subframe set. If the uplink subframe for the
first CG and the uplink subframe for the second CG are the uplink
subframe indicated by the TDD UL-DL configuration and the frame
structure type configured using the system information and the
uplink subframe indicated by the TDD UL-DL configured using the L1
signalling in the subframe n, the subframe n belongs to a second
subframe set. That is, the uplink subframe belonging to the first
subframe set is the uplink subframe configured using the system
information both in the first CG and the second CG. The uplink
subframe belonging to the first subframe set is the uplink subframe
configured using the system information (or higher layer
signalling) in the first CG, and is the uplink subframe configured
through the L1 signalling in the second CG.
[0834] In a case where the uplink transmission to the first CG and
the uplink transmission to the second CG occur in the first
subframe set, the terminal device 1 performs the uplink power
control through the hard split, and sets the transmit power of the
terminal device 1 in the uplink transmission to the first CG and
the transmit power of the terminal device 1 in the uplink
transmission to the second CG.
[0835] In a case where the uplink transmission to the first CG and
the uplink transmission to the second CG occur in the second
subframe set, the terminal device 1 performs the uplink power
control through the power sharing, and sets the transmit power of
the terminal device 1 in the uplink transmission to the first CG
and the transmit power of the terminal device 1 in the uplink
transmission to the second CG. In this case, after the transmit
power of the terminal device 1 in the uplink transmission to the
first CG is preferentially obtained, the transmit power of the
terminal device 1 in the uplink transmission to the second CG may
be set.
[0836] Hereinafter, the procedure of assigning the maximum output
power to each CG will be described.
[0837] Initially, the terminal device 1 calculates a transmit power
P.sub.req_MCG required for the uplink transmission of the MCG and a
transmit power P.sub.req_SCG required for the uplink transmission
of the SCG in a certain timing. For example, in a case where the
transmit power of the uplink transmission in the subframe j of the
SCG is calculated, the terminal device 1 calculates a transmit
power P.sub.req_SCG required in the uplink transmission in the
subframe j of the SCG and a transmit power P.sub.req_MCG required
in the uplink transmission of the subframe i of the SCG overlapping
with the uplink transmission of the subframe j of the SCG. The
transmit power P.sub.req_SCG required in the uplink transmission in
the subframe j of the SCG is calculated based on the TPC command or
the information of the PUSCH indicating the uplink transmission by
the uplink grant/uplink assignment. Meanwhile, as a reservation
power for guaranteeing the transmit power in the subframe i of the
MeNB or the MCG, X is configured for the transmit power
P.sub.req_MCG required in the uplink transmission in the subframe i
of the MCG. Here, as the P.sub.req_MCG, the transmit power in the
subframe i-1 of the MeNB or the MCG which overlaps with the
subframe j of the SeNB or the SCG and in which the uplink
transmission is started earlier than the uplink transmission in the
subframe j of the SeNB or the SCG may be taken into consideration.
In this case, the P.sub.req_MCG is, for example, the maximum value
of the reservation power X for guaranteeing the transmit power in
the subframe i of the MeNB or the MCG and the transmit power in the
subframe i-1 of the MeNB or the MCG. That is, the P.sub.req_MCG is
max(P.sub.MeNB(i-1), X). Here, in a case where the transmit power
in the subframe i of the MeNB or the MCG is able to be calculated,
the transmit power in the subframe i of the MeNB or the MCG may be
considered as the P.sub.req_MCG. In this case, the P.sub.req_MCG
is, for example, the maximum value between the transmit power in
the subframe i-1 of the MeNB or the MCG and the transmit power in
the subframe i-1 of the MCG. That is, the P.sub.req_MCG is
max(P.sub.MeNB(i-1), P.sub.MeNB(i)). The same is true of the case
where the transmit power of the uplink transmission in the subframe
i of the MCG is calculated.
[0838] Thereafter, in a case where the total of the P.sub.req_MCG
and the P.sub.req_SCG does not exceed the P.sub.UE_MAX, the
transmit power P.sub.req_MCG required in the uplink transmission of
the MCG is applied as the transmit power P.sub.MeNB
(P.sub.alloc_MCG) set to the uplink transmission for the MeNB, and
the transmit power P.sub.req_SCG required in the uplink
transmission of the SCG is applied as the transmit power P.sub.SeNB
(P.sub.alloc_SCG) set to the uplink transmission for the SeNB.
[0839] Meanwhile, in a case where the total of the P.sub.req_MCG
and the P.sub.req_SCG exceeds the P.sub.UE_MAX, the terminal device
1 calculates the maximum output power P.sub.MeNB_MAX
(P.sub.alloc_MCG) for the MeNB or the maximum transmit power
P.sub.SeNB_MAX (P.sub.alloc_SCG) for the SeNB.
[0840] The transmit power P.sub.MeNB_guar minimally guaranteed in
the MCG and the transmit power P.sub.SeNB_guar minimally guaranteed
in the SCG are configured for the terminal device 1. The total of
the transmit power P.sub.MeNB_guar minimally guaranteed in the MCG
and the transmit power P.sub.SeNB_guar minimally guaranteed in the
SCG is configured so as not to exceed the P.sub.UE_MAX. The
P.sub.MeNB_guar and the P.sub.SeNB_guar may be configured from the
higher layer. The values of the P.sub.MeNB_guar and the
P.sub.SeNB_guar may be individually configured depending on the
type of the uplink physical channel. For example, in a case where
the PUCCH is transmitted and in a case where the PUSCH is
transmitted, different values of the P.sub.MeNB_guar and the
P.sub.SeNB_guar may be applied. Zero may be configured for the
P.sub.MeNB_guar and the P.sub.SeNB_guar.
[0841] In a case where the P.sub.req_MCG is less than the
P.sub.MeNB_guar (P.sub.req_MCG<P.sub.MeNB_guar), the minimum
guaranteed power is assigned to the MCG. For example, the terminal
device 1 sets the P.sub.req_MCG to the P.sub.MeNB_MAX, and sets a
difference (P.sub.UE_MAX-P.sub.req_MCG) between the P.sub.UE_MAX
and the P.sub.req_MCG to the P.sub.SeNB_MAX. In a case where the
P.sub.req_SCG is less than the P.sub.SeNB_guar
(P.sub.req_SCG<P.sub.SeNB_guar), the minimum guaranteed power is
assigned to the SCG. For example, the terminal device 1 sets the
P.sub.req_SCG to the P.sub.SeNB_MAX, and sets a difference
(P.sub.UE_MAX-P.sub.req_MCG) between the P.sub.UE_MAX and the
P.sub.req_MCG to the P.sub.MeNB_MAX. In a case where the
P.sub.req_MCG is greater than the P.sub.MeNB_guar
(P.sub.req_MCG>P.sub.MeNB_guar) and the P.sub.req_SCG is greater
than the P.sub.SeNB_guar (P.sub.req_SCG>P.sub.SeNB_guar), a lot
of power is assigned to the high-priority CG. For example, in a
case where the priority of the MCG is greater than that of the SCG,
the terminal device 1 sets a difference
(P.sub.UE_MAX-P.sub.req_SCG) between the P.sub.UE_MAX and the
P.sub.req_SCG to the P.sub.MeNB_MAX, and sets the P.sub.req_SCG to
the P.sub.SeNB_MAX. For example, in a case where the priority of
the SCG is greater than that of the MCG, the terminal device 1 sets
a difference (P.sub.UE_MAX-P.sub.req_MCG) between the P.sub.UE_MAX
and the P.sub.req_MCG to the P.sub.SeNB_MAX and sets the
P.sub.req_MCG to the P.sub.MeNB_MAX.
[0842] That is, in a case where the total of the P.sub.req_MCG and
the P.sub.req_SCG exceeds the P.sub.UE_MAX, the transmit powers
P.sub.MeNB_guar and the P.sub.SeNB_guar minimally guaranteed in the
MCG and the SCG are assigned, and a surplus power is allocated
depending on the priority.
[0843] The CG having a high priority is determined depending on the
type of the transmitted uplink channel or uplink reference signal.
For example, in the case of the CG in which the PUCCH is
transmitted and the CG in which the PUSCH is transmitted, the CG in
which the PUCCH is transmitted is prioritized. For example, in the
case of the CG in which the PRACH is transmitted and the CG in
which the SRS is transmitted, the CG in which the PUCCH is
transmitted is prioritized. The CG having a high priority is
determined depending on the type of the transmitted information.
For example, in the case of the CG in which the UCI is transmitted
and the CG in which the UCI is not transmitted, the CG in which the
UCI is transmitted is prioritized. If the types of the uplink
channel and the information are the same, the MCG or the PCell may
be prioritized.
[0844] The transmit power (output power) of the uplink transmission
is determined in a subframe from the subframe in which the uplink
grant is received to the subframe in which the uplink transmission
is performed. For example, in the case of the FDD, the transmit
power is calculated by the terminal device 1 within 4 subframes
from the subframe in which the uplink grant is received to the
subframe in which the PUSCH is transmitted.
[0845] In order to guarantee the transmit power of the MeNB or the
MCG, the maximum output power P.sub.SeNB_MAX for the SeNB or the
SCG is restricted. If the uplink transmission of the overlapped
MeNB or MCG is previously recognized, the terminal device 1 may
restrict the maximum output power P.sub.SeNB_MAX for the SeNB or
the SCG before the output power for the SeNB or the SCG is
determined, and may ensure the transmit power assigned to the MeNB
or the MCG. As stated above, power sharing for ensuring the
transmit power assigned to the MeNB or the MCG is referred to as
second power sharing.
[0846] An example in which the maximum output power P.sub.MeNB_MAX
for the MeNB and the maximum output power P.sub.SeNB_MAX for the
SeNB are determined is illustrated.
