U.S. patent application number 14/354686 was filed with the patent office on 2014-10-02 for base station device, mobile station device, wireless communication method, wireless communication system, and integrated circuit.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. The applicant listed for this patent is Tatsushi Aiba, Shoichi Suzuki. Invention is credited to Tatsushi Aiba, Shoichi Suzuki.
Application Number | 20140293946 14/354686 |
Document ID | / |
Family ID | 48191767 |
Filed Date | 2014-10-02 |
United States Patent
Application |
20140293946 |
Kind Code |
A1 |
Suzuki; Shoichi ; et
al. |
October 2, 2014 |
BASE STATION DEVICE, MOBILE STATION DEVICE, WIRELESS COMMUNICATION
METHOD, WIRELESS COMMUNICATION SYSTEM, AND INTEGRATED CIRCUIT
Abstract
A base station device that communicates with a mobile station
device is provided. The base station device uses a physical
broadcast channel to transmit information instructing the mobile
station device to monitor a common search space or an enhanced
common search space for a physical downlink channel.
Inventors: |
Suzuki; Shoichi; (Osaka-shi,
JP) ; Aiba; Tatsushi; (Osaka-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Suzuki; Shoichi
Aiba; Tatsushi |
Osaka-shi
Osaka-shi |
|
JP
JP |
|
|
Assignee: |
SHARP KABUSHIKI KAISHA
Osaka-shi, Osaka
JP
|
Family ID: |
48191767 |
Appl. No.: |
14/354686 |
Filed: |
September 13, 2012 |
PCT Filed: |
September 13, 2012 |
PCT NO: |
PCT/JP2012/073451 |
371 Date: |
April 28, 2014 |
Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04L 5/0053 20130101;
H04L 5/0007 20130101; H04W 72/0446 20130101; H04W 48/12 20130101;
H04W 72/042 20130101; H04W 72/0413 20130101 |
Class at
Publication: |
370/329 |
International
Class: |
H04W 72/04 20060101
H04W072/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 2, 2011 |
JP |
2011-241104 |
Claims
1-34. (canceled)
35. A base station device that communicates with a mobile station
device, wherein the base station device uses a physical broadcast
channel to transmit information instructing the mobile station
device to monitor a common search space or an enhanced common
search space for a physical downlink channel.
36. The base station device according to claim 35, wherein the base
station device transmits the physical broadcast channel with 0th to
3rd OFDM symbols in a second slot of a 0th subframe in respective
radio frames in the time domain, and with the central 72 downlink
subcarriers of a cell in the frequency domain.
37. The base station device according to claim 35, wherein the base
station device transmits a physical downlink control channel in the
common search space, the base station device transmits an enhanced
physical downlink control channel in the enhanced common search
space, the physical downlink control channel is time-multiplexed
with a physical downlink shared channel, and the enhanced physical
downlink control channel is frequency-multiplexed with the physical
downlink shared channel.
38. The base station device according to claim 37, wherein in a
case in which the physical downlink control channel is not placed
in the cell used to communicate with the mobile station device, the
base station device instructs the mobile station device to monitor
the enhanced common search space for the enhanced physical downlink
control channel with the information.
39. The base station device according to claim 37, wherein in a
case in which the physical downlink control channel and the
enhanced physical downlink control channel are placed in the cell
used to communicate with the mobile station device, the base
station device instructs the mobile station device to monitor the
common search space for the physical downlink control channel with
the information.
40. The base station device according to claim 35, wherein the base
station device uses a physical downlink shared channel to transmit
a system information block which is common for a plurality of the
mobile station device and which includes information related to
configuration of an enhanced mobile station device-specific search
space.
41. The base station device according to claim 40, wherein the base
station device uses the physical downlink shared channel to
transmit dedicated radio resource control information for the
mobile station device, including information related to
configuration of the enhanced mobile station device-specific search
space.
42. The base station device according to claim 41, wherein until
transmitting the dedicated radio resource control information to
the mobile station device, the base station device, on the basis of
information related to configuration of the enhanced mobile station
device-specific search space included in the system information
block, transmits an enhanced physical downlink control channel
targeting the mobile station device in the enhanced mobile station
device-specific search space configured by the mobile station
device.
43. A mobile station device that communicates with a base station
device, wherein the mobile station device uses a physical broadcast
channel to receive information instructing the mobile station
device to monitor a common search space or an enhanced common
search space for a physical downlink channel, and on the basis of
the information, the mobile station device monitors the common
search space or the enhanced common search space for the physical
downlink channel.
44. The mobile station device according to claim 43, wherein the
physical broadcast channel is transmitted with 0th to 3rd OFDM
symbols in a second slot of a 0th subframe in respective radio
frames in the time domain, and with the central 72 downlink
subcarriers of a cell in the frequency domain.
45. The mobile station device according to claim 43, wherein the
mobile station device receives a physical downlink control channel
in the common search space, and receives an enhanced physical
downlink control channel in the enhanced common search space, the
physical downlink control channel is time-multiplexed with a
physical downlink shared channel, and the enhanced physical
downlink control channel is frequency-multiplexed with the physical
downlink shared channel.
46. The mobile station device according to claim 43, wherein the
mobile station device uses a physical downlink shared channel to
receive a system information block common for a plurality of the
mobile station device, and the system information block includes
information related to configuration of an enhanced mobile station
device-specific search space.
47. The mobile station device according to claim 46, wherein the
mobile station device uses the physical downlink shared channel to
receive dedicated radio resource control information for the mobile
station device, and the dedicated radio resource control
information includes information related to configuration of the
enhanced mobile station device-specific search space.
48. The mobile station device according to claim 47, wherein until
receiving the dedicated radio resource control information from the
base station device, the mobile station device monitors the
enhanced mobile station device-specific search space configured on
the basis of information related to configuration of the enhanced
mobile station device-specific search space included in the system
information block for an enhanced physical downlink control channel
targeting the device itself.
49. The mobile station device according to claim 48, wherein in a
case in which the enhanced mobile station device-specific search
space is configured on the basis of information related to
configuration of the enhanced mobile station device-specific search
space included in the dedicated radio resource control information,
the mobile station device does not configure the enhanced mobile
station device-specific search space on the basis of information
related to configuration of the enhanced mobile station
device-specific search space included in a subsequently received
system information block.
50. A wireless communication method used by a base station device
that communicates with a mobile station device, comprising: using a
physical broadcast channel to transmit information instructing the
mobile station device to monitor a common search space or an
enhanced common search space for a physical downlink channel.
51. The wireless communication method according to claim 50,
further comprising: using a physical downlink shared channel to
transmit a system information block which is common for a plurality
of the mobile station device, and which includes information
related to configuration of an enhanced mobile station
device-specific search space.
52. A wireless communication method used by a mobile station device
that communicates with a base station device, comprising: using a
physical broadcast channel to receive information instructing the
mobile station device to monitor a common search space or an
enhanced common search space for a physical downlink channel; and
on the basis of the information, monitoring the common search space
or the enhanced common search space for the physical downlink
channel.
53. The wireless communication method according to claim 52,
further comprising: using a physical downlink shared channel to
receive a system information block common for a plurality of the
mobile station device; wherein the system information block
includes information related to configuration of an enhanced mobile
station device-specific search space.
Description
TECHNICAL FIELD
[0001] The present invention relates to a base station device, a
mobile station device, a wireless communication method, a wireless
communication system, and an integrated circuit.
BACKGROUND ART
[0002] Advances in wireless access schemes and wireless networks
for cellular mobile communication (hereinafter designated "Long
Term Evolution (LTE)" or "Evolved Universal Terrestrial Radio
Access (EUTRA)") are being investigated in the 3rd Generation
Partnership Project (3GPP). With LTE, an orthogonal
frequency-division multiplexing (OFDM) scheme is used as the
communication scheme for the downlink from a base station device to
a mobile station device. Also, a single-carrier frequency-division
multiple access (SC-FDMA) scheme is used as the communication
scheme for the uplink from a mobile station device to a base
station device. Herein, in LTE, a base station device is also
designated Evolved Node B (eNodeB), and a mobile station device is
also designated User Equipment (UE). LTE is a cellular
communication system that plurally arranges areas covered by base
station devices into cells.
[0003] In LTE, a base station device uses 72 subcarriers in the
center of a cell to transmit a synchronization signal (SS) and a
physical broadcast channel (PBCH). In LTE, a mobile station device
conducts a cell search using a synchronization signal, and acquires
time timings, frequency timings, and a physical layer cell identity
(PCI). In LTE, after a cell search, the mobile station device uses
the physical broadcast channel to acquire a master information
block. The master information block is system information. In
addition, the master information block includes information
indicating the downlink bandwidth of the cell as well as
information indicating a system frame number (SFN), and the like. A
system frame is also designated a radio frame.
[0004] In LTE, after receiving the PBCH, a mobile station device
uses a physical downlink shared channel (PDSCH) to acquire multiple
system information blocks. The system information blocks are system
information. In addition, the system information blocks include
radio resource configuration information that is common for
multiple mobile station devices. A base station device transmits a
single system information block using a single PDCCH.
[0005] In LTE, a base station device assigns a portion of the
downlink band of a cell to the PDSCH. Also, in LTE, a base station
device transmits downlink control information (DCI) used to
schedule a single PDSCH using a single physical downlink control
channel (PDCCH). Also, in LTE, a base station device transmits
downlink control information used to schedule a PDSCH that
transmits a system information block with a PDCCH in a common
search space. The common search space is used for PDCCH
transmission which common for all mobile station devices. In LTE,
all mobile station devices monitor the common search space for a
PDCCH.
[0006] In LTE, a mobile station device configures a physical random
access channel (PRACH) on the basis of radio resource configuration
information included in system information blocks. In LTE, after
configuring the PRACH, a mobile station device starts a random
access procedure, and adjusts the uplink transmission timings. In
LTE, after adjusting the uplink transmission timings, a mobile
station device transmits a connection request message to a base
station device, and starts an initial connection establishment.
[0007] In LTE, a technology is used in which a mobile station
device and a base station device communicate by using multiple
cells (component carriers) with the same channel structure (cell
aggregation, also designated carrier aggregation). For example,
with communication using cell aggregation, a mobile station device
and a base station device are able to use multiple cells to
transmit and receive on multiple physical channels at the same
time. For example, after a mobile station device and a base station
device conduct initial connection establishment in one cell, the
base station device is able to add cells to be used for
communication with that mobile station device.
[0008] In 3GPP, in order to improve spectral efficiency, the
introduction of non-backward compatible component carriers is being
investigated. On a non-backward compatible component carrier, at
least one of the synchronization signal, PBCH, PDCCH, and system
information block is not transmitted (NPL 1). Consequently, a
mobile station device and a base station device are required to
conduct initial connection establishment on one backward compatible
component carrier, and afterwards add a non-backward compatible
component carrier to be used for communication between the base
station device and the mobile station device. In other words, a
non-backward compatible component carrier is required to be part of
a component carrier set that includes at least one backward
compatible component carrier. Backward compatible component
carriers are the component carriers that have been used in LTE
heretofore.
[0009] In addition, in 3GPP, the use of an enhanced physical
downlink control channel (E-PDCCH) to transmit downlink control
information is being investigated in order to increase the number
of terminals that a single base station is able to serve. The
E-PDCCH is mapped to the PDSCH space. Additionally, in 3GPP, the
introduction of technologies such as beamforming and spatial
multiplexing with respect to the E-PDCCH are being
investigated.
CITATION LIST
Non Patent Literature
[0010] NPL 1: "Additional Carrier Type for Rel-11", R1-113186, 3GPP
TSG-RAN WG1 Meeting #66bis, Zhuhai, China, 10-14 Oct. 2011 [0011]
NPL 2: "Enhancements for UE specific control signaling", R1-111332,
3GPP TSG-RAN WG1 Meeting #65, Barcelona, Spain, 9-13 May 2011
SUMMARY OF INVENTION
Technical Problem
[0012] Henceforth, many non-backward compatible component carriers
need to be introduced in order to improve spectral efficiency.
However, with the technology of the related art, a mobile station
device and a base station device are required to conduct initial
connection establishment (initial access) on one backward
compatible component carrier, and afterwards add a non-backward
compatible component carrier to be used for communication between
the base station device and the mobile station device. In other
words, with the technology of the related art, there is a problem
in that a mobile station device is unable to conduct initial
connection establishment on a non-backward compatible component
carrier.
[0013] The present invention has been devised in light of the above
points, and an object thereof is to provide a base station device,
a mobile station device a wireless communication method, a wireless
communication system, and an integrated circuit that enables a
mobile station device to efficiently conduct initial connection
establishment (initial access).
Solution to Problem
[0014] (1) According to an aspect of the present invention, a base
station device that communicates with a mobile station device is
provided. The base station device uses a physical broadcast channel
to transmit information instructing the mobile station device to
monitor a common search space or an enhanced common search space
for a physical downlink channel.
[0015] (2) Preferably, the above base station device transmits the
physical broadcast channel with 0th to 3rd OFDM symbols in a second
slot of a 0th subframe in respective radio frames in the time
domain, and with the central 72 downlink subcarriers of a cell in
the frequency domain.
[0016] (3) Preferably, the above base station device transmits a
physical downlink control channel in the common search space, and
transmits an enhanced physical downlink control channel in the
enhanced common search space. The physical downlink control channel
is time-multiplexed with a physical downlink shared channel, and
the enhanced physical downlink control channel is
frequency-multiplexed with the physical downlink shared
channel.
