U.S. patent application number 16/889331 was filed with the patent office on 2020-09-17 for method for transmitting control information, and apparatus therefor.
The applicant listed for this patent is LG Electronics Inc.. Invention is credited to Daesung HWANG, Seungmin LEE, Suckchel Yang.
Application Number | 20200295865 16/889331 |
Document ID | / |
Family ID | 1000004866958 |
Filed Date | 2020-09-17 |
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United States Patent
Application |
20200295865 |
Kind Code |
A1 |
Yang; Suckchel ; et
al. |
September 17, 2020 |
METHOD FOR TRANSMITTING CONTROL INFORMATION, AND APPARATUS
THEREFOR
Abstract
The present invention relates to a wireless communication
system. More specifically, the present invention relates to a
method for transmitting control information and an apparatus
therefor, the method comprising the steps of: detecting one or more
PDSCHs on a plurality of cells, wherein the plurality of cells are
divided into a first cell set having PCell and a first SCell, and a
second cell set having one or more second SCells; and as feedback
for the one or more PDSCHs, transmitting HARQ-ACK information over
PUCCH, wherein when the one or more PDSCHs are detected only in the
first cell set, the HARQ-ACK information contains only a HARQ-ACK
response for the first cell set, and when the one or more PDSCHs
are detected at least in the second cell set, the HARQ-ACK
information contains HARQ-ACK responses for both the first and the
second cell sets.
Inventors: |
Yang; Suckchel; (Seoul,
KR) ; HWANG; Daesung; (Seoul, KR) ; LEE;
Seungmin; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG Electronics Inc. |
Seoul |
|
KR |
|
|
Family ID: |
1000004866958 |
Appl. No.: |
16/889331 |
Filed: |
June 1, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15542301 |
Jul 7, 2017 |
10673556 |
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PCT/KR2016/000227 |
Jan 11, 2016 |
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16889331 |
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62261333 |
Dec 1, 2015 |
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62257271 |
Nov 19, 2015 |
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62250499 |
Nov 3, 2015 |
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62190744 |
Jul 10, 2015 |
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62128990 |
Mar 5, 2015 |
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62101383 |
Jan 9, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 1/0007 20130101;
H04W 72/0413 20130101; H04L 5/00 20130101; H04L 1/0028 20130101;
H04L 27/26 20130101; H04L 1/18 20130101; H04L 1/1671 20130101; H04L
1/0031 20130101; H04L 1/1861 20130101; H04L 5/0055 20130101; H04B
7/0626 20130101; H04L 1/1812 20130101; H04L 1/0026 20130101 |
International
Class: |
H04L 1/00 20060101
H04L001/00; H04L 1/18 20060101 H04L001/18; H04L 27/26 20060101
H04L027/26; H04L 5/00 20060101 H04L005/00; H04L 1/16 20060101
H04L001/16; H04B 7/06 20060101 H04B007/06; H04W 72/04 20060101
H04W072/04 |
Claims
1-10. (canceled)
11. A method for a user equipment (UE) to transmit control
information in a wireless communication system, the method
comprising: determining a reference value for a Physical Uplink
Control Channel (PUCCH) format based on a number of symbols
allocated for the PUCCH format, wherein the number of symbols
allocated for the PUCCH format is variable; based on a size of an
Uplink Control Information (UCI) payload including Hybrid ARQ
Acknowledgment (HARQ-ACK) information and channel state information
(CSI) being larger than the reference value, reducing a size of the
CSI so that a reduced UCI payload has a size no larger than the
reference value; and transmitting the reduced UCI payload via the
symbols allocated for the PUCCH format.
12. The method of claim 11, wherein the CSI includes periodic CSI
(p-CSI).
13. The method of claim 11, wherein a first reference payload size
of the PUCCH format when the number of symbols is M is less than a
second reference payload size of the PUCCH format when the number
of symbols is N, and wherein M is less than N.
14. The method of claim 13, wherein M is N-1.
15. The method of claim 11, wherein the symbols includes Orthogonal
Frequency Division Multiple Access (OFDMA)-based symbols.
16. The method of claim 11, wherein the reduced UCI payload
includes sub-blocks, and wherein each sub-block is mapped on a
respective symbol of the PUCCH format after a discrete fourier
transformation.
17. The method of claim 11, wherein based on the size of the UCI
payload being no larger than the reference value, further
comprising: transmitting the UCI payload without UCI payload size
reduction.
18. A User Equipment (UE) configured to operate in a wireless
communication system, the communication device comprising: at least
one Radio Frequency (RF) units; at least one processor; and at
least one computer memory operably connectable to the at least one
processor and storing instructions that, when executed by the at
least one processor, perform operations comprising: determining a
reference value for a Physical Uplink Control Channel (PUCCH)
format based on a number of symbols allocated for the PUCCH format,
wherein the number of symbols allocated for the PUCCH format is
variable, based on a size of an Uplink Control Information (UCI)
payload including Hybrid ARQ Acknowledgment (HARQ-ACK) information
and channel state information (CSI) being larger than the reference
value, reducing a size of the CSI so that a reduced UCI payload has
a size no larger than the reference value, and transmitting the
reduced UCI payload via the symbols allocated for the PUCCH
format.
19. The UE of claim 18, wherein the CSI includes periodic CSI
(p-CSI).
20. The UE of claim 18, wherein a first reference payload size of
the PUCCH format when the number of symbols is M is less than a
second reference payload size of the PUCCH format when the number
of symbols is N, and wherein M is less than N.
21. The UE of claim 20, wherein M is N-1.
22. The UE of claim 18, wherein the symbols includes Orthogonal
Frequency Division Multiple Access (OFDMA)-based symbols.
23. The UE of claim 8, wherein the reduced UCI payload includes
sub-blocks, and wherein each sub-block is mapped on a respective
symbol of the PUCCH format after a discrete fourier
transformation.
24. The UE of claim 18, wherein based on the size of the UCI
payload being no larger than the reference value, the operation
further comprises: transmitting the UCI payload without UCI payload
size reduction.
25. A communication device configured to operate in a wireless
communication system, the communication device comprising: at least
one processor; and at least one computer memory operably
connectable to the at least one processor and storing instructions
that, when executed by the at least one processor, perform
operations comprising: determining a reference value for a Physical
Uplink Control Channel (PUCCH) format based on a number of symbols
allocated for the PUCCH format, wherein the number of symbols
allocated for the PUCCH format is variable, based on a size of an
Uplink Control Information (UCI) payload including Hybrid ARQ
Acknowledgment (HARQ-ACK) information and channel state information
(CSI) being larger than the reference value, reducing a size of the
CSI so that a reduced UCI payload has a size no larger than the
reference value, and transmitting the reduced UCI payload via the
symbols allocated for the PUCCH format.
26. The communication device of claim 25, wherein the CSI includes
periodic CSI (p-CSI).
27. The communication device of claim 25, wherein a first reference
payload size of the PUCCH format when the number of symbols is M is
less than a second reference payload size of the PUCCH format when
the number of symbols is N, and wherein M is less than N.
28. The communication device of claim 27, wherein M is N-1.
29. The communication device of claim 25, wherein the symbols
includes Orthogonal Frequency Division Multiple Access
(OFDMA)-based symbols.
30. The communication device of claim 25, wherein the reduced UCI
payload includes sub-blocks, and wherein each sub-block is mapped
on a respective symbol of the PUCCH format after a discrete fourier
transformation.
31. The communication device of claim 25, wherein based on the size
of the UCI payload being no larger than the reference value, the
operation further comprises: transmitting the UCI payload without
UCI payload size reduction.
Description
TECHNICAL FIELD
[0001] The present invention relates to a wireless communication
system and, more specifically, to a method for transmitting control
information and an apparatus for the same.
BACKGROUND ART
[0002] Wireless communication systems have been widely deployed to
provide various types of communication services including voice and
data services. In general, a wireless communication system is a
multiple access system that supports communication among multiple
users by sharing available system resources (e.g. bandwidth,
transmit power, etc.) among the multiple users. The multiple access
system may adopt a multiple access scheme such as Code Division
Multiple Access (CDMA), Frequency Division Multiple Access (FDMA),
Time Division Multiple Access (TDMA), Orthogonal Frequency Division
Multiple Access (OFDMA), or Single Carrier Frequency Division
Multiple Access (SC-FDMA).
DETAILED DESCRIPTION OF THE INVENTION
Technical Problems
[0003] An object of the present invention is to provide a method of
efficiently transmitting control information in a wireless
communication system and an apparatus therefor. Another object of
the present invention is to provide a method of efficiently
transmitting uplink control information and efficiently managing
resources for the uplink control information in a carrier
aggregation (CA) system and an apparatus therefor.
[0004] The technical problems solved by the present invention are
not limited to the above technical problems and those skilled in
the art may understand other technical problems from the following
description.
Technical Solutions
[0005] According to an aspect of the present invention, provided
herein is a method for a user equipment to transmit Hybrid ARQ
Acknowledgment (HARQ-ACK) information, the method comprising:
generating an Uplink Control Information (UCI) payload including
the HARQ-ACK information within a maximum payload size of a
Physical Uplink Control Channel (PUCCH); generating an UCI codeword
from the UCI payload, wherein a size of the UCI codeword is matched
to a total resource amount of UCI Single Carrier Frequency Division
Multiple Access (SC-FDMA) symbols of the PUCCH; and transmitting
the UCI codeword through the PUCCH in a subframe, wherein a number
of the UCI SC-FDMA symbols is N or N-1 (N>1), and the maximum
payload size of the PUCCH is varied depending on the number of the
UCI SC-FDMA symbols.