[0847] The transmit power of the uplink transmission in the
subframe i of the MeNB or the MCG is determined in consideration of
the transmit power P.sub.req_SCG required in the uplink
transmission of the SeNB or the SCG overlapping with the subframe i
of the MeNB or the MCG.
[0848] Specifically, the transmit power of the uplink transmission
in the subframe i of the MeNB or the MCG is determined in
consideration of the transmit power in the subframe j-1 of the SeNB
or the SCG which overlaps with the subframe i of the MeNB or the
MCG and in which the uplink transmission is started earlier than
the uplink transmission in the subframe i of the MeNB or the MCG
(first power sharing). For example, the P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
transmit power P.sub.SeNB(j-1) in the subframe j-1 of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-P.sub.SeNB(j-1).
[0849] In a case where the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the MCG is
less than the minimum guaranteed power P.sub.MeNB_guar of the MCG,
the P.sub.MeNB_MAX is the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the
MCG.
[0850] The transmit power of the uplink transmission in the
subframe j of the SeNB or the SCG is determined in consideration of
the transmit power P.sub.req_MCG required in the uplink
transmission of the MeNB or the MCG overlapping with the subframe j
of the SeNB or the SCG. The calculation of the transmit power of
the uplink transmission in the subframe j of the SeNB or the SCG is
switched depending on whether or not the terminal device 1 is able
to recognize (predict) that the uplink transmission in the subframe
i of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is instructed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is
determined.
[0851] Specifically, in a case where the terminal device 1 is not
able to recognize (predict) that the uplink transmission in the
subframe i of the MeNB or the MCG which overlaps with the subframe
j of the SeNB or the SCG and in which the uplink transmission is
started later than the uplink transmission in the subframe j of the
SeNB or the SCG is not instructed before the transmit power of the
uplink transmission in the subframe j of the SeNB or the SCG is
determined or the uplink transmission is performed, the transmit
power of the uplink transmission in the subframe j of the SeNB or
the SCG is determined in consideration of the transmit power of the
subframe i-1 of the MeNB or the MCG which overlaps with the
subframe j of the SeNB or the SCG and in which the uplink
transmission is started earlier than the uplink transmission in the
subframe j of the SeNB or the SCG (first power sharing). For
example, the P.sub.SeNB_MAX applied in the subframe j of the SeNB
or the SCG is a difference between the maximum output power
P.sub.UE_MAX of the terminal device 1 and the transmit power
P.sub.MeNB(i-1) in the subframe 1 of the MeNB or the MCG. That is,
the P.sub.SeNB_MAX is P.sub.UE_MAX-P.sub.MeNB(i-1).
[0852] In a case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG which overlaps with the subframe j of the SeNB or
the SCG and in which the uplink transmission is started later than
the uplink transmission in the subframe j of the SeNB or the SCG is
instructed before the transmit power of the uplink transmission in
the subframe j of the SeNB or the SCG is determined, the transmit
power of the uplink transmission in the subframe j of the SeNB or
the SCG is determined in consideration of the transmit power in the
subframe i-1 and the subframe i of the MeNB or the MCG (second
power sharing). The P.sub.SeNB_MAX applied in the subframe j of the
SeNB or the SCG is a difference between the maximum output power
P.sub.UE_MAX of the terminal device 1 and the maximum value between
the transmit power P.sub.MeNB(i-1) in the subframe i-1 of the MeNB
or the MCG and the transmit power P.sub.MeNB(i) in the subframe i
of the MeNB or the MCG. That is, the P.sub.SeNB_MAX is
P.sub.UE_MAX-max(P.sub.MeNB(i-1), P.sub.MeNB(i)). In other words,
the P.sub.SeNB_MAX is min(P.sub.UE_MAX-P.sub.MeNB(i-1),
P.sub.UE_MAX-P.sub.MeNB(i)).
[0853] In a case where the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the SCG is
less than the minimum guaranteed power P.sub.SeNB_guar of the SCG,
the P.sub.SeNB_MAX is the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the
SCG.
[0854] The calculating order of the transmit power of the uplink
transmission in the terminal device 1 will be described. In the
first power sharing, the terminal device 1 calculates the transmit
power in the starting order of the uplink transmission in
consideration of the transmit power of the overlapped subframe in
another CG. That is, the powers of the MCG and the SCG are
alternately calculated. Meanwhile, in the second power sharing, if
the terminal device 1 is able to previously recognize that the
uplink transmission is performed in the MeNB or the MCG, in order
to preferentially perform the uplink transmission of the MeNB or
the MCG, the terminal device firstly calculates the transmit power
of the uplink transmission of the MeNB or the MCG, and calculates
the transmit power of the uplink transmission of the SeNB or the
SCG in consideration of the transmit power of the uplink
transmission of the MeNB or the MCG.
[0855] That is, in a case where the terminal device 1 is not able
to recognize (predict) that the uplink transmission in the subframe
i of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is not instructed or the uplink transmission is performed
before the transmit power of the uplink transmission in the
subframe j of the SeNB or the SCG is determined, the terminal
device 1 determines the transmit power of the uplink transmission
in the subframe i-1 of the MeNB or the MCG based on the transmit
power of the uplink transmission in the subframe j-1 of the SeNB or
the SCG, and determines the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG based on the
transmit power of the uplink transmission in the subframe i-1 of
the MeNB or the MCG. In a case where the terminal device 1 is able
to recognize (predict) that the uplink transmission in the subframe
i of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is instructed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is
determined, the terminal device 1 determines the transmit power of
the uplink transmission in the subframe i-1 of the MeNB or the MCG
based on the transmit power of the uplink transmission in the
subframe j-1 of the SeNB or the SCG, determines the transmit power
of the uplink transmission in the subframe i of the MeNB or the
MCG, and determines the transmit power of the uplink transmission
in the subframe j of the SeNB or the SCG based on the transmit
power of the uplink transmission in the subframe i-1 and the
subframe i of the MeNB or the MCG.
[0856] In order to guarantee the transmit power in the subframe j
of the SeNB or the SCG, X' may be configured for the terminal
device 1, and the transmit power of the uplink transmission of the
MeNB or the MCG may be calculated. The P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
maximum value between the transmit power P.sub.SeNB(j-1) in the
subframe j-1 of the SeNB or the SCG and a reservation power X' for
guaranteeing the transmit power in the subframe j of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-max(P.sub.SeNB(j-1), X'). In other words, the
P.sub.MeNB_MAX is min(P.sub.UE_MAX-P.sub.SeNB(i-1),
P.sub.UE_MAX-X').
[0857] If the surplus power remains in the terminal device 1 after
the transmit power P.sub.SeNB(j) of the uplink transmission in the
subframe j of the SeNB or the SCG is determined, the P.sub.MeNB(i)
may be recalculated before the uplink transmission is performed in
the subframe i of the MeNB or the MCG, and the surplus power may be
distributed to the uplink transmission of the MeNB or the MCG.
[0858] An example in which the maximum output power P.sub.MeNB_MAX
for the MeNB and the maximum output power P.sub.SeNB_MAX for the
SeNB are determined is illustrated.
[0859] The transmit power of the uplink transmission in the
subframe i of the MeNB or the MCG is determined in consideration of
the transmit power P.sub.req_SCG required in the uplink
transmission of the SeNB or the SCG overlapping with the subframe i
of the MeNB or the MCG.
[0860] Specifically, the transmit power of the uplink transmission
in the subframe i of the MeNB or the MCG is determined in
consideration of the transmit power in the subframe j-1 of the SeNB
or the SCG which overlaps with the subframe i of the MeNB or the
MCG and in which the uplink transmission is started earlier than
the uplink transmission in the subframe i of the MeNB or the MCG
(first power sharing). For example, the P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
transmit power P.sub.SeNB(j-1) in the subframe j-1 of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-P.sub.SeNB(j-1).
[0861] In a case where the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the MCG is
less than the minimum guaranteed power P.sub.MeNB_guar of the MCG,
the P.sub.MeNB_MAX is the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the
MCG.
[0862] The transmit power of the uplink transmission in the
subframe j of the SeNB or the SCG is determined in consideration of
the transmit power P.sub.req_MCG required in the uplink
transmission of the MeNB or the MCG overlapping with the subframe j
of the SeNB or the SCG. The calculation of the transmit power of
the uplink transmission in the subframe j of the SeNB or the SCG is
switched depending on whether or not the terminal device 1 is able
to recognize (predict) that the uplink transmission in the subframe
i of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is instructed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is
determined.
[0863] Specifically, in a case where the terminal device 1 is not
able to recognize (predict) that the uplink transmission in the
subframe i of the MeNB or the MCG which overlaps with the subframe
j of the SeNB or the SCG and in which the uplink transmission is
started later than the uplink transmission in the subframe j of the
SeNB or the SCG is not instructed or the uplink transmission is
performed before the transmit power of the uplink transmission in
the subframe j of the SeNB or the SCG is determined, the transmit
power of the uplink transmission in the subframe j of the SeNB or
the SCG is determined in consideration of the transmit power in the
subframe i-1 and the subframe i of the MeNB or the MCG (second
power sharing). For example, in order to guarantee the transmit
power in the subframe i of the MeNB or the MCG, X is configured for
the terminal device 1. The P.sub.SeNB_MAX applied in the subframe j
of the SeNB or the SCG is a difference between the maximum output
power P.sub.UE_MAX of the terminal device 1 and the maximum value
between the transmit power P.sub.MeNB(i-1) in the subframe i-1 of
the MeNB or the MCG and the reservation power X for guaranteeing
the transmit power in the subframe i of the MeNB or the MCG. That
is, the P.sub.SeNB_MAX is P.sub.UE_MAX-max(P.sub.MeNB(i-1), X). In
other words, the P.sub.SeNB_MAX is
min(P.sub.UE_MAX-P.sub.MeNB(i-1), P.sub.UE_MAX-X).