[0017] (4) Preferably, in a case in which the physical downlink
control channel is not placed in the cell used to communicate with
the mobile station device, the above base station device instructs
the mobile station device to monitor the enhanced common search
space for the enhanced physical downlink control channel with the
information.
[0018] (5) Preferably, in a case in which the physical downlink
control channel and the enhanced physical downlink control channel
are placed in the cell used to communicate with the mobile station
device, the base station device instructs the mobile station device
to monitor the common search space for the physical downlink
control channel with the information.
[0019] (6) According to another aspect of the present invention, a
base station device that communicates with a mobile station device
is provided. The base station device uses a physical downlink
shared channel to transmit a system information block which is
common for a plurality of the mobile station device and which
includes information related to configuration of an enhanced mobile
station device-specific search space.
[0020] (7) Preferably, the above base station device uses the
physical downlink shared channel to transmit dedicated radio
resource control information for the mobile station device,
including information related to configuration of the enhanced
mobile station device-specific search space.
[0021] (8) Preferably, until transmitting the dedicated radio
resource control information to the mobile station device, the base
station device, on the basis of information related to
configuration of the enhanced mobile station device-specific search
space included in the system information block, transmits an
enhanced physical downlink control channel targeting the mobile
station device in the enhanced mobile station device-specific
search space configured by the mobile station device.
[0022] (9) According to another aspect of the present invention, a
base station device that communicates with a mobile station device
is provided. The base station places downlink control information
in one or a plurality of contiguous enhanced control channel
elements, places the enhanced control channel elements in a
plurality of virtual resource blocks so that a plurality of the
enhanced control elements are placed in a single virtual resource
block, places the virtual resource blocks with numbers that are
consecutive in a first slot into physical resource blocks with
numbers that are distributed in a first slot, places the virtual
resource blocks with numbers that are consecutive in a second slot
into physical resource blocks with numbers that are distributed in
a second slot, and places a virtual resource block in the first
slot and a virtual resource block in the second slot with the same
number into the physical resource blocks with numbers that are
distributed.
[0023] (10) Preferably, the above base station device interleaves a
plurality of the enhanced control channel elements placed in a
virtual resource block in the first slot and a virtual resource
block in the second slot with the same number before placement in
the physical resource blocks, in units that are smaller than the
enhanced control channel elements.
[0024] (11) According to another aspect of the present invention, a
mobile station device that communicates with a base station device
is provided. The mobile station device uses a physical broadcast
channel to receive information instructing the mobile station
device to monitor a common search space or an enhanced common
search space for a physical downlink channel, and on the basis of
the information, monitors the common search space or the enhanced
common search space for the physical downlink channel.
[0025] (12) Preferably, in the above mobile station device, the
physical broadcast channel is transmitted with 0th to 3rd OFDM
symbols in a second slot of a 0th subframe in respective radio
frames in the time domain, and with the central 72 downlink
subcarriers of a cell in the frequency domain.
[0026] (13) Preferably, the mobile station device receives a
physical downlink control channel in the common search space, and
receives an enhanced physical downlink control channel in the
enhanced common search space. The physical downlink control channel
is time-multiplexed with a physical downlink shared channel, and
the enhanced physical downlink control channel is
frequency-multiplexed with the physical downlink shared
channel.
[0027] (14) According to another aspect of the present invention, a
mobile station device that communicates with a base station device
is provided. The mobile station device uses a physical downlink
shared channel to receive a system information block common for a
plurality of the mobile station device, and the system information
block includes information related to configuration of an enhanced
mobile station device-specific search space.
[0028] (15) Preferably, the above mobile station device uses the
physical downlink shared channel to receive dedicated radio
resource control information for the mobile station device, and the
dedicated radio resource control information includes information
related to configuration of the enhanced mobile station
device-specific search space.
[0029] (16) Preferably, until receiving the dedicated radio
resource control information from the base station device, the
mobile station device monitors the enhanced mobile station
device-specific search space configured on the basis of information
related to configuration of the enhanced mobile station
device-specific search space included in the system information
block for an enhanced physical downlink control channel targeting
the device itself.
[0030] (17) Preferably, in a case in which the enhanced mobile
station device-specific search space is configured on the basis of
information related to configuration of the enhanced mobile station
device-specific search space included in the dedicated radio
resource control information, the above mobile station device the
mobile station device does not configure the enhanced mobile
station device-specific search space on the basis of information
related to configuration of the enhanced mobile station
device-specific search space included in a subsequently received
system information block.
[0031] (18) According to another aspect of the present invention, a
mobile station device that communicates with a base station device
is provided. The mobile station device receives downlink control
information from the base station device. The downlink control
information is placed in one or a plurality of contiguous enhanced
control channel elements, the enhanced control channel elements are
placed in a plurality of virtual resource blocks so that a
plurality of the enhanced control elements are placed in a single
virtual resource block, the virtual resource blocks with numbers
that are consecutive in a first slot are placed into physical
resource blocks with numbers that are distributed in a first slot,
the virtual resource blocks with numbers that are consecutive in a
second slot are placed into physical resource blocks with numbers
that are distributed in a second slot, and a virtual resource block
in the first slot and a virtual resource block in the second slot
with the same number are placed into the physical resource blocks
with numbers that are distributed.
[0032] (19) Preferably, in the above mobile station device, a
plurality of the enhanced control channel elements placed in a
virtual resource block in a first slot and a virtual resource block
in a second slot with the same number are interleaved before
placement in the physical resource blocks, in units that are
smaller than the control channel elements.
[0033] (20) According to another aspect of the present invention, a
wireless communication method used by a base station device that
communicates with a mobile station device is provided. The wireless
communication method uses a physical broadcast channel to transmit
information instructing the mobile station device to monitor a
common search space or an enhanced common search space for a
physical downlink channel.
[0034] (21) According to another aspect of the present invention, a
wireless communication method used by a base station device that
communicates with a mobile station device is provided. The wireless
communication method uses a physical downlink shared channel to
transmit a system information block which is common for a plurality
of the mobile station device and which includes information related
to configuration of an enhanced mobile station device-specific
search space.
[0035] (22) According to another aspect of the present invention, a
wireless communication method used by a base station device that
communicates with a mobile station device is provided. The wireless
communication method places downlink control information in one or
a plurality of contiguous enhanced control channel elements, places
the enhanced control channel elements in a plurality of virtual
resource blocks so that a plurality of the enhanced control
elements are placed in a single virtual resource block, places the
virtual resource blocks with numbers that are consecutive in a
first slot into physical resource blocks with numbers that are
distributed in a first slot, places the virtual resource blocks
with numbers that are consecutive in a second slot into physical
resource blocks with numbers that are distributed in a second slot,
and places a virtual resource block in the first slot and a virtual
resource block in the second slot with the same number into the
physical resource blocks with numbers that are distributed.
[0036] (23) According to another aspect of the present invention, a
wireless communication method used by a mobile station device that
communicates with a base station device is provided. The wireless
communication method uses a physical broadcast channel to transmit
information instructing the mobile station device to monitor a
common search space or an enhanced common search space for a
physical downlink channel, and on the basis of the information,
monitors the common search space or the enhanced common search
space for the physical downlink channel.
[0037] (24) According to another aspect of the present invention, a
wireless communication method used by a mobile station device that
communicates with a base station device is provided. The wireless
communication method uses a physical downlink shared channel to
receive a system information block common for a plurality of the
mobile station device, and the system information block includes
information related to configuration of an enhanced mobile station
device-specific search space.
[0038] (25) According to another aspect of the present invention, a
wireless communication method used by a mobile station device that
communicates with a base station device is provided. The wireless
communication method receives downlink control information from the
base station device, the downlink control information is placed in
one or a plurality of contiguous enhanced control channel elements,
the enhanced control channel elements are placed in a plurality of
virtual resource blocks so that a plurality of the enhanced control
elements are placed in a single virtual resource block, the virtual
resource blocks with numbers that are consecutive in a first slot
are placed into physical resource blocks with numbers that are
distributed in a first slot, the virtual resource blocks with
numbers that are consecutive in a second slot are placed into
physical resource blocks with numbers that are distributed in a
second slot, and a virtual resource block in the first slot and a
virtual resource block in the second slot with the same number are
placed into the physical resource blocks with numbers that are
distributed.
[0039] (26) According to another aspect of the present invention, a
wireless communication system in which a mobile station device and
a base station device communicate is provided. In the wireless
communication system, the base station device uses a physical
broadcast channel to transmit information instructing the mobile
station device to monitor a common search space or an enhanced
common search space for a physical downlink channel. On the basis
of the information, the mobile station device monitors the common
search space or the enhanced common search space for the physical
downlink channel.
[0040] (27) According to another aspect of the present invention, a
wireless communication system in which a mobile station device and
a base station device communicate is provided. In the wireless
communication system, the base station device uses a physical
downlink shared channel to transmit a system information block
which is common for a plurality of the mobile station device and
which includes information related to configuration of an enhanced
mobile station device-specific search space. The mobile station
device configures the enhanced mobile station device-specific
search space on the basis of the information.
[0041] (28) According to another aspect of the present invention, a
wireless communication system in which a mobile station device and
a base station device communicate is provided. In the wireless
communication system, the base station device places downlink
control information in one or a plurality of contiguous enhanced
control channel elements, places the enhanced control channel
elements in a plurality of virtual resource blocks so that a
plurality of the enhanced control elements are placed in a single
virtual resource block, places the virtual resource blocks with
numbers that are consecutive in a first slot into physical resource
blocks with numbers that are distributed in a first slot, places
the virtual resource blocks with numbers that are consecutive in a
second slot into physical resource blocks with numbers that are
distributed in a second slot, places a virtual resource block in
the first slot and a virtual resource block in the second slot with
the same number into the physical resource blocks with numbers that
are distributed, and transmits a signal placed in the physical
resource blocks to the mobile station device. The mobile station
device receives the signal placed in the physical resource blocks,
and conducts a process of decoding the downlink control information
on the received signal.
[0042] (29) According to another aspect of the present invention,
an integrated circuit used by a base station device that
communicates with a mobile station device is provided. The
integrated circuit uses a physical broadcast channel to transmit
information instructing the mobile station device to monitor a
common search space or an enhanced common search space for a
physical downlink channel.
[0043] (30) According to another aspect of the present invention,
an integrated circuit used by a base station device that
communicates with a mobile station device is provided. The
integrated circuit uses a physical downlink shared channel to
transmit a system information block which is common for a plurality
of the mobile station device and which includes information related
to configuration of an enhanced mobile station device-specific
search space.
[0044] (31) According to another aspect of the present invention,
an integrated circuit used by a base station device that
communicates with a mobile station device is provided. The
integrated circuit places downlink control information in one or a
plurality of contiguous enhanced control channel elements, places
the enhanced control channel elements in a plurality of virtual
resource blocks so that a plurality of the enhanced control
elements are placed in a single virtual resource block, places the
virtual resource blocks with numbers that are consecutive in a
first slot into physical resource blocks with numbers that are
distributed in a first slot, places the virtual resource blocks
with numbers that are consecutive in a second slot into physical
resource blocks with numbers that are distributed in a second slot,
and places a virtual resource block in the first slot and a virtual
resource block in the second slot with the same number into the
physical resource blocks with numbers that are distributed.
[0045] (32) According to another aspect of the present invention,
an integrated circuit used by a mobile station device that
communicates with a base station device is provided. The integrated
circuit uses a physical broadcast channel to receive information
instructing the mobile station device to monitor a common search
space or an enhanced common search space for a physical downlink
channel, and on the basis of the information, monitors the common
search space or the enhanced common search space for the physical
downlink channel.
[0046] (33) According to another aspect of the present invention,
an integrated circuit used by a mobile station device that
communicates with a base station device is provided. The integrated
circuit uses a physical downlink shared channel to receive a system
information block common for a plurality of the mobile station
device, and the system information block includes information
related to configuration of an enhanced mobile station
device-specific search space.
[0047] (34) According to another aspect of the present invention,
an integrated circuit used by a mobile station device that
communicates with a base station device is provided. The integrated
circuit receives downlink control information from the base station
device, the downlink control information is placed in one or a
plurality of contiguous enhanced control channel elements, the
enhanced control channel elements are placed in a plurality of
virtual resource blocks so that a plurality of the enhanced control
elements are placed in a single virtual resource block, the virtual
resource blocks with numbers that are consecutive in a first slot
are placed into physical resource blocks with numbers that are
distributed in a first slot, the virtual resource blocks with
numbers that are consecutive in a second slot are placed into
physical resource blocks with numbers that are distributed in a
second slot, and a virtual resource block in the first slot and a
virtual resource block in the second slot with the same number are
placed into the physical resource blocks with numbers that are
distributed.
Advantageous Effects of Invention
[0048] According to the present invention, in a system in which
both a backward compatible component carrier and a non-backward
compatible component carrier coexist, a mobile station device is
able to efficiently conduct initial connection establishment
(initial access) on both component carriers.
BRIEF DESCRIPTION OF DRAWINGS
[0049] FIG. 1 is a conceptual diagram of a wireless communication
system according to an embodiment.
[0050] FIG. 2 is a diagram illustrating a schematic configuration
of a radio frame according to the present embodiment.
