Systems and methods for reducing uplink resources to provide channel performance feedback for adjustment of downlink MIMO channel data rates

• US 20060205357A1
• Filed: 03/11/2005
• Published: 09/14/2006
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kim, Byoung-Hoon
• Granted Patent: US 8,995,547 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04L 1/0656 Cyclotomic systems, e.g. Bell Labs Layered Space-Time [BLAST]
• CPC Class Codes: H04L 1/0675 characterised by the signaling

Abstract

Systems and methods for improving the performance of a MIMO wireless communication system by reducing the amount of uplink resources that are needed to provide channel performance feedback for the adjustment of data rates on the downlink MIMO channels. In one embodiment, a method comprises encoding each of a set of data streams according to corresponding data rates, permuting the data streams on a set of MIMO channels according to a full permutation of combinations, transmitting the permuted data streams, receiving the permuted data streams, decoding and determining an SNR for each of the data streams, computing a condensed SNR metric for the set of data streams, providing the condensed metric as feedback, determining a set of individual SNR metrics for the data streams based on the condensed SNR metric, and adjusting the data rates at which the data streams are encoded based on the individual SNR metrics.

Claims

1. A method implemented in a multiple-input, multiple-output (MIMO) wireless communication system, comprising:

transmitting each of a plurality of data streams from a first station to a second station in a permuted fashion over a plurality of MIMO channels;

inversely permuting the data streams at the second station;

determining a quality metric for each of the data streams at the second station;

determining a condensed quality metric at the second station based on the quality metrics for each of the data streams; and

transmitting the condensed quality metric from the second station to the first station.

2. The method of claim 1, further comprising:

encoding in the first station each the plurality of data streams according to corresponding data rates; and

adjusting the data rates at which the data streams are encoded at the first station based on the condensed quality metric.

3. The method of claim 2, wherein the quality metric comprises a signal-to-noise ratio (SNR), wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value, and wherein adjusting the data rates at which the data streams are encoded based on the condensed quality metric comprises adjusting the data rate for each channel based on the reference SNR value plus a multiple of the Δ

SNR value.

4. The method of claim 1, wherein the first station is a base station and the second station is a mobile station.

5. The method of claim 1, wherein transmitting the data streams in permuted fashion comprises mixing the data streams on the MIMO channels in a pseudorandom pattern.

6. The method of claim 5, wherein the pseudorandom pattern comprises a full permutation of possible combinations of the data streams and the MIMO channels.

7. The method of claim 1, wherein the quality metric comprises a signal-to-noise ratio (SNR).

8. The method of claim 7, wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value.

9. The method of claim 1, further comprising decoding the encoded data streams at the second station.

10. The method of claim 9, wherein the encoded data streams are decoded at the second station using successive interference cancellation.

11. A method for multiple-input, multiple-output (MIMO) wireless communication comprising:

encoding each of a plurality of data streams according to corresponding data rates;

transmitting the data streams in a permuted fashion over a plurality of MIMO channels to a second station;

receiving a condensed quality metric; and

adjusting the data rates at which the data streams are encoded based on the condensed quality metric.

12. The method of claim 11, wherein transmitting the data streams in permuted fashion comprises mixing the data streams on the MIMO channels in a pseudorandom pattern.

13. The method of claim 12, wherein the pseudorandom pattern comprises a full permutation of possible combinations of the data streams and the MIMO channels.

14. The method of claim 11, wherein the quality metric comprises a signal-to-noise ratio (SNR).

15. The method of claim 14, wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value.

16. The method of claim 15, wherein adjusting the data rates at which the data streams are encoded based on the condensed quality metric comprises adjusting the data rate for each channel based on the reference SNR value plus a multiple of the Δ

SNR value.

17. A method for multiple-input, multiple-output (MIMO) wireless communication comprising:

receiving a plurality of permuted data streams over a plurality of MIMO channels;

inversely permuting the data streams;

determining a quality metric for each of the data streams;

determining a condensed quality metric based on the quality metrics for each of the data streams; and

transmitting the condensed quality metric to a base station.

18. The method of claim 17, wherein the data streams are permuted in a pseudorandom pattern.

19. The method of claim 18, wherein the pseudorandom pattern comprises a full permutation of possible combinations of the data streams and the MIMO channels.

