METHOD FOR REPORTING CHANNEL STATE INFORMATION IN WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR

• US 20160211902A1
• Filed: 10/24/2014
• Published: 07/21/2016
• Est. Priority Date: 10/24/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Yoonsoo, Sung, Wonji, Kang, Hosik, Sung, Jihoon, Park, Jonghyun
• Granted Patent: US 10,116,371 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04B 7/0479 for multi-dimensional arrays, e.g. horizontal or vertical pre-distortion matrix index [PMI]
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0628 Diversity capabilities
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

Disclosed are a method for reporting channel state information in a wireless communication system and an apparatus therefor. A method by which user equipment reports channel state information (CSI) in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: receiving, from a base station, an RRC message including at least one CSI-reference signal (CSI-RS) configuration for a first direction domain; respectively receiving through different sub-frames, a first CSI-RS from a first subset and a second CSI-RS from a second subset among a plurality of physical antenna elements in the base station on the basis of the CSI-RS configuration; and performing a CSI report by using the first and second CSI-RSs, wherein when the CSI-RS configuration for the first direction domain is one, the first CSI-RS and the second CSI-RS are respectively received from the first subset and the second subset by virtualization-varying antenna ports related to one CSI-RS configuration in a predetermined period.

Claims

1. A method of reporting channel state information (CSI) by a user equipment in a wireless communication system, the method comprising:

receiving an RRC message containing at least one CSI-reference signal (CSI-RS) configuration for a first direction domain from a base station;

receiving, via different subframes respectively, a first CSI-RS from a first subset and a second CSI-RS from a second subset among a plurality of physical antenna elements of the base station based on the at least one CSI-RS configuration; and

performing CSI reporting using the first CSI-RS and the second CSI-RS,

wherein if a number of the at least one CSI-RS configuration for the first direction domain corresponds to one, the first CSI-RS and the second CSI-RS are respectively received from the first subset and the second subset according to virtualization-varying of antenna ports related to the one CSI-RS configuration, the virtualization-varying being performed in accordance with a predetermined period.

2. The method of claim 1, wherein the virtualization-varying comprises mapping a first antenna port used to be mapped to a first antenna element of the first subset to a second antenna element of the second subset according to the predetermined period.

3. The method of claim 1, wherein the CSI-RS configuration comprises information on a pattern of the virtualization-varying.

4. The method of claim 1,

wherein the RRC message further comprises at least one CSI-RS configuration for a second direction domain and

wherein performing the CSI reporting comprises transmitting first CSI for the first direction domain and second CSI for the second direction domain.

5. The method of claim 1, wherein if a number of the at least one CSI-RS configuration for the first direction domain is greater than one, the first CSI-RS and the second CSI-RS are received based on different CSI-RS configurations respectively.

6. The method of claim 1, wherein the CSI reporting is performed according to:

a first reporting scheme for respectively reporting separate CSI on a first partial channel corresponding to the first subset and a second partial channel corresponding to the second subset or

a second reporting scheme for reporting CSI on total channels obtained based on at least one of the first partial channel and the second partial channel.

7. The method of claim 6, wherein the total channels in the second reporting scheme are obtained by

performing interpolation on at least one of the first partial channel and the second partial channel or

matching the first partial channel and the second partial channel with each other.

8. The method of claim 6, further comprising receiving information indicating either the first reporting scheme or the second reporting scheme.

9. The method of claim 6,

wherein if the CSI reporting is performed according to the first reporting scheme, the CSI report comprises at least one of a precoding matrix index (PMI) selected from a 4 or 8-port-based codebook and an rank indicator (RI) indicating 4 or 8 and

wherein if the CSI reporting is performed according to the second reporting scheme, the CSI report comprises at least one of a precoding matrix index (PMI) selected from a 16 or 32-port-based codebook and a rank indicator (RI) indicating 16 or 32.

14. The method of claim 9, wherein if a number of the at least one CSI-RS configuration for the first direction domain is greater than one, the first CSI-RS and the second CSI-RS are received based on different CSI-RS configurations respectively.