[0051] FIG. 3 is a diagram illustrating an example of physical
downlink channel mapping on a backward compatible component carrier
according to the present embodiment.
[0052] FIG. 4 is a diagram illustrating an example of physical
downlink channel mapping on a non-backward compatible component
carrier according to the present embodiment.
[0053] FIG. 5 is a diagram illustrating the layout of a search
space according to the present embodiment.
[0054] FIG. 6 is a diagram illustrating a configuration of PDCCH
candidates and E-PDCCH candidates according to the present
embodiment.
[0055] FIG. 7 is a diagram illustrating a configuration of a search
space inside a PDCCH domain according to the present
embodiment.
[0056] FIG. 8 is a diagram illustrating a method of mapping the
PDCCH to resource elements according to the present embodiment.
[0057] FIG. 9 is a diagram illustrating a method of mapping the
E-PDCCH in the enhanced common search space to resource elements
according to the present embodiment.
[0058] FIG. 10 is a diagram illustrating another method of mapping
the E-PDCCH in the enhanced common search space to resource
elements according to the present embodiment.
[0059] FIG. 11 is a diagram illustrating a method using an offset
when mapping the E-PDCCH in the enhanced common search space to
resource elements according to the present embodiment.
[0060] FIG. 12 is a diagram illustrating another method using an
offset when mapping the E-PDCCH in the enhanced common search space
to resource elements according to the present embodiment.
[0061] FIG. 13 is a diagram illustrating a method of mapping the
E-PDCCH in the enhanced UE-specific search space to resource
elements according to the present embodiment.
[0062] FIG. 14 is a diagram for explaining initial connection
establishment between a base station device and a mobile station
device according to the present embodiment.
[0063] FIG. 15 is a flowchart illustrating a process of switching
the search space to monitor for the DCI format in a mobile station
device according to the present embodiment.
[0064] FIG. 16 is a schematic block diagram illustrating a
configuration of a mobile station device according to the present
embodiment.
[0065] FIG. 17 is a schematic block diagram illustrating a
configuration of a base station device according to the present
embodiment.
DESCRIPTION OF EMBODIMENT
[0066] Hereinafter, an embodiment of the present invention will be
described in detail and with reference to the drawings.
[0067] [Physical Channel]
[0068] First, a physical channel according to the present
embodiment will be described.
[0069] FIG. 1 is a conceptual diagram of a wireless communication
system according to the present embodiment. In FIG. 1, the wireless
communication system includes mobile station devices 1A to 1C, and
a base station device 3. FIG. 1 indicates that a synchronization
signal (SS), a downlink reference signal (DL RS), a physical
broadcast channel (PBCH), a physical downlink control channel
(PDCCH), an enhanced physical downlink control channel (E-PDCCH), a
physical downlink shared channel (PDSCH), a physical multicast
channel (PMCH), a physical control format indicator channel
(PCFICH), and a physical hybrid ARQ indicator channel (PHICH) are
used for wireless communication on the downlink from the base
station device 3 to the mobile station devices 1A to 1C.
[0070] In addition, FIG. 1 indicates that an uplink reference
signal (UL RS), a physical uplink control channel (PUCCH), a
physical uplink shared channel (PUSCH), and a physical random
access channel (PRACH) are used for wireless communication on the
uplink from the mobile station devices 1A to 1C to the base station
device 3. Hereinafter, the mobile station devices 1A to 1C may also
be designated the mobile station device 1.
[0071] The synchronization signal is used by the mobile station
device 1 to synchronize the frequency domain and the time domain of
the downlink. The downlink reference signal is used by the mobile
station device 1 to synchronize the frequency domain and the time
domain of the downlink, is used by the mobile station device 1 to
measure the reception quality of the downlink, and is used by the
mobile station device 1 to compensate the channels of the PDSCH and
the PDCCH. The PBCH is a physical channel used to broadcast system
information (master information block, broadcast channel (BCH))
used in common by the mobile station devices 1. The PBCH is
transmitted at a 40 ms interval. The timing of the 40 ms interval
is detected by blind detection in the mobile station device 1.
Also, the PBCH is retransmitted at a 10 ms interval.
[0072] The PDCCH and the E-PDCCH are physical channels used to
transmit downlink control information (DCI) such as a downlink
assignment (also designated a downlink grant) or an uplink grant. A
downlink assignment is made up of information related to the
modulation and coding scheme (MCS) for the PDSCH, information
indicating radio resource allocation, a transmission power control
(TPC) command for the PUSCH, and the like. An uplink grant is made
up of information related to the modulation and coding scheme for
the PUSCH, information indicating radio resource allocation, a TPC
command for the PUSCH, and the like.
[0073] Multiple formats are used in the downlink control
information. The format of the downlink control information is
called the DCI format. For example, DCI Format 0 is used for
scheduling of the PUSCH with a single-antenna port transmission
scheme within a single cell. DCI Format 4 is used for scheduling of
the PUSCH with a multi-antenna port transmission scheme within a
single cell. DCI Format 1A is used for scheduling of the PDSCH with
a single-antenna port transmission scheme or a transmission
diversity scheme within a single cell. DCI Format 2 is used for
scheduling of the PDSCH with a multi-antenna port transmission
scheme within a single cell. DCI Format 0 and DCI Format 4 are
uplink grants. DCI Format 1A and DCI Format 2 are downlink
assignments.
[0074] The PDSCH is a physical channel used to transmit paging
information (paging channel (PCH)), system information, and
downlink data (downlink shared channel (DL-SCH)). System
information transmitted by PUSCH is designated a system information
block. In addition, a system information block includes radio
resource configuration information common for multiple mobile
station devices. The PMCH is a physical channel used to transmit
information (multicast channel (MCH)) related to the Multimedia
Broadcast and Multicast Service (MBMS). The PCFICH is a physical
channel used to transmit information indicating the domain (OFDM
symbols) in which the PDCCH is placed. The PHICH is a physical
channel used to transmit a HARQ indicator (acknowledgement
information) that indicates whether or not uplink data received by
the base station device 3 was successfully decoded.
[0075] In the case in which the base station device 3 successfully
decodes uplink data included in the PUSCH, the HARQ indicator for
that uplink data indicates an acknowledgement (ACK), whereas in the
case in which the base station device 3 fails to decode uplink data
included in the PUSCH, the HARQ indicator indicates a negative
acknowledgement (NACK). A single PHICH transmits a HARQ indicator
for a single piece of uplink data. HARQ indicators for multiple
pieces of uplink data included in the same PUSCH are transmitted
using multiple PHICHs.
[0076] The uplink reference signal is a signal that is used by the
base station device 3 to synchronize the time domain of the uplink,
used by the base station device 3 to measure the reception quality
of the uplink, and used by the base station device 3 to compensate
the channels of the PUSCH and the PUCCH. The uplink reference
signal may be a demodulation reference signal (DMRS) that is
time-multiplexed with the PUSCH or PUCCH and transmitted, or a
sounding reference signal (SRS) that is transmitted irrespectively
of the PUSCH and PUCCH.
[0077] The PUCCH is a physical channel used to transmit uplink
control information (UCI), which is information used to control
communication, such as channel state information (CSI) indicating
the channel quality of the downlink, a scheduling request (SR)
indicating a PUSCH radio resource request, and an ACK/NACK
indicating whether or not downlink data received by the mobile
station device 1 was successfully decoded.
[0078] The PUSCH is a physical channel used to transmit uplink data
(uplink shared channel (UL-SCH)) and uplink control information.
The PRACH is a physical channel used to transmit a random access
preamble. The PRACH's primary purpose is for the mobile station
device 1 to synchronize the time domain with the base station
device 3, but the PRACH is otherwise used for the initial
connection establishment procedure, the handover procedure, the
connection re-establishment procedure, for synchronization of
uplink transmission (timing adjustment), and for uplink radio
resource allocation.
[0079] The BCH, UL-SCH, DL-SCH, and the like are transport
channels. The units by which the UL-SCH is transmitted by the
PUSCH, as well as the units by which the DL-SCH is transmitted by
the PDSCH, are called transport blocks (TBs). A transport block is
a unit of data that the Media Access Control (MAC) layer delivers
to the physical layer. In the MAC layer, HARQ (retransmission)
control is conducted for each transport block. Additionally, the
units of data by which the UL-SCH, DL-SCH, and the like are handled
in the MAC layer are also called MAC protocol data units (PDUs). In
the physical layer, transport blocks are mapped to code words, and
a coding process is conducted on each code word.
[0080] [Cell Aggregation (Carrier Aggregation)]
[0081] Hereinafter, cell aggregation (carrier aggregation)
according to the present embodiment will be described.
[0082] With cell aggregation, multiple serving cells are
aggregated. For example, in a cell aggregation process, three
serving cells (serving cell 1, serving cell 2, serving cell 3) are
aggregated. One serving cell from among the aggregated multiple
serving cells is the primary cell (Pcell).
[0083] The primary cell is the cell in which the mobile station
device 1 conducted an initial connection establishment procedure,
the cell in which the mobile station device 1 started a connection
re-establishment procedure, or the cell that was specified as the
primary cell in a handover procedure.
[0084] The serving cells excluding the primary cell are secondary
cells (Scells). Secondary cells are used to provide additional
radio resources. Secondary cells are primarily used for PDSCH,
PUSCH, PRACH transmission and reception. Secondary cells operate on
a different frequency than the primary cell, and are added by the
base station device 3 after establishing a connection between the
mobile station device 1 and the base station device 3. In addition,
secondary cells are reported to the mobile station device 1 from
the base station device 3 during a handover procedures. The mobile
station device 1 conducts PUCCH transmission in the primary cell
only, and does not conduct PUCCH transmission in the secondary
cells. The mobile station device 1 may also not receive paging and
system information transmitted by the PBCH and PDSCH of a secondary
cell.
[0085] The carrier corresponding to a serving cell on the downlink
is the downlink component carrier (DL CC), while the carrier
corresponding to a serving cell on the uplink is the uplink
component carrier (UL CC). The carrier corresponding to the primary
cell on the downlink is the downlink primary component carrier (DL
PCC), while the carrier corresponding to the primary cell on the
uplink is the uplink primary component carrier (UL PCC). The
carrier corresponding to a secondary cell on the downlink is the
downlink secondary component carrier (DL SCC), while the carrier
corresponding to a secondary cell on the uplink is the uplink
secondary component carrier (UL SCC).
[0086] A downlink component carrier may be a backward compatible
component carrier, or a non-backward compatible component carrier.
In the present embodiment, backward compatible component carriers
are the downlink component carriers on which all of the physical
downlink channels discussed above are transmitted. In the present
embodiment, non-backward compatible component carriers are the
downlink component carriers on which the PCFICH, PHICH, and PDCCH
are not transmitted. While the base station device 3 and the mobile
station device 1 are communicating using a component carrier, that
component carrier's type cannot be changed.
[0087] Each physical channel is transmitted in one of the serving
cells. In other words, a single physical channel is not transmitted
across multiple serving cells.
[0088] [Radio Frame]
[0089] Hereinafter, a radio frame according to the present
embodiment will be described.
[0090] FIG. 2 is a diagram illustrating a schematic configuration
of a radio frame according to the present embodiment. Each radio
frame has a 10 ms length. Also, each radio frame contains 20 slots.
Each slot has a 0.5 ms length, and is assigned a number from 0 to
19. Each subframe has a 1 ms length, and is defined by two
consecutive slots. The ith subframe within a radio frame contains
the (2.times.i)th slot and the (2.times.i+1)th slot. In other
words, 10 subframes may be used in each 10 ms interval.
[0091] The signal or physical channel transmitted in each slot is
expressed by a resource grid. The resource grid is defined by
multiple subcarriers and multiple OFDM symbols. The number of
subcarriers constituting one slot depends on the downlink bandwidth
of the cell. The number of OFDM symbols constituting one slot is 7.
Each element within the resource grid is designated a resource
element. A resource element is identified using a subcarrier number
and an OFDM symbol number.
[0092] A resource block is used to express a mapping of resource
elements in a given physical downlink channel (such as the PDSCH).
Among resource blocks, virtual resource blocks and physical
resource blocks are defined. A given physical downlink channel is
first mapped to a virtual resource block. Afterwards, the virtual
resource block is mapped to a physical resource block. One physical
resource block is defined from 7 continuous OFDM symbols in the
time domain and 12 contiguous subcarriers in the frequency domain.
Consequently, one physical resource block contains (7.times.12)
resource elements. In addition, one physical resource block
corresponds to one slot in the time domain, and corresponds to 180
kHz in the frequency domain. Physical resource blocks are numbered
starting from 0 in the frequency domain.
[0093] [Physical Downlink Channel Mapping]
[0094] Hereinafter, an example of physical downlink channel mapping
according to the present embodiment will be described.
[0095] FIG. 3 is a diagram illustrating an example of physical
downlink channel mapping on a backward compatible component carrier
according to the present embodiment. The PCFICH is mapped to the
0th (initial) OFDM symbol in the subframe. Also, the PCFICH is
mapped to four resource element groups distributed in the frequency
domain. A resource element group is made up of multiple contiguous
resource elements. The PHICH is mapped to the 0th (initial) OFDM
symbol in the subframe. One PCFICH is mapped to three resource
elements distributed in the frequency domain. In addition, the base
station device 3 may code-multiplex multiple PCFICHs onto the same
resource elements.