[0006] In another aspect of the present invention, provided herein
is A user equipment for use in a wireless communication, the user
equipment comprising: a radio frequency (RF) unit; and a processor,
wherein the processor is configured to generate an Uplink Control
Information (UCI) payload including the HARQ-ACK information within
a maximum payload size of a Physical Uplink Control Channel
(PUCCH), generate an UCI codeword from the UCI payload, wherein a
size of the UCI codeword is matched to a total resource amount of
UCI Single Carrier Frequency Division Multiple Access (SC-FDMA)
symbols of the PUCCH, and transmit the UCI codeword through the
PUCCH in a subframe, wherein a number of the UCI SC-FDMA symbols is
N or N-1 (N>1), and the maximum payload size of the PUCCH is
varied depending on the number of the UCI SC-FDMA symbols.
[0007] The maximum payload size of the PUCCH when the number of the
UCI SC-FDMA symbols is N-1 may be configured to be less than when
the number of the UCI SC-FDMA symbols is N.
[0008] If an original size of the UCI payload is larger than the
maximum payload size of the PUCCH, an operation for reducing a size
of the HARQ-ACK information may be performed.
[0009] Different information may be transmitted in each UCI SC-FDMA
symbol of the PUCCH.
[0010] The number of UCI SC-FDMA symbols may be N when a Sounding
Reference Signal (SRS) protection is not required at the subframe,
and the number of UCI SC-FDMA symbols may be N-1 when the SRS
protection is required at the subframe.
[0011] The number of UCI SC-FDMA symbols may be N when a Sounding
Reference Signal (SRS) transmission of the user equipment is not
present at the subframe, and the number of UCI SC-FDMA symbols may
be N-1 when the SRS transmission of the user equipment is present
at the subframe.
[0012] N may be 12 when a normal CP is configured, and N may be 10
when an extended CP is configured.
Advantageous Effects
[0013] According to the present invention, control information can
be efficiently transmitted in a wireless communication system.
Specifically, uplink control information can be efficiently
transmitted and resources for the uplink control information can be
efficiently managed in a CA system.
[0014] The effects of the present invention are not limited to the
above-described effects and other effects which are not described
herein will become apparent to those skilled in the art from the
following description.
DESCRIPTION OF DRAWINGS
[0015] The accompanying drawings, which are included to provide a
further understanding of the invention, illustrate embodiments of
the invention and together with the description serve to explain
the principle of the invention. In the drawings:
[0016] FIG. 1 illustrates a radio frame structure;
[0017] FIG. 2 illustrates a resource grid of a downlink slot;
[0018] FIG. 3 illustrates a downlink subframe structure;
[0019] FIG. 4 illustrates an uplink subframe structure;
[0020] FIG. 5 illustrates a slot level structure of physical uplink
control channel (PUCCH) format 1a/1b;
[0021] FIG. 6 illustrates a slot level structure of PUCCH format
2/2a/2b;
[0022] FIG. 7 illustrates a slot level structure of PUCCH format
3;
[0023] FIG. 8 illustrates a TDD A/N transmission procedure in
single cell situation;
[0024] FIG. 9 illustrates a carrier aggregation (CA) communication
system;
[0025] FIG. 10 illustrates scheduling when a plurality of carriers
is aggregated;
[0026] FIG. 11 illustrates a slot level structure of PF4;
[0027] FIG. 12 illustrates normal and shortened formats of PUCCH
format 1a/1b;
[0028] FIG. 13 illustrates normal and shortened formats of PUCCH
format 3;
[0029] FIG. 14 illustrates normal and shortened formats of PUCCH
format 4;
[0030] FIG. 15 illustrates UCI coding;
[0031] FIG. 16 illustrates a UCI transmission method according to
an embodiment of the present invention; and
[0032] FIG. 17 illustrates a BS and a UE to which embodiments of
the present invention are applicable.
BEST MODE FOR CARRYING OUT THE INVENTION
[0033] Embodiments of the present invention are applicable to a
variety of wireless access technologies such as Code Division
Multiple Access (CDMA), Frequency Division Multiple Access (FDMA),
Time Division Multiple Access (TDMA), Orthogonal Frequency Division
Multiple Access (OFDMA), and Single Carrier Frequency Division
Multiple Access (SC-FDMA). CDMA can be implemented as a radio
technology such as Universal Terrestrial Radio Access (UTRA) or
CDMA2000. TDMA can be implemented as a radio technology such as
Global System for Mobile communications (GSM)/General Packet Radio
Service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA
can be implemented as a radio technology such as Institute of
Electrical and Electronics Engineers (IEEE) 802.11 (Wireless
Fidelity (Wi-Fi)), IEEE 802.16 (Worldwide interoperability for
Microwave Access (WiMAX)), IEEE 802.20, Evolved UTRA (E-UTRA). UTRA
is a part of Universal Mobile Telecommunications System (UMTS). 3rd
Generation Partnership Project (3GPP) Long Term Evolution (LTE) is
a part of Evolved UMTS (E-UMTS) using E-UTRA, employing OFDMA for
downlink and SC-FDMA for uplink. LTE-Advanced (LTE-A) is an
evolution of 3GPP LTE.
[0034] While the following description is given, centering on 3GPP
LTE/LTE-A for clarity, this is purely exemplary and thus should not
be construed as limiting the present invention. It should be noted
that specific terms disclosed in the present invention are proposed
for convenience of description and better understanding of the
present invention, and the use of these specific terms may be
changed to other formats within the technical scope or spirit of
the present invention.
[0035] FIG. 1 illustrates a radio frame structure. In a cellular
OFDM wireless packet communication system, uplink/downlink data
packet transmission is performed on a subframe-by-subframe basis. A
subframe is defined as a predetermined time interval including a
plurality of OFDM symbols. LTE(-A) supports a type-1 radio frame
structure applicable to FDD (Frequency Division Duplex) and a
type-2 radio frame structure applicable to TDD (Time Division
Duplex).
[0036] FIG. 1(a) illustrates the type-1 radio frame structure. A DL
radio frame includes 10 subframes, each subframe including two
slots in the time domain. A time required to transmit one subframe
is defined as a transmission time interval (TTI). For example, one
subframe may be 1 ms long and one slot may be 0.5 ms long. One slot
includes a plurality of OFDM symbols in the time domain and a
plurality of resource blocks (RBs) in the frequency domain. Since
an LTE(-A) system uses OFDMA for DL, an OFDM symbol indicates one
symbol period. The OFDM symbol may be called an SC-FDMA symbol or
symbol period. An RB is a resource allocation unit including a
plurality of contiguous subcarriers in one slot.
[0037] The number of OFDM symbols included in one slot may be
changed according to configuration of a cyclic prefix (CP). For
example, if each OFDM symbol is configured to include a normal CP,
one slot may include 7 OFDM symbols. If each OFDM symbol is
configured to include an extended CP, one slot may include 6 OFDM
symbols.
[0038] FIG. 2(b) illustrates a type-2 radio frame structure. The
type-2 radio frame includes 2 half frames. Each half frame includes
5 subframes each of which is composed of 2 slots.
[0039] Table 1 shows UL-DL configurations (UL-DL Cfgs) of subframes
in a radio frame in the TDD mode.
TABLE-US-00001 TABLE 1 Uplink- Downlink- downlink to-Uplink config-
Switch-point Subframe number uration periodicity 0 1 2 3 4 5 6 7 8
9 0 5 ms D S U U U D S U U U 1 5 ms D S U U D D S U U D 2 5 ms D S
U D D D S U D D 3 10 ms D S U U U D D D D D 4 10 ms D S U U D D D D
D D 5 10 ms D S U D D D D D D D 6 5 ms D S U U U D S U U D
[0040] In Table 1, D denotes a downlink subframe, U denotes an
uplink subframe and S denotes a special subframe.
[0041] The special subframe includes a DwPTS (Downlink Pilot
TimeSlot), GP (Guard Period), and UpPTS (Uplink Pilot TimeSlot).
DwPTS is a period reserved for downlink transmission and UpPTS is a
period reserved for uplink transmission.
[0042] Table 2 shows DwPTS/GP/UpPTS according to special subframe
configuration. In Table 2, T.sub.s denotes sampling time.
TABLE-US-00002 TABLE 2 Normal cyclic prefix in downlink Extended
cyclic prefix in downlink UpPTS UpPTS Normal Extended Normal
Extended Special cyclic cyclic cyclic cyclic subframe prefix in
prefix in prefix in prefix in configuration DwPTS uplink uplink
DwPTS uplink uplink 0 6592 T.sub.s 2192 T.sub.s 2560 T.sub.s 7680
T.sub.s 2192 T.sub.s 2560 T.sub.s 1 19760 T.sub.s 20480 T.sub.s 2
21952 T.sub.s 23040 T.sub.s 3 24144 T.sub.s 25600 T.sub.s 4 26336
T.sub.s 7680 T.sub.s 4384 T.sub.s 5120 T.sub.s 5 6592 T.sub.s 4384
T.sub.s 5120 T.sub.s 20480 T.sub.s 6 19760 T.sub.s 23040 T.sub.s 7
21952 T.sub.s -- -- -- 8 24144 T.sub.s -- -- --
[0043] The radio frame structure is merely exemplary and the number
of subframes included in the radio frame, the number of slots
included in a subframe, and the number of symbols included in a
slot can vary.
[0044] FIG. 2 illustrates a resource grid of a downlink slot.