[0864] In a case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG which overlaps with the subframe j of the SeNB or
the SCG and in which the uplink transmission is started later than
the uplink transmission in the subframe j of the SeNB or the SCG is
instructed before the transmit power of the uplink transmission in
the subframe j of the SeNB or the SCG is determined, the transmit
power of the uplink transmission in the subframe j of the SeNB or
the SCG is determined in consideration of the transmit power in the
subframe i-1 and the subframe i of the MeNB or the MCG (second
sharing). The P.sub.SeNB_MAX applied in the subframe j of the SeNB
or the SCG is a difference between the maximum output power
P.sub.UE_MAX of the terminal device 1 and the maximum value between
the transmit power P.sub.MeNB(i-1) in the subframe i-1 of the MeNB
or the MCG and the transmit power P.sub.MeNB(i) in the subframe i
of the MeNB or the MCG. That is, the P.sub.SeNB_MAX is
P.sub.UE_MAX-max(P.sub.MeNB(i-1), P.sub.MeNB(i)). In other words,
the P.sub.SeNB_MAX is min(P.sub.UE_MAX-P.sub.MeNB(i-1),
P.sub.UE_MAX-P.sub.MeNB(i)).
[0865] In a case where the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the SCG is
less than the minimum guaranteed power P.sub.SeNB_guar of the SCG,
the P.sub.SeNB_MAX is the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the
SCG.
[0866] An example in which the maximum output power P.sub.MeNB_MAX
for the MeNB and the maximum output power P.sub.SeNB_MAX for the
SeNB are determined is illustrated.
[0867] The transmit power of the uplink transmission in the
subframe i of the MeNB or the MCG is determined in consideration of
the transmit power P.sub.req_SCG required in the uplink
transmission of the SeNB or the SCG overlapping with the subframe i
of the MeNB or the MCG.
[0868] Specifically, the transmit power of the uplink transmission
in the subframe i of the MeNB or the MCG is determined in
consideration of the transmit power in the subframe j-1 of the SeNB
or the SCG which overlaps with the subframe i of the MeNB or the
MCG and in which the uplink transmission is started earlier than
the uplink transmission in the subframe i of the MeNB or the MCG
(first power sharing). For example, the P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
transmit power P.sub.SeNB(j-1) in the subframe j-1 of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-P.sub.SeNB(j-1).
[0869] In a case where the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the MCG is
less than the minimum guaranteed power P.sub.MeNB_guar of the MCG,
the P.sub.MeNB_MAX is the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the
MCG.
[0870] The transmit power of the uplink transmission in the
subframe j of the SeNB or the SCG is determined in consideration of
the transmit power P.sub.req_MCG required in the uplink
transmission of the MeNB or the MCG overlapping with the subframe j
of the SeNB or the SCG. The calculation of the transmit power of
the uplink transmission in the subframe j of the SeNB or the SCG is
switched depending on whether or not the terminal device 1 is able
to recognize (predict) that the uplink transmission in the subframe
i of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is instructed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is
determined.
[0871] Specifically, in a case where the terminal device 1 is not
able to recognize (predict) that the uplink transmission in the
subframe i of the MeNB or the MCG which overlaps with the subframe
j of the SeNB or the SCG and in which the uplink transmission is
started later than the uplink transmission in the subframe j of the
SeNB or the SCG is not instructed before the transmit power of the
uplink transmission in the subframe j of the SeNB or the SCG is
determined or the uplink transmission is performed, the transmit
power of the uplink transmission in the subframe j of the SeNB or
the SCG is determined in consideration of the transmit power of the
subframe i-1 of the MeNB or the MCG which overlaps with the
subframe j of the SeNB or the SCG and in which the uplink
transmission is started earlier than the uplink transmission in the
subframe j of the SeNB or the SCG (first power sharing). For
example, the P.sub.SeNB_MAX applied in the subframe j of the SeNB
or the SCG is a difference between the maximum output power
P.sub.UE_MAX of the terminal device 1 and the transmit power
P.sub.MeNB(i-1) in the subframe i-1 of the MeNB or the MCG. That
is, the P.sub.SeNB_MAX is P.sub.UE_MAX-P.sub.MeNB(i-1).
[0872] In a case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG which overlaps with the subframe j of the SeNB or
the SCG and in which the uplink transmission is started later than
the uplink transmission in the subframe j of the SeNB or the SCG is
instructed before the transmit power of the uplink transmission in
the subframe j of the SeNB or the SCG is determined, the transmit
power of the uplink transmission in the subframe j of the SeNB or
the SCG is determined in consideration of the transmit power in the
subframe i-1 and the subframe i of the MeNB or the MCG (second
sharing). For example, in order to guarantee the transmit power in
the subframe i of the MeNB or the MCG, X is configured for the
terminal device 1. The P.sub.SeNB_MAX applied in the subframe j of
the SeNB or the SCG is a difference between the maximum output
power P.sub.UE_MAX of the terminal device 1 and the maximum value
between the transmit power P.sub.MeNB(i-1) in the subframe i-1 of
the MeNB or the MCG and the reservation power X for guaranteeing
the transmit power in the subframe i of the MeNB or the MCG. That
is, the P.sub.SeNB_MAX is P.sub.UE_MAX-max(P.sub.MeNB(i-1), X). In
other words, the P.sub.SeNB_MAX is min
(P.sub.UE_MAX-P.sub.MeNB(i-1), P.sub.UE_MAX-X).
[0873] In a case where the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the SCG is
less than the minimum guaranteed power P.sub.SeNB_guar of the SCG,
the P.sub.SeNB_MAX is the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the
SCG.
[0874] In this case, in order to restrict the maximum output power
of the SeNB or the SCG such that the transmit power of the uplink
transmission of the MeNB or the MCG is able to be ensured, the
terminal device 1 calculates the transmit power in the starting
order of the uplink transmission in consideration of the transmit
power of the overlapped subframe in another CG. That is, in both of
the first power sharing and the second power sharing, the transmit
powers in the uplink are calculated in the MCG and the SCG. The
maximum output power of the SeNB or the SCG is determined without
previously calculating the transmit power of the uplink
transmission of the MeNB or the MCG.
[0875] In order to guarantee the transmit power in the subframe j
of the SeNB or the SCG, X' may be configured for the terminal
device 1, and the transmit power of the uplink transmission of the
MeNB or the MCG may be calculated. The P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
maximum value between the transmit power P.sub.SeNB(j-1) in the
subframe j-1 of the SeNB or the SCG and a reservation power X' for
guaranteeing the transmit power in the subframe j of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-max(P.sub.SeNB(j-1), X'). In other words, the
P.sub.MeNB_MAX is min(P.sub.UE_MAX-P.sub.SeNB(i-1),
P.sub.UE_MAX-X').
[0876] An example in which the maximum output power P.sub.MeNB_MAX
for the MeNB and the maximum output power P.sub.SeNB_MAX for the
SeNB are determined is illustrated.
[0877] The transmit power of the uplink transmission in the
subframe i of the MeNB or the MCG is determined in consideration of
the transmit power P.sub.req_SCG required in the uplink
transmission of the SeNB or the SCG overlapping with the subframe i
of the MeNB or the MCG.
[0878] Specifically, the transmit power of the uplink transmission
in the subframe i of the MeNB or the MCG is determined in
consideration of the transmit power in the subframe j-1 of the SeNB
or the SCG which overlaps with the subframe i of the MeNB or the
MCG and in which the uplink transmission is started earlier than
the uplink transmission in the subframe i of the MeNB or the MCG
(first power sharing). For example, the P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
transmit power P.sub.SeNB(j-1) in the subframe j-1 of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-P.sub.SeNB(j-1).
[0879] In a case where the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the MCG is
less than the minimum guaranteed power P.sub.MeNB_guar of the MCG,
the P.sub.MeNB_MAX is the transmit power P.sub.req_MCG required in
the uplink transmission in the subframe i of the MeNB or the
MCG.
[0880] The transmit power of the uplink transmission in the
subframe j of the SeNB or the SCG is determined in consideration of
the transmit power in the subframe i-1 and the subframe i of the
MeNB or the MCG (second power sharing). For example, in order to
guarantee the transmit power in the subframe i of the MeNB or the
MCG, X is configured for the terminal device 1. The P.sub.SeNB_MAX
applied in the subframe j of the SeNB or the SCG is a difference
between the maximum output power P.sub.UE_MAX of the terminal
device 1 and the maximum value between the transmit power
P.sub.MeNB(i-1) in the subframe i-1 of the MeNB or the MCG and the
reservation power X for guaranteeing the transmit power in the
subframe i of the MeNB or the MCG. That is, the P.sub.SeNB_MAX is
P.sub.UE_MAX max(P.sub.MeNB(i-1), X). In other words, the
P.sub.SeNB_MAX is min(P.sub.UE_MAX-P.sub.MeNB(i-1),
P.sub.UE_MAX-X).
[0881] In a case where the terminal device 1 recognizes (predicts)
that the uplink transmission in the subframe i of the MeNB or the
MCG which overlaps with the subframe j of the SeNB or the SCG and
in which the uplink transmission is started later than the uplink
transmission in the subframe j of the SeNB or the SCG is not
instructed before the transmit power of the uplink transmission in
the subframe j of the SeNB or the SCG is determined, X is 0. In
this case, the same is true of the first power sharing.
[0882] In a case where the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the SCG is
less than the minimum guaranteed power P.sub.SeNB_guar of the SCG,
the P.sub.SeNB_MAX is the transmit power P.sub.req_SCG required in
the uplink transmission in the subframe j of the SeNB or the
SCG.
