Systems and methods for communication of channel state information

• US 9,077,498 B2
• Filed: 09/28/2011
• Issued: 07/07/2015
• Est. Priority Date: 09/29/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Abraham, Santosh Paul, Merlin, Simone, Vermani, Sameer, Sampath, Hemanth
• Primary Examiner(s): LIU, JUNG
• Application Number:
  US13/247,047
• Publication Number:
  US 20120250543A1
• Time in Patent Office: 1,378 Days
• Field of Search: 370/203, 370204-215, 370229-240, 370310-337, 370338-350, 370351-394, 370/395.1, 370/395.3, 370/395.4, 370/395.41, 370/395.42, 370/395.5, 370/395.52, 370431-457, 370458-463, 370464-497, 370498-529
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0636 Feedback format
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/0039 other detection of signalling, e.g. detection of TFCI explicit signalling H04L1/0046, H04L27/0012 and H04L25/0262 take precedence
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Certain aspects of the present disclosure relate to a technique for communicating Channel State Information (CSI) feedback. In some aspects, the CSI feedback is communicated in a very high throughput (VHT) wireless communications system.

Claims

1. A method of wireless communication, comprising:

receiving a request for channel state information;

determining parameters of the channel state information based on information included in the request;

determining the channel state information based at least in part on the determined parameters; and

transmitting a frame comprising at least a portion of the determined channel state information, wherein at least one of the parameters comprises a number of columns of a matrix for the channel state information that is requested, and wherein the request comprises a first field indicating the number.

2. The method of claim 1, wherein the request further comprises a second field indicating an association identifier of an apparatus from which the channel state information is requested.

3. The method of claim 2, wherein the second field comprises 12 bits.

4. The method of claim 2, wherein the request is received at a first apparatus, and wherein the method further comprises determining that the first apparatus is identified by the association identifier.

5. The method of claim 1, wherein the first field comprises at least 3 bits.

6. The method of claim 1, wherein at least a portion of the determined channel state information is represented as a matrix comprising a number of columns equal to the number indicated in the first field.

7. The method of claim 1, wherein the information comprises at least one bit indicating whether the channel state information will be used for a single user protocol or a multi-user protocol.

8. The method of claim 1, wherein the request comprises a null data packet announcement, the null data packet announcement comprising a sequence number, and wherein the transmitted frame comprises data indicating the sequence number.

9. The method of claim 1, wherein the transmitted frame comprises a control field indicating the determined parameters.

10. The method of claim 1, further comprising determining a bandwidth of the determined channel state information based on the determined parameters.

11. The method of claim 10, wherein the request comprises a first indicator signifying whether the channel state information is requested for single user or multi-user, and a second indicator signifying a number of columns of a matrix for the channel state information that is requested.

12. The method of claim 10, wherein the determined bandwidth is indicated in the frame.

13. The method of claim 1, further comprising:

receiving a polling message requesting an additional portion of the determined channel state information; and

transmitting an additional frame comprising the additional portion of the determined channel state information.

14. An apparatus for wireless communications, comprising:

a receiver configured to receive a request for channel state information;

a processing system configured to determine parameters of the channel state information based on information included in the request, and to determine the channel state information based at least in part on the determined parameters; and

a transmitter configured to transmit a frame comprising at least a portion of the determined channel state information, wherein at least one of the parameters comprises a number of columns of a matrix for the channel state information that is requested, and wherein the request comprises a first field indicating the number.

15. The apparatus of claim 14, wherein the request further comprises a second field indicating an association identifier of an apparatus from which the channel state information is requested.

16. The apparatus of claim 15, wherein the second field comprises 12 bits.

17. The apparatus of claim 15, wherein the processing system is further configured to determine that the apparatus is identified by the association identifier.

18. The apparatus of claim 14, wherein the first field comprises at least 3 bits.

19. The apparatus of claim 14, wherein at least a portion of the determined channel state information is represented as a matrix comprising a number of columns equal to the number indicated in the first field.