[0045] Referring to FIG. 2, a downlink slot includes a plurality of
OFDM symbols in the time domain. One downlink slot may include 7(6)
OFDM symbols, and one resource block (RB) may include 12
subcarriers in the frequency domain. Each element on the resource
grid is referred to as a resource element (RE). One RB includes
12.times.7 (or 6) REs. The number N.sub.RB of RBs depends on a
system bandwidth (BW). The structure of an uplink slot may be same
as that of the downlink slot except that OFDM symbols by replaced
by SC-FDMA symbols.
[0046] FIG. 3 illustrates a downlink subframe structure.
[0047] Referring to FIG. 3, a maximum of 3 (4) OFDM symbols located
in a front portion of a first slot within a subframe correspond to
a control region to which a control channel is allocated. The
remaining OFDM symbols correspond to a data region to which a
physical downlink shared chancel (PDSCH) is allocated. Examples of
downlink control channels include a physical control format
indicator channel (PCFICH), a physical downlink control channel
(PDCCH), a physical hybrid ARQ indicator channel (PHICH), etc. The
PCFICH is transmitted at a first OFDM symbol of a subframe and
carries information regarding the number of OFDM symbols used for
transmission of control channels within the subframe. The PHICH is
a response of uplink transmission and carries an HARQ
acknowledgment (ACK)/not-acknowledgment (NACK) signal.
[0048] Control information transmitted through the PDCCH is
referred to as downlink control information (DCI). Formats 0, 3, 3A
and 4 for uplink and formats 1, 1A, 1B, 1C, 1D, 2, 2A, 2B and 2C
for downlink are defined as DCI formats. The DCI formats
selectively include information such as hopping flag, RB
allocation, MCS (Modulation Coding Scheme), RV (Redundancy
Version), NDI (New Data Indicator), TPC (Transmit Power Control),
cyclic shift for a DMRS (Demodulation Reference Signal), CQI
(Channel Quality Information) request, HARQ process number, TPMI
(Transmitted Precoding Matrix Indicator), PMI (Precoding Matrix
Indicator) confirmation according as necessary.
[0049] The PDCCH may carry a transport format and a resource
allocation of a downlink shared channel (DL-SCH), resource
allocation information of an uplink shared channel (UL-SCH), paging
information on a paging channel (PCH), system information on the
DL-SCH, information on resource allocation of an upper-layer
control message such as a random access response transmitted on the
PDSCH, a set of Tx power control commands on individual UEs within
an arbitrary UE group, a Tx power control command, information on
activation of a voice over IP (VoIP), etc. A plurality of PDCCHs
can be transmitted within a control region. A UE can monitor the
plurality of PDCCHs. The PDCCH is transmitted on an aggregation of
one or several consecutive control channel elements (CCEs). The CCE
is a logical allocation unit used to provide the PDCCH with a
coding rate based on a state of a radio channel. The CCE
corresponds to a plurality of resource element groups (REGs). A
format of the PDCCH and the number of bits of the available PDCCH
are determined by the number of CCEs. A BS determines a PDCCH
format according to DCI to be transmitted to the UE, and attaches a
cyclic redundancy check (CRC) to control information. The CRC is
masked with a unique identifier (referred to as a radio network
temporary identifier (RNTI)) according to an owner or usage of the
PDCCH. If the PDCCH is for a specific UE, then an identifier (e.g.,
cell-RNTI (C-RNTI)) of the UE may be masked to the CRC.
Alternatively, when the PDCCH is for a paging message, a paging
identifier (e.g., paging-RNTI (P-RNTI)) may be masked to the CRC.
When the PDCCH is for system information (more specifically, a
system information block (SIB)), a system information RNTI
(SI-RNTI) may be masked to the CRC. When the PDCCH is for a random
access response, a random access-RNTI (RA-RNTI) may be masked to
the CRC.
[0050] FIG. 4 illustrates an uplink subframe structure used in
LTE.
[0051] Referring to FIG. 4, an uplink subframe includes a plurality
of (e.g. 2) slots. A slot may include different numbers of SC-FDMA
symbols according to CP lengths. The uplink subframe is divided
into a control region and a data region in the frequency domain.
The data region is allocated with a PUSCH and used to carry a data
signal such as audio data. The control region is allocated a PUCCH
and used to carry uplink control information (UCI). The PUCCH
includes an RB pair located at both ends of the data region in the
frequency domain and hopped in a slot boundary.
[0052] The PUCCH can be used to transmit the following control
information.
[0053] Scheduling Request (SR): This is information used to request
a UL-SCH resource and is transmitted using On-Off Keying (OOK)
scheme.
[0054] HARQ-ACK: This is a response to a downlink data packet (e.g.
codeword) on a PDSCH and indicates whether the downlink data packet
has been successfully received. A 1-bit A/N signal is transmitted
as a response to a single downlink codeword and a 2-bit A/N signal
is transmitted as a response to two downlink codewords.
[0055] Channel Quality Indicator (CQI): This is feedback
information about a downlink channel. MIMO (Multiple Input Multiple
Output)-related feedback information includes a rank indicator
(RI), a precoding matrix indicator (PMI) and a precoding type
indicator (PTI). 20 bits per subframe are used.
[0056] Table 3 shows the mapping relationship between PUCCH formats
and UCI in LTE.
TABLE-US-00003 TABLE 3 PUCCH format UCI (Uplink Control
Information) Format 1 SR (Scheduling Request) (non-modulated
waveform) Format 1a 1-bit HARQ ACK/NACK (SR exist/non-exist) Format
1b 2-bit HARQ ACK/NACK (SR exist/non-exist) Format 2 CQI (20 coded
bits) Format 2 CQI and 1- or 2-bit HARQ ACK/NACK (20 bits)
(corresponding to only extended CP) Format 2a CQI and 1-bit HARQ
ACK/NACK (20 + 1 coded bits) Format 2b CQI and 2-bit HARQ ACK/NACK
(20 + 2 coded bits) Format 3 HARQ ACK/NACK + SR (48 bits)
(LTE-A)
[0057] FIG. 5 illustrates a slot level structure of PUCCH format
1a/1b. PUCCH format 1a/1b is used for ACK/NACK transmission. In a
normal CP, SC-FDMA #2/#3/#4 is used to transmit a DMRS. In an
extended CP, SC-FDMA #2/#3 is used to transmit the DMRS. Therefore,
4 SC-FDMA symbols in a slot are used for ACK/NACK transmission. For
convenience, PUCCH format 1a/1b is referred to as PUCCH format
1.
[0058] Referring to FIG. 5, 1-bit [b(0)] and 2-bit [b(0)b(1)] A/N
information are modulated according to BPSK (binary phase shift
keying) and QPSK (quadrature phase shift keying) modulation schemes
respectively, to generate one ACK/NACK modulation symbol d.sub.0.
Each bit [b(i), i=0, 1] of the ACK/NACK information indicates a
HARQ response to a corresponding DL transport block, corresponds to
1 in the case of positive ACK and corresponds to 0 in case of
negative ACK (NACK). Table 4 shows a modulation table defined for
PUCCH formats 1a and 1b in LTE.
TABLE-US-00004 TABLE 4 PUCCH format b(0), . . . , b(M.sub.bit - 1)
d(0) 1a 0 1 1 -1 1b 00 1 01 -j 10 j 11 -1
[0059] In PUCCH format 1a/1b, cyclic shift (CS) (.alpha..sub.cs,x)
is performed in the frequency domain and spreading is performed
using an orthogonal code (OC) (e.g. Walsh-Hadamard or DFT code) w0,
w1, w2, w3 in the time domain. Since code multiplexing is used in
both the frequency domain and the time domain, more UEs may be
multiplexed in the same PUCCH RB.
[0060] FIG. 6 illustrates PUCCH format 2/2a/2b. PUCCH format
2/2a/2b is used for CQI transmission. In a normal CP, one subframe
includes 10 QPSK data symbols in addition to RS symbols. Each of
the QPSK symbols is spread by a CS in the frequency domain and then
mapped to a corresponding SC-FDMA symbol. CS hopping of an SC-FDMA
symbol level may be applied for randomization of inter-cell
interference. An RS may be multiplexed by CDM using a CS. For
example, if the number of available CSs is 12 or 6, then 12 or 6
UEs may be multiplexed in the same PRB.
[0061] FIG. 7 illustrates the structure of PUCCH format 3 in a slot
level. PUCCH format 3 is used to transmit a plurality of ACK/NACK
information, and information such as CSI and/or SR may be
transmitted together.
[0062] Referring to FIG. 7, one symbol sequence is transmitted over
the frequency domain, and OCC-based time-domain spreading is
applied to the symbol sequence. Control signals of a plurality of
UEs may be multiplexed into the same RB using OCCs. Specifically, 5
SC-FDMA symbols (i.e. a UCI data part) are generated from one
symbol sequence {d1, d2, . . . } using a length-5 OCC. Here, the
symbol sequence {d1, d2, . . . } may be a modulation symbol
sequence or a codeword bit sequence. The symbol sequence {d1, d2, .
. . } may be generated by performing joint coding (e.g.,
Reed-Muller coding, tail-biting convolutional coding, etc.),
block-spreading, and SC-FDMA modulation on a plurality of ACK/NACK
information.
[0063] An ACK/NACK payload for PUCCH format 3 is configured per
cell and then configured ACK/NACK payloads are concatenated
according to cell index order. HARQ-ACK ACK feedback bits for a
c-th serving cell (or DL CC) are given as
o.sub.c,0.sup.ACKo.sub.c,1.sup.ACK, . . . ,
o.sup.ACKc,O.sub.c.sup.ACK-1 (where c>0). O.sup.ACK.sub.c
represents the number of bits (i.e., size) of a HARQ-ACK payload
for the c-th serving cell. When a transmission mode supporting
single transport block transmission is configured or spatial
bundling is used for the c-th serving cell, O.sup.ACK.sub.c may be
set as, O.sup.ACK.sub.c=B.sup.DL.sub.c. If a HARQ-ACK response
represents ACK, a HARQ-ACK feedback bit is set to 1 and, if the
HARQ-ACK response represents NACK or discontinuous transmission
(DTX), the HARQ-ACK feedback bit is set to 0.
