Transmission scheduling for receiver feedback

• US 20080005219A1
• Filed: 09/25/2006
• Published: 01/03/2008
• Est. Priority Date: 01/10/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Nabar, Rohit U., Lou, Hui-Ling
• Granted Patent: US 8,155,597 B2
• Time in Patent Office: Days
• US Class Current: 709/201
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

A network device includes a first feedback module and a first calibration module. The first feedback module selectively generates a first transmission schedule that is transmitted to a link partner, wherein the first transmission schedule includes a first matrix map. The first calibration module selectively transmits a first set of training signals to the link partner, receives a first set of channel state information (CSI) for the training signals from the link partner according to the first transmission schedule, and generates a first CSI matrix based on the first set of CSI and the first matrix map.

Claims

1. A network device, comprising:

a first feedback module that selectively generates a first transmission schedule that is transmitted to a link partner, wherein said first transmission schedule includes a first matrix map; and

a first calibration module that selectively transmits a first set of training signals to said link partner, that receives a first set of channel state information (CSI) for said training signals from said link partner according to said first transmission schedule, and that generates a first CSI matrix based on said first set of CSI and said first matrix map.

2. The network device of claim 1 further comprising:

a first steering module that generates a first steering matrix based on said first CSI matrix;

a first control module that adjusts beamforming weights of said network device based on said first steering matrix; and

a first beamforming module that directs transmission of radio frequency (RF) signals toward said link partner based on said beamforming weights, wherein said beamforming weights determine gain of said RF signals.

3. The network device of claim 2 wherein said first transmission schedule includes a first subcarrier schedule that determines an order of transmitting subcarriers of said RF signals, and wherein said first matrix map determines a sequence for communicating elements of said first set of CSI that constitute elements of said first CSI matrix.

4. The network device of claim 3 wherein said first calibration module generates said first set of training signals for each of said subcarriers and receives said first set of CSI for each of said subcarriers, and wherein said first set of CSI includes signal to noise ratios (SNRs) of said subcarriers.

5. The network device of claim 4 wherein said first feedback module determines correspondence between each of said subcarriers and said first CSI matrix for each of said subcarriers based on said first subcarrier schedule.

6. A wireless network comprising the network device of claim 2 and further comprising said link partner, wherein said link partner includes a second calibration module that determines said first set of CSI for said first set of training signals, that generates said first CSI matrix based on said first set of CSI and said first matrix map, and that communicates said first set of CSI to said network device based on said first transmission schedule.

7. The wireless network of claim 6 wherein said link partner further comprises a second feedback module that generates a second transmission schedule that is transmitted to said network device when said first feedback module does not generate said first transmission schedule, and wherein said second transmission schedule includes a second matrix map.

8. The wireless network of claim 7 wherein said first feedback module receives said second transmission schedule, and wherein said first calibration module receives said first set of CSI from said link partner according to said second transmission schedule and generates said first CSI matrix based on said first set of CSI and said second matrix map.

9. The wireless network of claim 7 wherein said second calibration module transmits a second set of training signals to said network device, and wherein said first calibration module determines a second set of CSI for said second set of training signals and generates a second CSI matrix based on said second set of CSI and one of said first and second matrix maps.

10. The wireless network of claim 9 wherein said second calibration module receives said second set of CSI from said network device according to one of said first and second transmission schedules and generates said second CSI matrix based on one of said first and second matrix maps.

11. The wireless network of claim 10 wherein said link partner further comprises:

a second steering module that generates a second steering matrix based on said second CSI matrix;

a second control module that adjusts beamforming weights of said link partner based on said second steering matrix; and

a second beamforming module that directs transmission of radio frequency (RF) signals toward said network device based on said beamforming weights of said link partner, wherein said beamforming weights of said link partner determine gain of said RF signals.

12. The wireless network of claim 11 wherein said second transmission schedule includes a second subcarrier schedule that determines an order of transmitting subcarriers of said RF signals, and wherein said second matrix map determines a sequence for communicating elements of one of said first and second sets of CSI.

13. The wireless network of claim 12 wherein said second calibration module generates said second set of training signals for each of said subcarriers and receives said second set of CSI for each of said subcarriers, and wherein said second set of CSI includes signal to noise ratios (SNRs) of said subcarriers, and wherein elements of said second set of CSI constitute elements of said second CSI matrix.

