Method for WiFi beamforming, feedback, and sounding (WiBEAM)

Patent metadata

Field	Value
Publication number	US-9979446-B2
Application number	US-201715599651-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	Sep 28, 2012
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

Methods for WiFi beamforming, feedback, and sounding (WiBEAM) are described. Codebook based beamforming feedback signaling and sounding mechanisms for use in wireless communications are disclosed. The methods described herein improve the feedback efficiency by using Givens rotation based decompositions and quantizing the resulting angles of the Givens rotation based decompositions using a range from a subset of [0, 2π]. Feedback may also be divided into multiple components to improve feedback efficiency/accuracy. Time domain beamforming reports for taking advantage of channel reciprocity while still taking into account practical radio frequency (RF) channel impairments are also described. Beamforming feedback that prioritized the feedback bits in accordance with the significance of the bits is also disclosed. A preamble structure to enable the use of smoothing methods for improved channel estimation, codebook designs that may be used for codebook based beamforming feedback, and multi-resolution explicit feedback are disclosed as well.

First claim

What is claimed is:

1. A method for use in a wireless transmit/receive unit (WTRU) for providing beamforming feedback, the method comprising:
receiving a sounding frame;
performing a first measurement on the sounding frame;
performing a first decomposition on the performed first measurement;
performing a second decomposition on the performed first measurement to generate a set of resulting angles;
selecting a first subset of the set of resulting angles;
quantizing each angle of the first subset of the set of resulting angles to generate first quantized angles by:
determining a first range based on first angle statistics associated with the first subset of the set of resulting angles,
assigning the first range to a first angle of the first subset of the set of resulting angles,
determining a second range based on the first angle statistics associated with the first subset of the set of resulting angles, and
assigning the second range to a second angle of the first subset of the set of resulting angles, wherein the first range is different than the second range;

selecting a second subset of the set of resulting angles;
quantizing each angle of the second subset of the set of resulting angles to generate second quantized angles by:
determining a third range based on second angle statistics associated with the second subset of the set of resulting angles,
assigning the third range to a first angle of the second subset of the set of resulting angles,
determining a fourth range based on the second angle statistics associated with the second subset of the set of resulting angles, and
assigning the fourth range to a second angle of the second subset of the set of resulting angles, wherein the third range is different than the fourth range; and

transmitting at least one of a subset of the first quantized angles or a subset of the second quantized angles in a beamforming feedback frame.

2. The method of claim 1 wherein the first decomposition is a singular value decomposition (SVD).

3. The method of claim 1 wherein the second decomposition is a Givens rotation based decomposition.

4. The method of claim 1 wherein the beamforming feedback frame is a codebook component feedback frame.

5. The method of claim 1 wherein the beamforming feedback frame comprises results of a monitored transmission by another WTRU.

6. The method of claim 1 wherein the first subset of the set of resulting angles is associated with a diagonal matrix and the second subset of the set of resulting angles is associated with a Givens rotation matrix.

7. The method of claim 1 wherein the at least one of the subset of the first quantized angles or the subset of the second quantized angles is transmitted in multiple beamforming feedback frames.

8. The method of claim 1 wherein the beamforming feedback frame comprises a plurality of subframes, and wherein each subframe of the plurality of subframes comprises a separate cyclic redundancy check (CRC).

9. The method of claim 1 wherein the beamforming feedback frame comprises a plurality of subframes, and wherein feedback bits are assigned to each subframe of the plurality of subframes based on significance.

10. The method of claim 1 wherein the beamforming feedback frame is transmitted in a plurality of feedback elements.

11. A wireless transmit/receive unit (WTRU) configured for providing beamforming feedback, the WTRU comprising:
a receiver configured to receive a sounding frame;
a processor configured to:
perform a first measurement on the sounding frame,
perform a first decomposition on the performed first measurement,
perform a second decomposition on the performed first measurement to generate a set of resulting angles,
select a first subset of the set of resulting angles, and
quantize each angle of the first subset of the set of resulting angles to generate first quantized angles, wherein the processor configured to quantize each angle of the first subset of the set of resulting angles to generate the first quantized angles comprises the processor configured to:
determine a first range based on first angle statistics associated with the first subset of the set of resulting angles,
assign the first range to a first angle of the first subset of the set of resulting angles,
determine a second range based on the first angle statistics associated with the first subset of the set of resulting angles, and
assign the second range to a second angle of the first subset of the set of resulting angles, wherein the first range is different than the second range, select a second subset of the set of resulting angles,

quantize each angle of the second subset of the set of resulting angles to generate second quantized angles, wherein the processor configured to quantize each angle of the second subset of the set of resulting angles to generate the second quantized angles comprises the processor configured to:
determine a third range based on second angle statistics associated with the second subset of the set of resulting angles,
assign the third range to a first angle of the second subset of the set of resulting angles,
determine a fourth range based on the second angle statistics associated with the second subset of the set of resulting angles, and
assign the fourth range to a second angle of the second subset of the set of resulting angles, wherein the third range is different than the fourth range; and

a transmitter configured to transmit at least one of a subset of the first quantized angles or a subset of the second quantized angles in a beamforming feedback frame.

12. The WTRU of claim 11 wherein the first decomposition is a singular value decomposition (SVD).

13. The WTRU of claim 11 wherein the second decomposition is a Givens rotation based decomposition.

14. The WTRU of claim 11 wherein the beamforming feedback frame is a codebook component feedback frame.

15. The WTRU of claim 11 wherein the beamforming feedback frame comprises results of a monitored transmission by another WTRU.

16. The WTRU of claim 11 wherein the at least one of the subset of the first quantized angles or the subset of the second quantized angles is transmitted in multiple beamforming feedback frames.

17. The WTRU of claim 11 wherein the beamforming feedback frame comprises a plurality of subframes, and wherein each subframe of the plurality of subframes comprises a separate cyclic redundancy check (CRC).

18. The WTRU of claim 11 wherein the beamforming feedback frame comprises a plurality of subframes, and wherein feedback bits are assigned to each subframe of the plurality of subframes based on significance.

19. The WTRU of claim 11 wherein the beamforming feedback frame is transmitted in a plurality of feedback elements.

20. The WTRU of claim 11 wherein the first subset of the set of resulting angles is associated with a diagonal matrix and the second subset of the set of resulting angles is associated with a Givens rotation matrix.

Assignees

• Interdigital Patent Holdings Inc

Inventors

• Xia Pengfei
• Ghosh Monisha
• Lou Hanqing
• Olesen Robert L
• Oteri Oghenekome

Classifications

• H04B7/0641

  Differential feedback · CPC title

• H04B7/0628

  Diversity capabilities · CPC title

• H04B7/0639

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title

• H04L1/0073

  Special arrangements for feedback channel · CPC title

• H04B7/0617

  for beam forming · CPC title