Method and system for beamforming communication in high throughput wireless communication systems

• US 8,417,191 B2
• Filed: 03/17/2008
• Issued: 04/09/2013
• Est. Priority Date: 03/17/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Xia, Pengfei, Niu, Huaning, Ngo, Chiu
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Hanidu, Ganiyu A
• Application Number:
  US12/050,071
• Publication Number:
  US 20090233556A1
• Time in Patent Office: 1,849 Days
• Field of Search: 455/63.4, 455/68, 455/101, 455/137, 455/562.1, 375/299, 375/292, 375/267, 375/260, 375/141, 375/340, 342/385, 342/368, 342/377, 342372-374
• US Class Current: 455/69
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]

Abstract

A method and system for beamforming communication in high throughput wireless communications. Analog beamforming involves constructing analog beamforming coefficients for beamforming communication on a wireless channel. Constructing analog beamforming coefficients includes selecting a signal tap from a multi-tap wireless channel for beamforming communication, wherein the selected signal tap has a higher signal quality relative to other signals taps, and determining beamforming coefficients for the selected tap by iterative acquisition of the coefficients based on power iteration.

Claims

1. A method of analog beamforming in a communication system, comprising:

constructing analog beamforming coefficients for beamforming communication on communication channels, including;

selecting a signal tap from a multi-tap channel for beamforming communication, wherein the selected signal tap has a higher signal quality relative to other signals taps; and

acquiring beamforming coefficients for the selected signal tap by power iteration comprising selecting the signal tap in a multi-tap wireless channel without a search for an optimum steering vector across the multi-tap wireless channel based on raising a ratio of diagonal components of a channel matrix to a power of an iteration index that increases for each successive power iteration.

2. The method of claim 1 further including utilizing one channel matrix on the selected tap for determining the coefficients.

3. The method of claim 1, wherein selecting a signal tap further includes computing a performance metric for all channel taps and selecting a signal tap with the highest performance metric.

4. The method of claim 3 selecting a signal tap further includes selecting a signal tap with the largest Frobenius norms.

5. The method of claim 1, wherein acquiring beamforming coefficients includes determining beamforming transmit coefficients based on an iterative beam acquisition process, wherein each iteration includes estimating analog transmit beamforming coefficients based on receive beamforming coefficients obtained in a most recent iteration, until the beamforming coefficients converge.

6. The method of claim 1, wherein acquiring beamforming coefficients includes determining beamforming receive coefficients based on an iterative beam acquisition process, wherein each iteration includes estimating analog receive beamforming coefficients based on transmit beamforming coefficients obtained in a most recent iteration, until the beamforming coefficients converge.

7. The method of claim 1, wherein acquiring beamforming coefficients further includes estimating a transmit beamforming coefficient vector in a reverse direction without explicit feedback using a training sequence.

8. The method of claim 1, wherein acquiring beamforming coefficients further includes estimating a transmit beamforming coefficient vector in a forward direction based on feedback using a training sequence.

9. The method of claim 1, wherein acquiring beamforming coefficients further includes estimating a receive beamforming coefficient vector in a forward direction without explicit feedback using a training sequence.

10. The method of claim 1, wherein acquiring beamforming coefficients further includes estimating beamforming coefficients by power iterations based on channel reciprocity.

11. The method of claim 1, wherein estimating beamforming coefficients by power iterations includes:

(a) selecting initial transmit beamforming coefficients;

(b) estimating receive beamforming coefficients based on the transmit beamforming coefficients;

(c) estimating transmit beamforming coefficients based on the receive beamforming coefficients;

(d) repeating step (b) and (c) until the iteration converges.

12. The method of claim 1, wherein estimating beamforming coefficients by power iterations includes:

(a) selecting initial receive beamforming coefficients;

(b) selecting transmit beamforming coefficients based on the receive beamforming coefficients to maximize gain of equivalent multiple-input-single-output (MISO) channel;

(c) selecting receive beamforming coefficients based on the transmit beamforming coefficients to maximize gain of equivalent single-input-multiple-output (SIMO) channel;

(d) repeating step (b) and (c) until the achieved gain converges.

13. The method of claim 1, wherein the channel comprises a wireless channel.

14. The method of claim 1, wherein the channel comprises a non-wireless channel.

30. The method of claim 1, wherein selecting the signal tap further comprises estimating Nt*Nr*(L+1) channel coefficients and performing L+1 singular value decompositions, wherein Nt is a number of transmit antennas, Nr is a number of receive antennas and L+1 is a maximum number of taps for all transmit/receive antenna pairs.

31. The method of claim 1, wherein beamforming vectors are determined using one channel matrix on a signal tap representing a strongest signal power path in the multi-tap wireless channel for reducing signaling overhead.