[0064] If a transmission mode supporting transmission of multiple
transport blocks (e.g., two transport blocks) is configured and
spatial bundling is not used for the c-th serving cell,
O.sup.ACK.sub.c may be given as O.sup.ACK.sub.c=2B.sup.DL.sub.c.
When HARQ-ACK feedback bits are transmitted through a PUCCH or when
the HARQ-ACK feedback bits are transmitted through a PUSCH but W
corresponding to the PUSCH is not present (e.g., an SPS based
PUSCH), B.sup.DL.sub.c is given as B.sup.DL.sub.c=M. M denotes the
number of elements in set K defined in Table 3. If TDD UL-DL
configurations are #1, #2, #3, #4, and #6 and HARQ-ACK feedback
bits are transmitted through the PUSCH, B.sup.DL.sub.c is given as
B.sup.DL.sub.c=W.sup.UL.sub.DAI. Herein, W.sup.UL.sub.DAI denotes a
value indicated by a UL DAI field in a UL grant PDCCH (Table 7) and
is simply shorten to W. If a TDD UL-DL configuration is #5, then
B.sub.c.sup.DL=W.sub.DAI.sup.UL+4.left
brkt-top.(U-W.sub.DAI.sup.UL)/4.right brkt-bot.. Herein, U denotes
a maximum value of Uc, Uc representing the total number of PDSCH(s)
received in subframe n-k and PDCCHs indicating (DL) SPS release in
a c-th serving cell. Subframe n is a subframe in which the HARQ-ACK
feedback bits are transmitted. .left brkt-top. .right brkt-bot.
denotes a ceiling function.
[0065] When a transmission mode supporting transmission of a single
transport block is configured or spatial bundling is used for the
c-th serving cell, the position of each ACK/NACK bit in the
HARQ-ACK payload of the serving cell is given as
o.sub.c,DAI(k)-1.sup.ACK.
[0066] DAI(k) represents a DL DAI value detected from a DL subframe
n-k. Meanwhile, when a transmission mode supporting transmission of
multiple transport blocks (e.g., two transport blocks) is
configured and spatial bundling is not used for the c-th serving
cell, the positions of respective ACK/NACK bits in the HARQ-ACK
payload of the serving cell are given as o.sub.c,2DAI(k)-2.sup.ACK
and o.sub.c,2DAI(k)-1.sup.ACK. Herein, o.sub.c,2DAI(k)-2.sup.ACK
represents HARQ-ACK for codeword 0 and o.sub.c,2DAI(k)-1.sup.ACK
represents HARQ-ACK for codeword 1. Codeword 0 and codeword 1
correspond to transport block 0 and transport block 1,
respectively, or transport block 1 and transport block 0,
respectively, according to swapping. When PUCCH format 3 is
transmitted in a subframe configured for SR transmission, PUCCH
format 3 is transmitted together with ACK/NACK bits and 1 SR
bit.
[0067] FIG. 8 illustrates a TDD UL A/N transmission procedure in
single cell situation.
[0068] Referring to FIG. 8, a UE can receive one or more DL
transmission signals (e.g. PDSCH signals) in M DL subframes (SFs)
(S502_0 to S502_M-1). Each PDSCH signal is used to transmit one or
more (e.g. 2) transport blocks (TBs) (or codewords) according to
transmission mode. A PDCCH signal that requires an ACK/NACK
response, for example, a PDCCH signal indicating SPS
(Semi-Persistent Scheduling) release (simply, SPS release PDCCH
signal) may also be received in step S502_0 to S502_M-1, which is
not shown. When a PDSCH signal and/or an SPS release PDCCH signal
is present in the M DL subframes, the UE transmits ACK/NACK through
a UL subframe corresponding to the M DL subframes via a procedure
for transmitting ACK/NACK (e.g. ACK/NACK (payload) generation,
ACK/NACK resource allocation, etc.) (S504). ACK/NACK includes
acknowledgment information about the PDSCH signal and/or SPS
release PDCCH received in step S502_0 to S502_M-1. While ACK/NACK
is transmitted through a PUCCH basically, ACK/NACK may be
transmitted through a PUSCH when the PUSCH is transmitted at an
ACK/NACK transmission time. Various PUCCH formats shown in Table 3
can be used for ACK/NACK transmission. To reduce the number of
transmitted ACK/NACK bits, various methods such as ACK/NACK
bundling and ACK/NACK channel selection can be used.
[0069] As described above, in TDD, ACK/NACK for data received in
the M DL subframes is transmitted through one UL subframe (i.e. M
DL SF(s): 1 UL SF) and the relationship therebetween is determined
by a downlink association set index (DASI).
[0070] Table 5 shows DASI (K: {k0, k1, . . . , k-1}) defined in
LTE(-A). Table 5 shows intervals between a UL subframe transmitting
ACK/NACK and a DL subframe associated with the UL subframe from the
perspective of the UL subframe. Specifically, when a PDCCH that
indicates PDSCH transmission and/or SPS release is present in
subframe n-k (where k.di-elect cons.K), the UE transmits ACK/NACK
in subframe n.
TABLE-US-00005 TABLE 5 UL-DL Config- Subframe n uration 0 1 2 3 4 5
6 7 8 9 0 -- -- 6 -- 4 -- -- 6 -- 4 1 -- -- 7, 6 4 -- -- -- 7, 6 4
-- 2 -- -- 8, 7, -- -- -- -- 8, 7, -- -- 4, 6 4, 6 3 -- -- 7, 6, 11
6, 5 5, 4 -- -- -- -- -- 4 -- -- 12, 8, 6, 5, -- -- -- -- -- -- 7,
11 4, 7 5 -- -- 13, 12, 9, -- -- -- -- -- -- -- 8, 7, 5, 4, 11, 6 6
-- -- 7 7 5 -- -- 7 7 --
[0071] Meanwhile, in FDD, ACK/NACK for data received in one DL
subframe is transmitted through one UL subframe and k=4. That is,
when a PDCCH that indicates PDSCH transmission and/or SPS release
is present in subframe n-4, the UE transmits ACK/NACK in subframe
n.
[0072] FIG. 9 illustrates a carrier aggregation (CA) communication
system. LTE-A aggregates a plurality of UL/DL frequency blocks to
support a wider UL/DL bandwidth in order to use a wider frequency
band. Each frequency block is transmitted using a component carrier
(CC). The CC may be regarded as a carrier frequency (or center
carrier or a center frequency) for the corresponding frequency
block.
[0073] Referring to FIG. 9, a plurality of UL/DL component carriers
(CCs) can be aggregated to support a wider UL/DL bandwidth. The CCs
may be contiguous or non-contiguous in the frequency domain.
Bandwidths of the CCs can be independently determined. Asymmetrical
CA in which the number of UL CCs is different from the number of DL
CCs can be implemented. For example, when there are two DL CCs and
one UL CC, the DL CCs can correspond to the UL CC in the ratio of
2:1. A DL CC/UL CC link can be fixed or semi-statically configured
in the system. Even if the system bandwidth is configured with N
CCs, a frequency band that a specific UE can monitor/receive can be
limited to L (<N) CCs. Various parameters with respect to CA can
be set cell-specifically, UE-group-specifically, or
UE-specifically. Control information may be transmitted/received
only through a specific CC. This specific CC can be referred to as
a primary CC (PCC) (or anchor CC) and other CCs can be referred to
as secondary CCs (SCCs).
[0074] In LTE-A, the concept of a cell is used to manage radio
resources [see, 36.300 V10.2.0 (2010-12) 5.5. Carrier Aggregation;
7.5. Carrier Aggregation]. A cell is defined as a combination of
downlink resources and uplink resources. Yet, the uplink resources
are not mandatory. Therefore, a cell may be composed of downlink
resources only or both downlink resources and uplink resources. The
linkage between the carrier frequencies (or DL CCs) of downlink
resources and the carrier frequencies (or UL CCs) of uplink
resources may be indicated by system information when carrier
aggregation is supported. A cell operating in primary frequency
resources (or a PCC) may be referred to as a primary cell (PCell)
and a cell operating in secondary frequency resources (or an SCC)
may be referred to as a secondary cell (SCell). The PCell is used
for a UE to establish an initial connection or re-establish a
connection. The PCell may refer to a cell indicated during
handover. The SCell may be configured after an RRC connection is
established and may be used to provide additional radio resources.
The PCell and the SCell may collectively be referred to as a
serving cell. Accordingly, a single serving cell composed of a
PCell only exists for a UE in an RRC_CONNECTED state, for which CA
is not set or which does not support CA. On the other hand, one or
more serving cells exist, including a PCell and entire SCells, for
a UE in an RRC_CONNECTED state, for which CA is set. For CA, a
network may configure one or more SCells in addition to an
initially configured PCell, for a UE supporting CA during
connection setup after an initial security activation operation is
initiated.
[0075] When cross-carrier scheduling (or cross-CC scheduling) is
applied, a PDCCH for downlink allocation can be transmitted on DL
CC #0 and a PDSCH corresponding thereto can be transmitted on DL CC
#2. For cross-CC scheduling, introduction of a carrier indicator
field (CIF) can be considered. Presence or absence of the CIF in a
PDCCH can be determined by higher layer signaling (e.g. RRC
signaling) semi-statically and UE-specifically (or UE
group-specifically). The baseline of PDCCH transmission is
summarized as follows.