14. The wireless network of claim 13 wherein said first feedback module determines correspondence between each of said subcarriers and said second CSI matrix for each of said subcarriers based on said second subcarrier schedule.

15. The wireless network of claim 6 wherein said network device parses a frame into a plurality of radio frequency (RF) signals and transmits said RF signals toward said link partner via N_TX antennas and said link partner receives said RF signals via N_RXantennas, where N_TX and N_RX are integers greater than or equal to 1.

16. The wireless network of claim 6 wherein said link partner parses a frame into a plurality of radio frequency (RF) signals and transmits said RF signals toward said network device via N_TX antennas and said network device receives said RF signals via N_RX antennas, where N_TX and N_RX are integers greater than or equal to 1.

17. The wireless network of claim 9 wherein said first and second CSI matrices are (N_TX×

N_RX) matrices, where N_TX and N_RX are integers greater than or equal to 1 and represent number of transmit and receive antennas, respectively.

18. The wireless network of claim 11 wherein said network device further comprises a third steering module that generates a third steering matrix based on said second set of CSI according to one of said first and second matrix maps when said link partner does not include at least one of said second and third steering modules and does not generate said second steering matrix.

19. The wireless network of claim 18 wherein said second control module adjusts said beamforming weights of said link partner based on said third steering matrix received from said network device according to one of said first and second transmission schedules.

20. The wireless network of claim 18 wherein said third steering matrix is a (N_TX×

N_SS) matrix, where N_TX is an integer greater than or equal to 1 and represents a number of transmit antennas and N_SS is an integer greater than or equal to 1 and represents spatial streams of a frame.

21. The wireless network of claim 18 wherein said link partner receives said third steering matrix for each subcarrier of said RF signals, and wherein said second feedback module determines correspondence between each subcarrier and said third steering matrix for each subcarrier based on one of said first and second transmission schedules.

22. The wireless network of claim 11 wherein said link partner further comprises a third steering module that generates a third steering matrix based on said first set of CSI according to one of said first and second matrix maps when said network device does not include at least one of said second and third steering modules and does not generate said first steering matrix.

23. The wireless network of claim 22 wherein said first control module adjusts said beamforming weights of said network device based on said third steering matrix received from said link partner according to one of said first and second transmission schedules.

24. The wireless network of claim 22 wherein said third steering matrix is a (N_TX×

N_SS) matrix, where N_TX is an integer greater than or equal to 1 and represents a number of transmit antennas and N_SS is an integer greater than or equal to 1 and represents spatial streams of a frame.

25. The wireless network of claim 22 wherein said network device receives said third steering matrix for each subcarrier of radio frequency (RF) signals that said network device transmits toward said link partner, and wherein said first feedback module determines correspondence between each subcarrier and said third steering matrix for each subcarrier based on one of said first and second transmission schedules.

26. A method, comprising:

selectively generating a first transmission schedule that includes a first matrix map;

transmitting said first transmission schedule from a network device to a link partner;

selectively transmitting a first set of training signals to said link partner;

receiving a first set of channel state information (CSI) for said training signals from said link partner according to said first transmission schedule; and

generating a first CSI matrix based on said first set of CSI and said first matrix map.

27. The method of claim 26 further comprising:

generating a first steering matrix based on said first CSI matrix;

adjusting beamforming weights of said network device based on said first steering matrix; and

directing transmission of radio frequency (RF) signals toward said link partner based on said beamforming weights, wherein said beamforming weights determine gain of said RF signals.

28. The method of claim 27 further comprising generating a first subcarrier schedule that determines an order of transmitting subcarriers of said RF signals and determining a sequence for communicating elements of said first set of CSI that constitute elements of said first CSI matrix based on said first matrix map.

29. The method of claim 28 further comprising generating said first set of training signals for each of said subcarriers and receiving said first set of CSI for each of said subcarriers, wherein said first set of CSI includes signal to noise ratios (SNRs) of said subcarriers.

30. The method of claim 29 further comprising determining correspondence between each of said subcarriers and said first CSI matrix for each of said subcarriers based on said first subcarrier schedule.