[0883] In order to guarantee the transmit power in the subframe j
of the SeNB or the SCG, X' may be configured for the terminal
device 1, and the transmit power of the uplink transmission of the
MeNB or the MCG may be calculated. The P.sub.MeNB_MAX applied in
the subframe i of the MeNB or the MCG is a difference between the
maximum output power P.sub.UE_MAX of the terminal device 1 and the
maximum value between the transmit power P.sub.SeNB(j-1) in the
subframe j-1 of the SeNB or the SCG and a reservation power X' for
guaranteeing the transmit power in the subframe j of the SeNB or
the SCG. That is, the P.sub.MeNB_MAX is
P.sub.UE_MAX-max(P.sub.SeNB(j-1), X'). In other words, the
P.sub.MeNB_MAX is min(P.sub.UE_MAX-P.sub.SeNB(i-1),
P.sub.UE_MAX-X').
[0884] In order to guarantee the transmit power P.sub.CGhigh of the
CG having a high priority, the maximum output power P.sub.CGlow_MAX
for the CG having a low priority is restricted.
[0885] An example in which the maximum output power
P.sub.CGhigh_MAX for the high-priority CG and the maximum output
power P.sub.CGlow_MAX for the low-priority CG are determined is
illustrated.
[0886] The transmit power of the uplink transmission in the
subframe j of the high-priority CG is determined in consideration
of the transmit power in the subframe i-1 of the low-priority CG
which overlaps with the subframe j of the high-priority CG and in
which the uplink transmission is started earlier than the uplink
transmission in the subframe j of the high-priority CG (first power
sharing). For example, the P.sub.CGhigh_MAX applied in the subframe
j of the high-priority CG is a difference between the maximum
output power P.sub.UE_MAX of the terminal device 1 and the transmit
power P.sub.CGlow(i-1) of the subframe i-1 of the low-priority CG.
That is, the P.sub.CGlow_MAX is P.sub.UE_MAX-P.sub.CGlow(i-1).
[0887] The transmit power of the uplink transmission in the
subframe i of the low-priority CG is determined in consideration of
the transmit power in the subframe j-1 of the high-priority CG
which overlaps with the subframe i of the low-priority CG and in
which the uplink transmission is started earlier than the uplink
transmission in the subframe i of the low-priority CG (first power
sharing). For example, the P.sub.CGlow_MAX applied in the subframe
i of the low-priority CG is a difference between the maximum output
power P.sub.UE_MAX of the terminal device 1 and the transmit power
P.sub.CGhigh(j-1) in the subframe j-1 of the high-priority CG. That
is, the P.sub.CGlow_MAX is P.sub.UE_MAX-P.sub.CGhigh(j-1).
[0888] Here, in a case where the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe j
of the high-priority CG which overlaps with the subframe i of the
low-priority CG and in which the uplink transmission is started
later than the uplink transmission in the subframe i of the
low-priority CG before the transmit power of the uplink
transmission in the subframe i of the low-priority CG is
determined, the transmit power is determined in consideration of
the transmit power in the subframe j-1 and the subframe j of the
high-priority CG (second power sharing). The P.sub.CGlow_MAX
applied in the subframe i of the low-priority CG is a difference
between the maximum output power P.sub.UE_MAX of the terminal
device 1 and the maximum value between the transmit power
P.sub.CGhigh(j-1) in the subframe j-1 of the high-priority CG and
the transmit power P.sub.CGhigh(j) in the subframe j of the
high-priority CG. That is, the P.sub.CGlow_MAX is the
P.sub.UE_MAX-max(P.sub.CGhigh(j-1), P.sub.CGhigh(j)).
[0889] An example in which the maximum output power
P.sub.CGhigh_MAX for the high-priority CG and the maximum output
power P.sub.CGlow_MAX for the low-priority CG are determined is
illustrated.
[0890] The transmit power of the uplink transmission in the
subframe j of the high-priority CG is determined in consideration
of the transmit power in the subframe i-1 of the low-priority CG
which overlaps with the subframe j of the high-priority CG and in
which the uplink transmission is started earlier than the uplink
transmission in the subframe j of the high-priority CG (first power
sharing). For example, the P.sub.CGhigh_MAX applied in the subframe
j of the high-priority CG is a difference between the maximum
output power P.sub.UE_MAX of the terminal device 1 and the transmit
power P.sub.CGlow(i-1) of the subframe i-1 of the low-priority CG.
That is, the P.sub.CGlow_MAX is P.sub.UE_MAX-P.sub.CGlow(i-1).
[0891] The transmit power of the uplink transmission in the
subframe i of the low-priority CG is determined in consideration of
the transmit power in the subframe j-1 of the high-priority CG
which overlaps with the subframe i of the low-priority CG and in
which the uplink transmission is started earlier than the uplink
transmission in the subframe i of the low-priority CG (first power
sharing). For example, the P.sub.CGlow_MAX applied in the subframe
i of the low-priority CG is a difference between the maximum output
power P.sub.UE_MAX of the terminal device 1 and the transmit power
P.sub.CGhiih(j-1) in the subframe j-1 of the high-priority CG. That
is, the P.sub.CGlow_MAX is P.sub.UE_MAX-P.sub.CGhigh(j-1).
[0892] Here, in a case where the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe j
of the high-priority CG which overlaps with the subframe i of the
low-priority CG and in which the uplink transmission is started
later than the uplink transmission in the subframe i of the
low-priority CG before the transmit power of the uplink
transmission in the subframe i of the low-priority CG is
determined, the transmit power is determined in consideration of
the transmit power in the subframe j-1 and the subframe j of the
high-priority CG (second power sharing). For example, in order to
guarantee the transmit power in the subframe j of the high-priority
CG, X is configured for the terminal device 1. The P.sub.CGlow_MAX
applied in the subframe i of the low-priority CG is a difference
between the maximum output power P.sub.UE_MAX of the terminal
device 1 and the maximum value between the transmit power
P.sub.CGhigh(j-1) in the subframe j-1 of the high-priority CG and
the reservation power X for guaranteeing the transmit power in the
subframe j of the high-priority CG. That is, the P.sub.CGlow_MAX is
the P.sub.UE_MAX-max(P.sub.CGhigh(j-1), X). In other words, the
P.sub.low_MAX is min(P.sub.UE_MAX-P.sub.CGhigh(i-1),
P.sub.UE_MAX-X).
[0893] An example in which the maximum output power
P.sub.CGhigh_MAX for the high-priority CG and the maximum output
power P.sub.CGlow_MAX for the low-priority CG are determined is
illustrated.
[0894] In a case where the transmit power P.sub.req_MCG required in
the uplink transmission of the MCG is greater than the minimum
guaranteed power P.sub.MeNB_guar of the MeNB or the MCG
(P.sub.req_MCG>P.sub.MeNB_guar) and the transmit power
P.sub.req_SCG required in the uplink transmission of the SCG is
greater than the minimum guaranteed power P.sub.SeNB_guar of the
SeNB or the SCG (P.sub.req_SCG>P.sub.SeNB_guar) a lot of power
is assigned to the high-priority CG. For example, the terminal
device 1 sets a difference (P.sub.UE_MAX-P.sub.req_CGlow) between
the maximum output power P.sub.UE_MAX of the terminal device 1 and
the minimum guaranteed power P.sub.req_SCG of the low-priority CG
to the P.sub.CGhigh_MAX, and sets the P.sub.req_CGlow to the
P.sub.CGlow_MAX.
[0895] The example in which the maximum output power P.sub.MeNB_MAX
for the MeNB and the maximum output power P.sub.SeNB_MAX for the
SeNB are determined is performed in a case where at least the total
of the transmit power P.sub.req_MCG required in the uplink
transmission of the MCG and the transmit power P.sub.req_SCG
required in the uplink transmission of the SCG exceeds the maximum
output power P.sub.UE_MAX of the terminal device 1. In a case where
the total of the transmit power P.sub.req_MCG required in the
uplink transmission of the MCG and the transmit power P.sub.req_SCG
required in the uplink transmission of the SCG does not exceed the
maximum output power P.sub.UE_MAX of the terminal device 1, the
maximum output power P.sub.MeNB_MAX for the MeNB and the maximum
output power P.sub.SeNB_MAX for the SeNB may not be determined.
[0896] Hereinafter, the details of the configuration of the
reservation power X for guaranteeing the transmit power of the
uplink transmission of the MeNB or the MCG is illustrated.
[0897] X may be configured by the higher layer parameter. X may be
included in the configuration information of the dual connectivity
and may be configured.
[0898] X may be previously configured.
[0899] X may be individually configured depending on the type of
the uplink channel or the uplink reference signal in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG. For example, the magnitude of the value of X may be
configured using difference values depending on the PRACH, PUCCH,
PUSCH and SRS. In this case, it is preferable that the magnitude of
the value of X is configured such that
PRACH>PUCCH>PUSCH>SRS. A different value may be configured
for X between the PUSCH which accompanies by the UCI and the PUSCH
which does not accompany by the UCI which are different types of
uplink channels in the subframe i of the MeNB or the MCG. In this
case, it is preferable that the magnitude of the value of X is
configured such that PUSCH which accompanies by UCI>PUSCH which
does not accompany by UCI. A different value may be configured for
X between the periodic SRS (trigger type 0 SRS) and the aperiodic
SRS (trigger type 1 SRS) which are different types of uplink
reference signals in the subframe i of the MeNB or the MCG.
[0900] X may be individually configured for the serving cell
belonging to the MeNB or the MCG. Specifically, different values of
X may be configured between the primary cell and the secondary cell
which belong to the MeNB or the MCG. In this case, it is preferable
that primary cell>secondary cell. In a case where the value of X
is individually configured for the serving cell, the value of X
configured for the serving cell in which the uplink transmission is
performed is applied. In a case where the uplink transmission is
performed in the plurality of serving cells, the value of X
configured for the serving cell of which the index of the serving
cell is the smallest. X may be individually configured depending on
the number of times the uplink transmission of the serving cell
belonging to the MeNB or the MCG is performed. Specifically, in a
case where at least one cell belonging to the MeNB or the MCG is
the TDD cell, X may be individually configured by the TDD UL/DL
configuration or the uplink reference UL/DL configuration. For
example, in the TDD cell for which the eIMTA is configured, the
value of X may be configured for each TDD UL/DL configuration that
is likely to be configured in the L1 signalling. In this case, it
is preferable that a larger value is configured for X as the number
of uplink subframes of the MeNB or the MCG becomes smaller.
