METHOD AND APPARATS FOR PERFORMING EFFICIENT FEEDBACK IN WIRELESS COMMUNICATION SYSTEM SUPPORTING MULTIPLE ANTENNA

• US 20120076023A1
• 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, Lee, Moonil, Chung, Jaehoon, Lim, Dongguk
• Granted Patent: US 8,903,328 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• 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 for transmitting channel status information (CSI) of downlink transmission via uplink in a wireless communication system includes transmitting a rank indicator (RI) and a precoder type indicator (PTI) at a first subframe, transmitting at a second subframe a first precoding matrix indicator (PMI) when the PTI has a first value and transmitting a second PMI and a wideband channel quality indicator (WB CQI) when the PTI has a second value, and transmitting at a third subframe a second PMI and a WB CQI when the PTI has a first value and transmitting a subband (SB) CQI and a second PMI when the PTI has a second value. A user equipment (UE) preferred precoding matrix is indicated by a combination of the first PMI and the second PMI. Subsampled codebooks of precoding codebooks of individual Rank-2, Rank-3 and Rank-4 are applied to the second PMI.

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) and a precoder type indicator (PTI) at a first subframe;

at a second subframe, transmitting a first precoding matrix indicator (PMI) when the PTI has a first value, and transmitting a second PMI and a wideband channel quality indicator (WB CQI) when the PTI has a second value; and

at a third subframe, transmitting a second PMI and a WB CQI when the PTI has a first value, and transmitting a subband (SB) CQI and a second PMI when the PTI has a second value,

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

subsampled codebooks of precoding codebooks of individual Rank-2, Rank-3 and Rank-4 are applied to the second PMI.

2. The method according to claim 1, wherein:

the precoding codebook for the Rank-2 is represented by the following table;

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

4. The method according to claim 1, wherein the precoding codebook for the Rank-4 is represented by the following table:

5. The method according to claim 1, wherein:

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

the first PMI, or the second PMI and WB CQI is transmitted over a PUCCH of the second subframe, and

the second PMI and WB CQI, or the SB CQI and second PMI is transmitted through a PUCCH of the third subframe.

6. 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.

7. The method according to claim 1, wherein:

the RI and the PTI are transmitted according to a first report cycle,

the first PMI is transmitted according to a second report cycle,

the second PMI and the WB CQI are transmitted according to a third report cycle, and

the SB CQI and the second PMI are transmitted according to a fourth report cycle.

8. 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) and a precoder type indicator (PTI) at a first subframe;

at a second subframe, receiving a first precoding matrix indicator (PMI) when the PTI has a first value, and receiving a second PMI and a wideband channel quality indicator (WB CQI) when the PTI has a second value; and

at a third subframe, receiving a second PMI and a WB CQI when the PTI has a first value, and receiving a subband (SB) CQI and a second PMI when the PTI has a second value,

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

subsampled codebooks of precoding codebooks of individual Rank-2, Rank-3 and Rank-4 are applied to the second PMI.

9. The method according to claim 8, wherein:

the precoding codebook for the Rank-2 is represented by the following table;

10. The method according to claim 8, wherein the precoding codebook for the Rank-3 is represented by the following table:

11. The method according to claim 8, wherein the precoding codebook for the Rank-4 is represented by the following table:

12. The method according to claim 8, wherein:

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

the first PMI, or the second PMI and WB CQI is transmitted over a PUCCH of the second subframe, and

the second PMI and WB CQI, or the SB CQI and second PMI is transmitted through a PUCCH of the third subframe.

13. The method according to claim 8, 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.

14. The method according to claim 8, wherein:

the RI and the PTI are transmitted according to a first report cycle,

the first PMI is transmitted according to a second report cycle,

the second PMI and the WB CQI are transmitted according to a third report cycle, and

the SB CQI and the second PMI are transmitted according to a fourth report cycle.

15. 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) and a precoder type indicator (PTI) at a first subframe,

the processor, through the transmission module, at a second subframe, transmits a first precoding matrix indicator (PMI) when the PTI has a first value and transmits a second PMI and a wideband channel quality indicator (WB CQI) when the PTI has a second value, and

the processor, through the transmission module, at a third subframe, transmits a second PMI and a WB CQI when the PTI has a first value, and transmits a subband (SB) CQI and a second PMI when the PTI has a second value,

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

subsampled codebooks of precoding codebooks of individual Rank-2, Rank-3 and Rank-4 are applied to the second PMI.

16. 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) and a precoder type indicator (PTI) at a first subframe,

the processor, through the reception module, at a second subframe, receives a first precoding matrix indicator (PMI) when the PTI has a first value, and receives a second PMI and a wideband channel quality indicator (WB CQI) when the PTI has a second value, and

the processor, through the reception module, at a third subframe, receives a second PMI and a WB CQI when the PTI has a first value, and receives a subband (SB) CQI and a second PMI when the PTI has a second value,

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

subsampled codebooks of precoding codebooks of individual Rank-2, Rank-3 and Rank-4 are applied to the second PMI.