METHOD AND APPARATUS FOR COMMUNICATING PRECODING OR BEAMFORMING INFORMATION TO USERS IN MIMO WIRELESS COMMUNICATION SYSTEMS

• US 20080233902A1
• Filed: 03/21/2008
• Published: 09/25/2008
• Est. Priority Date: 03/21/2007
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Pan, Kyle Jung-Lin, Grieco, Donald M.
• Application Number:
  US12/053,186
• Publication Number:
  US 20080233902A1
• Time in Patent Office: Days
• US Class Current: 455/114.3
• CPC Class Codes: H04B 7/0417 Feedback systems
• 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: H04B 7/0654 at the receiver, e.g. antenna verification at mobile station
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012

Abstract

Methods and apparatus for communicating precoding or beamforming information to users are disclosed. A feedback signal including a reported preceding matrix index (PMI) is received and a determination made as to the state of the feedback. Precoding rules associated with the determined state are then used to select a precoding matrix. The state information is transmitted to a wireless transmit receive unit (WTRU), which uses the state information and the precoding rules associated therewith to select the precoding matrix used to precoded a received precoded data signal.

Claims

1. A method for determining a preceding matrix comprising:

determining a state of a feedback signal;

selecting, based on predetermined preceding rules associated with the determined state, a preceding matrix index (PMI); and

determining the precoding matrix using the selected PMI.

2. The method of claim 1, wherein the predetermined precoding rules identify which precoding matrix is used.

3. The method of claim 1, wherein the state of the feedback signal categorizes the reliability of the feedback signal.

4. The method of claim 2, wherein the preceding rules include using a reported PMI when the feedback state of the feedback signal indicates that no error was detected in the feedback signal.

5. The method of claim 4, wherein the preceding rules further includes using a PMI associated with a previously used precoding matrix when the feedback state of the feedback signal indicates that an error was detected.

6. The method of claim 5, wherein the precoding rules further includes using a PMI associated with a default precoding matrix when the feedback state of the feedback signal indicates that the feedback signal is not reliable.

7. The method of claim 6, wherein the default preceding matrix is an identity matrix.

8. The method of claim 2, wherein each of a plurality of precoding rules is associated with at least one of a plurality of feedback states.

9. The method of claim 8, wherein each feedback state is identified by one of each of a plurality of feedback signals, the feedback state signal being a signal included in a control channel.

10. The method of claim 8, further comprising:

receiving the control channel including the feedback state signal that identifies the feedback state of the feedback signal.

11. The method of claim 10, further comprising:

decoding the control channel to detect the feedback state signal; and

associating the selected state signal with the precoding rule.

12. The method of claim 8, further comprising:

receiving a precoding matrix information;

blind detecting the precoded reference signal to detect the precoding information;

performing PMI validation using a set of PMIs associated with the precoding rules; and

using the detected preceding information to determine the most likely used precoding matrix.

13. The method of claim 12, wherein based on the most likely used precoding matrix determining the state of the feedback signal based on the precoding rules.

14. A method for determining a precoding matrix comprising:

decoding a control channel including a feedback state signal to determine a state of a feedback signal;

selecting, based on predetermined preceding rules associated with the determined state, a precoding matrix index (PMI); and

determining the precoding matrix using the selected PMI.

15. The method of claim 14, wherein the predetermined precoding rules identify which precoding matrix is used.

16. The method of claim 14, wherein the state of the feedback signal categorizes the reliability of the feedback signal.

17. The method of claim 15, wherein the precoding rules include using a reported PMI when the feedback state of the feedback signal indicates that no error was detected in the feedback signal.

18. The method of claim 17, wherein the precoding rules further includes using a PMI associated with a previously used precoding matrix when the feedback state of the feedback signal indicates that an error was detected.

19. The method of claim 18, wherein the precoding rules further includes using a PMI associated with a default precoding matrix when the feedback state of the feedback signal indicates that the feedback signal is not reliable.