[0096] The PDCCH is mapped to the 0th, the 0th and 1st, or from the
0th to the 2nd OFDM symbols in the subframe. In the 0th OFDM
symbol, the PDCCH is mapped so as to avoid resource elements mapped
with the PCFICH and the PHICH. The mobile station device 1
recognizes the OFDM symbols mapped with the PDCCH on the basis of
information received by the PCFICH. In addition, the base station
device 3 may time- and frequency-multiplex multiple PDCCHs.
[0097] The PDSCH and the E-PDCCH are mapped to OFDM symbols not
mapped with the PDCCH in the subframe. The base station device 3
may frequency-multiplex, time-multiplex, and/or spatially multiplex
multiple PDSCHs. In addition, the base station device 3 may
frequency-multiplex, time-multiplex, and/or spatially multiplex
multiple E-PDCCHs. In addition, the base station device 3
frequency-multiplexes the PDSCH and the E-PDCCH.
[0098] In the time domain, the synchronization signal is
transmitted in the 0th and 5th subframes in each radio frame. In
those 0th and 5th subframes, the synchronization signal is
transmitted with the 5th and 6th OFDM symbols in the first slot.
Also, in the frequency domain, the synchronization signal is
transmitted with the 72 subcarriers in the center of the downlink
of the cell.
[0099] In the time domain, the PBCH is transmitted in the 0th
subframe in each radio frame. In that 0th subframe, the PBCH is
transmitted with the 0th to the 3rd OFDM symbols in the second
slot. Also, in the frequency domain, the PBCH is transmitted with
the 72 subcarriers in the center of the downlink of the cell. Note
that illustration of the downlink reference signal and the PMCH is
omitted from FIG. 3.
[0100] FIG. 4 is a diagram illustrating an example of physical
downlink channel mapping on a non-backward compatible component
carrier according to the present embodiment. The base station
device does not map any of the PCFICH, the PHICH, and the PDCCH
onto a non-backward compatible component carrier. Consequently, the
PDSCH and the E-PDCCH may be mapped starting from the 0th OFDM
symbol in each subframe. The mapping of the other physical downlink
channels is the same as for a backward compatible component
carrier, and thus the description will not be repeated. Note that
in FIG. 4, illustration of the downlink reference signal and the
PMCH is not given.
[0101] [Search Space]
[0102] Hereinafter, a search space according to the present
embodiment will be described.
[0103] FIG. 5 is a diagram illustrating the layout of a search
space according to the present embodiment. The PDCCH domain
contains a common search space (CSS) and a UE-specific search space
(USS). The common search space and the UE-specific search space are
sets of resources that the base station device 3 may use to
transmit the PDCCH. The mobile station device 1 monitors the common
search space and the UE-specific search space for the PDCCH. Since
the PDCCH is not transmitted on a non-backward compatible component
carrier, the common search space and the UE-specific search space
do not exist in a non-backward compatible component carrier.
[0104] The E-PDCCH domain contains an enhanced common search space
(E-CSS) and an enhanced UE-specific search space (E-USS). The
enhanced common search space and the enhanced UE-specific search
space are sets of resources that the base station device 3 may use
to transmit the E-PDCCH. The mobile station device 1 monitors the
enhanced common search space and the enhanced UE-specific search
space for the E-PDCCH.
[0105] The common search space and the enhanced common search space
are defined by resources that are common for multiple mobile
station devices 1. The UE-specific search space and the enhanced
UE-specific search space are independently defined for each mobile
station device 1. In the common search space and the enhanced
common search space, the base station device 3 transmits a DCI
format targeted at multiple mobile station devices and/or a DCI
format targeted at a specific mobile station device. For example,
the DCI format targeted at multiple mobile station devices is a DCI
format used for scheduling of system information blocks, or a DCI
format used for scheduling of random access responses. In the
UE-specific search space and the enhanced UE-specific search space,
the base station device 3 transmits a DCI format targeted at a
specific mobile station device.
[0106] Resource candidates that possibly may be used to transmit
the PDCCH within the common search space and the UE-specific search
space are designated PDCCH candidates. Also, PDCCH candidates are
made up of multiple control channel elements (CCEs). Candidates
that possibly may be used to transmit the E-PDCCH within the
enhanced common search space and the enhanced UE-specific search
space are designated E-PDCCH candidates. Also, E-PDCCH candidates
are made up of multiple enhanced control channel elements
(E-CCEs).
[0107] FIG. 6 is a diagram illustrating a configuration of PDCCH
candidates and E-PDCCH candidates according to the present
embodiment. A PDCCH candidate is made up of one or contiguous
control channel elements. A PDCCH candidate made up of n contiguous
control channel elements starts only on a control channel element
having a number (index) whose remainder is 0 in the case of
dividing the number (index) of the control channel element by n. A
PDCCH candidate corresponding to a search space within the E-PDCCH
domain is made up of one or contiguous enhanced control channel
elements. A PDCCH candidate made up of n contiguous enhanced
control channel elements starts only on an enhanced control channel
element having a number (index) whose remainder is 0 in the case of
dividing the number (index) of the enhanced control channel element
by n.
[0108] In FIG. 6, the ith PDCCH candidate of aggregation level 8 is
made up of the (i.times.8)th to the (i.times.8+7)th control channel
elements. In FIG. 6, the ith PDCCH candidate of aggregation level 4
is made up of the (i.times.4)th to the (i.times.4+3)th control
channel elements. In FIG. 6, the ith PDCCH candidate of aggregation
level 2 is made up of the (i.times.2)th and the (i.times.2+1)th
control channel elements. In FIG. 6, the ith PDCCH candidate of
aggregation level 1 is made up of the ith control channel
element.
[0109] In FIG. 6, the ith E-PDCCH candidate of aggregation level 8
is made up of the (i.times.8)th to the (i.times.8+7)th enhanced
control channel elements. In FIG. 6, the ith E-PDCCH candidate of
aggregation level 4 is made up of the (i.times.4)th to the
(i.times.4+3)th enhanced control channel elements. In FIG. 6, the
ith E-PDCCH candidate of aggregation level 2 is made up of the
(i.times.2)th and the (i.times.2+1)th enhanced control channel
elements. In FIG. 6, the ith E-PDCCH candidate of aggregation level
1 is made up of the ith enhanced control channel element.
[0110] The number of control channel elements constituting a PDCCH
candidate, or the number of enhanced control channel elements
constituting an E-PDCCH, is designated the aggregation level. The
aggregation level is 1, 2, 4, or 8. A search space is defined for
each aggregation level. The common search space and the enhanced
common search space may take aggregation levels 4 and 8. The
UE-specific search space and the enhanced UE-specific search space
may take aggregation levels 1, 2, 4, and 8.
[0111] The search space of aggregation level 1 is made up of six
contiguous PDCCH candidates or E-PDCCH candidates. The search space
of aggregation level 2 is made up of six contiguous PDCCH
candidates or E-PDCCH candidates. The search space of aggregation
level 4 is made up of two contiguous PDCCH candidates or E-PDCCH
candidates. The search space of aggregation level 8 is made up of
two contiguous PDCCH candidates or E-PDCCH candidates.
[0112] [Common Search Space and UE-Specific Search Space]
[0113] Hereinafter, the common search space and the UE-specific
search space according to the present embodiment will be
described.
[0114] FIG. 7 is a diagram illustrating a configuration of a search
space inside a PDCCH domain according to the present embodiment.
The PDCCH domain contains an aggregation level 4 common search
space, an aggregation level 8 common search space, an aggregation
level 1 UE-specific search space, an aggregation level 2
UE-specific search space, an aggregation level 4 UE-specific search
space, and an aggregation level 8 UE-specific search space.
[0115] The common search space is made up of control channel
elements with predetermined numbers. In FIG. 7, the aggregation
level 4 common search space and the aggregation level 8 common
search space are made up of control channel elements 0 to 15. The
control channel elements constituting the UE-specific search space
are determined on the basis of information such as a radio network
temporary identifier (RNTI) assigned to the mobile station device 1
by the base station device 3, the aggregation level, and the slot
number inside the radio frame. During initial access, the base
station device 3 transmits a random access response including a
temporary cell-radio network temporary identifier (temporary
C-RNTI) to the mobile station device 1. After initial access, the
base station device 3 may also reconfigure the temporary cell-radio
network temporary identifier (C-RNTI) of the mobile station device
1.
[0116] FIG. 8 is a diagram illustrating a method of mapping the
PDCCH to resource elements according to the present embodiment. In
FIG. 8, the number 800 and the number 801 indicate PDCCHs
transmitted by the base station device 3 using one control channel.
In FIG. 8, the number 802 and the number 803 indicate PDCCHs
transmitted by the base station device 3 using two control
channels. The number 804 indicates the domain mapped with the
PDCCH/PHICH/PCFICH in a subframe of a given component carrier. The
number 805 and the number 806 indicate the PDSCH domain in a
subframe of a given component carrier. The number 807 indicates the
E-PDCCH domain in a subframe of a given component carrier.
[0117] One control channel element is used to transmit 36
modulation symbols (complex symbols). One control channel element
is made up of nine mini-CCEs. One mini-CCE is made up of four
modulation symbols. The base station device 3 maps one mini-CCE to
one resource element group. One resource element group is made up
of four contiguous resource elements. In other words, one
modulation symbol is mapped to one resource element.
[0118] The base station device 3 interleaves the control channel
elements from number 800 to number 803 in units of mini-CCEs. Next,
the base station device 3 cyclically shifts the interleaved
mini-CCEs. The base station device 3 determines the value by which
to cyclically shift the mini-CCEs on the basis of the physical
layer cell identity (PCI). In other words, cells having different
physical layer cell identities undergo differently valued cyclic
shifts. In so doing, PDCCH interference between cells may be
randomized.
[0119] Next, the base station device 3 maps the cyclically shifted
mini-CCEs to resource element groups of the PDCCH/PHICH/PCFICH
domain 804. The base station device 3 maps the PDCCH mini-CCEs to
resource element groups other than the resource element groups
mapped with the PCFICH.
[0120] [Enhanced Common Search Space]
[0121] Hereinafter, the enhanced common search space according to
the present embodiment will be described.
[0122] The enhanced common search space is made up of control
channel elements with predetermined numbers. The aggregation level
4 enhanced common search space and the aggregation level 8 enhanced
common search space are made up of enhanced control channel
elements 0 to 15. FIG. 9 is a diagram illustrating a method of
mapping the E-PDCCH in the enhanced common search space to resource
elements according to the present embodiment. In FIG. 9, the number
900 and the number 901 indicate E-PDCCHs in the enhanced common
search space transmitted by the base station device 3 using four
enhanced control channels. In FIG. 9, the number 902 indicates an
E-PDCCH in the enhanced common search space transmitted by the base
station device 3 using eight control channels. In FIG. 9, the bold
squares indicate enhanced control channel elements. In FIG. 9, the
numbers labeling the bold squares indicate enhanced control channel
element numbers.
[0123] The base station device 3 maps the enhanced control channel
elements 0 to 15 onto the virtual resource blocks 0 to 3. The base
station device 3 maps two enhanced control channel elements onto
one virtual resource block. In other words, the base station device
3 maps four enhanced control channel elements onto one virtual
resource block pair made up of a virtual resource block in the
first slot, and a virtual resource block in the second slot with
the same number as the number of the virtual resource block in the
first slot. Next, the base station device 3 maps virtual resource
blocks to physical resource blocks distributed in the frequency
domain. The base station device 3 maps virtual resource blocks in
the first slot to physical resource blocks in the first slot. The
base station device 3 maps virtual resource blocks in the second
slot to physical resource blocks in the second slot.
[0124] In FIG. 9, the enhanced physical downlink control channels
with the number 900 and the number 901 are mapped only to the first
slot, while the enhanced physical downlink control channel with the
number 902 is mapped only to the second slot. Consequently, there
is a problem in that the benefit of diversity in the time domain is
not obtained for the enhanced physical downlink control channels.
Accordingly, the base station device 3 interleaves the enhanced
control channel elements mapped to virtual resource block pairs in
units of modulation symbols or modulation symbol groups. At this
point, the number of modulation symbols constituting a modulation
symbol group is preferably smaller than the number of modulation
symbols corresponding to the enhanced control channel elements. The
base station device 3 maps the virtual resource block in the first
slot and the second virtual resource block of a virtual resource
block pair with interleaved modulation symbols onto physical
resource blocks distributed in the frequency domain. Consequently,
since a single enhanced physical downlink control channel is mapped
in a distributed manner between the first slot and the second slot
in the time domain, it becomes possible to obtain the benefits of
diversity in the time domain. For example, in FIG. 9, the enhanced
control channel elements 0, 4, 8, and 12 are mapped in a
distributed manner between the physical resource block 0 in the
first slot and the physical resource block 12 in the second
slot.
[0125] As a result, since enhanced physical downlink control
channels (downlink control information) are transmitted using
distributed resource elements, the advantages of frequency
diversity and time diversity may be obtained.
[0126] Note that the base station device 3 may also map enhanced
control channel elements to virtual resource blocks according to a
method other than the method described in FIG. 9. FIG. 10 is a
diagram illustrating another method of mapping the E-PDCCH in the
enhanced common search space to resource elements according to the
present embodiment. In addition, the base station device 3 may also
map a number of enhanced control channel elements other than 4 to
one virtual resource block pair.