[0901] In a case where the transmit power of the uplink
transmission in the subframe i of the MeNB or the MCG which
overlaps with the subframe j of the SeNB or the SCG and in which
the uplink transmission is started later than the uplink
transmission in the subframe j of the SeNB or the SCG is able to be
determined before the transmit power of the uplink transmission in
the subframe j of the SeNB or the SCG, the value of X may be the
transmit power of the uplink transmission in the subframe i of the
MeNB or the MCG. As the value of X may be acquired by adding a
value for guaranteeing the uplink transmission configured from the
higher layer to the transmit power of the uplink transmission in
the subframe i of the MeNB or the MCG.
[0902] The value of X may be changed depending on the resource
block (bandwidth) used in the uplink transmission. In this case, it
is preferable that the larger value of X is configured as the
number of resource blocks used in the uplink transmission becomes
larger.
[0903] The configuration of the X may be similarly applied to the
configuration of X' for guaranteeing the transmit power of the
uplink transmission of the SeNB or the SCG.
[0904] In a case where it is possible to predict that the uplink
transmission of the MeNB or the MCG is performed before the
transmit power of the SeNB or the SCG is determined, the uplink
transmission of the MeNB or the MCG can be considered as the
transmit power of the SeNB or the SCG. For example, if as much time
as 4 subframes is required in the determination of the transmit
power of the SeNB or the SCG, the uplink transmission of the MeNB
or the MCG is determined earlier than the 4 subframes, and thus,
the uplink transmission of the MeNB or the MCG can be considered in
the calculation of the transmit power of the SeNB or the SCG.
Hereinafter, an example in which it is possible to predict that the
uplink transmission of the MeNB or the MCG is performed before the
transmit power of the SeNB or the SCG is determined is
described.
[0905] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0906] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the instruction for
the uplink transmission in the subframe i of the MeNB or the MCG is
received in a timing earlier than the reception of the instruction
for the uplink transmission in the subframe j of the SeNB or the
SCG.
[0907] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0908] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the uplink
transmission in the subframe i of the MeNB or the MCG is instructed
by the periodically transmitted configuration. The uplink
transmission performed by the periodically transmitted
configuration is, for example, the transmission of PUSCH through
the semi-persistent scheduling, the transmission of the PUCCH
accompanying by the periodic CQI or the SR, or the transmission of
the SRS using the trigger type 0.
[0909] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0910] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the uplink
transmission in the plurality of continuous subframes including the
subframe i of the MeNB or the MCG. For example, the uplink
transmission in the plurality of continuous subframes including the
subframe i of the MeNB or the MCG is the transmission of the PUSCH
through subframe bundling or the case where the iterative
re-transmission of the uplink transmission is configured. The case
where the iterative re-transmission of the uplink transmission is
configured is, for example, a case where low-cost machine type
communication (MTC) is performed, and is a case where
e-HARQ-Pattern is configured.
[0911] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0912] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where k is greater than 4 in
the subframe i-k in which the grant (uplink grant) of the uplink
transmission for instructing the transmission of the PUSCH in the
subframe i of the MeNB or the MCG is received. In other words, this
case is a case where the PUSCH of the MeNB or the MCG is
transmitted in a subframe which is positioned after four subframes
from the subframe in which the uplink grant is received. In a case
where the uplink transmission is instructed for 4 subframes from
the subframe in which the uplink grant is received, since the
terminal device 1 is not able to recognize (predict) that the
uplink transmission in the subframe i of the MeNB or the MCG is
performed, the transmit power of the uplink transmission of the
MeNB or the MCG is not considered or is considered as the
reservation power. In a case where the uplink transmission is
instructed for the subframe after 4 subframes from the subframe in
which the uplink grant is received, since the terminal device 1 is
able to recognize (predict) that the uplink transmission in the
subframe i of the MeNB or the MCG is performed, the transmit power
of the uplink transmission of the MeNB or the MCG is
considered.
[0913] Specifically, in the TDD cell of the MeNB or the MCG, the
case where the terminal device 1 configures 0 and 1 for the TDD
UL/DL configuration or the uplink reference UL/DL configuration and
receives the uplink grant in the subframe 1 or 6, the case where
the terminal device 1 configures 6 for the TDD UL/DL configuration
or the uplink reference UL/DL configuration and receives the uplink
grant in the subframe i-k, or the case where the terminal device 1
configures 0 for the TDD UL/DL configuration or the uplink
reference UL/DL configuration and the least significant bit (LSB)
of the UL index included in the uplink grant is 1.
[0914] Specifically, this case is a case where the transmission of
the PUSCH for two or more uplink subframes is instructed by one
uplink grant and the subframe i of the MeNB or the MCG is the
uplink subframe after the second uplink subframe. In other words,
as to the first uplink subframe, since the terminal device 1 is not
able to recognize (predict) that the uplink transmission in the
subframe i of the MeNB or the MCG is performed, the transmit power
of the uplink transmission of the MeNB or the MCG is not considered
as the transmit power of the uplink transmission of the SeNB or the
SCG or is considered as the reservation power. As to the uplink
subframe after the second uplink subframe, since the terminal
device 1 is able to recognize (predict) that the uplink
transmission in the subframe i of the MeNB or the MCG is performed,
the transmit power of the uplink transmission of the MeNB or the
MCG is considered as the transmit power of the uplink transmission
of the SeNB or the SCG.
[0915] Specifically, this case is a case where the value of k is
determined based on the information included in the uplink grant
and the uplink transmission is instructed for the subframe after 4
subframes from the subframe in which the uplink grant is
received.
[0916] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0917] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the transmission of
the PUSCH is instructed in the subframe before the subframe i of
the MeNB or the MCG and the PUSCH is continuously transmitted
through subframe bundling (TTI bundling) even in the subframe i of
the MeNB or the MCG. Meanwhile, since the terminal device 1 is not
able to recognize (predict) that the uplink transmission is
performed in the leading subframe in which the PUSCH is transmitted
through the subframe bundling (TTI bundling), the transmit power of
the uplink transmission of the MeNB or the MCG is not considered as
the transmit power of the uplink transmission of the SeNB or the
SCG.
[0918] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0919] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the transmission of
the PUSCH through the semi-persistent scheduling (SPS) in the
subframe i of the MeNB or the MCG is configured and the SPS
activation is performed before 4 subframes from the subframe i.
[0920] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0921] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the PUCCH accompanying
by the HARQ-ACK in the subframe i of the MeNB or the MCG is
transmitted and at least one k is greater than 4 in the subframe
i-k in which the PDSCH corresponding to the HARQ-ACK is received.
In other words, this case is a case where the PUCCH accompanying by
the HARQ-ACK of the MeNB or the MCG is transmitted in the subframe
after 4 subframes from the subframe in which the PDSCH
corresponding to at least one HARQ-ACK is received.
[0922] Specifically, this case is a case where the PDSCH is
received in the subframe of which k defined by a downlink-related
set is greater than 4 in the TDD primary cell of the MeNB or the
MCG.
[0923] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0924] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the transmission of
the PUCCH accompanying by the periodic CQI is configured in the
subframe i.
[0925] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0926] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the transmission of
the PUCCH accompanying by the SR is configured in the subframe
i.
[0927] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0928] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the transmission of
the periodic SRS (trigger type 0 SRS) is configured in the subframe
i.
[0929] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0930] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the transmission of
the aperiodic SRS (trigger type 1 SRS) is configured in the
subframe i and the transmission of the aperiodic SRS (trigger type
1 SRS) is triggered by the DCI before 4 subframes from the subframe
i.
[0931] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0932] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is a case where the notification indicating that
the uplink transmission in the subframe i is performed is performed
using the information for notifying that the uplink transmission in
the subframe i of the MeNB or the MCG other than the uplink grant
for instructing that the uplink transmission in the subframe j of
the SeNB or the SCG is performed.
[0933] An example in which the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG which overlaps with the subframe j of the
SeNB or the SCG and in which the uplink transmission is started
later than the uplink transmission in the subframe j of the SeNB or
the SCG is performed before the transmit power of the uplink
transmission in the subframe j of the SeNB or the SCG is determined
is illustrated.
[0934] The case where the terminal device 1 is able to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed is a case where the terminal device 1
has high processing capability to complete the calculation of the
transmit power within 4 subframes and has capability to recognize
(predict) that the uplink transmission in the subframe i of the
MeNB or the MCG is performed. In this case, the terminal device 1
may notify the base station apparatus 3 of information (capability)
related to capability of the terminal device 1 which is able to
recognize (predict) that the uplink transmission in the subframe i
of the MeNB or the MCG is performed.
[0935] Even in a case where the terminal device 1 is able to
recognize (predict) that the uplink transmission in the subframe j
of the SeNB or the SCG which overlaps with the subframe i of the
MeNB or the MCG and in which the uplink transmission is started
later than the uplink transmission in the subframe i of the MeNB or
the MCG before the transmit power of the uplink transmission in the
subframe i of the MeNB or the MCG is determined, the
above-described example similarly becomes the condition.
[0936] Hereinafter, another details of the discovery reference
signal (DRS) will be described.
[0937] The DRS includes at least the PSS, the SSS, and the CRS. The
DRS may include the CSI-RS. In the following description, the PSS,
the SSS, the CRS, and the CSI-RS are described as the signals
(signals configured as the DRS) included in the DRS. That is, the
terminal device 1 may regard the PSS, the SSS, the CRS, and the
CSI-RS included in the DRS as signals different from the PSS, the
SSS, the CRS, and the CSI-RS of the related art.