20. The method of claim 19, wherein the default precoding matrix is an identity matrix.

21. The method of claim 20, wherein each of a plurality of preceding rules is associated with at least one of a plurality of feedback states.

22. The method of claim 21, wherein each feedback state is identified by one of each of a plurality of feedback signals, the feedback state signal being a signal included in a control channel.

23. The method of claim 19, further comprising:

receiving the control channel including the feedback state signal that identifies the feedback state of the feedback signal.

24. The method of claim 20, further comprising:

decoding the control channel to detect the feedback state signal; and

associating the selected state signal with the precoding rule.

25. A method for determining a preceding matrix comprising:

blind detecting a precoded reference signal to determine precoding information;

performing precoding matrix index (PMI) validation using PMIs associated with a predetermined precoding rules and the detected precoding information; and

selecting, based on the PMI validation, the precoding matrix.

26. The method of claim 25, wherein the predetermined precoding rules identify which precoding matrix is used.

27. The method of claim 25, wherein the state of the feedback signal categorizes the reliability of the feedback signal.

28. The method of claim 26, wherein the precoding rules include using a reported PMI when the feedback state of the feedback signal indicates that no error was detected in the feedback signal.

29. The method of claim 28, wherein the precoding rules further includes using a PMI associated with a previously used precoding matrix when the feedback state of the feedback signal indicates that an error was detected.

30. The method of claim 29, wherein the precoding rules further includes using a PMI associated with a default precoding matrix when the feedback state of the feedback signal indicates that the feedback signal is not reliable.

31. The method of claim 30, wherein the default precoding matrix is an identity matrix.

32. The method of claim 31, wherein each of a plurality of precoding rules is associated with at least one of a plurality of feedback states.

33. The method of claim 32, further comprising:

receiving the precoding matrix information; and

using the detected preceding information to determine the most likely used precoding matrix out of the PMIs associated with the precoding rules.

34. The method of claim 33, further comprising, based on the most likely used preceding matrix determining the state of the feedback signal based on the precoding rules.

35. A wireless transmit receive unit (WTRU) for determining a precoding matrix comprising:

a precoding matrix index (PMI) processor for determining a state of a feedback signal to select, based on predetermined precoding rules associated with the determined state, a precoding matrix index (PMI).

36. The WTRU of claim 35, wherein the predetermined precoding rules identify which precoding matrix is used.

37. The WTRU of claim 35, wherein the state of the feedback signal categorizes the reliability of the feedback signal.

38. The WTRU of claim 36, wherein the precoding rules include using a reported PMI when the feedback state of the feedback signal indicates that no error was detected in the feedback signal.

39. The WTRU of claim 38, wherein the preceding rules further includes using a PMI associated with a previously used preceding matrix when the feedback state of the feedback signal indicates that an error was detected.

40. The WTRU of claim 39, wherein the precoding rules further includes using a PMI associated with a default precoding matrix when the feedback state of the feedback signal indicates that the feedback signal is not reliable.

41. The WTRU of claim 40, wherein the default precoding matrix is an identity matrix.

42. The WTRU of claim 41, wherein each of a plurality of precoding rules is associated with at least one of a plurality of feedback states.

43. The WTRU of claim 42, wherein each feedback state is identified by one of each of a plurality of feedback signals, the feedback state signal being a signal included in a control channel.

44. The WTRU of claim 40 further comprises a receiver receiving the control channel including the feedback state signal that identifies the feedback state of the feedback signal.

45. The WTRU of claim 41, wherein the PMI processor decodes the control channel to detect the feedback state signal, the selected feedback state signal is associated with the appropriate precoding rule.

46. The WTRU of claim 42, further comprising:

a receiver for receiving a precoding matrix information;

the PMI processor blind detecting the precoded reference signal to detect the precoding information;

wherein a set of PMIs associated with the preceding rules and the detected precoding information are used for PMI validation.

47. The WTRU of claim 46 wherein a most likely used precoding matrix is determined from the PMI validation.

48. The WTRU of claim 47, wherein based on the most likely used precoding matrix, the state of the feedback signal based on the precoding rules is determined.