METHOD AND APPARATUS FOR EFFICIENT FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM SUPPORTING MULTIPLE ANTENNA

• US 20120076236A1
• Filed: 09/23/2011
• Published: 03/29/2012
• Est. Priority Date: 09/26/2010
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Ko, Hyunsoo, Kim, Sunam, Lim, Dongguk, Lee, Moonil, Chung, Jaehoon
• Granted Patent: US 8,625,698 B2
• Time in Patent Office: Days
• US Class Current: 375/296
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0469 taking special antenna structures, e.g. cross polarized antennas into account
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04B 7/0486 taking channel rank into account
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/063 Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0057 : Physical resource allocation for CQI
• CPC Class Codes: H04L 5/006 : Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 48/08 : Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 72/00 : Local resource management
• CPC Class Codes: H04W 72/0446 : Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/21 : in the uplink direction of a wireless link, i.e. towards the network

Abstract

A method and apparatus for transmitting effective channel status information (CSI) in a wireless communication system supporting multiple carriers are disclosed. A method for transmitting CSI of DL transmission via uplink in a wireless communication system includes transmitting a rank indicator (RI) at a first subframe, and transmitting a first precoding matrix indicator (PMI), a second PMI, and a wideband (WB) channel quality indicator (CQI) at a second subframe. UE preferred precoding matrix is indicated by a combination of the first PMI and the second PMI. A subsampled codebook for each precoding codebook of ranks from Rank-1 to Rank-4 is applied to the first PMI and the second PMI, and a sum of the first PMI and the second PMI for each of Rank-1 to Rank-4 is comprised of 4 bits.

Claims

1. A method for transmitting channel status information (CSI) of downlink transmission via uplink in a wireless communication system, the method comprising:

transmitting a rank indicator (RI) at a first subframe; and

transmitting a first precoding matrix indicator (PMI), a second PMI, and a wideband (WB) channel quality indicator (CQI) at a second subframe,

wherein a user equipment (UE) preferred precoding matrix is indicated by a combination of the first PMI and the second PMI, and

a subsampled codebook for each precoding codebook of ranks from Rank-1 to Rank-4 is applied to the first PMI and the second PMI, and a sum of the first PMI and the second PMI for each of Rank-1 to Rank-4 is comprised of 4 bits.

2. The method according to claim 1, wherein, in association with each of the Rank-1 and the Rank-2, the first PMI is comprised of 3 bits in the subsampled codebook, and the second PMI is comprised of 1 bit.

3. The method according to claim 2, wherein the precoding codebook for the Rank-1 is represented by the following table:

4. The method according to claim 2, wherein the precoding codebook for the Rank-2 is represented by the following table:

5. The method according to claim 1, wherein, in association with each of the Rank-3 and the Rank-4, the first PMI is comprised of 1 bit in the subsampled codebook, and the second PMI is comprised of 3 bits.

6. The method according to claim 5, wherein the precoding codebook for the Rank-3 is represented by the following table:

7. The method according to claim 5, wherein the precoding codebook for the Rank-4 is represented by the following table:

8. The method according to claim 1, wherein:

the RI is transmitted over a physical uplink control channel (PUCCH) of the first subframe, and

the first PMI, the second PMI, and the CQI are transmitted over a PUCCH of the second subframe.

9. The method according to claim 1, wherein the RI, the first PMI, the second PMI, and the CQI are contained in channel status information (CSI) of downlink 8 transmission (Tx) antennas.

10. The method according to claim 1, wherein:

the RI is transmitted according to a first report cycle, and

the first PMI, the second PMI, and the CQI are transmitted according to a second report cycle.

11. A method for receiving channel status information (CSI) of downlink transmission via uplink in a wireless communication system, the method comprising:

receiving a rank indicator (RI) at a first subframe; and

receiving a first precoding matrix indicator (PMI), a second PMI, and a wideband (WB) channel quality indicator (CQI) at a second subframe,

wherein a user equipment (UE) preferred precoding matrix is indicated by a combination of the first PMI and the second PMI, and

a subsampled codebook for each precoding codebook of ranks from Rank-1 to Rank-4 is applied to the first PMI and the second PMI, and a sum of the first PMI and the second PMI for each of Rank-1 to Rank-4 is comprised of 4 bits.

12. The method according to claim 11, wherein, in association with each of the Rank-1 and the Rank-2, the first PMI is comprised of 3 bits in the subsampled codebook, and the second PMI is comprised of 1 bit.

13. The method according to claim 12, wherein the precoding codebook for the Rank-1 is represented by the following table:

14. The method according to claim 12, wherein the precoding codebook for the Rank-2 is represented by the following table:

15. The method according to claim 11, wherein, in association with each of the Rank-3 and the Rank-4, the first PMI is comprised of 1 bit in the subsampled codebook, and the second PMI is comprised of 3 bits.

16. The method according to claim 15, wherein the precoding codebook for the Rank-3 is represented by the following table:

17. The method according to claim 15, wherein the precoding codebook for the Rank-4 is represented by the following table:

18. The method according to claim 11, wherein:

the RI is received over a physical uplink control channel (PUCCH) of the first subframe, and

the first PMI, the second PMI, and the CQI are received over a PUCCH of the second subframe.

19. The method according to claim 11, wherein the RI, the first PMI, the second PMI, and the CQI are contained in channel status information (CSI) of downlink 8 transmission (Tx) antennas.

20. The method according to claim 11, wherein:

the RI is received according to a first report cycle, and

the first PMI, the second PMI, and the CQI are received according to a second report cycle.

21. A user equipment (UE) for transmitting channel status information (CSI) of downlink transmission via uplink in a wireless communication system comprising:

a reception module for receiving a downlink signal from a base station (BS);

a transmission module for transmitting an uplink signal to the base station (BS); and

a processor for controlling the user equipment (UE) including the reception module and the transmission module,

wherein the processor, through the transmission module, transmits a rank indicator (RI) at a first subframe, and transmits a first precoding matrix indicator (PMI), a second PMI, and a wideband (WB) channel quality indicator (CQI) at a second subframe,

a UE preferred precoding matrix is indicated by a combination of the first PMI and the second PMI, and

a subsampled codebook for each precoding codebook of ranks from Rank-1 to Rank-4 is applied to the first PMI and the second PMI, and a sum of the first PMI and the second PMI for each of Rank-1 to Rank-4 is comprised of 4 bits.

22. A base station (BS) for receiving channel status information (CSI) of downlink transmission via uplink in a wireless communication system comprising:

a reception module for receiving an uplink signal from a user equipment (UE);

a transmission module for transmitting a downlink signal to the user equipment (UE); and

a processor for controlling the base station (BS) including the reception module and the transmission module,

wherein the processor, through the reception module, receives a rank indicator (RI) at a first subframe, and receives a first precoding matrix indicator (PMI), a second PMI, and a wideband (WB) channel quality indicator (CQI) at a second subframe,

a UE preferred precoding matrix is indicated by a combination of the first PMI and the second PMI, and a subsampled codebook for each precoding codebook of ranks from Rank-1 to Rank-4 is applied to the first PMI and the second PMI, and a sum of the first PMI and the second PMI for each of Rank-1 to Rank-4 is comprised of 4 bits.