CQI FEEDBACK FOR MIMO DEPLOYMENTS

• US 20080013610A1
• Filed: 06/06/2007
• Published: 01/17/2008
• Est. Priority Date: 05/17/2006
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Onggosanusi, Eko, Varadarajan, Badri
• Application Number:
  US11/759,221
• Publication Number:
  US 20080013610A1
• Time in Patent Office: Days
• US Class Current: 375/221
• CPC Class Codes: H04B 7/0417 Feedback systems
• 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 7/0634 Antenna weights or vector/matrix coefficients
• 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: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 25/03929 with layer mapping, e.g. codeword-to layer design for space-time coding H04L1/0618
• CPC Class Codes: H04L 25/03949 equalizer selection or adaptation based on feedback multiple signaling inclusive of a precoding command for adapting the transmitter H04L1/0031; feedback for transmit diversity systems H04B7/0619; selection of codebook or precoding matrix for MIMO diversity systems H04B7/0456

Abstract

The present disclosure provides a receiver, a transmitter and methods of operating a receiver and a transmitter. In one embodiment, the receiver includes a receive portion employing transmission signals from a transmitter, having multiple transmit antennas, that is capable of transmitting at least one spatial codeword and adapting a transmission rank. The receiver also includes a feedback generator portion configured to provide a channel quality indicator that is feedback to the transmitter, wherein the channel quality indicator corresponds to at least one transmission rank.

Claims

1. A receiver, comprising:

a receive portion employing transmission signals from a transmitter having multiple transmit antennas that is capable of transmitting at least one spatial codeword and adapting a transmission rank; and

a feedback generator portion configured to provide a channel quality indicator that is feedback to the transmitter, wherein the channel quality indicator corresponds to at least one transmission rank.

2. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to a preferred transmission rank.

3. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to a channel quality of a plurality of transmission ranks.

4. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to a channel quality across at least one spatial codeword.

5. The receiver as recited in claim 4 wherein the channel quality indicator corresponding to a spatial codeword is represented as a difference relative to another channel quality indicator corresponding to another spatial codeword.

6. The receiver as recited in claim 4 wherein the channel quality indicator corresponds to a channel quality across distinct spatial codewords for a multiple codeword transmission.

7. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to a channel quality across distinct spatial layers.

8. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to at least one signal-to-interference-plus-noise ratio (SINR) parameter.

9. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to at least one transmission rate recommendation.

10. The receiver as recited in claim 1 wherein the channel quality indicator corresponds to a channel quality of a single spatial codeword transmission.

11. The receiver as recited in claim 1 wherein the channel quality indicator is accompanied by a successive interference cancellation indicator for performing successive interference cancellation.

12. The receiver as recited in claim 11 wherein the channel quality indicator is accompanied by a detection ordering indicator.

13. A method of operating a receiver, comprising:

receiving transmission signals from a transmitter having multiple transmit antennas that is capable of transmitting at least one spatial codeword and adapting a transmission rank; and

feeding back a channel quality indicator to the transmitter, wherein the channel quality indicator corresponds to at least one transmission rank.

14. The method as recited in claim 13 wherein the channel quality indicator corresponds to a preferred transmission rank.

15. The method as recited in claim 13 wherein the channel quality indicator corresponds to a channel quality of a plurality of transmission ranks.

16. The method as recited in claim 13 wherein the channel quality indicator corresponds to a channel quality across at least one spatial codeword.

17. The method as recited in claim 16 wherein the channel quality indicator corresponding to a second spatial codeword is represented as a difference relative to another channel quality indicator corresponding to another spatial codeword.

18. The method as recited in claim 16 wherein the channel quality indicator corresponds to the channel quality across distinct spatial codewords for a multiple codeword transmission.

19. The method as recited in claim 13 wherein the channel quality indicator corresponds to a channel quality across distinct spatial layers.

20. The method as recited in claim 13 wherein the channel quality indicator corresponds to at least one signal-to-interference-plus-noise ratio (SINR) parameter.