31. The method of claim 27 further comprising determining said first set of CSI for said first set of training signals received by said link partner, generating said first CSI matrix based on said first set of CSI and said first matrix map, and communicating said first set of CSI to said network device based on said first transmission schedule.

32. The method of claim 31 further comprising generating a second transmission schedule that includes a second matrix map and transmitting said second transmission schedule from said link partner to said network device when said network device does not generate said first transmission schedule.

33. The method of claim 32 further comprising receiving said second transmission schedule, receiving said first set of CSI from said link partner according to said second transmission schedule, and generating said first CSI matrix based on said first set of CSI and said second matrix map.

34. The method of claim 32 further comprising transmitting a second set of training signals to said network device, determining a second set of CSI for said second set of training signals received by said network device, and generating a second CSI matrix based on said second set of CSI and one of said first and second matrix maps.

35. The method of claim 34 further comprising receiving said second set of CSI from said network device according to one of said first and second transmission schedules and generating said second CSI matrix based on one of said first and second matrix maps.

36. The method of claim 35 further comprising:

generating a second steering matrix based on said second CSI matrix;

adjusting beamforming weights of said link partner based on said second steering matrix; and

directing transmission of radio frequency (RF) signals toward said network device based on said beamforming weights of said link partner, wherein said beamforming weights of said link partner determine gain of said RF signals.

37. The method of claim 36 further comprising generating a second subcarrier schedule that determines an order of transmitting subcarriers of said RF signals and determining a sequence for communicating elements of one of said first and second sets of CSI based on said second matrix map.

38. The method of claim 37 further comprising generating said second set of training signals for each of said subcarriers and receiving said second set of CSI for each of said subcarriers, wherein said second set of CSI includes signal to noise ratios (SNRs) of said subcarriers, and wherein elements of said second set of CSI constitute elements of said second CSI matrix.

39. The method of claim 38 further comprising determining correspondence between each of said subcarriers and said second CSI matrix for each of said subcarriers based on said second subcarrier schedule.

40. The method of claim 31 further comprising parsing a frame into a plurality of radio frequency (RF) signals, transmitting said RF signals toward said link partner via N_TX antennas, and receiving said RF signals via N_RX antennas, where N_TX and N_RX are integers greater than or equal to 1.

41. The method of claim 31 further comprising parsing a frame into a plurality of radio frequency (RF) signals, transmitting said RF signals toward said network device via N_TX antennas, and receiving said RF signals via N_RX antennas, where N_TX and N_RX are integers greater than or equal to 1.

42. The method of claim 34 wherein said first and second CSI matrices are (N_TX×

N_RX) matrices, where N_TX and N_RX are integers greater than or equal to 1 and represent number of transmit and receive antennas, respectively.

43. The method of claim 36 further comprising generating a third steering matrix based on said second set of CSI according to one of said first and second matrix maps when said link partner does not generate said second steering matrix.

44. The method of claim 43 further comprising adjusting said beamforming weights of said link partner based on said third steering matrix received from said network device according to one of said first and second transmission schedules.

45. The method of claim 43 wherein said third steering matrix is a (N_TX×

N_SS) matrix, where N_TX is an integer greater than or equal to 1 and represents a number of transmit antennas and N_SS is an integer greater than or equal to 1 and represents spatial streams of a frame.

46. The method of claim 43 further comprising receiving said third steering matrix for each subcarrier of said RF signals and determining correspondence between each subcarrier and said third steering matrix for each subcarrier based on one of said first and second transmission schedules.

47. The method of claim 36 further comprising generating a third steering matrix based on said first set of CSI according to one of said first and second matrix maps when said network device does not generate said first steering matrix.

48. The method of claim 47 further comprising adjusting said beamforming weights of said network device based on said third steering matrix received from said link partner according to one of said first and second transmission schedules.

49. The wireless network of claim 47 wherein said third steering matrix is a (N_TX×

N_SS) matrix, where N_TX is an integer greater than or equal to 1 and represents a number of transmit antennas and N_SS is an integer greater than or equal to 1 and represents spatial streams of a frame.

50. The method of claim 47 further comprising receiving said third steering matrix for each subcarrier of radio frequency (RF) signals that said network device transmits toward said link partner and determining correspondence between each subcarrier and said third steering matrix for each subcarrier based on one of said first and second transmission schedules.