[0127] In FIGS. 9 and 10, multiple base station devices 3 would
construct enhanced common search spaces on the same physical
resource blocks (physical resource blocks 0, 6, 12, and 18).
Consequently, the E-PDCCH transmitted in the enhanced common search
space by a given base station device 3 would interfere with the
E-PDCCH transmitted in the enhanced common search space by another
base station device 3. Accordingly, an offset is used in the case
in which the base station device 3 decides the virtual resource
block to which to map enhanced control channel elements. FIG. 11 is
a diagram illustrating a method using an offset when mapping the
E-PDCCH in the enhanced common search space to resource elements
according to the present embodiment. In FIGS. 9 and 10, enhanced
control channel elements are mapped to the virtual resource blocks
0 to 3, but in FIG. 11, enhanced control channel elements are
mapped to the virtual resource blocks from 4 to 7. In other words,
in FIG. 11, a value of 4 is used as an offset when deciding the
virtual resource block to which to map enhanced control channel
elements.
[0128] The base station device 3 may also receive information
indicating an offset value to be used by that base station device 3
from another base station device 3. The base station device 3 may
also decide on an offset value to be used by the device itself from
such received information indicating an offset value. The base
station device 3 may also transmit information indicating such a
decided offset value to another base station device 3. The base
station device 3 may also transmit information indicating such a
decided offset value in the PBCH. Consequently, the mobile station
device 1 becomes able to receive information indicating an offset
value in the PBCH, and ascertain the physical resource block in
which the E-PDCCH in the enhanced common search space is
transmitted.
[0129] In addition, the base station device 3 may also compute an
offset value on the basis of the device's own physical layer cell
identity. The mobile station device 1 detects the physical layer
cell identity of a base station device 3 from the synchronization
signal transmitted by that base station device 3. Consequently, the
mobile station device 1 is able to compute an offset value on the
basis of a physical layer cell identity detected from a
synchronization signal being transmitted by the base station device
3. Consequently, since the base station device 3 no longer has to
transmit information indicating an offset value to the mobile
station device 1, the signal overhead from the base station device
3 to the mobile station device 1 may be reduced.
[0130] Consequently, in FIG. 11, the E-PDCCH in the enhanced common
search space is mapped to different physical resource blocks than
in FIGS. 9 and 10. In FIGS. 9 and 10, the base station device 3
maps the E-PDCCH in the enhanced common search space to the
physical resource blocks 0, 6, 12, and 18. On the other hand, in
FIG. 11, the base station device 3 maps the E-PDCCH in the enhanced
common search space to the physical resource blocks 1, 7, 13, and
19. For example, by having a given base station device 3 use 0 as
an offset value and another base station device 3 use 4 as an
offset value, interference between E-PDCCHs in the enhanced common
search space may be avoided.
[0131] FIG. 12 is a diagram illustrating another method using an
offset when mapping the E-PDCCH in the enhanced common search space
to resource elements according to the present embodiment. In FIG.
12, the base station device 3 uses an offset when deciding the
enhanced control channel elements constituting the enhanced common
search space. In FIG. 12, the offset value is 16. Consequently, in
FIG. 12, the enhanced common search space is made up of the
enhanced control channel elements 16 to 31. In FIG. 12, the
enhanced control channel elements 16 to 31 are mapped to the
virtual resource blocks 4 to 7. Consequently, the method of FIG. 12
is able to obtain advantages similar to using 4 as the offset value
in FIG. 11.
[0132] [Enhanced UE-Specific Search Space]
[0133] Hereinafter, the enhanced UE-specific search space according
to the present embodiment will be described.
[0134] FIG. 13 is a diagram illustrating a method of mapping the
E-PDCCH in the enhanced UE-specific search space to resource
elements according to the present embodiment. In FIG. 13, the
number 1300 and the number 1301 indicate E-PDCCHs in the enhanced
UE-specific search space transmitted by the base station device 3
using eight enhanced control channels. In FIG. 13, the number 1302
and the number 1303 indicate E-PDCCHs in the enhanced UE-specific
search space transmitted by the base station device 3 using one
enhanced control channel. In FIG. 13, the number 1304 indicates an
E-PDCCH in the enhanced UE-specific search space transmitted by the
base station device 3 using two enhanced control channels. In FIG.
13, the number 1305 indicates an E-PDCCH in the enhanced
UE-specific search space transmitted by the base station device 3
using four enhanced control channels.
[0135] The base station device 3 configures virtual resource blocks
to which to map enhanced control channel elements corresponding to
the enhanced UE-specific search space. Hereinafter, such configured
virtual resource blocks will be simply designated the "configured
virtual resource blocks". The base station device 3 transmits
dedicated radio resource configuration information, including
information indicating the configured virtual resource blocks, to
the mobile station device 1. The mobile station device 1, upon
receiving the dedicated radio resource configuration information,
configures virtual resource blocks to which to map enhanced control
channel elements corresponding to the enhanced UE-specific search
space, on the basis of the information indicating the configured
virtual resource blocks included in the dedicated radio resource
configuration information. The base station device 3 is able to
configure different virtual resource blocks as the configured
virtual resource blocks for each mobile station device 1. In
addition, the base station device 3 is able to configure the same
virtual resource blocks as the configured virtual resource blocks
to a group of mobile station devices 1. In addition, the base
station device 3 is able to configure the same virtual resource
blocks as the configured virtual resource blocks to all mobile
station devices 1.
[0136] In FIG. 13, the virtual resource blocks 7, 8, 9, 10, 13, and
14 are the configured virtual resource blocks. The number of the
configured virtual resource block with the smallest virtual
resource block number is 0. In FIG. 13, 0 is the number of the
configured virtual resource block configured with the virtual
resource block whose virtual resource block number is 7. The number
of enhanced control channel elements corresponding to the enhanced
UE-specific search space depends on the number of configured
virtual resource blocks. The number of enhanced control channel
elements corresponding to the enhanced UE-specific search space may
be computed by multiplying the number of configured virtual
resource blocks by the number of enhanced control channel elements
mapped to one virtual resource block. In FIG. 13, since the number
of configured virtual resource blocks is 6, and the number of
enhanced control channel elements mapped to one virtual resource
block is 4, the number of enhanced control channel elements
corresponding to the enhanced UE-specific search space is 24.
[0137] The base station device 3 additionally configures the
enhanced control channel elements to constitute the enhanced
UE-specific search space from among the enhanced control channel
elements corresponding to the enhanced UE-specific search space.
The base station device 3 transmits dedicated radio resource
configuration information, including information indicating the
enhanced control channel elements constituting the enhanced
UE-specific search space, to the mobile station device 1. The
mobile station device 1, upon receiving the dedicated radio
resource configuration information, configures the enhanced
UE-specific search space to monitor for the E-PDCCH, on the basis
of the information indicating the enhanced control channel elements
constituting the enhanced UE-specific search space included in the
dedicated radio resource configuration information. The base
station device 3 may also configure a different start point of the
enhanced UE-specific search space for each aggregation level for
the mobile station device 1. The base station device 3 may also
configure a start point of the enhanced UE-specific search space
that is common for all aggregation levels for the mobile station
device 1. The base station device 3 may also configure a different
start point of the enhanced UE-specific search space for each
mobile station device 1. In addition, the base station device 3 may
also configure the same start point of the enhanced UE-specific
search space for a group of mobile station devices 1.
[0138] For example, in FIG. 13, the base station device 3 may
configure 8 as the common start point for the enhanced UE-specific
search space of all aggregation levels for a given mobile station
device 1. In this case, the aggregation level 1 enhanced
UE-specific search space is made up of the enhanced control channel
elements 8 to 13. Also, the aggregation level 2 enhanced
UE-specific search space is made up of the enhanced control channel
elements 8 to 19. Also, the aggregation level 4 enhanced
UE-specific search space is made up of the enhanced control channel
elements 8 to 23. Also, the aggregation level 8 enhanced
UE-specific search space is made up of the enhanced control channel
elements 8 to 23.
[0139] The base station device 3 maps enhanced control channel
elements corresponding to the enhanced UE-specific search space to
the configured virtual resource blocks. After that, the base
station device 3 maps the configured virtual resource blocks to
physical resource blocks with the same numbers as the numbers of
the configured virtual resource blocks. Note that the base station
device 3 may be configured to map virtual resource blocks
corresponding to the UE-specific search space to physical resource
blocks with different numbers than the numbers of the virtual
resource blocks, or to physical resource blocks with the same
numbers as the numbers of the virtual resource blocks.
[0140] [Initial Connection Establishment Procedure]
[0141] Hereinafter, an initial connection establishment procedure
according to the present embodiment will be described.
[0142] FIG. 14 is a diagram for explaining initial connection
establishment between the base station device 3 and the mobile
station device 1 according to the present embodiment. First, FIG.
14 will be used to describe initial connection establishment
procedure between the base station device 3 and the mobile station
device 1 on a backward compatible component carrier.
[0143] First, the mobile station device 1 conducts cell detection
(a cell search) using a synchronization signal transmitted by the
base station device 3 on the central 72 subcarriers of the cell
(1400). On the basis of the synchronization signal, the mobile
station device 1 acquires time timings, frequency timings, and a
physical layer cell identity. The mobile station device 1 acquires
a master information block using the PBCH transmitted by the base
station device 3 on the central 72 subcarriers of the cell (1402).
From information included in the master information block, the
mobile station device 1 configures the downlink bandwidth of the
cell and the system frame number.
[0144] The master information block includes 1-bit information
indicating the component carrier type. The base station device 3
sets the 1-bit information indicating the component carrier type to
0 when communicating with the mobile station device 1 using a
backward compatible component carrier. In other words, in the case
in which the PDCCH and E-PDCCH are placed in the cell used for
communication with the mobile station device 1, the base station
device 3 instructs the mobile station device 1 to monitor the
common search space for the PDCCH with the 1-bit information
indicating the component carrier type. In the case in which the
1-bit information indicating the component carrier type has been
set to 0, the mobile station device 1 configures itself to monitor
the common search space and the UE-specific search space for the
PDCCH.
[0145] Also, the base station device 3 sets the 1-bit information
indicating the component carrier type to 1 when communicating with
the mobile station device 1 using a non-backward compatible
component carrier. In other words, in the case in which the PDCCH
is not placed but the E-PDCCH is placed in the cell used for
communication with the mobile station device 1, the base station
device 3 instructs the mobile station device 1 to monitor the
enhanced common search space for the PDCCH with the 1-bit
information indicating the component carrier type. In the case in
which the 1-bit information indicating the component carrier type
has been set to 1, the mobile station device 1 configures itself to
monitor the enhanced common search space and the enhanced
UE-specific search space for the E-PDCCH. Consequently, the 1-bit
information indicating the component carrier type may also be
referred to as information instructing the mobile station device 1
to monitor the PDCCH or the E-PDCCH. As a result, the mobile
station device 1 is no longer required to monitor for both the
PDCCH and the E-PDCCH, and thus the load of the DCI format
receiving process on the mobile station device 1 may be
reduced.
[0146] The mobile station device 1 acquires a system information
block 1 transmitted by the base station device 3 using the PDSCH
(1404). The system information block 1 includes information related
to the transmission timings of system information blocks other than
the system information block 1.
[0147] The mobile station device 1 acquires a system information
block 2 transmitted by the base station device 3 using the PDSCH
(1406). The system information block 2 includes radio resource
configuration information that is common to multiple mobile station
devices 1. Such common radio resource configuration information
includes information related to the PRACH configuration. The mobile
station device 1 configures the PRACH in accordance with the
information related to the PRACH configuration. The base station
device 3 transmits the DCI format used for scheduling of system
information blocks using the PDCCH in the common search space.
[0148] The mobile station device 1 randomly selects a random access
preamble number. The mobile station device 1 uses the PRACH to
transmit the random access preamble of the selected number to the
base station device 3 (1408). The base station device 3 receives
the random access preamble transmitted in the PRACH. The base
station device 3 uses the random access preamble to estimate the
uplink transmission timings. The base station device 3 transmits a
random access response in the PDSCH. The random access response
includes multiple pieces of information regarding the random access
preamble detected by the base station device 3. The multiple pieces
of information are the random access preamble number, a temporary
cell-radio network temporary identifier, a timing advance (TA)
command, and information used for PUSCH scheduling (random access
response grant). The timing advance (TA) command is used to
instruct the mobile station device 1 to adjust the uplink
transmission timings. In the case in which the transmitted random
access preamble number is included in the random access response,
the mobile station device 1 determines that the relevant random
access response is targeted to the device itself. The base station
device 3 transmits the DCI format used for scheduling of the random
access response using the PDCCH in the common search space.
[0149] The mobile station device 1 adjusts the uplink transmission
timings on the basis of the TA command included in the random
access response. The mobile station device 1 transmits a connection
request message to the base station device 3 using the PUSCH
scheduled by the random access response grant (1412). The
connection request message includes an identifier that identifies
the mobile station device 1 (Initial UE-Identity). In the case in
which S-TMSI is provided, the mobile station device 1 sets an
identifier for identifying the mobile station device 1 within the
tracking area (System architecture evolution Temporary Mobile
Subscriber Identity (S-TMSI)) to the Initial UE-Identity.
Meanwhile, in the case in which S-TMSI is not provided, the mobile
station device 1 randomly selects a value from the range 0 to
2.sup.40-1, and sets the selected value to the Initial
UE-Identity.