[0076] CIF disabled: a PDCCH on a DL CC is used to allocate a PDSCH
resource on the same DL CC or a PUSCH resource on a linked UL
CC.
[0077] CIF enabled: a PDCCH on a DL CC can be used to allocate a
PDSCH or PUSCH resource on a specific DL/UL CC from among a
plurality of aggregated DL/UL CCs using the CIF.
[0078] When the CIF is present, the BS can allocate a PDCCH
monitoring DL CC to reduce BD complexity of the UE. The PDCCH
monitoring DL CC set includes one or more DL CCs as parts of
aggregated DL CCs and the UE detects/decodes a PDCCH only on the
corresponding DL CCs. That is, when the BS schedules a PDSCH/PUSCH
for the UE, a PDCCH is transmitted only through the PDCCH
monitoring DL CC set. The PDCCH monitoring DL CC set can be set in
a UE-specific, UE-group-specific or cell-specific manner. The term
"PDCCH monitoring DL CC" can be replaced by the terms such as
"monitoring carrier" and "monitoring cell". The term "CC"
aggregated for the UE can be replaced by the terms such as "serving
CC", "serving carrier" and "serving cell".
[0079] FIG. 10 illustrates scheduling when a plurality of carriers
is aggregated. It is assumed that 3 DL CCs are aggregated and DL CC
A is set to a PDCCH monitoring DL CC in FIG. 11. DL CC A, DL CC B
and DL CC C can be called serving CCs, serving carriers, serving
cells, etc. In case of CIF disabled, a DL CC can transmit only a
PDCCH that schedules a PDSCH corresponding to the DL CC without a
CIF according to LTE PDCCH rule. When the CIF is enabled, DL CC A
(monitoring DL CC) can transmit not only a PDCCH that schedules the
PDSCH corresponding to the DL CC A but also PDCCHs that schedule
PDSCHs of other DL CCs using the CIF. In this case, A PDCCH is not
transmitted in DL CC B/C which is not set to a PDCCH monitoring DL
CC.
[0080] UCI Transmission Method Considering UCI Coding Rate (Or Code
Rate)
[0081] Currently, a Rel-10/11/12 based LTE-A system may support CA
up to 5 cells/carriers (hereinafter, referred to collectively as
cells) with respect to one UE. In addition, a PUCCH has a structure
configured to be transmitted only through a PCell. Meanwhile, in
future systems, aggregation of 5 or more cells with respect to one
UE is under consideration for the purpose of a higher data
transmission rate. In this case, in consideration of increase in
UCI size caused by increase in the number of cells, a new PUCCH
format supporting a payload of a larger size than a legacy PUCCH
format (e.g., PUCCH format 3) may be considered. In addition, in
order to reduce increase in the number of UCI transmissions/UCI
size and overhead of PUCCH resources in the PCell due to the
increased UCI transmissions/UCI size, a method of enabling the
PUCCH to be transmitted even through a specific SCell (hereinafter,
ACell) may be considered.
[0082] In a legacy CA situation, a PUCCH format 3 (hereinafter,
PF3) based method may be configured as a HARQ-ACK (hereinafter,
A/N) feedback transmission method. PF3 may be applied to a CA
situation supporting up to 5 cells. The PF3 based method configures
A/N (bit) corresponding to each cell as one payload and
maps/transmits a coded bit generated through a series of coding
(e.g., Reed Muller (RM) coding) processes to a PF3 resource. A
maximum input size of a UCI code that can be transmitted based on
PF3 is 20 or 21 bits and an output size of the UCI code
corresponding thereto is 48 bits. The PF3 resource may be allocated
as one of a plurality of PF3 resources (previously) configured by a
higher layer signal (e.g., RRC signaling) (regardless of whether
cross-CC scheduling is configured). For example, a PF3 resource
indicated by an A/N resource indicator (ARI) in a DL grant for
scheduling an SCell, among a plurality of PF3 resources
(previously) configured by a higher layer signal (e.g., RRC
signaling), may be used for A/N transmission. The ARI may be
included in a TPC field of a PDCCH corresponding to a PDSCH on the
SCell. Different PF3 resources may be distinguished by at least one
of an RB, an orthogonal cover code (OCC), and a cyclic shift (CS).
Meanwhile, in the future systems, CA is configured by a larger
number of cells and, for A/N feedback transmission corresponding to
the cells, introduction of a new PUCCH format (hereinafter, PF4)
occupying more UL control resources (e.g., a large number of RBs,
an OCC of a short length, and a CS of a wide interval). Through
PF4, a payload of a larger size can be supported.
[0083] Meanwhile, in PF4, a UCI code output size in the case of
using a shortened PUCCH format (configured for SRS transmission and
protection) may be different from that in the case of using a
normal PUCCH format, according to structure such as the number of
DMRS symbols and the length of the OCC. For example, a UCI code
output size in the shortened format may be decreased relative to
that in the normal format and thus, a UCI coding rate in the case
of using the shortened format may be increased relative to that in
the case of using the normal format. Similarly, a UCI code output
size through extended CP based PF4 may be smaller than that through
normal CP based PF4 and thus, a UCI coding rate through PF4 in an
extended CP may be higher than that in a normal CP. In addition,
when simultaneous transmission of A/N through a PUCCH and periodic
CSI is configured, a UCI code input size in a CSI reporting
subframe (in which the two UCIs can be transmitted) may be larger
than that in a normal subframe (i.e., a subframe in which only A/N
is transmitted because CSI reporting is not configured) and thus, a
UCI coding rate in the CSI reporting subframe may be higher than
that in normal subframe. Such variation in the UCI coding rate over
the PUCCH according to variation in the UCI code input/output size
may be generated or may be relatively increased particularly in a
PF4 structure (i.e., PUSCH-similar structure) in which the OCC is
not applied on the time/symbol axis (except for a DMRS) as opposed
to legacy PF3.
[0084] The above example is described in more detail with reference
to FIGS. 11 to 15.
[0085] FIG. 11 illustrates a slot level structure of PF4. In FIG.
11, PF4 has a PUSCH-similar structure (refer to the data region of
FIG. 4). That is, only one RS SC-FDMA symbol is present per slot
and the OCC is not applied to the time/symbol domain. Hence,
different information is carried on each UCI SC-FDMA symbol (data
block in the drawing). For example, a symbol sequence {d1,d2, . . .
} may be sequentially carried from the first UCI SC-FDMA symbol to
the last UCI SC-FDMA symbol of PF4. The symbol sequence {d1,d2, . .
. } may be generated from a plurality of A/N through (joint) coding
(e.g., Reed-Muller coding, tail-biting convolutional coding,
etc.).
[0086] Tables 6 and 7 show cell-specific SRS transmission
parameters and UE-specific SRS transmission parameters,
respectively, for SRS transmission, defined in LTE.
TABLE-US-00006 TABLE 6 Configuration Transmission srs- Period
offset SubframeConfig Binary T.sub.SFC (subframes) .DELTA..sub.SFC
(subframes) 0 0000 1 {0} 1 0001 2 {0} 2 0010 2 {1} 3 0011 5 {0} 4
0100 5 {1} 5 0101 5 {2} 6 0110 5 {3} 7 0111 5 {0, 1} 8 1000 5 {2,
3} 9 1001 10 {0} 10 1010 10 {1} 11 1011 10 {2} 12 1100 10 {3} 13
1101 10 {0, 1, 2, 3, 4, 6, 8} 14 1110 10 {0, 1, 2, 3, 4, 5, 6, 8}
15 1111 reserved reserved
[0087] T.sub.SFC denotes cell-specific subframe configuration and
.DELTA..sub.SFC denotes a cell-specific subframe offset.
srs-SubframeConfig is provided by higher layers. SRS is transmitted
through a subframe satisfying .left brkt-bot.n.sub.s/2.right
brkt-bot.modT.sub.SFC .di-elect cons..DELTA..sub.SFC, wherein
n.sub.s denotes a slot index, .left brkt-bot. .right brkt-bot.
denotes a floor function, and mod denotes a modulo operation.
TABLE-US-00007 TABLE 7 SRS Configuration Index SRS Periodicity SRS
Subframe Offset I.sub.SRS T.sub.SRS (ms) T.sub.offset 0-1 2
I.sub.SRS 2-6 5 I.sub.SRS - 2 7-16 10 I.sub.SRS - 7 17-36 20
I.sub.SRS - 17 37-76 40 I.sub.SRS - 37 77-156 80 I.sub.SRS - 77
157-316 160 I.sub.SRS - 157 317-636 320 I.sub.SRS - 317 637-1023
reserved reserved
[0088] An SRS configuration index I.sub.SRS is signaled on a per UE
basis and each UE checks an SRS transmission periodicity T.sub.SRS
and an SRS subframe offset T.sub.offset using the SRS configuration
index I.sub.SRS.
[0089] The cell-specific SRS transmission parameter indicates
subframes occupied for SRS transmission in a cell to the UE and the
UE-specific SRS transmission parameter indicates subframes that the
UE is to actually use among the subframes occupied for SRS
transmission. Next, the UE transmits an SRS through a specific
symbol (e.g., last symbol) of a subframe designated by the
UE-specific SRS transmission parameter (UE-specific SRS subframe).
Meanwhile, in order to protect SRS transmission in subframes
occupied through the cell-specific SRS transmission parameter
(cell-specific SRS subframes), the UE may not transmit a UL signal
on the last symbol of a subframe regardless of whether the SRS is
actually transmitted in the corresponding subframe.