20. The method of claim 17, wherein the quality metric comprises a signal-to-noise ratio (SNR).

21. The method of claim 20, wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value.

22. The method of claim 17, further comprising decoding the encoded data streams.

23. The method of claim 22, wherein the encoded data streams are decoded using successive interference cancellation.

24. A base station for a MIMO wireless communication system comprising:

a processing subsystem; and

a transceiver subsystem having a plurality of transmit antennas and being coupled to the processing subsystem;

wherein the processing subsystem is configured to

encode each of a plurality of data streams according to a corresponding data rate,

permute the data streams and control the transceiver subsystem to transmit each of the data streams over a plurality of MIMO channels corresponding to the transmit antennas,

receive a condensed quality metric associated with all of the data streams,

determine an individual quality metric associated with each of the data streams based on the condensed quality metric, and

adjust the data rates at which each of the data streams is encoded based on the individual quality metric associated with each of the data streams.

25. The base station of claim 24, wherein the processing subsystem is configured to mix the data streams on the MIMO channels in a pseudorandom pattern

26. The base station of claim 25, wherein the pseudorandom pattern comprises a full permutation of possible combinations of the data streams and the MIMO channels

27. The base station of claim 24, wherein the quality metric comprises a signal-to-noise ratio (SNR)

28. The base station of claim 27, wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value

29. The base station of claim 28, wherein the processing subsystem is configured to adjust the data rate at which each data stream is encoded by computing a corresponding SNR equal to the reference SNR value plus a multiple of the Δ

SNR value, wherein successive ones of the data streams have successively higher SNRs

30. A mobile station for a MIMO wireless communication system comprising:

a processing subsystem; and

a transceiver subsystem having a plurality of receive antennas and being coupled to the processing subsystem;

wherein the processing subsystem is configured to

receive permuted data streams via the receive antennas,

inversely permute the data streams,

decode the data streams,

determine an individual quality metric corresponding to each of the data streams,

determine a condensed quality metric based on the individual quality metrics corresponding to each of the data streams, and

control the transceiver subsystem to transmit the condensed quality metric to a base station.

31. The mobile station of claim 30, wherein the processing subsystem is configured to inversely permute the data streams according to a pseudorandom pattern.

32. The mobile station of claim 31, wherein the pseudorandom pattern comprises a full permutation of possible combinations of the data streams and the MIMO channels.

33. The mobile station of claim 30, wherein the quality metric comprises a signal-to-noise ratio (SNR).

34. The mobile station of claim 33, wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value.

35. The mobile station of claim 30, further comprising the processing subsystem decoding the encoded data streams.

36. The mobile station of claim 35, wherein the processing subsystem decodes the encoded data streams using successive interference cancellation.

37. A multiple-input, multiple-output (MIMO) wireless communication system, comprising:

means for transmitting each of a plurality of data streams from a first station to a second station in a permuted fashion over a plurality of MIMO channels;

means for inversely permuting the data streams at the second station;

means for determining a quality metric for each of the data streams at the second station;

means for determining a condensed quality metric at the second station based on the quality metrics for each of the data streams; and

means for transmitting the condensed quality metric from the second station to the first station.

38. The system of claim 37, further comprising:

means for encoding in the first station each the plurality of data streams according to corresponding data rates; and

means for adjusting the data rates at which the data streams are encoded at the first station based on the condensed quality metric.

39. The system of claim 38, wherein the quality metric comprises a signal-to-noise ratio (SNR), wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value, and wherein the means for adjusting the data rates is configured to adjust the data rate for each channel based on the reference SNR value plus a multiple of the Δ

SNR value.

40. The system of claim 37, wherein the first station is a base station and the second station is a mobile station.

41. The system of claim 37, wherein the means for transmitting the data streams in permuted fashion is configured to mix the data streams on the MIMO channels in a pseudorandom pattern.

42. The system of claim 41, wherein the pseudorandom pattern comprises a full permutation of possible combinations of the data streams and the MIMO channels.

43. The system of claim 37, wherein the quality metric comprises a signal-to-noise ratio (SNR).

44. The system of claim 43, wherein the condensed quality metric comprises a reference SNR value and a Δ

SNR value.

45. The system of claim 37, further comprising means for decoding the encoded data streams at the second station.

46. The system of claim 45, wherein the means for decoding the encoded data streams is configured to decode the encoded data streams using successive interference cancellation.