[0150] The base station device 3 transmits a contention resolution
identity with the same value as the Initial UE-Identity included in
the PUSCH received from the mobile station device 1 to the mobile
station device 1 using the PDSCH (1414). In the case in which the
value of the received contention resolution identity and the value
of the transmitted Initial UE-Identity match, the mobile station
device 1 (1) regards contention resolution of the random access
preamble as successful, (2) sets the value of the temporary
cell-radio network temporary identifier to the cell-radio network
temporary identifier, (3) discards the temporary cell-radio network
temporary identifier, and (4) regards the random access procedure
as successfully completed.
[0151] The base station device 3 transmits the DCI format
corresponding to the PUSCH used to transmit the contention
resolution identity using the PDSCH in the common search space or
the UE-specific search space. At this point, the UE-specific search
space is decided on the basis of the temporary cell-radio network
temporary identifier assigned to the mobile station device 1.
[0152] The base station device 3 transmits dedicated radio resource
configuration information to the mobile station device 1 using the
PDSCH (1416). The base station device 3 is able to use the
dedicated radio resource configuration information to configure
which search space the mobile station device 1 monitors for the DCI
format. In addition, the base station device 3 is able to use the
dedicated radio resource configuration information to configure the
enhanced UE-specific search space. The base station device 3
transmits the DCI format used for scheduling of the dedicated radio
resource configuration information using the PDCCH in the common
search space or the UE-specific search space. At this point, the
UE-specific search space is decided on the basis of the cell-radio
network temporary identifier.
[0153] The base station device 3 transmits the DCI format used for
scheduling of the PUSCH in the search space configured using the
dedicated radio resource configuration information. The mobile
station device 1 transmits to the base station device 3 a
connection setup complete message indicating that configuration was
completed in accordance with the dedicated radio resource
configuration information using the scheduled PUSCH (1418). After
successfully transmitting the connection setup complete message,
the mobile station device 1 regards the initial connection
establishment procedure as successfully completed.
[0154] Next, FIG. 14 will be used to describe initial connection
establishment between the base station device 3 and the mobile
station device 1 on a non-backward compatible component carrier.
Description will not be repeated for items common to the initial
connection establishment between the base station device 3 and the
mobile station device 1 on a backward compatible component
carrier.
[0155] The mobile station device 1 acquires a master information
block using the PBCH transmitted by the base station device 3 on
the central 72 subcarriers of the cell (1402). From information
included in the master information block, the mobile station device
1 configures the downlink bandwidth of the cell and the system
frame number. In addition, in the case in which the 1-bit
information indicating the component carrier type included in the
master information block has been set to 1, the mobile station
device 1 configures itself to monitor the enhanced common search
space and the enhanced UE-specific search space for the
E-PDCCH.
[0156] The base station device 3 transmits the DCI format used for
scheduling of system information blocks using the E-PDCCH in the
enhanced common search space. The mobile station device 1 monitors
the enhanced common search space for the DCI format used for
scheduling of system information blocks (1404, 1406). The base
station device 3 transmits the system information block 2 including
information indicating the enhanced UE-specific search space. In
other words, the base station device 3 broadcasts information
indicating the enhanced UE-specific search space. The mobile
station device 1 configures the enhanced UE-specific search space
on the basis of the information indicating the enhanced UE-specific
search space included in the system information block 2.
Consequently, on a non-backward compatible component carrier, the
mobile station device 1 is able to configure the UE-specific search
space before receiving dedicated radio resource control
information. In addition, the base station device 3 is able to
transmit the DCI format to the mobile station device 1 using the
enhanced UE-specific search space before transmitting dedicated
radio resource control information to the mobile station device
1.
[0157] Note that on a non-backward compatible component carrier,
the UE-specific search space before the mobile station device 1
receives dedicated radio resource control information may be made
up of enhanced control channel elements, virtual resource blocks,
or physical resource blocks with predetermined numbers. In
addition, on a non-backward compatible component carrier, the
mobile station device 1 may also configure virtual resource blocks
corresponding to the enhanced UE-specific search space on the basis
of the information indicating the enhanced UE-specific search space
included in the system information block 2. In addition, the mobile
station device 1 may also regard enhanced control channel elements
with predetermined numbers from among the enhanced control channel
elements corresponding to such configured virtual resource blocks
as being the enhanced UE-specific search space. In addition, the
mobile station device 1 may also regard configured virtual resource
blocks with predetermined numbers from among such configured
virtual resource blocks as being the enhanced UE-specific search
space.
[0158] However, if the mobile station device 1 configures the
enhanced UE-specific search space on the basis of information
indicating the enhanced UE-specific search space included in the
system information block 2, there is a problem in that multiple
mobile station devices 1 would configure the same enhanced
UE-specific search space, and there would be insufficient resources
for the enhanced UE-specific search space. Accordingly, after the
initial connection establishment procedure ends, the base station
device 3 preferably reconfigures the enhanced UE-specific search
space using the dedicated radio resource control information.
[0159] The base station device 3 transmits the DCI format used for
scheduling of the random access response using the PDCCH in the
common search space. The mobile station device 1 monitors the
enhanced common search space for the DCI format used for scheduling
of the random access response (1410).
[0160] The base station device 3 transmits the DCI format
corresponding to the PUSCH used to transmit the contention
resolution identity using the E-PDCCH in the enhanced common search
space or the enhanced UE-specific search space. At this point, the
enhanced UE-specific search space is configured on the basis of the
information indicating the enhanced UE-specific search space
included in the system information block 2.
[0161] The base station device 3 transmits dedicated radio resource
configuration information to the mobile station device 1 using the
PDSCH (1416). The base station device 3 is able to use the
dedicated radio resource configuration information to reconfigure
the enhanced UE-specific search space. The base station device 3
transmits the DCI format used for scheduling of the dedicated radio
resource configuration information using the E-PDCCH in the
enhanced common search space or the enhanced UE-specific search
space. At this point, the enhanced UE-specific search space is
configured on the basis of the information indicating the enhanced
UE-specific search space included in the system information block
2.
[0162] The base station device 3 transmits the DCI format used for
scheduling of the PUSCH in the enhanced common search space or the
UE-specific search space configured using the dedicated radio
resource configuration information. The mobile station device 1
transmits to the base station device 3 a connection setup complete
message indicating that configuration was completed in accordance
with the dedicated radio resource configuration information using
the scheduled PUSCH (1418). After successfully transmitting the
connection setup complete message, the mobile station device 1
regards the initial connection establishment procedure as
successfully completed.
[0163] Note that in the case in which the PDCCH and E-PDCCH are
placed in the cell used to communicate with the mobile station
device 1, the base station device 3 may also instruct the mobile
station device 1 to monitor the common search space for the PDCCH
or monitor the enhanced common search space for the E-PDCCH with
the information that instructs the mobile station device 1 to
monitor for the PDCCH or E-PDCCH. However, the mobile station
device 1 instructed by such information to monitor for the E-PDCCH
during the initial connection establishment procedure is unable to
identify whether the PCFICH is being transmitted on a component
carrier. For this reason, the mobile station device 1 is unable to
identify the OFDM symbols in which the PDCCH and E-PDCCH are
placed, and is unable to correctly monitor for the E-PDCCH.
[0164] Accordingly, the base station device 3 may also use the PBCH
to transmit information instructing the mobile station device 1 to
monitor for the PDCCH or E-PDCCH, together with information
indicating the OFDM symbols in which the E-PDCCH is placed. In the
case of being instructed to monitor for the E-PDCCH by information
instructing to monitor for the PDCCH or E-PDCCH, the mobile station
device 1 recognizes the OFDM symbols in which the E-PDCCH is placed
on the basis of the information indicating the OFDM symbols in
which the E-PDCCH is placed. Meanwhile, in the case of being
instructed to monitor for the PDCCH by information instructing to
monitor for the PDCCH or E-PDCCH, the mobile station device 1
recognizes the OFDM symbols in which the PDCCH is placed on the
basis of information received using the PCFICH.
[0165] In addition, the OFDM symbols in which the E-PDCCH is placed
may also be predefined. For example, the OFDM symbols in which the
E-PDCCH is placed may always be the OFDM symbols in the first slot
excluding the 0th, 1st, and 2nd OFDM symbols, as well as all OFDM
symbols in the second slot.
[0166] Consequently, in the case in which the PDCCH and E-PDCCH are
placed in the cell used to communicate with the mobile station
device 1, the base station device 3 instructs the mobile station
device 1 to monitor the common search space for the PDCCH or
monitor the enhanced common search space for the E-PDCCH with the
information that instructs the mobile station device 1 to monitor
for the PDCCH or E-PDCCH. Even in this case, the mobile station
device 1 is able to correctly monitor for the E-PDCCH.
[0167] Note that the enhanced common search space may be
constructed inside the central 72 subcarriers of the cell, and the
base station device 3 may transmit the system information block 1
and the system information block 2 using the PDSCH placed inside
the central 72 subcarriers of the cell. Consequently, in FIG. 14,
before conducting the process of receiving the random access
response and the DCI format used for scheduling of the random
access response, the mobile station device 1 is able to receive the
system information block 1 and the system information block 2 from
the base station device 3 using only the central 72 subcarriers of
the cell, and thus the load of the receiving process on the mobile
station device 1 may be reduced.
[0168] [Process of Switching the Space to Monitor for the DCI
Format]
[0169] Hereinafter, a process of switching the search space to
monitor for the DCI format in the mobile station device 1 according
to the present embodiment will be described.
[0170] FIG. 15 is a flowchart illustrating a process of switching
the search space to monitor for the DCI format in the mobile
station device 1 according to the present embodiment. The mobile
station device 1 receives a master information block using the PBCH
(step S1501). The mobile station device 1 identifies the component
carrier type on the basis of 1-bit information indicating the
component carrier type included in the master information block
(step S1502).
[0171] In step S1502, in the case of regarding the component
carrier type to be a backward compatible component carrier, the
mobile station device 1 monitors the common search space (CSS) and
the UE-specific search space (USS) for the PDCCH (step S1503).
After step S1503, the mobile station device 1 receives dedicated
radio resource control information. In addition, the mobile station
device 1 configures the search space to monitor for the PDCCH or
E-PDCCH in accordance with the dedicated radio resource control
information (step S1504). The mobile station device 1 monitors for
the PDCCH or the E-PDCCH in the configured search space (one of
either the common search space or the enhanced common search space,
and one of either the UE-specific search space or the enhanced
UE-specific search space) (step S1505).
[0172] In step S1502, in the case of regarding the component
carrier type to be a non-backward compatible component carrier, the
mobile station device 1 monitors the enhanced common search space
(E-CSS) for the E-PDCCH (step S1506). After step S1506, the mobile
station device 1 receives the system information block 2 (step
S1507). The mobile station device 1 monitors the enhanced common
search space (E-CSS), and the enhanced UE-specific search space
(E-USS) configured on the basis of the system information block,
for the E-PDCCH (step S1508).
[0173] After step S1508, the mobile station device 1 receives
dedicated radio resource control information. In addition, the
mobile station device 1 reconfigures the enhanced UE-specific
search space (E-USS) on the basis of the dedicated radio resource
control information (step S1509). The mobile station device 1
monitors the enhanced common search space (E-CSS), and the
reconfigured enhanced UE-specific search space (E-USS), for the
E-PDCCH (step S1510). The mobile station device 1 also reconfigures
the search space on the basis of received dedicated radio resource
control information after step S1505 or step S1510. In addition,
after step S1510, the mobile station device 1 does not reconfigure
the enhanced UE-specific search space (E-USS), even if the system
information block 2 is received again. In other words, in the case
in which the enhanced UE-specific search space (E-USS) has been
configured on the basis of dedicated radio resource control
information, the mobile station device 1 does not configure
(reconfigure) the enhanced UE-specific search space (E-USS) on the
basis of an additionally received system information block.
[0174] [Device Configurations]
[0175] Hereinafter, device configurations according to the present
embodiment will be described.
[0176] FIG. 16 is a schematic block diagram illustrating a
configuration of the mobile station device 1 according to the
present embodiment. As illustrated in the drawing, the mobile
station device 1 comprises a higher layer processing section 101, a
control section 103, a reception section 105, a transmission
section 107, and a transceiving antenna 109. In addition, the
higher layer processing section 101 comprises a radio resource
control section 1011, a scheduling information interpretation
section 1013, and a search space control section 1015. In addition,
the reception section 105 comprises a decoding section 1051, a
demodulation section 1053, a multiplexing/demultiplexing section
1055, a radio reception section 1057, and a channel measurement
section 1059. In addition, the transmission section 107 comprises
an encoding section 1071, a modulation section 1073, a multiplexing
section 1075, a radio transmission section 1077, and an uplink
reference signal generation section 1079.
[0177] The higher layer processing section 101 outputs uplink data
(transport blocks) generated by user operations or the like to the
transmission section 107. In addition, the higher layer processing
section 101 conducts processing in 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.
[0178] The radio resource control section 1011 provided in the
higher layer processing section 101 manages various configuration
information of the device itself. For example, the radio resource
control section 1011 manages an RNTI such as the C-RNTI. In
addition, the radio resource control section 1011 generates
information to be placed in respective uplink channels, and outputs
the information to the transmission section 107.