[0938] In a case where the higher layer performs the configuration
in which the CSI-RS is included in the DRS for the terminal device
1, the terminal device 1 assumes the CSI-RS in order to perform the
RSRP and/or RSRQ measurement. The terminal device 1 assumes only
the DRS signal in the RSRP and/or RSRQ measurement based on the
DRS. The configuration of the CSI-RS of the DRS may be regarded as
the configuration of the resource element of the DRS.
[0939] One DRS measurement timing configuration is configured for
the terminal device 1 for each frequency. The DRS measurement
timing configuration is a configuration related to a timing when
the terminal device 1 measures the DRS in the cell on the
frequency. The DRS measurement timing configuration is configured
as information specific to the terminal device 1 or information
specific to the base station apparatus 3 through the higher layer
signalling from the base station apparatus 3. The DRS measurement
timing configuration includes a bandwidth in which the DRS is
measured, a measurement period as a duration during which the DRS
is measured, an interval between the measurement periods, and/or an
offset from a timing as a reference of the measurement period. For
example, the measurement period is any one of one subframe to five
subframes. The interval between the measurement periods is any one
of 40, 80 and 160 subframes. The offset is any one of 0 to a
(N-1)-th subframes in a case where the interval between the
measurement periods is N subframes.
[0940] In a case where only the measurement based on the DRS is
configured in a prescribed frequency and the (activated) serving
cell activated in this frequency is not configured for the terminal
device 1 (that is, the serving cell on the frequency is not
activated), the terminal device 1 assumes that there is no signal
or channel other than the DRS for the measurement period of the DRS
measurement timing configuration.
[0941] In the DRS, the scrambling IDs of the PSS, the SSS, and the
CRS may be physical cell IDs, and the scrambling ID of the CSI-RS
may be different from the physical cell ID. The scrambling ID is a
parameter for generating a sequence (scrambling sequence) used for
this signal. The DRS may be transmitted in only the downlink region
(DwPTS region) of the downlink subframe or the special
subframe.
[0942] The terminal device 1 reports the RSRP based on the DRS, the
RSRQ based on the DRS, the associated physical cell ID, and/or the
transmission point ID. The transmission point ID is information for
identifying the transmission point. The transmission point ID is
assigned based on the configuration (configuration related to the
mapping of the resource element to the RB pair) of the CSI-RS, the
scrambling ID, the subframe offset of the CSI-RS from the SSS or
the PSS, the subframe offset of the CSI-RS from the measurement
interval, the scrambling sequence, and/or the scrambling ID.
[0943] The measurement based on the DRS, the terminal device 1
assumes the DRS in a certain cell. Each of the DRSs may include at
least one PSS, one SSS, and a CRS of a prescribed antenna port, and
may include one CSI-RS. Thus, the PSS, the SSS, the CRS, and/or the
CSI-RS included in the DRS may be referred to as a configuration
related to the DRS, a DRS instance, or a DRS occasion in addition
to the DRS. The signals included in the DRS are transmitted in the
same subframe or different subframes. One or more DRSs are
configured for the terminal device 1. The DRS may indicate the CRS
or the CSI-RS used as the measurement (RSRP or RSRQ) based on the
DRS. The DRS may indicate the measurement in the DRS measurement
timing configuration.
[0944] The DRS includes one PSS and SSS. The DRS includes at least
the CRS transmitted in the same subframe as that of the PSS and/or
the SSS. The DRS includes one CSI-RS.
[0945] The DRS may include a plurality of CSI-RSs. In a case where
the DRS includes the plurality of CSI-RSs, these CSI-RSs are
allocated to only the same subframe. In a case where the DRS
includes the plurality of CSI-RSs, these CSI-RSs may be allocated
to different subframes. In a case where the DRS includes the
plurality of CSI-RSs, a sequence of these CSI-RSs is assigned based
on the independently configured scrambling IDs. In a case where the
DRS includes the plurality of CSI-RSs, a sequence of these CSI-RSs
is assigned based on the same scrambling ID.
[0946] In a case where the DRS includes the plurality of CSI-RSs,
the terminal device may perform the measurement based on the DRS by
assuming that these CSI-RSs are transmitted from the same
transmission point (cell). That is, it is assumed that the signal
included in the DRS is transmitted from the quasi-co-location. The
DRS may be regarded as a unit at which the RSRP/RSRQ measurement
and reporting are performed. Accordingly, the accuracy of the
measurement based on the DRS is improved.
[0947] In a case where the DRS includes the plurality of CSI-RSs,
the terminal device can perform the measurement based on the DRS by
assuming that these CSI-RSs are transmitted from different
transmission points (cells). That is, it is not assumed that these
CSI-RSs included in one DRS are transmitted from the
quasi-co-location. One DRS may performing the RSRP/RSRQ measurement
and reporting on the plurality of transmission points. These
CSI-RSs commonly use the PSS, the SSS, and the CRS included in the
DRS. Accordingly, the configuration using one DRS can be performed
for the plurality of transmission points, and thus, it is possible
to reduce information amount.
[0948] The DRS includes a prescribed number of continuous
subframes. The prescribed number may be the same as the measurement
period in the DRS measurement timing configuration. The prescribed
number may be independently configured of the measurement period in
the DRS measurement timing configuration. It is preferable that the
prescribed number is a value equal to or less than the measurement
period. There may be subframes in which the DRSs are not allocated
in the subframes (that is, a prescribed number of continuous
subframes) constituted by the DRSs. A part or all of the DRSs may
be allocated to all of the subframes (that is, a prescribed number
of continuous subframes) constituted by the DRSs.
[0949] The DRS are transmitted at a prescribed number of subframe
intervals. The prescribed number of subframe intervals may be the
same as the interval between the measurement periods in the DRS
measurement timing configuration. The prescribed number of subframe
intervals may be independently configured of the interval between
the measurement periods in the DRS measurement timing
configuration.
[0950] The DRS includes the zero-power CSI-RS. The configuration of
the zero-power CSI-RS is a prescribed number of bitmap information
items. Each bit of the configuration of the zero-power CSI-RS
corresponds to the resource element to which the CSI-RS is mapped
in one RB pair. That is, each bit of the configuration of the
zero-power CSI-RS indicates whether or not the corresponding
resource element is configured as the zero-power CSI-RS. Each bit
of the configuration of the zero-power CSI-RS corresponds to the
CSI-RS indicated by the configuration of the CSI-RSs of four
antenna ports. The terminal device 1 may assume that the resource
element configured as the zero-power CSI-RS is a resource element
in which any signal is not transmitted.
[0951] In the configuration of the DRS, the configuration of the
zero-power CSI-RS of one DRS is performed. The configuration of the
zero-power CSI-RS of the DRS is applied to all the subframes
configured as the measurement periods. The configuration of the
zero-power CSI-RS of the DRS may be independently performed on each
of the subframes configured as the measurement periods.
[0952] The CSI-RSs of the prescribed number of antenna ports may be
configured for the DRS. That is, the CSI-RSs of one or more antenna
ports are configured for the DRS. Accordingly, the accuracy of the
measurement based on the DRS is improved. The prescribed number may
be a prefixed value.
[0953] In the configuration of the CSI-RS within the DRS, the
terminal device 1 may assume that the corresponding CSI-RS is
transmitted in one subframe. In the configuration of the CSI-RS
within the DRS, the terminal device 1 may assume that the
corresponding CSI-RS is transmitted in one or more subframes. In
this case, it is preferable that the CSI-RS is transmitted in a
part or all of the subframes configured as the measurement
periods.
[0954] The terminal device 1 may assume that at least the CRS of
the antenna port 0 is transmitted in all the subframes to which the
DRSs are allocated. The terminal device 1 may assume that at least
the CRS of the antenna port 0 is transmitted in all the subframes
configured as the measurement periods.
[0955] As already described above, the signals included in the DRS
are transmitted in the same subframe or different subframes.
[0956] The subframe in which the DRS is transmitted in a case where
the serving cell is the FDD is as follows. At least the PSS, the
SSS and the CRS are transmitted in the same subframe. The CSI-RSs
are transmitted in the same subframe as or different subframes from
the subframe in which the PSS, the SSS and the CRS are transmitted.
Thus, a relative subframe offset (relative relationship) between
the subframe in which the CSI-RS is transmitted and the subframe in
which the SSS (the PSS or the CRS may be used) is transmitted is
configured.
[0957] The subframe in which the DRS is transmitted in a case where
the serving cell is the TDD is as follows. The PSS and the SSS are
transmitted in different subframes, but the relative relationship
between the subframe in which the PSS is transmitted and the
subframe in which the SSS is transmitted is previously defined. The
CRSs are transmitted in the subframe in which the PSS is
transmitted and/or the subframe in which the SSS is transmitted.
The CSI-RSs are transmitted in the same subframe as or different
subframes from the subframe in which the PSS, the SSS and the CRS
are transmitted. Thus, the relative subframe offset between the
subframe in which the CSI-RS is transmitted and the subframe in
which the SSS (the PSS or the CRS may be used) is transmitted is
configured.
[0958] Hereinafter, the details of the relative subframe offset
between the subframe in which the CSI-RS is transmitted and the
subframe in which the SSS (the PSS or the CRS may be used) is
transmitted will be described. In the following description, a case
where the SSS is allocated to a Z-th subframe from the first
subframe of the measurement period during the measurement periods
which are N continuous subframes is considered. However, Z is an
integer which is equal to or greater than 1 and is equal to or less
than N.
[0959] The relative subframe offset is included in the
configuration of the DRS. In a case where the plurality of CSI-RSs
is configured, the relative subframe offset is independently
configured for each of the CSI-RSs. Even in a case where the
plurality of CSI-RSs is configured, one relative subframe offset
may be configured, and may be common to the CSI-RSs.