21. The method as recited in claim 13 wherein the channel quality indicator corresponds to at least one transmission rate recommendation.

22. The method as recited in claim 13 wherein the channel quality indicator corresponds to a channel quality of a single spatial codeword transmission.

23. The method as recited in claim 13 wherein the channel quality indicator is accompanied by a successive interference cancellation indicator for performing successive interference cancellation.

24. The method as recited in claim 23 wherein the channel quality indicator is accompanied by a detection ordering indicator.

25. A transmitter having multiple transmit antennas that is capable of transmitting at least one spatial codeword and adapting a transmission rank, comprising:

a feedback decoding portion configured to extract a channel quality indicator provided by a feedback signal from a receiver;

wherein the channel quality indicator corresponds to at least one transmission rank; and

a transmit portion coupled to the multiple transmit antennas that provides a subsequent transmission based on the channel quality indicator.

26. The transmitter as recited in claim 25 wherein the feedback decoding portion is further configured to extract a channel quality indicator employed for providing a modulation coding scheme to code the subsequent transmission.

27. The transmitter as recited in claim 25 wherein the feedback decoding portion is further configured to extract a channel quality indicator employed for scheduling the subsequent transmission.

28. The transmitter as recited in claim 25 wherein the transmission employs a plurality of spatial codewords for transmission rank higher than one and an independent modulation-coding scheme selection is performed across the distinct spatial codewords.

29. The transmitter as recited in claim 25 wherein the transmission employs a single spatial codeword for transmission rank higher than one and independent modulation scheme selection is performed across the distinct spatial layers.

30. The transmitter as recited in claim 25 wherein the transmission employs a single spatial codeword for transmission rank higher than one and a single modulation-coding scheme is selected for the distinct spatial layers.

31. The transmitter as recited in claim 25 wherein an ordering is performed across spatial layers in response to a detection ordering and a successive interference cancellation indicator feedback from the receiver.

32. The transmitter as recited in claim 25, wherein each user is assigned to the layer corresponding to the first layer indicated in a detection ordering indicator for transmitting to multiple users across distinct spatial layers.

33. The transmitter as recited in claim 25 wherein a channel quality indicator is reconstructed from a channel quality indicator feedback consisting of a base and at least one delta channel quality indicator.

34. The transmitter as recited in claim 25 wherein the transmitter adapts a codeword-to-layer mapping in response to a channel quality indicator feedback that is defined across spatial layer.

35. A method of operating a transmitter having multiple transmit antennas that is capable of transmitting at least one spatial codeword and adapting a transmission rank, comprising:

extracting a channel quality indicator provided by a feedback signal from a receiver;

selecting a transmission rank and a modulation-coding scheme for a subsequent transmission in response to the decoded channel quality indicator feedback;

selecting a user in response to the decoded channel quality indicator feedback; and

generating the subsequent transmission with the multiple transmit antennas.

36. The method as recited in claim 35 wherein the transmission employs a plurality of spatial codewords for transmission rank higher than one and independent modulation-coding scheme selection across the distinct spatial codewords.

37. The method as recited in claim 35 wherein the transmission employs a single spatial codeword for transmission rank higher than one and an independent modulation scheme selection across the distinct spatial layers.

38. The method as recited in claim 35 wherein the transmission employs a single spatial codeword for transmission rank higher than one and selects a single modulation-coding scheme for the distinct spatial layers.

39. The method as recited in claim 35 wherein an ordering is performed across spatial layers in response to a detection ordering and a successive interference cancellation indicator feedback from the receiver.

40. The method as recited in claim 35 wherein each user is assigned to a layer corresponding to the first layer indicated in a detection ordering indicator for transmitting to multiple users across distinct spatial layers.

41. The method as recited in claim 35 wherein a channel quality indicator is reconstructed from a channel quality indicator feedback consisting of a base and at least one delta channel quality indicator.

42. The method as recited in claim 35 wherein the transmitter adapts a codeword-to-layer mapping in response to a channel quality indicator feedback that is defined across spatial layers.