[0179] The scheduling information interpretation section 1013
provided in the higher layer processing section 101 interprets
information used for scheduling of physical channels (such as the
PUSCH and PDSCH) received via the reception section 105, and on the
basis of the results of interpreting the information, generates
control information for controlling the reception section 105 and
the transmission section 107, which is output to the control
section 103.
[0180] The search space control section 1015 provided in the higher
layer processing section 101 interprets the 1-bit information
indicating the component carrier type received via the reception
section 105. On the basis of the result of interpreting the
information, the search space control section 1015 generates
control information for controlling the monitoring for the PDCCH or
E-PDCCH by the reception section 105, and outputs the control
information to the control section 103. Also, the search space
control section 1015 computes the control channel element numbers
constituting the UE-specific search space on the basis of the RNTI.
Also, on the basis of radio resource control information received
via the reception section 105, the search space control section
1015 configures (identifies) the enhanced control channel elements
constituting the UE-specific search space, virtual resource blocks,
and physical resource blocks.
[0181] On the basis of the control information from the higher
layer processing section 101, the control section 103 generates
control signals that control the reception section 105 and the
transmission section 107. The control section 103 outputs the
generated control signals to the reception section 105 and the
transmission section 107, and controls the reception section 105
and the transmission section 107.
[0182] The reception section 105, following a control signal input
from the control section 103, demultiplexes, demodulates, and
decodes a reception signal received from the base station device 3
via the transceiving antenna 109, and outputs the decoded
information to the higher layer processing section 101.
[0183] The radio reception section 1057 downconverts a downlink
signal received via the transceiving antenna 109 to an intermediate
frequency, removes unwanted frequency components, controls the
amplification level so that the signal level is suitably
maintained, conducts orthogonal demodulation on the basis of the
in-phase components and the orthogonal components of the received
signal, and converts the orthogonally demodulated analog signal
into a digital signal. The radio reception section 1057 removes a
portion corresponding to a guard interval (GI) from the converted
digital signal, applies the fast Fourier transform (FFT) to the
signal with the guard interval removed, and extracts a signal in
the frequency domain.
[0184] The multiplexing/demultiplexing section 1055 demultiplexes
the extracted signal into the PHICH, PDCCH, E-PDCCH, PDSCH, and
downlink reference signal. Also, the multiplexing/demultiplexing
section 1055 compensates the channels of the PHICH, PDCCH, and
PDSCH from estimated channel values input from the channel
measurement section 1059. In addition, the
multiplexing/demultiplexing section 1055 outputs the demultiplexed
downlink reference signal to the channel measurement section
1059.
[0185] The demodulation section 1053 multiplies and combines
corresponding signs with the PHICH, conducts demodulation according
to a binary phase shift keying (BPSK) scheme on the combined
signal, and outputs to the decoding section 1051. The decoding
section 1051 decodes the PHICH addressed to the current device, and
outputs the decoded HARQ indicator to the higher layer processing
section 101. The demodulation section 1053 conducts demodulation
according to a QPSK modulation scheme on the PDCCH and/or E-PDCCH,
and outputs to the decoding section 1051. The decoding section 1051
attempts blind decoding of the PDCCH and/or E-PDCCH, and in the
case of successful blind decoding, outputs the decoded downlink
control information and the RNTI included in the downlink control
information to the higher layer processing section 101.
[0186] The demodulation section 1053 conducts demodulation on the
PDSCH according to a modulation scheme broadcast in the downlink
assignment, such as quadrature phase shift keying (QPSK), 16-QAM
(quadrature amplitude modulation), or 64-QAM, and outputs to the
decoding section 1051. The decoding section 1051 conducts decoding
on the basis of information related to the coding rate broadcast in
the downlink control information, and outputs the decoded downlink
data (transport blocks) to the higher layer processing section
101.
[0187] The channel measurement section 1059 measures the downlink
path loss and channel state from the downlink reference signal
input from the multiplexing/demultiplexing section 1055, and
outputs the measured path loss and channel state to the higher
layer processing section 101. In addition, the channel measurement
section 1059 computes estimated downlink channel values from the
downlink reference signal, and outputs to the
multiplexing/demultiplexing section 1055.
[0188] The transmission section 107, following a control signal
input from the control section 103, generates an uplink reference
signal, encodes and modulates uplink data (transport blocks) input
from the higher layer processing section 101, multiplexes the
PUCCH, PUSCH, and generated uplink reference signal, and transmits
the multiplexed signal to the base station device 3 via the
transceiving antenna 109.
[0189] The encoding section 1071 encodes uplink control information
input from the higher layer processing section 101 using
convolutional codes, block codes, or the like. In addition, the
encoding section 1071 conducts encoding using turbo codes on the
basis of information used for scheduling of the PUSCH.
[0190] The modulation section 1073 modulates the encoded bits input
from the encoding section 1071 according to a modulation scheme
broadcast in the downlink control information or a modulation
scheme predetermined for each channel, such as BPSK, QPSK, 16-QAM,
or 64-QAM. On the basis of information used for scheduling of the
PUSCH, the modulation section 1073 decides on the number of data
sequences to spatially multiplex, maps the multiple uplink data to
be transmitted in the same PUSCH by using MIMO SM onto multiple
sequences, and precodes the sequences.
[0191] The uplink reference signal generation section 1079
generates a sequence computed according to predetermined rules, on
the basis of information such as a physical layer cell identity
(PCI; also referred to as a cell ID) for identifying the base
station device 3, the bandwidth in which the uplink reference
signal is placed, the cyclic shift reported in the uplink grant,
and the values of parameters for generating a DMRS sequence. The
multiplexing section 1075, following a control signal input from
the control section 103, reorders the PUSCH modulation symbols in
parallel and then applies the discrete Fourier transform (DFT). In
addition, the multiplexing section 1075 multiplexes the PUCCH and
PUSCH signals and the generated uplink reference signal for each
transmit antenna port. In other words, the multiplexing section
1075 places the PUCCH and PUSCH signals and the generated uplink
reference signal into resource elements for each transmit antenna
port.
[0192] The radio transmission section 1077 applies the inverse fast
Fourier transform (IFFT) to the multiplexed signal, conducts
modulation according to the SC-FDMA scheme, adds a guard interval
to the SC-FDMA modulated SC-FDMA symbols, generates a digital
signal in the baseband, converts the digital signal in the baseband
to an analog signal, generates in-phase components and orthogonal
components of an intermediate frequency from the analog signal,
removes excess frequency components from the intermediate frequency
band, upconverts the signal of intermediate frequency to a signal
of high frequency, removes excess frequency components, amplifies
the signal power, outputs to the transceiving antenna 109, and
transmits the signal.
[0193] FIG. 17 is a schematic block diagram illustrating a
configuration of the base station device 3 according to the present
embodiment. As illustrated in the drawing, the base station device
3 comprises a higher layer processing section 301, a control
section 303, a reception section 305, a transmission section 307,
and a transceiving antenna 309. In addition, the higher layer
processing section 301 comprises a radio resource control section
3011, a scheduling section 3013, and a control information
generation section 3015. In addition, the reception section 305
comprises a decoding section 3051, a demodulation section 3053, a
multiplexing/demultiplexing section 3055, a radio reception section
3057, and a channel measurement section 3059. In addition, the
transmission section 307 comprises an encoding section 3071, a
modulation section 3073, a multiplexing section 3075, a radio
transmission section 3077, and a downlink reference signal
generation section 3079.
[0194] The higher layer processing section 301 conducts processing
in 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. In addition, the
higher layer processing section 301 generates control information
for controlling the reception section 305 and the transmission
section 307, and outputs to the control section 303.
[0195] The radio resource control section 3011 provided in the
higher layer processing section 301 generates, or acquires from a
higher node, downlink data (transport blocks) to be placed in the
downlink PDSCH, an RRC signal, and a MAC control element (CE), and
outputs to the transmission section 307. In addition, the radio
resource control section 3011 manages various configuration
information for each mobile station device 1. For example, the
radio resource control section 3011 conducts RNTI management, such
as assigning a C-RNTI to the mobile station device 1.
[0196] The scheduling section 3013 provided in the higher layer
processing section 301 decides on factors such as the frequencies
and subframes to which to assign physical channels (the PDSCH and
PUSCH), the coding rate and modulation scheme of the physical
channels (the PDSCH and PUSCH), as well as the transmit power, from
information such as estimated channel values and channel quality
input from the channel measurement section 3059. On the basis of
the scheduling results, the scheduling section 3013 generates
control information for controlling the reception section 305 and
the transmission section 307, and outputs to the control section
303. In addition, the scheduling section 3013 outputs scheduling
results for the physical channels (the PDSCH and PUSCH) to the
control information generation section 3015.
[0197] The control information generation section 3015 generates
information used for scheduling of physical channels (the PDSCH and
PUSCH) on the basis of scheduling results input from the scheduling
section 3013. The control information generation section 3015
generates information such as a master information block that
includes 1-bit information indicating the component carrier type, a
system information block 2 that includes information indicating the
enhanced UE-specific search space, and dedicated radio resource
control information that indicates the enhanced UE-specific search
space. In addition, the control information generation section 3015
outputs generated information to the transmission section 307.
[0198] On the basis of the control information from the higher
layer processing section 301, the control section 303 generates
control signals that control the reception section 305 and the
transmission section 307. The control section 303 outputs the
generated control signals to the reception section 305 and the
transmission section 307, and controls the reception section 305
and the transmission section 307.
[0199] The reception section 305, following a control signal input
from the control section 303, demultiplexes, demodulates, and
decodes a reception signal received from the mobile station device
1 via the transceiving antenna 309, and outputs the decoded
information to the higher layer processing section 301. The radio
reception section 3057 downconverts an uplink signal received via
the transceiving antenna 309 to an intermediate frequency, removes
unwanted frequency components, controls the amplification level so
that the signal level is suitably maintained, conducts orthogonal
demodulation on the basis of the in-phase components and the
orthogonal components of the received signal, and converts the
orthogonally demodulated analog signal into a digital signal.
[0200] The radio reception section 3057 removes portions
corresponding to a guard interval (GI) from the converted digital
signal. The radio reception section 3057 applies the fast Fourier
transform (FFT) to the signal with the guard interval removed,
extracts a signal in the frequency domain, and outputs to the
multiplexing/demultiplexing section 3055.
[0201] The multiplexing/demultiplexing section 1055 demultiplexes
the signal input from the radio reception section 3057 into signals
such as the PUCCH, the PUSCH, and the uplink reference signal. Note
that this demultiplexing is conducted on the basis of radio
resource allocation information included in an uplink grant decided
by the radio resource control section 3011 of the base station
device 3 in advance and reported to the mobile station device 1.
Also, the multiplexing/demultiplexing section 3055 compensates the
channel of the PUCCH and PUSCH from estimated channel values input
from the channel measurement section 3059. In addition, the
multiplexing/demultiplexing section 3055 outputs the demultiplexed
uplink reference signal to the channel measurement section
3059.
[0202] The demodulation section 3053 applies the inverse discrete
Fourier transform (IDFT) to the PUSCH, acquires modulation symbols,
and for each modulation symbol in the PUCCH and PUSCH, demodulates
the received signal using a modulation scheme that is predetermined
or reported in advance by the current device to each mobile station
device 1 in the uplink grant, such as binary phase shift keying
(BPSK), QPSK, 16-QAM, or 64-QAM. The demodulation section 3053
separates the modulation symbols in multiple streams of uplink data
transmitted on the same PUSCH by using MIMO SM, on the basis of the
number of spatially multiplexed sequences reported in advance in
the uplink grant to each mobile station device 1, and information
giving instructions on precoding to be conducted on these
sequences.
[0203] The decoding section 3051 decodes the encoded bits of the
demodulated PUSCH and PUSCH according to a predetermined coding
scheme at a coding rate that is predetermined or reported in
advance by the current device to the mobile station device 1 in the
uplink grant, and outputs the decoded uplink data and uplink
control information to the higher layer processing section 101. In
the case in which the PUSCH is retransmitted, the decoding section
3051 conducts decoding using encoded bits and demodulated encoded
bits being held in a HARQ buffer input from the higher layer
processing section 301. The channel measurement section 3059
measures factors such as estimated channel values and channel
quality from the uplink reference signal input from the
multiplexing/demultiplexing section 3055, and outputs to the
multiplexing/demultiplexing section 3055 and the higher layer
processing section 301.
[0204] The transmission section 307, following a control signal
input from the control section 303, generates a downlink reference
signal, encodes and modulates a HARQ indicator, downlink control
information, and downlink data input from the higher layer
processing section 301, multiplexes the PHICH, PDCCH, E-PDCCH,
PDSCH, and downlink reference signal, and transmits a signal to the
mobile station device 1 via the transceiving antenna 309.
[0205] The encoding section 3071 encodes a HARQ indicator, downlink
control information, and downlink data input from the higher layer
processing section 301 using a predetermined coding scheme, such as
block codes, convolutional codes, or turbo codes, or alternatively,
encodes using a coding scheme decided by the radio resource control
section 3011. The modulation section 3073 modulates encoded bits
input from the encoding section 3071 according to a modulation
scheme that is predetermined or decided by the radio resource
control section 3011, such as BPSK, QPSK, 16-QAM, or 64-QAM.