20. The apparatus of claim 14, wherein the information comprises at least one bit indicating whether the channel state information will be used for a single user protocol or a multi-user protocol.

21. The apparatus of claim 14, wherein the request comprises a null data packet announcement, the null data packet announcement comprising a sequence number, and wherein the transmitted frame comprises data indicating the sequence number.

22. The apparatus of claim 14, wherein the transmitted frame comprises a control field indicating the determined parameters.

23. The apparatus of claim 14, wherein the processing system is configured to determine a bandwidth of the determined channel state information based on the determined parameters.

24. The apparatus of claim 23, wherein the request comprises a first indicator signifying whether the channel state information is requested for single user or multi-user, and a second indicator signifying a number of columns of a matrix for the channel state information that is requested.

25. The apparatus of claim 23, wherein the determined bandwidth is indicated in the frame.

26. The apparatus of claim 14, wherein the receiver is further configured to receive a polling message requesting an additional portion of the determined channel state information, and wherein the transmitter is further configured to transmit an additional frame comprising the additional portion of the determined channel state information.

27. An apparatus for wireless communications, comprising:

means for receiving a request for channel state information;

means for determining parameters of the channel state information based on information included in the request;

means for determining the channel state information based at least in part on the determined parameters; and

means for transmitting a frame comprising at least a portion of the determined channel state information, wherein at least one of the parameters comprises a number of columns of a matrix for the channel state information that is requested, and wherein the request comprises a first field indicating the number.

28. The apparatus of claim 27, wherein the request further comprises a second field indicating an association identifier of an apparatus from which the channel state information is requested.

29. The apparatus of claim 28, wherein the second field comprises 12 bits.

30. The apparatus of claim 28, wherein the apparatus further comprises means for determining that the apparatus is identified by the association identifier.

31. The apparatus of claim 27, wherein the first field comprises at least 3 bits.

32. The apparatus of claim 27, wherein at least a portion of the determined channel state information is represented as a matrix comprising a number of columns equal to the number indicated in the first field.

33. The apparatus of claim 27, wherein the information comprises at least one bit indicating whether the channel state information will be used for a single user protocol or a multi-user protocol.

34. The apparatus of claim 27, wherein the request comprises a null data packet announcement, the null data packet announcement comprising a sequence number, and wherein the transmitted frame comprises data indicating the sequence number.

35. The apparatus of claim 27, wherein the transmitted frame comprises a control field indicating the determined parameters.

36. The apparatus of claim 27, further comprising means for determining a bandwidth of the determined channel state information based on the determined parameters.

37. The apparatus of claim 36, wherein the request comprises a first indicator signifying whether the channel state information is requested for single user or multi-user, and a second indicator signifying a number of columns of a matrix for the channel state information that is requested.

38. The apparatus of claim 36, wherein the determined bandwidth is indicated in the frame.

39. The apparatus of claim 27, further comprising:

means for receiving a polling message requesting an additional portion of the determined channel state information; and

means for transmitting an additional frame comprising the additional portion of the determined channel state information.

40. A computer program product for wirelessly communicating comprising a non-transitory computer readable medium comprising instructions that when executed cause an apparatus to:

receive a request for channel state information;

determine parameters of the channel state information based on information included in the request;

determine the channel state information based at least in part on the determined parameters; and

transmit a frame comprising at least a portion of the determined channel state information, wherein at least one of the parameters comprises a number of columns of a matrix for the channel state information that is requested, and wherein the request comprises a field indicating the number.

41. An access terminal, comprising:

at least one antenna;

a receiver configured to receive, via the at least one antenna, a request for channel state information;

a processing system configured to determine parameters of the channel state information based on information included in the request, and to determine the channel state information based at least in part on the determined parameters; and

a transmitter configured to transmit a frame comprising at least a portion of the determined channel state information, wherein at least one of the parameters comprises a number of columns of a matrix for the channel state information that is requested, and wherein the request comprises a field indicating the number.