METHOD AND APPARATUS FOR DETERMINING THE SPATIAL CHANNELS IN AN SPATIAL DIVISION MULTIPLE ACCESS (SDMA)-BASED WIRELESS COMMUNICATION SYSTEM

• US 20090290616A1
• Filed: 12/04/2008
• Published: 11/26/2009
• Est. Priority Date: 05/21/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sridhara, Vinay, Abraham, Santosh P., Nanda, Sanjiv
• Granted Patent: US 8,848,816 B2
• Time in Patent Office: Days
• US Class Current: 375/146
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal

Abstract

An access point is disclosed herein that comprises a wireless network adapter configured to support a backhaul connection for a peer node to a network; a processing system configured to calculate precoding matrices that define spatial streams; and a transceiver configured to transmit data to the nodes on the spatial streams.

Claims

1. An apparatus for communicating with a plurality of nodes, comprising:

a processing system configured to calculate preceding matrices that define spatial streams; and

a transceiver configured to transmit data to the nodes on the spatial streams.

2. The apparatus of claim 1 wherein the processing system is further configured to request training from the nodes and receive training responses from the nodes in response thereto, the processing system being further configured to calculate the preceding matrices from the training responses.

3. The apparatus of claim 2 wherein the processing system is further configured to receive the training responses that are transmitted by the nodes simultaneously within the same frequency band.

4. The apparatus of claim 2 wherein the processing system is further configured to request training by requesting each of the nodes to use a particular signature in its training response.

5. The apparatus of claim 2 wherein the processing system is further configured to calculate a channel state information matrix for each of the nodes from the training response and use the calculated channel state information matrices to calculate the precoding matrices.

6. The apparatus of claim 2 wherein each of the training responses comprises a channel state information matrix for the node transmitting that training response.

7. The apparatus of claim 6 wherein the processing system is further configured to use the channel state information matrices in the training responses to calculate the precoding matrices.

8. The apparatus of claim 2 wherein the processing system is further configured to request training by generating a training request message for transmission by the transceiver to the nodes, wherein the training request message comprises a schedule for the nodes to transmit their training responses.

9. The apparatus of claim 2 wherein the nodes transmit their training responses simultaneously.

10. The apparatus of claim 9 wherein the processing system is further configured to receive the training responses covered with spreading or scrambling codes.

11. The apparatus of claim 2 wherein the processing system is further configured to receive the training responses at different times.

12. The apparatus of claim 1 wherein the processing system is further configured to use the precoding matrices to precode the data transmitted by the transceiver to the nodes.

13. The apparatus of claim 1 further comprising a plurality of antennas, wherein each of the antennas supports one of the spatial streams for the transceiver to transmit data to the nodes.

14. The apparatus of claim 2 wherein the processing system is further configured to request training by providing to the nodes information relating to spreading or scrambling codes for the training responses.

15. The apparatus of claim 14 wherein the information comprises the spreading or scrambling codes.

16. The apparatus of claim 14 wherein the information provides sufficient information for computing the spreading or scrambling codes.

17. A method for communicating with a plurality of nodes, comprising:

calculating preceding matrices that define spatial streams; and

transmitting data by a transceiver to the nodes on the spatial streams.

18. The method of claim 17 further comprising requesting training from the nodes and receiving training responses from the nodes in response thereto, wherein the precoding matrices are calculated from the training responses.

19. The method of claim 18 wherein the training responses are received simultaneously within the same frequency band.

20. The method of claim 18 wherein the training from the nodes are requested by requesting each of the nodes to use a particular signature in its training response.

21. The method of claim 18 further comprising calculating a channel state information matrix for each of the nodes from the training response wherein the precoding matrices are calculated using the calculated channel state information matrices.

22. The method of claim 18 wherein each of the training responses comprises a channel state information matrix for the node transmitting that training response.

23. The method of claim 22 wherein the channel state information matrices in the training responses are used in calculating the preceding matrices.

24. The method of claim 18 wherein the requesting is done by generating a training request message for transmission by the transceiver to the nodes, wherein the training request message comprises a schedule for the nodes to transmit their training responses.

25. The method of claim 18 wherein the nodes transmit their training responses simultaneously.

26. The method of claim 25 wherein the training responses are received covered with spreading or scrambling codes.

27. The method of claim 18 wherein the training responses are received at different times.

28. The method of claim 17 further comprising using the precoding matrices to precode the data transmitted by the transceiver to the nodes.

29. The method of claim 17 further comprising supporting by each of a plurality of antennas, one of the spatial streams for the transceiver to transmit data to the stations.

30. The method of claim 18 further comprising requesting training by providing to the nodes information relating to spreading or scrambling codes for the training responses.

31. The method of claim 30 wherein the information comprises the spreading or scrambling codes.

32. The method of claim 30 wherein the information provides sufficient information for computing the spreading or scrambling codes.

33. An apparatus for communicating with a plurality of nodes, comprising:

means for calculating precoding matrices that define spatial streams; and

means for transmitting data by a transceiver to the nodes on the spatial streams.

34. The apparatus of claim 33 further comprising means for requesting training from the nodes and means for receiving training responses from the nodes in response thereto, wherein the means for calculating preceding matrices is configured to calculate the preceding matrices from the training responses.

35. The apparatus of claim 34 wherein the means for receiving training responses is configured to receive the training responses simultaneously within the same frequency band.

36. The apparatus of claim 34 wherein the means for requesting training from the nodes is configured to request training by requesting each of the nodes to use a particular signature in its training response.

37. The apparatus of claim 34 further comprising means for calculating a channel state information matrix for each of the nodes from the training response, wherein the means for calculating preceding matrices is configured to calculate preceding matrices using the calculated channel state information matrices.

38. The apparatus of claim 34 wherein each of the training responses comprises a channel state information matrix for the node transmitting that training response.

39. The apparatus of claim 38 wherein the means for calculating precoding matrices is configured to calculate the preceding matrices using the channel state information matrices in the training responses.

40. The apparatus of claim 34 wherein the means for requesting is configured to request by generating a training request message for transmission by the transceiver to the nodes, wherein the training request message comprises a schedule for the nodes to transmit their training responses.

41. The apparatus of claim 34 wherein the nodes transmit their training responses simultaneously.

42. The apparatus of claim 41 wherein the means for receiving is configured to receive the training responses covered with spreading or scrambling codes.

43. The apparatus of claim 34 wherein the means for receiving is configures to receive the training responses at different times.

44. The apparatus of claim 33 further comprising means for using the preceding matrices to precode the data transmitted by the transceiver to the nodes.

45. The apparatus of claim 33 further comprising means for supporting by each of a plurality of antennas, one of the spatial streams for the transceiver to transmit data to the stations.

46. The apparatus of claim 34 further comprising means for requesting training by providing to the nodes information relating to spreading or scrambling codes for the training responses.

47. The apparatus of claim 46 wherein the information comprises the spreading or scrambling codes.

48. The apparatus of claim 46 wherein the information provides sufficient information for computing the spreading or scrambling codes.

49. A computer-program product for communication, comprising:

a machine-readable medium encoded with instructions executable to;

calculate preceding matrices that define spatial streams; and

transmit data to the nodes on the spatial streams.

50. An access point, comprising:

a wireless network adapter configured to support a backhaul connection for a peer node to a network;

a processing system configured to calculate precoding matrices that define spatial streams; and

a transceiver configured to transmit data to the nodes on the spatial streams.