[0206] The downlink reference signal generation section 3079
generates, as a downlink reference signal, a sequence known to the
mobile station device 1 and computed according to predetermined
rules on the basis of information such as a physical layer cell
identity (PCI) for identifying the base station device 3. The
multiplexing section 3075 multiplexes the modulated modulation
symbols of each channel and the generated downlink reference
signal. In other words, the multiplexing section 3075 places the
modulated modulation symbols of each channel and the generated
downlink reference signal into resource elements.
[0207] The radio transmission section 3077 applies the inverse fast
Fourier transform (IFFT) to the multiplexed modulation symbols and
the like, conducts modulation according to the OFDM scheme, adds a
guard interval to the OFDM modulated OFDM symbols, generates a
digital signal in the baseband, converts the digital signal in the
baseband to an analog signal, generates in-phase components and
orthogonal components of an intermediate frequency from the analog
signal, removes excess frequency components from the intermediate
frequency band, upconverts the signal of intermediate frequency to
a signal of high frequency, removes excess frequency components,
amplifies the signal power, outputs to the transceiving antenna
309, and transmits the signal.
Other Embodiments
[0208] (a) Namely, a base station device according to the present
embodiment is a base station device that communicates with a mobile
station device. The base station device uses a physical broadcast
channel (PBCH) to transmit information instructing the mobile
station device to monitor a common search space (CSS) or an
enhanced common search space (E-CSS) for a physical downlink
channel.
[0209] (b) Also, the base station device according to the present
embodiment transmits the physical broadcast channel with 0th to 3rd
OFDM symbols in a second slot of a 0th subframe in respective radio
frames in the time domain, and with the central 72 downlink
subcarriers of a cell in the frequency domain.
[0210] (c) Also, the base station device according to the present
embodiment transmits a physical downlink control channel in the
common search space, and transmits an enhanced physical downlink
control channel in the enhanced common search space. Namely, the
base station device according to the present embodiment places a
physical downlink control channel in the common search space, and
places an enhanced physical downlink control channel in the
enhanced common search space.
[0211] (d) Also, in a case in which the physical downlink control
channel is not placed in the cell used to communicate with the
mobile station device, the base station device according to the
present embodiment instructs the mobile station device to monitor
the enhanced common search space for the enhanced physical downlink
control channel with the information.
[0212] (e) Also, in a case in which the physical downlink control
channel and the enhanced physical downlink control channel are
placed in the cell used to communicate with the mobile station
device, the base station device according to the present embodiment
instructs the mobile station device to monitor the common search
space for the physical downlink control channel with the
information.
[0213] (f) Also, a base station device according to the present
embodiment is a base station device that communicates with a mobile
station device, and uses a physical downlink shared channel to
transmit a system information block which is common for a plurality
of the mobile station device and which includes information related
to configuration of an enhanced mobile station device-specific
search space.
[0214] (g) Also, the base station device according to the present
embodiment uses the physical downlink shared channel to transmit
dedicated radio resource control information for the mobile station
device, including information related to configuration of the
enhanced mobile station device-specific search space.
[0215] (h) Also, until transmitting the dedicated radio resource
control information to the mobile station device, the base station
device according to the present embodiment, on the basis of
information related to configuration of the enhanced mobile station
device-specific search space included in the system information
block, transmits an enhanced physical downlink control channel
targeting the mobile station device in the enhanced mobile station
device-specific search space configured by the mobile station
device.
[0216] (i) Also, a base station device according to the present
embodiment is a base station device that communicates with a mobile
station device, and places each of one or a plurality of pieces of
downlink control information (enhanced downlink control channels)
in one or a plurality of enhanced control channel elements. Also,
the base station device places the enhanced control channel
elements in a plurality of virtual resource blocks so that a
plurality of the enhanced control elements are placed in a single
virtual resource block. Also, the base station device places the
virtual resource blocks with numbers that are consecutive in a
first slot into physical resource blocks with numbers that are
distributed in a first slot. Also, the base station device places
the virtual resource blocks with numbers that are consecutive in a
second slot into physical resource blocks with numbers that are
distributed in a second slot. Also, the base station device places
a virtual resource block in the first slot and a virtual resource
block in the second slot with the same number into the physical
resource blocks with numbers that are distributed.
[0217] (j) Also, the base station device according to the present
embodiment interleaves a plurality of the enhanced control channel
elements placed in a virtual resource block in the first slot and a
virtual resource block in the second slot with the same number
before placement in the physical resource blocks, in units that are
smaller than the enhanced control channel elements.
[0218] (k) Also, a mobile station device according to the present
embodiment is a mobile station device that communicates with a base
station device. The mobile station device uses a physical broadcast
channel to receive information instructing the mobile station
device to monitor a common search space or an enhanced common
search space for a physical downlink channel, and on the basis of
the information, monitors the common search space or the enhanced
common search space for the physical downlink channel.
[0219] (l) Also, in a mobile station device according to the
present embodiment, the physical broadcast channel is transmitted
with 0th to 3rd OFDM symbols in a second slot of a 0th subframe in
respective radio frames in the time domain, and with the central 72
downlink subcarriers of a cell in the frequency domain.
[0220] (m) Also, the mobile station device according to the present
embodiment receives a physical downlink control channel in the
common search space, and receives an enhanced physical downlink
control channel in the enhanced common search space. In the mobile
station device according to the present embodiment, the physical
downlink control channel is time-multiplexed with a physical
downlink shared channel, and the enhanced physical downlink control
channel is frequency-multiplexed with the physical downlink shared
channel.
[0221] (n) Also, a mobile station device according to the present
embodiment is a mobile station device that communicates with a base
station device. The mobile station device uses a physical downlink
shared channel to receive a system information block common for a
plurality of the mobile station device. In the mobile station
device according to the present embodiment, the system information
block includes information related to configuration of an enhanced
mobile station device-specific search space.
[0222] (o) Also, the mobile station device according to the present
embodiment uses the physical downlink shared channel to receive
dedicated radio resource control information for the mobile station
device. In the mobile station device according to the present
embodiment, the dedicated radio resource control information
includes information related to configuration of the enhanced
mobile station device-specific search space.
[0223] (p) Also, until receiving the dedicated radio resource
control information from the base station device, the mobile
station device according to the present embodiment monitors the
enhanced mobile station device-specific search space configured on
the basis of information related to configuration of the enhanced
mobile station device-specific search space included in the system
information block for an enhanced physical downlink control channel
targeting the device itself.
[0224] (q) Also, in a case in which the enhanced mobile station
device-specific search space is configured on the basis of
information related to configuration of the enhanced mobile station
device-specific search space included in the dedicated radio
resource control information, the mobile station device according
to the present embodiment does not configure the enhanced mobile
station device-specific search space on the basis of information
related to configuration of the enhanced mobile station
device-specific search space included in a subsequently received
system information block. In other words, in a case in which the
enhanced mobile station device-specific search space is configured
on the basis of information related to configuration of the
enhanced mobile station device-specific search space included in
the dedicated radio resource control information, the mobile
station device according to the present embodiment does not apply
information related to configuration of the enhanced mobile station
device-specific search space included in a subsequently received
system information block.
[0225] (q) Also, a mobile station device according to the present
embodiment is a mobile station device that communicates with a base
station device. The mobile station device receives one or a
plurality of pieces of downlink control information (enhanced
physical downlink control channels) from the base station device.
In the mobile station device according to the present embodiment,
each of one or a plurality of pieces of downlink control
information (enhanced downlink control channels) is placed in one
or a plurality of enhanced control channel elements. Also, the
enhanced control channel elements are placed in a plurality of
virtual resource blocks so that a plurality of the enhanced control
elements are placed in a single virtual resource block. Also, the
virtual resource blocks with numbers that are consecutive in a
first slot are placed into physical resource blocks with numbers
that are distributed in a first slot. Also, the virtual resource
blocks with numbers that are consecutive in a second slot are
placed into physical resource blocks with numbers that are
distributed in a second slot. Also, a virtual resource block in the
first slot and a virtual resource block in the second slot with the
same number are placed into the physical resource blocks with
numbers that are distributed.
[0226] (r) Also, in the mobile station device according to the
present embodiment, a plurality of the enhanced control channel
elements placed in a virtual resource block in a first slot and a
virtual resource block in a second slot with the same number are
interleaved before placement in the physical resource blocks, in
units that are smaller than the control channel elements.
[0227] (s) Also, a wireless communication system according to the
present embodiment is a wireless communication system in which a
mobile station device and a base station device communicate. The
base station device uses a physical broadcast channel to transmit
information instructing the mobile station device to monitor a
common search space or an enhanced common search space for a
physical downlink channel. Also, on the basis of the information,
the mobile station device monitors the common search space or the
enhanced common search space for the physical downlink channel.
[0228] (t) Also, a wireless communication system according to the
present embodiment is a wireless communication system in which a
mobile station device and a base station device communicate. The
base station device uses a physical downlink shared channel to
transmit a system information block common for a plurality of the
mobile station device and including information related to
configuration of an enhanced mobile station device-specific search
space. Also, the mobile station device configures the enhanced
mobile station device-specific search space on the basis of the
information.
[0229] (u) Also, a wireless communication system according to the
present embodiment is a wireless communication system in which a
mobile station device and a base station device communicate. The
base station device places downlink control information in one or a
plurality of contiguous enhanced control channel elements. Also,
the base station device places the enhanced control channel
elements in a plurality of virtual resource blocks so that a
plurality of the enhanced control elements are placed in a single
virtual resource block. Also, the base station device places the
virtual resource blocks with numbers that are consecutive in a
first slot into physical resource blocks with numbers that are
distributed in a first slot. Also, the base station device places
the virtual resource blocks with numbers that are consecutive in a
second slot into physical resource blocks with numbers that are
distributed in a second slot. Also, the base station device places
a virtual resource block in the first slot and a virtual resource
block in the second slot with the same number into the physical
resource blocks with numbers that are distributed. Also, the base
station device transmits a signal placed in the physical resource
blocks to the mobile station device. Also, the mobile station
device receives the signal placed in the physical resource blocks,
and conducts a process of decoding the downlink control information
on the received signal.
[0230] A program operating on a base station device 3 and a mobile
station device 1 according to the present embodiment may be a
program that controls a central processing unit (CPU) or the like
(a program that causes a computer to function) so as to realize the
functions of the above embodiment in accordance with the present
invention. Additionally, information handled by these devices is
temporarily accumulated in random access memory (RAM) during the
processing thereof, and thereafter stored in various types of
read-only memory (ROM) such as flash ROM or on a hard disk drive
(HDD), and then read out and modified/written by the CPU as
necessary.
[0231] Note that parts of the mobile station device 1 and the base
station device 3 in the embodiment discussed above may also be
realized with a computer. In this case, a program for realizing the
control functions may be recorded to a computer-readable recording
medium, and the devices may be realized by causing a computer
system to read and execute the program recorded on the recording
medium.
[0232] Note that the "computer system" referred to herein is a
computer system built into the mobile station device 1 or the base
station device 3, and is assumed to include an OS and hardware such
as peripheral devices. In addition, the "computer-readable
recording medium" refers to a portable medium such as a flexible
disk, a magneto-optical disc, ROM, or a CD-ROM, or a storage device
such as a hard disk built into the computer system.
[0233] Furthermore, the term "computer-readable recording medium"
may also encompass media that briefly or dynamically retain the
program, such as a communication line in the case of transmitting
the program via a network such as the Internet or a communication
channel such as a telephone line, as well as media that retain the
program for a given period of time, such as volatile memory inside
the computer system acting as the server or client in the above
case. Moreover, the above program may be a program for realizing
part of the functions discussed earlier, but may also be able to
realize the functions discussed earlier in combination with
programs already recorded onto the computer system.
[0234] In addition, all or part of the mobile station device 1 and
the base station device 3 in the foregoing embodiment may also be
realized as LSI, which is typically an integrated circuit, or be
realized as a chipset. The various function blocks of the mobile
station device 1 and the base station device 3 may be realized as
individual chips, or all or part thereof may be integrated as a
single chip. Furthermore, the circuit integration methodology is
not limited to LSI and may be also be realized with special-purpose
circuits, or with general-purpose processors. In addition, if
progress in semiconductor technology yields integrated circuit
technology that may substitute for LSI, the use of an integrated
circuit according to that technology is also possible.
[0235] The foregoing thus describes an embodiment of the present
invention in detail and with reference to the drawings. However,
specific configurations are not limited to the foregoing, and
various design modifications and the like are possible within a
scope that does not depart from the principal matter of the present
invention.
REFERENCE SIGNS LIST
[0236] 1 (1A, 1B, 1C) mobile station device [0237] 3 base station
device [0238] 101, 301 higher layer processing section [0239] 103,
303 control section [0240] 105, 305 reception section [0241] 107,
307 transmission section [0242] 109, 309 transceiving antenna
[0243] 1011, 3011 radio resource control section [0244] 1013
scheduling information interpretation section [0245] 1015 search
space control section [0246] 1051, 3051 decoding section [0247]
1053, 3053 demodulation section [0248] 1055, 3055
multiplexing/demultiplexing section [0249] 1057, 3057 radio
reception section [0250] 1059, 3059 channel measurement section
[0251] 1071, 3071 encoding section [0252] 1073, 3073 modulation
section [0253] 1075, 3075 multiplexing section [0254] 1077, 3077
radio transmission section [0255] 1079 uplink reference signal
generation section [0256] 3013 scheduling section [0257] 3015
control information generation section [0258] 3079 downlink
reference signal generation section
* * * * *