[0090] FIGS. 12 to 14 illustrate normal formats and shortened
formats of a PUCCH. The shortened format is used when an SRS of a
UE or an SRS of another UE should be protected. Specifically, the
shortened format is used (i) when PUCCH transmission and SRS
transmission of a UE collide in the same subframe (i.e., when a
PUCCH is transmitted in a UE-specific SRS subframe) and (ii) when
PUCCH transmission and SRS transmission of another UE collide in
the same subframe (i.e., (a) when a PUCCH is transmitted in a
cell-specific SRS subframe and a cell-specific SRS band and a PUCCH
transmission band overlap or (b) the PUCCH is transmitted in the
cell-specific SRS subframe). Otherwise, the normal format is used.
The shortened format is not defined in PUCCH format 2/2a/2b.
Collision of a CQI and an SRS is avoided by scheduling or is solved
by SRS transmission dropping.
[0091] Referring to FIGS. 12 to 14, in the shortened format of the
PUCCH, the last SC-FDMA symbol of a subframe is excluded from PUCCH
transmission. Therefore, the number of UCI SC-FDMA symbols of the
shortened format is less than that of the normal format by one.
Since an OCC is applied to PF1 and PF3 in the time domain on a slot
basis, use of the shortened format decreases the number of UCI
SC-FDMA symbols in the second slot and, thus, the length of the OCC
is also decreased (FIGS. 12 and 13). Meanwhile, since the OCC is
not applied to PF4 in the time domain, use of the shortened format
decreases only one UCI SC-FDMA symbol in the second slot (FIG.
14).
[0092] FIG. 15 illustrates UCI coding. A UCI payload (i.e., UCI
code input) is converted into a UCI codeword (i.e., UCI code
output) through a coding block. Coding may be performed using
various legacy methods (e.g., Reed-Muller coding, tail-biting
convolutional coding, etc.). A coding rate is defined as (UCI
payload size/UCI codeword size). If the UCI payload size is n bits
and the UCI codeword size is m bits, the coding rate is n/m. The
UCI codeword corresponds to the symbol sequence of FIG. 11.
[0093] In PF1, the same information is repeated on a slot basis and
information of one UCI SC-FDMA symbol in a slot is spread to a
plurality of UCI SC-FDMA symbols through the OCC. That is, the
information of one UCI SC-FDMA symbol is repeated on all UCI
SC-FDMA symbols. Therefore, the UCI codeword size is determined
based on a resource of one SC-FDMA symbol. Even when the number of
UCI SC-FDMA symbols varies, the UCI codeword size is constant.
Specifically, in the normal/shortened format, the UCI codeword size
is identically maintained as one bit (BPSK) or two bits (QPSK).
Similarly, even in PF3, the OCC is applied to a plurality of
SC-FDMA symbols in a slot. PF3 has a form in which the information
of one UCI SC-FDMA symbol per slot is repeated on all UCI SC-FDMA
symbols. Accordingly, even when the number of UCI SC-FDMA symbols
varies, the UCI codeword size is constant. That is, in the
normal/shortened format, the UCI codeword size is identically
maintained as 48 bits (QPSK).
[0094] On the other hand, in PF4, since the OCC is not applied in
the time domain, the UCI codeword size is determined to match the
amount of resources of all UCI SC-FDMA symbols. For example, the
UCI codeword size of PF4 may be given as (number of REs of all UCI
SC-FDMA symbols*modulation order). Accordingly, the UCI codeword
size varies according to the number of UCI SC-FDMA symbols and,
thus, the UCI coding rate varies. Then, the coding rate of the
shortened format may be higher than that of the normal format.
[0095] In this way, the UCI coding rate in PF4 may differ according
to subframe and, if the UCI coding rate increases too much,
reliability of UCI transmission may deteriorate. Since PF4 has a
structure similar to a PUSCH, the coding rate of a transport block
may also differ according to subframe even in the PUSCH. However,
since a HARQ process is applied to PUSCH transmission, even if
transmission fails due to increase in coding rate, restoration of
transmission is possible through retransmission. However, the HARQ
process is not applied to UCI, failure of UCI transmission may have
a significant effect on a system. In particular, since A/N is
information which is dynamically transmitted only once, restoration
is not possible upon transmission failure.
[0096] To solve this problem, a method for guaranteeing/maintaining
UCI transmission performance is needed even in a situation in which
the UCI coding rate increases. Hereinbelow, there is provided an
adaptive UCI transmission method considering variation in UCI
coding rate as a UCI code input/output size per subframe is changed
in a CA situation. Specifically, the following four methods are
provided in consideration of UCI transmission performance in a
situation (e.g., a specific subframe) in which the UCI coding rate
relatively increases. Meanwhile, in the present invention, A/N may
be replaced with/extended to specific UCI (e.g., A/N (and/or SR)
feedback itself or periodic CSI feedback) or a combination of a
plurality of different UCIs (e.g., a combination of A/N (and/or SR)
and periodic CSI). In addition, in the present invention, A/N
includes an SR.
[0097] Hereinafter, a specific subframe includes a subframe in
which a shortened PUCCH format is configured and/or a subframe in
which periodic CSI reporting is configured (based on a specific
cell (e.g., PCell)). For convenience, a subframe other than the
specific subframe is referred to as a normal subframe. The subframe
in which the shortened PUCCH format is configured includes (i) a
UE-specific SRS subframe, (ii) a subframe in which a cell-specific
SRS transmission band overlaps with a PUCCH transmission band among
cell-specific SRS subframes, or (iii) a cell-specific SRS
subframe.
[0098] Method 1-0) Indication of UCI Simultaneous Transmission
[0099] This method is to directly indicate, through (DL grant) DCI,
whether to permit simultaneous transmission of plural UCIs (through
a PUCCH) or not (e.g., ON/OFF), at a timing when transmission of
the plural UCIs (e.g., periodic CSI (i.e., p-CSI) or an SRS)
including A/N is simultaneously demanded. Specifically, when the
plural UCIs consist of A/N and p-CSI, if simultaneous transmission
OFF is indicated through the DCI, only A/N may be transmitted
(through a PUCCH) with omission (dropping) of p-CSI transmission.
Conversely, if simultaneous transmission ON is indicated through
the DCI, simultaneous transmission of A/N and p-CSI (through the
PUCCH) may be performed. In addition, when the plural UCIs consist
of A/N and an SRS, if simultaneous transmission OFF is indicated
through the DCI, only A/N may be transmitted using a normal PUCCH
format with omitting (dropping) SRS transmission. Conversely, if
simultaneous transmission ON is indicated through the DCI,
simultaneous transmission of A/N and the SRS may be performed using
a shortened PUCCH format. As another method, regardless of whether
the SRS is included in UCI configuration, if simultaneous
transmission OFF is indicated through the DCI, A/N may be
transmitted using the normal PUCCH format and, if simultaneous
transmission ON is indicated through the DCI, A/N may be
transmitted using the shortened PUCCH format. Herein, A/N
corresponding to the case in which simultaneous transmission ON is
indicated through the DCI may be configured by shortened A/N by
applying Method 1-1.
[0100] Meanwhile, when simultaneous transmission ON/OFF is
indicated through the DCI, simultaneous transmission ON/OFF may be
configured to be linked with an ARI value indicating an A/N
transmission resource without an additional independent
field/signaling. The ARI may be included in a TPC field of a PDCCH
corresponding to a PDSCH on an SCell. For example, if a specific
ARI value (set) is indicated with respect to a p-CSI reporting
subframe or an SRS transmission subframe, the same operation as the
case of simultaneous transmission ON of (A/N+p-CSI) or (A/N+SRS)
may be performed and, if the other ARI values (sets) are indicated,
the same operation as the case of simultaneous transmission OFF may
be performed. As another method, if an A/N payload size (e.g., the
number of A/N bits) or an A/N coding rate over a (shortened format)
PUCCH exceeds a specific level, the operation corresponding to
simultaneous transmission OFF may be applied and, otherwise, the
operation corresponding to simultaneous transmission ON may be
applied.
[0101] Method 1-1) Reduction of A/N Size
[0102] This method entails configure an A/N size (e.g., the number
of A/N bits) transmitted in a specific subframe to be smaller than
that in a normal subframe. That is, the A/N size may be configured
to differ according to subframe.
[0103] An example of using A/N to be transmitted in a specific
subframe is as follows.
[0104] 1) A/N may be configured only for some of all cells included
in CA and the other cells may be regarded as not having been
scheduled. On the other hand, in a normal subframe, A/N may be
configured for all cells. Alternatively,
[0105] 2) the A/N size may be reduced based on a scheme of
compressing A/N for each cell (or each cell group) to one bit (or
two bits) through bundling by logical AND operation (hereinafter,
A/N size reduction). On the other hand, in the normal subframe,
compression of the A/N size may be performed to be less than in the
specific subframe or an A/N size compression process may be
omitted.
[0106] Meanwhile, a maximum UCI payload size supportable for
shortened PF4 may be reduced so as to be less than that for normal
PF4. For example, when the maximum UCI payload size for shortened
PF4 is configured independently of the maximum UCI payload size for
normal PF4, the maximum UCI payload size for shortened PF4 may be
configured to be smaller than the maximum UCI payload size for
normal PF4. As such, in shortened PF4, A/N feedback of fewer bits
may be transmitted or p-CSI feedback of fewer bits may be
transmitted, through A/N compression, as compared with normal
PF4.