[0960] In a case where the CRS is used in the measurement based on
the DRS (a case where the CSI-RS is not included in the DRS), the
terminal device 1 assumes that the SSS is allocated to an arbitrary
subframe within the measurement period (DRS instance) in the DRS
measurement timing configuration. The terminal device 1 performs
the RSRP/RSRQ measurement based on the CRS within the subframe to
which the SSS is allocated. That is, the terminal device assumes
that the relative subframe offset is zero.
[0961] In a case where the CSI-RS is used in the measurement based
on the DRS (a case where the CSI-RS is included in the DRS), the
terminal device 1 may assume various methods as the method related
to the allocation of the SSS within the measurement period in the
DRS measurement timing configuration.
[0962] In a first method related to the allocation of the SSS, the
terminal device 1 assumes that the SSS is allocated to a previously
defined subframe within the measurement period in the DRS
measurement timing configuration. For example, in the first method
related to the allocation of the SSS, the previously defined
subframe is the first subframe within the measurement period in the
FDD cell, and is the second subframe within the measurement period
in the TDD cell.
[0963] In a second method related to the allocation of the SSS, the
terminal device 1 assumes that the SSS is allocated to the subframe
configured by the higher layer within the measurement period in the
DRS measurement timing configuration. In the second method related
to the allocation of the SSS, the subframe to which the SSS is
allocated is configured as information specific to the DRS by using
the subframe offset with the first subframe within the measurement
period as a reference point.
[0964] In a third method related to the allocation of the SSS, the
terminal device 1 assumes that the SSS is allocated to an arbitrary
subframe within the measurement subframe in the DRS measurement
timing configuration.
[0965] In a case where the CSI-RS is used in the measurement based
on the DRS (a case where the CSI-RS is included in the DRS), the
terminal device 1 may assume various methods as the method related
to the relative subframe offset for the SSS of the CSI-RS. In the
following description, a case where the relative subframe offset is
zero indicates that the CSI-RS and the SSS are allocated to the
same subframe. A case where the relative subframe offset is a plus
integer indicates that the CSI-RS is allocated to the subframe
after the subframe to which the SSS is allocated. A case where the
relative subframe offset is a minus integer indicates that the
CSI-RS is allocated to the subframe before the subframe to which
the SSS is allocated.
[0966] In a first method related to the relative subframe offset,
the terminal device 1 assumes that the CSI-RS is allocated to the
subframe designated by the previously defined relative subframe
offset. For example, the terminal device assumes that the relative
subframe offset is zero. In the first method related to the
relative subframe offset, the terminal device 1 assumes that the
CSI-RS is allocated to the same subframe as that of the SSS. That
is, the subframe to which the CSI-RS is allocated is determined by
only the subframe to which the SSS is allocated within the
measurement period. Accordingly, the base station apparatus 3 does
not need to configure the relative subframe offset for the terminal
device 1, and thus, the number of processes of the base station
apparatus 3 and the terminal device 1 is reduced.
[0967] In a second method related to the relative subframe offset,
the terminal device 1 assumes that the CSI-RS is allocated to the
subframe designated by the relative subframe offset configured
through the higher layer signalling within the measurement period.
The CSI-RS may be allocated to an arbitrary subframe within the
measurement period. In a case where the SSS is allocated to the
Z-th subframe, a value that may be obtained as the relative
subframe offset is an integer which is equal or greater than -Z+1
and is equal to or less than N-Z. That is, the subframe to which
the CSI-RS is allocated is determined by the subframe to which the
SSS is allocated and the configured relative subframe offset within
the measurement period. Accordingly, the base station apparatus 3
may efficiently configure the subframe to which the SSS is
allocated and the subframe to which the CSI-RS is allocated for the
terminal device 1.
[0968] In a third method related to the relative subframe offset,
the terminal device 1 assumes that the CSI-RS is allocated to the
subframe designated by the relative subframe offset configured
through the higher layer signalling. The CSI-RS is allocated to the
subframe after the subframe to which the SSS is allocated within
the measurement period. That is, the CSI-RS is not allocated to the
subframe before the subframe to which the SSS is allocated within
the measurement period. In a case where the SSS is allocated to the
Z-th subframe, a value that may be obtained as the relative
subframe offset is an integer which is equal or greater than 0 and
is equal to or less than N-Z. The subframe to which the CSI-RS is
allocated is determined by the subframe to which the SSS is
allocated and the configured relative subframe offset within the
measurement period. The CSI-RS is allocated to the subframe after
the subframe to which the SSS is allocated. Accordingly, the base
station apparatus 3 may efficiently configure the subframe to which
the SSS is allocated and the subframe to which the CSI-RS is
allocated for the terminal device 1. Since the CSI-RS is allocated
to the subframe after the subframe to which the SSS is allocated,
the terminal device 1 does not need to retain the subframe before
the frequency synchronization based on the SSS is achieved in order
to detect the CSI-RS.
[0969] In the above-described methods, the value that may be
obtained as the relative subframe offset may be different depending
on the configuration of the serving cell or the configuration of
the DRS. For example, in a case where the subframe in which the SSS
may be allocated is different between the TDD cell and the FDD
cell, the value that may be obtained as the relative subframe
offset is different between the TDD cell and the FDD cell. For
example, in a case where the SSS is allocated to an arbitrary
subframe within the measurement period, the value that may be
obtained as the relative subframe offset is determined depending on
the subframe to which the SSS is allocated.
[0970] Hereinafter, the details of the configuration of the
relative subframe offset for the terminal device 1 by the base
station apparatus 3 will be described.
[0971] In an example of the configuration of the relative subframe
offset, the base station apparatus 3 directly configures the
relative subframe offset for the terminal device 1 through the
higher layer. Accordingly, the terminal device 1 may use the
configured relative subframe offset as it is, the number of
processes of the terminal device 1 is reduced.
[0972] In an example of the configuration of the relative subframe
offset, a table for configuring the relative subframe offset is
used. The table for configuring the relative subframe offset
includes the relative subframe offset and an index corresponding
thereto. The base station apparatus 3 notifies the terminal device
1 of the index through the higher layer and the terminal device 1
uses the table and the index, so that the relative subframe offset
is configured. This index may be regarded as information for
configuring the relative subframe offset. For example, in the
table, a value that may be obtained as the index is an integer
which is equal or greater than 0 and is equal to or less than 4,
and a value that may be obtained as the relative subframe offset
corresponding to this index is an integer which is equal or greater
than -Z+1 and is equal to or less than N-Z. The index of the table
may correspond to a different relative subframe offset between the
FDD cell and the TDD cell. The table for configuring the relative
subframe offset may be independently defined based on a
configuration related to the DRS, a configuration related to the
measurement period, a configuration related to the subframe to
which the SSS is allocated in the measurement period, a
configuration related to the MBSFN subframe, an uplink/downlink
configuration in the TDD cell, and/or a frame structure type (that
is, FDD or TDD) of the serving cell. Accordingly, since the
information of the higher layer for configuring the relative
subframe offset may be the same irrespective of the configuration
of the serving cell and/or the configuration related to the DRS, a
load for the control and notification is reduced.
[0973] In an example of the configuration of the relative subframe
offset, the expression for configuring the relative subframe offset
is used. The expression for configuring the relative subframe
offset is used for calculating the relative subframe offset based
on a parameter configured from the higher layer. This parameter may
be regarded as a parameter related to the relative subframe offset.
The expression for configuring the relative subframe offset
includes at least a parameter configured from the higher layer. The
expression for configuring the relative subframe offset may include
a parameter related to the DRS, a parameter related to the
measurement period, a parameter related to the subframe to which
the SSS is allocated in the measurement period, a parameter related
to the MBSFN subframe, a parameter related to the uplink/downlink
configuration in the TDD cell, and/or a parameter related to the
frame structure type (that is, FDD or TDD) of the serving cell.
That is, the relative subframe offset is determined based on the
parameter included in the expression for configuring the relative
subframe offset. Accordingly, since the information of the higher
layer for configuring the relative subframe offset may be the same
irrespective of the configuration of the serving cell and/or the
configuration related to the DRS, a load for the control and
notification is reduced.
[0974] An example of the expression for configuring the relative
subframe offset includes a parameter (S) configured from the higher
layer, a value (Z) indicating the position of the subframe to which
the SSS is allocated in the measurement period, and the number of
subframes (N) constituting the measurement period. S is an integer
which is equal to or greater than 0 and is less than N. For
example, the relative subframe offset is determined based on the
rest obtained by dividing a value obtained by adding S and Z by N.
Accordingly, since the information of the higher layer for
configuring the relative subframe offset may be the same
irrespective of the position of the subframe to which the SSS is
allocated in the measurement period, the load of the control and
notification is reduced.
[0975] As already described, the base station apparatus 3 may
configure one or more DRSs for the terminal device 1. The terminal
device 1 performs the monitoring or detection of the DRS
(transmission point or cell), the RSRP/RSRQ measurement, or the
RSRP/RSRQ reporting based on the configured DRS.
[0976] The configuration of the DRS is performed through the higher
layer (RRC) signalling. The configuration of the DRS may be
regarded as assistant information related to the DRS. As the
assistant information related to the DRS, there are assistant
information used as a configuration common to the plurality of
DRSs, and assistant information used as a configuration specific to
each DRS.
[0977] For example, the assistant information used as the
configuration common to the plurality of DRSs includes information
related to the DRS measurement timing configuration. That is, the
assistant information used as the configuration common to the
plurality of DRSs includes a bandwidth in which the DRS is
measured, a measurement period which is a duration during which the
DRS is measured, an interval between the measurement periods,
and/or an offset from the timing as a reference of the measurement
period. The assistant information used as the configuration common
to the plurality of DRSs may include the configuration of the
zero-power CSI-RS.
[0978] For example, the assistant information used as the
configuration specific to each DRS includes the configuration
related to the DRS. That is, the assistant information used as the
configuration specific to each DRS includes the configuration
related to the PSS, SSS, CRS and/or CSI-RS included in this DRS.
