Supporting high dimensional MU-MIMO beamforming by sounding multiple frames with different sets of antenna patterns

• US 9,871,569 B2
• Filed: 08/31/2015
• Issued: 01/16/2018
• Est. Priority Date: 02/19/2014
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Garrett, David, Zheng, Jun, Jindal, Nihar
• Primary Examiner(s): Garcia, Santiago
• Application Number:
  US14/841,378
• Publication Number:
  US 20150372739A1
• Time in Patent Office: 869 Days
• Field of Search: 375267
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals

Abstract

In some aspects, the disclosure is directed to methods and systems for performing channel estimation between a beamformer and a beamformee. A beamformer can determine that a beamformee is configured to perform channel estimation for up to a pre-configured number of transmit spatial streams from the beamformer. The pre-configured number of transmit spatial streams can be less than a plurality of transmit spatial streams of the beamformer. The beamformer can determine a plurality of subsets of transmit spatial streams from the plurality of transmit spatial streams. The beamformer can send a plurality of sounding frames to the beamformee for channel estimation based at least on the determined plurality of subsets of transmit spatial streams.

Claims

1. A method for performing channel estimation, the method comprising:

determining, by a beamformer, a plurality of subsets of transmit spatial streams from a plurality of transmit spatial streams of the beamformer, wherein a first subset of the plurality of subsets has at least one transmit spatial stream from a same antenna of the beamformer as at least one transmit spatial stream in another subset from the plurality of subsets; and

sending, by the beamformer, a plurality of sounding frames to a beamformee for channel estimation according to the determined plurality of subsets of transmit spatial streams.

2. The method of claim 1, wherein each of the plurality of subsets has at least one transmit spatial stream from an antenna of the beamformer that is common with that of at least one transmit spatial stream in another subset from the plurality of subsets.

3. The method of claim 1, wherein the beamformee is configured to perform channel estimation for up to a pre-configured number of transmit spatial streams from the beamformer, the pre-configured number of transmit spatial streams is less than the plurality of transmit spatial streams of the beamformer.

4. The method of claim 1, further comprising receiving responses from the beamformee to the plurality of sounding frames, the responses comprising channel estimation for the plurality of subsets of transmit spatial streams.

5. The method of claim 4, further comprising generating full channel estimation information based on the received responses, the full channel estimation information comprising channel estimation information corresponding to all the transmit spatial streams that the beamformer can provide.

6. The method of claim 5, further comprising steering, by the beamformer, the plurality of transmit antennas of the beamformer based on the full channel estimation information.

7. The method of claim 1, further comprising configuring a first beamformer and a second beamformer to operate as the beamformer.

8. The method of claim 1, further comprising configuring a first beamformer and a second beamformer to operate as the beamformer, the first beamformer and the second beamformer operably coupled via a backbone connection.

9. The method of claim 1, further comprising communicating, by the beamformer, to a plurality of beamformees.

10. The method of claim 1, further comprising configuring a first beamformer and a second beamformer to operate as the beamformer, the first beamformer and the second beamformer using frequency diversity to simultaneously send a sounding frame from the first beamformer and a sounding frame from the second beamformer.

11. A system for performing channel estimation, the system comprising:

circuitry of a beamformer, configured to determine a plurality of subsets of transmit spatial streams from a plurality of transmit spatial streams of the beamformer, wherein a first subset of the plurality of subsets has at least one transmit spatial stream from a same antenna of the beamformer as at least one transmit spatial stream in another subset from the plurality of subsets; and

a plurality of antennas of the beamformer, configured to send a plurality of sounding frames to a beamformee for channel estimation based at least on the determined plurality of subsets of transmit spatial streams, each of the plurality of antennas corresponding to one of the plurality of transmit spatial streams.

12. The system of claim 11, wherein each of the plurality of subsets has at least one transmit spatial stream from an antenna of the beamformer that is common with that of at least one transmit spatial stream in another subset from the plurality of subsets.

13. The system of claim 11, further comprising an integration module configured to combine channel estimation for the plurality of subsets of transmit spatial streams, the channel estimation from responses received from the beamformee to the plurality of sounding frames.

14. The system of claim 11, wherein the plurality of antennas comprises at least one antenna of a first beamformer and at least one antenna of a second beamformer, the first beamformer and the second beamformer configured to operate as the beamformer.

15. A method for performing channel estimation, the method comprising:

determining, between a first beamformer and a second beamformer, a plurality of subsets of transmit spatial streams from a first plurality of transmit spatial streams of the first beamformer and a second plurality of transmit spatial streams of the second beamformer, wherein a first subset of the plurality of subsets has at least one transmit spatial stream from a same antenna of the first or second beamformer as at least one transmit spatial stream in another subset from the plurality of subsets; and

coordinating, between the first beamformer and the second beamformer, transmission of a plurality of sounding frames to a first beamformee for channel estimation based at least on the determined plurality of subsets of transmit spatial streams.

16. The method of claim 15, further comprising configuring the first beamformer and the second beamformer to communicate with the first beamformee, the first beamformer and the second beamformer operably coupled via a backbone connection.

17. The method of claim 15, further comprising combining at least some responses from the first beamformee to the plurality of sounding frames, the responses comprising channel estimation for the plurality of subsets of transmit spatial streams.

18. The method of claim 17, further comprising generating full channel estimation information between the first beamformer and the second beamformer, based on the combination of the at least some responses.

19. The method of claim 15, further comprising configuring the first beamformer and the second beamformer to communicate with a plurality of beamformees.

20. The method of claim 15, further comprising using frequency diversity to simultaneously send a sounding frame from the first beamformer and a sounding frame from the second beamformer.