[0107] In addition, in the case of transmission of different UCIs
(e.g., UCI including A/N and UCI including only p-CSI) even for the
same PF4, a maximum supportable UCI payload size may differ.
Herein, for the same PF4, the maximum UCI payload size may be
independently configured with respect to each UCI combination. For
example, the maximum UCI payload size of UCI including A/N may be
configured to be less than the maximum UCI payload size of UCI
including only p-CSI).
[0108] Meanwhile, a maximum A/N payload size supportable through
extended CP based PF4 (hereinafter, PF4_eCP) may be less than that
supportable through normal CP based PF4 (hereinafter, PF4_nCP).
Therefore, the maximum number of cells configurable in CA when
PF4_eCP is configured may be less than that when PF4_nCP is
configured. In addition, the maximum number of cells configurable
in CA may be identical regardless of CP length, while A/N
compression such as bundling may be applied only when PF4_eCP is
configured (compared with the case of PF4_nCP with respect to the
same number of cells or the same number of A/N bits).
[0109] FIG. 16 illustrates a UCI transmission method according to
an embodiment of the present invention. It is assumed that PF4 is
configured for A/N transmission in a CA situation. It is also
assumed that an OCC is not applied to PF4 in the time domain (refer
to FIG. 11).
[0110] Referring to FIG. 16, when A/N transmission is demanded in a
subframe, a UE may generate a UCI payload including A/N information
within a maximum payload size of a PUCCH (i.e. PF4) in the subframe
(S1602). Herein, the A/N information includes A/N information
(e.g., ACK, NACK, or DTX) about a PDSCH and/or an SPS release PDCCH
received through a plurality of cells. Next, the UE generates a UCI
codeword from the UCI payload, wherein the size of the UCI codeword
matches the total amount of resources of UCI SC-FDMA symbols of the
PUCCH (S1604). For example, the total amount of resources of UCI
SC-FDMA symbols in PF4 may be given as (frequency band (e.g., in
units of subcarriers) assigned to PF4) * (number of UCI SC-FDMA
symbols). Herein, the frequency band may be given as (number of
PRBs assigned to PF4)*(number of REs (e.g., 12) per PRB).
Thereafter, the UE may transmit the UCI codeword through the PUCCH
(S1606). The UCI codeword may be transmitted through processes of
scrambling, modulation, resource mapping, etc. Herein, the maximum
payload size of the PUCCH is varied depending on the number of UCI
SC-FDMA symbols.
[0111] In the same CP, the number of UCI SC-FDMA symbols of PF4 may
be N or N-1 (where N>1). For example, the number of UCI SC-FDMA
symbols of PF4 may be given as.
[0112] Normal CP: {12 UCI SC-FDMA symbols in a normal PF4 format,
11 UCI SC-FDMA symbols in a shortened PF4 format}
[0113] Extended CP: {10 UCI SC-FDMA symbols in a normal PF4 format,
9 UCI SC-FDMA symbols in a shortened PF4 format}
[0114] That is, the number of UCI SC-FDMA symbols of PF4 may be 9
to 12 according to (i) CP configuration and (ii) subframe in which
the PUCCH is transmitted.
[0115] Specifically, when the number of UCI SC-FDMA symbols is N-1,
the maximum payload size of the PUCCH may be set to be smaller than
the case in which the number of UCI SC-FDMA symbols is N. Herein,
if SRS protection in a corresponding subframe is not demanded, the
number of UCI SC-FDMA symbols may be N and, if SRS protection in a
corresponding subframe is demanded, the number of UCI SC-FDMA
symbols may be N-1. In addition, if there is no SRS transmission of
the UE in a corresponding subframe, the number of UCI SC-FDMA
symbols may be N and, if there is SRS transmission of the UE in a
corresponding subframe, the number of UCI SC-FDMA symbols may be
N-1.
[0116] In addition, when an original size of the UCI payload is
greater than the maximum payload size of the PUCCH, an operation
(e.g., bundling) for reducing the size of A/N information may be
performed. Different information may be transmitted on respective
UCI SC-FDMA symbols in the PUCCH.
[0117] Method 1-2) Increase of PUCCH Power
[0118] This method entails configuring the power of a PUCCH
(carrying A/N) transmitted in a specific subframe to be increased
more than that in a normal subframe. For example, an additional
power offset to be applied to the A/N PUCCH may be differently
configured according to subframe. A specific power offset P_off
value (e.g., having a positive value) in addition to a legacy power
control parameter may be additionally applied to a PUCCH to be
transmitted in the specific subframe. On the other hand, an offset
other than P_off (e.g., a value less than P_off) may be applied or
no offset may be added to a PUCCH to be transmitted in the normal
subframe.
[0119] Meanwhile, a power offset (for open-loop power control)
configured for PF4_eCP may be different from a power offset
configured for PF4_nCP. That is, different power offset values may
be assigned to respective PUCCH formats by regarding PF4 having a
different CP length as a different PUCCH format. In addition, a
power offset (for open-loop power control) configured for shortened
PF4 may be different from a power offset configured for normal PF4.
That is, different power offset values may be assigned to
respective PUCCH formats by regarding PF4 having a different format
length as a different PUCCH format.
[0120] Method 1-3) Change of PUCCH Format
[0121] This method entails configuring the (maximum) payload size
of a PUCCH format (carrying A/N) transmitted in a specific subframe
to be extended more than that in a normal subframe. In other words,
an A/N PUCCH format having a different payload size per subframe is
configured. Herein, different PUCCH formats may be divided
according to the number of RBs, an OCC length, and a DMRS structure
which constitute a PUCCH resource. As an example, when a PUCCH
format having a relatively small payload is referred to as an S-PF
and a PUCCH format having a relatively large payload is referred to
as an L-PF, the L-PF may be allocated as an A/N transmission
resource in the specific subframe and the S-PF may be allocated as
an A/N transmission resource in the normal subframe. The L-PF
resource and the S-PF resource may be configured on the same cell
(e.g., a PCell)) or different cells (e.g., the PCell and a specific
SCell).
[0122] Specifically, a scheme may be considered in which a PUCCH
format indicated by an ARI is differently configured according to
subframe, a PUCCH transmission cell indicated by the ARI is
differently configured according to subframe, or each ARI indicates
a PUCCH resource on a different cell. As an example, the ARI may be
configured to indicate one of a plurality of L-PF resources for a
specific subframe and indicate one of a plurality of S-PF resources
for a normal subframe. Alternatively, the ARI may be configured to
indicate one of a plurality of PF4 resources on cell #1 for the
specific subframe and indicate one of a plurality of PF4 resources
on cell #2 for the normal subframe. Alternatively, the ARI may be
configured to indicate one of a plurality of L-PF resources on cell
#1 for the specific subframe and indicate one of a plurality of
S-PF resources on cell #2 for the normal subframe. As another
example, ARI values 0 and 1 may be configured to indicate PUCCH
resources 0 and 1 on cell #1, respectively, and ARI values 2 and 3
may be configured to indicate PUCCH resources 1 and 2 on cell #2.
Herein, a PUCCH format configured on cell #1 may be equal to or
different from a PUCCH format configured on cell #2 (Case 1). As
another example, the ARI may be configured to indicate PUCCH
resources on a plurality of cells for the specific subframe and
indicate a PUCCH resource on a single cell for the normal subframe,
as in Case 1. Even in this case, a PUCCH format configured for the
specific subframe may be equal to or different from a PUCCH format
configured for the normal subframe.
[0123] Even when the PUCCH transmission cell is changed according
to subframe by Methods 1 to 3, an A/N transmission timing
corresponding to each cell (e.g., reference configuration for the
A/N transmission timing) may always be determined based only on one
specific PUCCH transmission cell (e.g., a PCell) (e.g., based on a
combination with a specific cell) regardless of a subframe (i.e., a
PUCCH transmission cell). In addition, (when the specific cell is
assumed to be the PCell), a TPC may be signaled through a DL grant
corresponding to the PCell (in FDD) regardless of a subframe (i.e.,
a PUCCH transmission cell) or corresponding to a first scheduled
subframe (in TDD) in the PCell and an ARI may be signaled through a
DL grant corresponding to the other cells/subframes. As such, when
only the PCell (regardless of a subframe) or one subframe in the
PCell is scheduled, only A/N related to corresponding scheduling
may be transmitted using an implicit PUCCH format 1a/1b
(hereinafter, PF1) resource linked to a DL grant transmission
resource (this operation is referred to as fallback) and, for the
other cases, A/N for all CA configured cells may be transmitted
using a PUCCH (e.g., PF3 or PF4) indicated by the ARL
[0124] Meanwhile, in a normal CA situation including the above
proposals, a plurality of PUCCH transmission cells (without
limiting to one specific cell (e.g., a PCell) as a fallback cell)
or a plurality of (E)PDCCH transmission cells (performing
scheduling) may be configured as fallback cells. Therefore, if only
one of the plural cells is scheduled, only A/N related to
corresponding scheduling may be transmitted using a PF1 resource
and, for the other cases, A/N for all CA configured cells may be
transmitted using a PUCCH resource indicated by the ARI. Herein,
the PF1 resource may be a PF1 resource on a scheduled cell or a PF1
resource on a specific cell (e.g., PCell).
[0125] Simultaneous Transmission Method of A/N and p-CSI Through
PUCCH
[0126] In this method, an operation when a PUCCH resource, a UCI
transmission control parameter, and A/N, which are configured for
the UE, collide with periodic CSI (p-CSI) is described. Herein, A/N
may include an SR.
[0127] 1) For UE Configured with PF4 for A/N Transmission:
[0128] A. 4 PF4 resources (supporting different maximum payload
sizes) and 4 PF3 resources may be configured for A/N
transmission.