32. The method of claim 1, wherein selecting the ratio of diagonal components is based on:

33. The method of claim 32, wherein s(1)>

S(2)>

. . . s(m).

15. A system for analog beamforming on wireless channels, comprising:

a tap differentiator configured for selecting a signal tap from a multi-tap wireless channel for beamforming communication, wherein the selected signal tap has a higher signal quality relative to other signals taps;

a beamforming controller configured for acquiring analog beamforming coefficients for the selected signal tap by power iteration comprising selecting the signal tap in a multi-tap wireless channel without a search for an optimum steering vector across the multi-tap wireless channel based on raising a ratio of diagonal components of a multi-tap wireless channel matrix to a power of an iteration index that increases for each successive power iteration; and

a beamformer configured for applying the beamforming coefficients to signals for transmission over the selected tap.

16. The system of claim 15, wherein the tap differentiator comprises a digital tap differentiator operating in the digital domain, the beamforming controller comprises a digital tap differentiator operating in the digital domain, and the beamformer comprises an analog beamformer operating in the analog domain.

17. The system of claim 15, wherein the tap differentiator comprises a digital tap differentiator, the beamforming controller comprises a digital tap differentiator and the beamformer comprises a digital beamformer, all operating in the digital domain.

18. The system of claim 15, wherein the beamforming controller is further configured for utilizing one channel matrix on the selected tap for determining the coefficients.

19. The system of claim 15, wherein the tap differentiator is configured for selecting a signal tap by computing a Frobenius norm for all channel taps, and selecting a signal tap with the largest Frobenius norms.

20. The system of claim 15, wherein the beamforming controller is configured for determining beamforming transmit coefficients based on an iterative beam acquisition process, wherein each iteration includes estimating analog transmit beamforming coefficients based on receive beamforming coefficients obtained in a most recent iteration, until the beamforming coefficients converge.

21. The system of claim 15, wherein the beamforming controller is configured for determining beamforming receive coefficients based on an iterative beam acquisition process, wherein each iteration includes estimating analog receive beamforming coefficients based on transmit beamforming coefficients obtained in a most recent iteration, until the beamforming coefficients converge.

22. The system of claim 15, wherein the beamforming controller is configured for estimating beamforming coefficients by power iterations including:

(a) selecting initial transmit beamforming coefficients;

(b) estimating receive beamforming coefficients based on the transmit beamforming coefficients;

(c) estimating transmit beamforming coefficients based on the receive beamforming coefficients;

(d) repeating step (b) and (c) until the iteration converges.

23. The system of claim 15, wherein the beamforming controller is configured for estimating beamforming coefficients by power iterations including:

(a) selecting initial receive beamforming coefficients;

(b) selecting transmit beamforming coefficients based on the receive beamforming coefficients to maximize gain of equivalent multiple-input-single-output (MISO) channel;

(c) selecting receive beamforming coefficients based on the transmit beamforming coefficients to maximize gain of equivalent single-input-multiple-output (SIMO) channel; and

(d) repeating step (b) and (c) until the achieved gain converges.

24. The system of claim 15 wherein the beamforming coefficients include transmit beamforming coefficients and receiver beamforming coefficients, the system further comprising:

a wireless transmitter configured for transmitting signals on the selected tap by beamforming based on the beamforming coefficients; and

a wireless receiver configured for receiving signals on the selected tap by beamforming based on the beamforming coefficients.

25. The system of claim 15 further including a transmitter and a receiver, the transmitter configured for acquiring beamforming coefficients by estimating a transmit beamforming coefficient vector in a reverse direction from a receiver without explicit feedback using a training sequence.

26. The system of claim 15 further including a transmitter and a receiver, the transmitter configured for acquiring beamforming coefficients by estimating a transmit beamforming coefficient vector in a forward direction from the transmitter based on feedback using a training sequence.

27. An analog beamforming control module for wireless communication, comprising:

a tap differentiator configured for selecting a signal tap from a multi-tap wireless channel for beamforming communication, wherein the selected signal tap has a higher signal quality relative to other signals taps; and

a beamforming controller configured for acquiring analog beamforming coefficients for the selected signal tap by power iteration comprising selecting the signal tap in a multi-tap wireless channel without a search for an optimum steering vector across the multi-tap wireless channel based on raising a ratio of diagonal components of a multi-tap wireless channel matrix to a power of an iteration index that increases for each successive power iteration.

28. The control module of claim 27, wherein the beamforming controller is further configured for utilizing one channel matrix on the selected tap for determining the coefficients.

29. The control module of claim 27, wherein the tap differentiator is configured for selecting a signal tap by computing a Frobenius norm for all channel taps, and selecting a signal tap with the largest Frobenius norms.