15. The method of claim 9, wherein the CSI report is received according to:

a first reporting scheme for respectively reporting separate CSI on a first partial channel corresponding to the first subset and a second partial channel corresponding to the second subset or

a second reporting scheme for reporting CSI on total channels obtained based on at least one of the first partial channel and the second partial channel.

16. The method of claim 15, wherein the total channels in the second reporting scheme are obtained by

performing interpolation on at least one of the first partial channel and the second partial channel or

matching the first partial channel and the second partial channel with each other.

17. The method of claim 15, further comprising transmitting information indicating either the first reporting scheme or the second reporting scheme.

18. The method of claim 15,

wherein if the CSI report is performed according to the first reporting scheme, the CSI report comprises at least one of a precoding matrix index (PMI) selected from a 4 or 8-port-based codebook and a rank indicator (RI) indicating 4 or 8 and

wherein if the CSI report is performed according to the second reporting scheme, the CSI report comprises at least one of a precoding matrix index (PMI) selected from a 16 or 32-port-based codebook and a rank indicator (RI) indicating 16 or 32.

10. A method of receiving channel state information (CSI) by a base station in a wireless communication system, the method comprising:

transmitting an RRC message containing at least one CSI-RS configuration for a first direction domain to a user equipment;

transmitting, to the user equipment via different subframes respectively, a first CSI-RS mapped to a first subset and a second CSI-RS mapped to a second subset among a plurality of physical antenna elements of the base station; and

receiving a CSI report using the first CSI-RS and the second CSI-RS,

wherein if a number of the at least one CSI-RS configuration for the first direction domain corresponds to one, the first CSI-RS and the second CSI-RS are respectively transmitted through the first subset and the second subset according to virtualization-varying of antenna ports related to the one CSI-RS configuration, the virtualization-varying being performed in accordance with a predetermined period.

11. The method of claim 10, wherein the virtualization-varying comprises mapping a first antenna port used to be mapped to a first antenna element of the first subset to a second antenna element of the second subset according to the predetermined period.

12. The method of claim 10, wherein the CSI-RS configuration comprises information on a pattern of the virtualization-varying.

13. The method of claim 10,

wherein the RRC message further comprises at least one CSI-RS configuration for a second direction domain and

wherein receiving the CSI report comprises receiving first CSI for the first direction domain and second CSI for the second direction domain.

19. A user equipment reporting channel state information (CSI) in a wireless communication system, comprising:

a receiver configured to receive an RRC message containing at least one CSI-RS configuration for a first direction domain from a base station and to receive, via different subframes respectively, a first CSI-RS from a first subset and a second CSI-RS from a second subset among a plurality of physical antenna elements of the base station based on the at least one CSI-RS configuration; and

a processor configured to perform CSI reporting using the first CSI-RS and the second CSI-RS,

wherein if a number of the at least one CSI-RS configuration for the first direction domain corresponds to one, the first CSI-RS and the second CSI-RS are respectively received from the first subset and the second subset according to virtualization-varying of antenna ports related to the one CSI-RS configuration, the virtualization-varying being performed in accordance with a predetermined period.

20. A base station receiving channel state information (CSI) in a wireless communication system, comprising:

a transmitter configured to transmit an RRC message containing at least one CSI-RS configuration for a first direction domain to a user equipment and to transmit, to the user equipment via different subframes respectively, a first CSI-RS mapped to a first subset and a second CSI-RS mapped to a second subset among a plurality of physical antenna elements of the base station;

a receiver configured to receive a CSI report using the first CSI-RS and the second CSI-RS; and

a processor configured to control the transmitter and the receiver,

wherein if a number of the at least one CSI-RS configuration for the first direction domain corresponds to one, the first CSI-RS and the second CSI-RS are respectively received from the first subset and the second subset according to virtualization-varying of antenna ports related to the one CSI-RS configuration, the virtualization-varying being performed in accordance with a predetermined period.