[0129] i. A PF to be used for A/N may be determined between PF3 and
PF4 based on an A/N payload size (e.g., PF3 is used for up to X
(e.g., X=22) bits, whereas PF4 is used for more than X bits).
[0130] ii. PF3/4 resource used for A/N transmission is indicated by
an ARI.
[0131] B. Up to two PF4 resources supporting different maximum
payload sizes may be configured only for periodic CSI
transmission.
[0132] i. Resources used for p-CSI transmission may be determined
between two PF4 resources based on a CSI payload size (e.g., small
PF4 resource #1 is used for up to Y bits corresponding to the
maximum payload size of the PF4 resource #1, whereas large PF4
resource #2 is used for more than Y bits).
[0133] 2) Parameter to Enable/Disable Simultaneous A/N+p-CSI
Transmission
[0134] A. R10_param: simultaneous A/N+CSI transmission on PF2
(PUCCH format 2/2a/2b) is enabled/disabled.
[0135] B. R11_param: simultaneous A/N+p-CSI transmission on PF3 is
enabled/disabled.
[0136] C. R13_param: simultaneous A/N+p-CSI transmission on PF4 is
enabled/disabled.
[0137] 3) Case #1: Collision of (A/N without ARI only+(one or)
multiple p-CSIs) in a subframe
[0138] A. Alt 1-1: A PF2 resource is used for A/N+CSI.
[0139] i. This is applied only if R10_param is ON.
[0140] ii. Single CSI with highest priority is selected for
transmission.
[0141] B. Alt 1-2: A PF4 resource configured for p-CSI transmission
is used for A/N+CSI.
[0142] i. This is applied only if R13_param is ON. Otherwise, Alt
1-1 is applied.
[0143] ii. When two PF4 resources are configured for p-CSI
transmission, a resource used for A/N+CSI is determined based on a
total UCI payload size. For example, the total UCI payload size
includes both A/N bits and CSI bits.
[0144] 1. For example, small PF4 resource #1 is used for up to Y
bits corresponding to the maximum payload size of the PF4 resource
#1, whereas large PF4 resource #2 is used for more than Y bits.
[0145] 4) Case #2: Collision of (A/N with ARI.ltoreq.X bits+(one
or) multiple p-CSIs) in one subframe
[0146] A. Alt 2-1: A PF3 resource indicated by an ARI is used for
A/N+CSI
[0147] i. This is applied only if R11_param is ON.
[0148] ii. If total UCI payload size >X bits, some or all CSI(s)
are dropped.
[0149] B. Alt 2-2: A PF4 resource configured for p-CSI transmission
is used for A/N+CSI.
[0150] i. This is applied if R13_param is ON. Otherwise, Alt 2-1 is
applied.
[0151] ii. When two PF4 resources are configured for p-CSI
transmission, the resource used for A/N+CSI is determined based on
a total UCI payload size. For example, the total UCI payload may
include both A/N bits and CSI bits.
[0152] 1. For example, small PF4 resource #1 is used for up to Y
bits corresponding to the maximum payload size of PF4 resource #1,
whereas large PF4 resource #2 is used for more than Y bits.
[0153] In a situation in which A/N and (plural) CSIs are
simultaneously transmitted in a specific PUCCH format/resource (or
PUSCH) through an arbitrary method including the above proposed
schemes, the total number of UCI bits including A/N and CSIs may
exceed a maximum UCI payload size (i.e., max_UCI_size) configured
for the specific PUCCH format/resource. In this case, a UE may
perform the following UCI transmission operations. The specific
PUCCH format/resource may include a PUCCH format/resource indicated
by an ARI in a DL grant or a PUCCH format/resource configured for
CSI transmission.
[0154] 1) Method 2-1: A/N Bundling First
[0155] In this method, (spatial) bundling is applied first to A/N.
Next, the bundled A/N and CSI are transmitted through a
designated/configured PUCCH format/resource. If the total number of
UCI bits including the bundled A/N and the CSI still exceeds
max_UCI_size, only specific CSI(s) having a high priority may be
selected from among (plural) CSIs and the bundled A/N and the
selected CSI(s) may be transmitted through the
designated/configured PUCCH format/resource. In this case, the
number of selected CSI(s) may be determined such that the total
number of bits of the bundled A/N and selected CSI(s) becomes the
maximum number of bits less than max_UCI_size. Meanwhile, when the
number of UCI bits including the bundled A/N and one CSI having the
highest priority exceeds max_UCI_size, all CSIs are dropped and
only the bundled A/N may be transmitted through the
designated/configured PUCCH format/resource.
[0156] 2) Method 2-2: CSI Dropping First
[0157] In this method, only specific CSI(s) having a high priority
are selected from among (plural) CSIs and the selected CSI(s) and
A/N are transmitted through a designated/configured PUCCH
format/resource. In this case, the number of selected CSI(s) may be
determined such that the total number of bits of the A/N and
selected CSI(s) becomes the maximum number of bits less than
max_UCI_size. If the total number of UCI bits including the A/N and
one CSI having the highest priority exceeds max_UCI_size, all CSIs
are dropped and only the A/N may be transmitted through the
designated/configured PUCCH format/resource. Meanwhile, when the
number of A/N bits alone exceeds max_UCI_size, (spatial) bundling
is applied to A/N and only the bundled A/N (without CSI) may be
transmitted through the designated/configured PUCCH
format/resource.
[0158] 3) Method 2-3: Modified Method 2-2
[0159] In this method, basic operation steps are the same as in
Method 2 (e.g., CSI dropping first and A/N bundling second). In a
state in which (spatial) bundling is applied to A/N which is the
last step, only specific CSI(s) having a high priority may be
selected again from among (plural) CSIs and the bundled A/N and
selected CSI(s) may be transmitted through a designated/configured
PUCCH format/resource. In this case, the number of selected CSI(s)
may be determined such that the total number of bits of the bundled
A/N and selected CSI(s) becomes the maximum number of bits less
than max_UCI_size. Meanwhile, when the number of UCI bits including
the bundled A/N and one CSI having the highest priority exceeds
max_UCI_size, all CSIs are dropped and only the bundled A/N may be
transmitted through the designated/configured PUCCH
format/resource.
[0160] FIG. 17 illustrates a BS and a UE to which embodiments of
the present invention are applicable. When a wireless communication
system includes a relay, the BS or the UE can be replaced by the
relay.
[0161] Referring to FIG. 17, the wireless communication system
includes the BS 110 and the UE 120. The BS 110 may include a
processor 112, a memory 114 and a radio frequency (RF) unit 116.
The processor 112 may be configured to implement procedures and/or
methods proposed by the present invention. The memory 114 may be
connected to the processor 112 and store information related to
operations of the processor 112. The RF unit 116 may be connected
to the processor 112 and transmit and/or receive RF signals. The UE
120 may include a processor 122, a memory 124 and an RF unit 126.
The processor 122 may be configured to implement procedures and/or
methods proposed by the present invention. The memory 124 may be
connected to the processor 122 and store information related to
operations of the processor 122. The RF unit 126 may be connected
to the processor 122 and transmit and/or receive RF signals. The BS
110 and/or the UE 120 may include a single antenna or multiple
antennas.
[0162] The embodiments of the present invention described
hereinbelow are combinations of elements and features of the
present invention. The elements or features may be considered
selective unless otherwise mentioned. Each element or feature may
be practiced without being combined with other elements or
features. Further, an embodiment of the present invention may be
constructed by combining parts of the elements and/or features.
Operation orders described in embodiments of the present invention
may be rearranged. Some constructions of any one embodiment may be
included in another embodiment and may be replaced with
corresponding constructions of another embodiment. It is obvious to
those skilled in the art that claims that are not explicitly cited
in each other in the appended claims may be presented in
combination as an embodiment of the present invention or included
as a new claim by subsequent amendment after the application is
filed.
[0163] A specific operation described as performed by the BS may be
performed by an upper node of the BS. Namely, it is apparent that,
in a network comprised of a plurality of network nodes including a
BS, various operations performed for communication with a UE may be
performed by the BS, or network nodes other than the BS. The term
BS may be replaced with the term, fixed station, Node B, eNode B
(eNB), access point, etc. The term terminal may be replaced with
the terms UE, MS, Mobile Subscriber Station (MSS), etc.
[0164] The embodiments of the present invention may be achieved by
various means, for example, hardware, firmware, software, or a
combination thereof. In a hardware configuration, an embodiment of
the present invention may be achieved by one or more ASICs
(application specific integrated circuits), DSPs (digital signal
processors), DSPDs (digital signal processing devices), PLDs
(programmable logic devices), FPGAs (field programmable gate
arrays), processors, controllers, microcontrollers,
microprocessors, etc.
[0165] In a firmware or software configuration, an embodiment of
the present invention may be implemented in the form of a module, a
procedure, a function, etc. Software code may be stored in a memory
unit and executed by a processor. The memory unit is located at the
interior or exterior of the processor and may transmit and receive
data to and from the processor via various known means.
[0166] Those skilled in the art will appreciate that the present
invention may be carried out in other specific ways than those set
forth herein without departing from the spirit and essential
characteristics of the present invention. The above embodiments are
therefore to be construed in all aspects as illustrative and not
restrictive. The scope of the invention should be determined by the
appended claims and their legal equivalents, not by the above
description, and all changes coming within the meaning and
equivalency range of the appended claims are intended to be
embraced therein.
INDUSTRIAL APPLICABILITY
[0167] The present invention can be used for wireless communication
apparatuses such as a UE, a relay, a BS, etc.
* * * * *