METHOD FOR REPORTING CHANNEL STATE INFORMATION ON A COORDINATED MULTI-POINT TRANSMISSION AND RECEPTION AGGREGATION, AND APPARATUS THEREFOR

• US 20140254708A1
• Filed: 10/25/2012
• Published: 09/11/2014
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Seo, Hanbyul, Kim, Kijun, Kim, Hyungtae
• Granted Patent: US 9,461,721 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• 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 7/0626 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: H04J 11/0053 using co-ordinated multipoint transmission/reception co-ordinated antenna or beam-forming aspects H04B7/022

Abstract

According to one embodiment of the present invention, a method is disclosed in which user equipment (UE) that communicates with a coordinated multi-point transmission and reception (CoMP) aggregation transmits channel state information (CSI) on said CoMP aggregation in a wireless communication system. The method may enable the determination of the number of bits for inter-point phase information for points that belong to said CoMP aggregation, and the number of bits for a channel quality indicator (CQI) for said CoMP aggregation based on rank indicator (RI) information within the number of bits allocated for transmission of the channel state information, and may enable the transmission of the channel state information including the inter-point phase information and CQI on the CoMP aggregation to at least one of a plurality of points that belong to the CoMP aggregation in accordance with said determined number of bits.

Claims

1. A method for transmitting channel state information (CSI) for a coordinated multi-point transmission and reception (CoMP) set by a user equipment (UE) communicating with the CoMP set in a wireless communication system, the method comprising:

determining the number of bits for phase information between points (inter-point phase information) belonging to the CoMP set and the number of bits for a channel quality indicator (CQI) for the CoMP set, based on rank indicator (RI) information within the number of bits allocated for transmission of the CSI; and

transmitting the CSI including the inter-point phase information and the CQI for the CoMP set to at least one of the points belonging to the CoMP set according to the determined numbers of bits.

2. The method according to claim 1, wherein the RI information includes an RI for the CoMP set and an RI for each of the points belonging to the CoMP set.

3. The method according to claim 1, further comprising transmitting a precoding matrix indicator (PMI) for the CoMP set to at least one of the points belonging to the CoMP set.

4. The method according to claim 1, further comprising deriving a precoding matrix index (PMI) for the CoMP set by concatenating PMIs for each of the points of the CoMP set, when an RI for the CoMP set is the same as an RI for each of the points of the CoMP set.

5. The method according to claim 1, further comprising padding a zero vector to a PMI for each of the points of the CoMP set and acquiring the PMI for the CoMP set by concatenating the PMIs to which the zero vector is padded, when an RI for the CoMP set is greater than an RI for each of the points of the CoMP set.

6. The method according to claim 5, wherein the number of bits for the inter-point phase information is set to zero, when the zero vector is padded.

7. The method according to claim 1, wherein, when an RI for the CoMP set is 2 or more, the number of bits for the inter-point phase information is set to zero.

8. A method for receiving channel state information (CSI) for a coordinated multi-point transmission and reception (CoMP) set from a user equipment (UE) in a wireless communication system, the method comprising:

receiving phase information between points (inter-point phase information) belonging to the CoMP set and a channel quality indicator (CQI) for the CoMP set, the inter-point phase information having the first number of bits and the CQI having the second number of bits, determined based on rank indicator (RI) information within the number of bits allocated for transmission of the CSI,

wherein the RI information includes an RI for the CoMP set and an RI for each of the points belonging to the CoMP set.

9. A user equipment (UE) for communicating with a coordinated multi-point transmission and reception (CoMP) set and transmitting channel state information (CSI) for the CoMP set in a wireless communication system, the UE comprising:

a radio frequency (RF) unit configured to transmit or receive a radio signal; and

a processor configured to control the RF unit,

wherein the processor determines the number of bits for phase information between points (inter-point phase information) belonging to the CoMP set and the number of bits for a channel quality indicator (CQI) for the CoMP set, based on rank indicator (RI) information within the number of bits allocated for transmission of the CSI, and

transmits the CSI including the inter-point phase information and the CQI for the CoMP set to at least one of the points belonging to the CoMP set according to the determined numbers of bits.

10. The UE according to claim 9, wherein the RI information includes an RI for the CoMP set and an RI for each of the points belonging to the CoMP set.

11. The UE according to claim 9, wherein the processor is configured to transmit a precoding matrix indicator (PMI) for the CoMP set to at least one of the points belonging to the CoMP set.

12. The UE according to claim 9, wherein the processor is configured to derive a precoding matrix index (PMI) for the CoMP set by concatenating PMIs for each of the points of the CoMP set, when an RI for the CoMP set is the same as an RI for each of the points of the CoMP set.

13. The UE according to claim 9, wherein the processor is configured to pad a zero vector to a PMI for each of the points of the CoMP set and derive a PMI for the CoMP set by concatenating the PMI to which the zero vector is padded, when an RI for the CoMP set is greater than an RI for each of the points of the CoMP set.

14. The UE according to claim 13, wherein the processor is configured to set the number of bits for the inter-point phase information to zero, when the zero vector is padded.

15. The UE according to claim 9, wherein, when an RI value for the CoMP set is 2 or more, the processor is configured to set the number of bits for the inter-point phase information to zero.

16. A base station (BS) for receiving channel state information (CSI) for a coordinated multi-point transmission and reception (CoMP) set from a user equipment (UE) in a wireless communication system, the BS comprising:

a radio frequency (RF) unit configured to transmit or receive a radio signal; and

a processor configured to control the RF unit,

wherein the processor receives phase information between points (inter-point phase information) belonging to the CoMP set and a channel quality indicator (CQI) for the CoMP set, the inter-point phase information having the first number of bits and the CQI having the second number of bits, determined based on rank indicator (RI) information within the number of bits allocated for transmission of the CSI, and

wherein the RI information includes an RI for the CoMP set and an RI for each of the points belonging to the CoMP set.