For example, the assistant information used as the configuration
specific to each DRS includes the physical cell ID, the
configuration of the CSI-RS, the configuration related to the
MBSFN, the UL/DL configuration in the TDD cell, and the relative
subframe offset between the subframe in which the CSI-RS is
transmitted and the subframe in which the SSS is transmitted. The
configuration of the CSI-RS includes, for example, a configuration
related to the mapping of the CSI-RS to the resource element, the
number of antenna ports of the CSI-RSs, and the scrambling ID of
the CSI-RS.
[0979] In the above description, the configuration of the CSI-RS
included in the DRS may be limited. For example, in a case where
another signal or channel is allocated to the resource element to
which the CSI-RS is allocated in one RB pair, the configuration of
the CSI-RS is limited. Specifically, in a case where the serving
cell is the TDD and the CRSs of four antenna ports are configured,
the resource elements for the CSI-RS based on the configuration of
a part of the CSI-RSs includes the resource element to which this
CRS is allocated. In this case, in order to preferentially perform
the allocation of the CRS, the configuration of a part of the
CSI-RSs is limited. That is, the base station apparatus 3
configures the CSI-RS other than the configuration of a part of the
CSI-RS for the DRS for terminal device 1.
[0980] In the above description, the DRS may be configured for only
the secondary cell. That is, the DRS may not be configured for the
primary cell.
[0981] In the above description, the configuration (signalling) of
the higher layer including the configuration of the DRS is
performed by the higher layer processing unit 101 and the higher
layer processing unit 301. The transmission of the DRS is performed
by the transmission unit 307. The reception of the DRS is performed
by the reception unit 105. The RSRP/RSRQ measurement based on the
DRS is performed by the reception unit 105 or the channel
measurement unit 1059.
[0982] In the above description, the measurement period may be the
detection subframe which is the resource for monitoring the
discovery reference signal. As already described, the detection
subframe is a prescribed number of continuous subframes, and is
periodically configured every prescribed number of subframes.
[0983] In the above description, the CRS included in the DRS is
also referred to as a first reference signal, and the CSI-RS
included in the DRS is also referred to as a second reference
signal. The PSS included in the DRS is also referred to as a first
synchronization signal, and the SSS included in the DRS is also
referred to as a second synchronization signal.
[0984] In the above description, it may be assumed that the
subframe (resource) to which the DRS is allocated is only the DwPTS
of the downlink subframe and the special subframe in the
measurement period. In the TDD cell, the subframe (resource) to
which the DRS is allocated may be determined based on the UL/DL
configuration configured by the higher layer. In the TDD cell, the
subframe (resource) to which the DRS is allocated may be determined
based on the uplink reference UL/DL configuration configured by the
higher layer. In the TDD cell, the subframe (resource) to which the
DRS is allocated may be determined based on the UL/DL configuration
designated by the control channel (PDCCH) of the physical
layer.
[0985] The various methods, procedures, configurations and/or
processes described in the present embodiment may be independent
between the Pcell and the pScell in the dual connectivity.
[0986] The terminal device 1 according to the above-described
embodiment may support a function (ul-CoMP) of performing uplink
CoMP.
[0987] The terminal device 1 according to the above-described
embodiment may support a function (supportedBandCombination or
supportedBandListEUTRA) of performing band combination (CA or
non-CA).
[0988] The terminal device 1 according to the above-described
embodiment may support a function (crossCarrierScheduling) of
performing cross carrier scheduling.
[0989] The terminal device 1 according to the above-described
embodiment may support a function (multipleTimingAdvance) of
multiple timing advances.
[0990] The terminal device 1 according to the above-described
embodiment may support a CSI process function.
[0991] The terminal device 1 according to the above-described
embodiment may support a function of performing communication using
cells (a plurality of cells) of different TDD UL-DL
configurations.
[0992] The terminal device 1 according to the above-described
embodiment may support a function of performing eIMTA.
[0993] The terminal device 1 according to the above-described
embodiment may support a function of performing communication using
the small cell.
[0994] The terminal device 1 according to the above-described
embodiment may support a function (dual-connectivity) of
simultaneously performing communication with a plurality of base
station apparatuses.
[0995] The terminal device 1 according to the above-described
embodiment may support a function of performing communication using
cell (a plurality of cells) of different frame structure types.
[0996] The terminal device 1 according to the above-described
embodiment may support a function of simultaneously performing
transmission and reception.
[0997] The terminal device 1 according to the above-described
embodiment may support a function of receiving the EPDCCH.
[0998] The terminal device 1 according to the above-described
embodiment may transmit information (UE-EUTRA-capability or
FeatureGroupIndicator) indicating the supported function to the
base station apparatus 3.
[0999] In the above-described embodiment, the PDCCH subframe may be
defined as the subframe accompanying by EPDCCH (EnhancedPDCCH) or
R-PDCCH (Relay-PDCCH) in addition to being defined as the subframe
accompanying by the PDCCH.
[1000] From the details of the above-described embodiment, it is
possible to improve transmission efficiency in the wireless
communication system in which the base station apparatus 3 and the
terminal device 1 communicate.
[1001] The programs operated in the base station apparatus 3 and
the terminal device 1 according to the present invention may be
programs (causing a computer to function) for controlling a central
processing unit (CPU) such that the functions of the
above-described embodiments according to the present invention are
realized. The information treated in these devices is temporarily
accumulated in a random access memory (RAM) at the time of the
processing, and then is stored in various ROMs such as flash
read-only memory (ROM) or hard disk drive (HDD). When necessary,
the information is read by the CPU, and is modified or
rewritten.
[1002] A part of the terminal device 1 and the base station
apparatus 3 according to the above-described embodiment may be
realized as a computer. In this case, the program for realizing the
control function may be recorded in a computer-readable recording
medium, and the program recorded in the recording medium may be
realized by being read and executed in a computer system.
[1003] It is assumed that the "computer system" mentioned herein is
a computer system built into the terminal device 1 or the base
station apparatus 3, and includes OS or hardware such as peripheral
devices. The "computer-readable recording medium" refers to a
portable medium such as a flexible disk, a magneto-optical disk, a
ROM or a CD-ROM, and a storage device such as a hard disk built
into the computer system.
[1004] The "computer-readable recording medium" may include a
medium that dynamically retains programs for a short period of time
such as a communication line in a case where programs are
transmitted via a network such as the Internet or a communication
circuit such as a telephone line, and a medium that retains
programs for a regular period of time such as a volatile memory
within the computer system which is a server or a client in this
case. The program may be used to realize a part of the
above-described functions, or may be realized by a combination of
the above-described functions and programs already recorded in the
computer system.
[1005] The base station apparatus 3 according to the
above-described embodiment may be realized as an aggregate (device
group) constituted by a plurality of devices. Each of the devices
constituting the device group may include a part or all of the
functions or functional blocks of the base station apparatus 3
according to the above-described embodiment. The device group may
have the general functions or functional blocks of the base station
apparatus 3. The terminal device 1 according to the above-described
embodiment may communicate with the base station apparatus 3 as the
aggregate.
[1006] The base station apparatus 3 according to the
above-described embodiment may be Evolved Universal Terrestrial
Radio Access Network (EUTRAN). The base station apparatus 3
according to the above-described embodiment may have a part or all
of the functions of the higher node for the eNodeB.
[1007] A part or all of the terminal device 1 and the base station
apparatus 3 according to the above-described embodiment may be
typically realized as LSI which is an integrated circuit, or may be
realized as a chipset. The functional blocks of the terminal device
1 and the base station apparatus 3 may be individually realized as
a chip, or a part or all thereof may be realized as a chip by being
integrated. The method of realizing the devices or functional
blocks as the integrated circuit is not limited to the LSI, and a
dedicated circuit or a general-purpose processor may be used. In a
case where a technology of realizing the devices or functional
blocks as the integrated circuit has appeared instead of the LSI
due to the advance of semiconductor technology, an integrated
circuit produced using this technology may be used.
[1008] Although it has been described in the embodiment that the
terminal device is used as an example of the terminal device or the
communication device, the present invention is not limited thereto.
The present invention may also be applied to terminal devices or
communication devices of stationary or non-movable electronic
devices which are installed indoors or outdoors, such as AV
devices, kitchen devices, cleaning and washing machines, air
conditioners, office devices, vending machines, and other home
appliances.
[1009] The embodiments of the present invention have been described
with reference to the drawings. However, the detailed structure is
not limited to the above-described embodiments, and the present
invention also includes a change in the design within the gist of
the invention. The present invention may be variously changed
without departing from the claims, and embodiments acquired by
appropriately combining technical means disclosed in different
embodiments are included in the technical range of the present
invention. The elements described in the respective embodiments and
structures acquired by replacing the elements that exhibit the same
effects are included therein.
INDUSTRIAL APPLICABILITY
[1010] The present invention is applicable to communication devices
including the terminal device, other electronic devices, AV
devices, other home appliances, bending machines, and other
devices.
REFERENCE SIGNS LIST
[1011] 1 (1A, 1B, 1C) Terminal device [1012] 3 Base station
apparatus [1013] 101 Higher layer processing unit [1014] 103
Control unit [1015] 105 Reception unit [1016] 107 Transmission unit
[1017] 301 Higher layer processing unit [1018] 303 Control unit
[1019] 305 Reception unit [1020] 307 Transmission unit [1021] 1011
Radio resource control unit [1022] 1013 Subframe configuration unit
[1023] 1015 Scheduling information interpretation unit [1024] 1017
CSI report control unit [1025] 3011 Radio resource control unit
[1026] 3013 Subframe configuration unit [1027] 3015 Scheduling unit
[1028] 3017 CSI report control unit [1029] 1301 Measurement unit
[1030] 13011 Layer 1 filtering unit [1031] 13012 Layer 3 filtering
unit [1032] 13013 Report criteria evaluation unit
* * * * *