Method for efficient beamformee implementation for Wi-Fi

Patent metadata

Field	Value
Publication number	US-11539413-B1
Application number	US-201916689894-A
Country	US
Kind code	B1
Filing date	Nov 20, 2019
Priority date	Nov 20, 2018
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

Methods and systems for providing beamforming feedback in a communication channel are disclosed. A data packet is received at a beamformee circuitry of the first communication device configured to generate beam steering data for use by a transmitter of a second communication device. Each of a plurality of tones of the received data packet is processed to generate a compressed steering matrix corresponding to the communication channel. In parallel to the processing of the received plurality of tones, an immediate feedback packet comprising a plurality of data symbols is constructed, where the data symbols include the generated compressed steering matrix. At least a first data symbol of the immediate feedback packet is transmitted prior to completing the processing of all the plurality of tones of the received data packet.

First claim

What is claimed is:

1. A method for providing beamforming feedback in a communication channel, the method comprising:
receiving, at a first communication device, a data packet from a second communication device via the communication channel;
processing, at a beamformee circuitry of the first communication device configured to generate beam steering data for use by a transmitter of the second communication device, a plurality of tones of the received data packet to generate a compressed steering matrix corresponding to the communication channel;
constructing, in parallel to the processing of the plurality of tones, at the beamformee circuitry of the first communication device, at least a first data symbol of an immediate feedback packet comprising a plurality of data symbols; and
transmitting the at least flail the first data symbol of the plurality of data symbols of the immediate feedback packet, prior to completing the processing of all the plurality of tones of the received data packet and construction of a remainder of the plurality of data symbols of the immediate feedback packet, from the first communication device to the second communication device, the plurality of data symbols of the immediate feedback packet being for use by the second communication device to steer at least one subsequent transmission to the first communication device and including the compressed steering matrix.

2. The method of claim 1 , wherein a size of each of the plurality of data symbols of the immediate feedback packet depends on a number of data bits per symbol specified in a modulation and coding scheme (MCS) defined for the immediate feedback packet, a number of available streams, and available bandwidth.

3. The method of claim 2 , wherein each data symbol of the immediate feedback packet is constructed at a rate specified by the number of data bits per symbol specified in the MCS.

4. The method of claim 2 , wherein each data symbol of the immediate feedback packet is constructed by processing the plurality of tones of the received data packet to generate the compressed steering matrix at a rate specified by the number of data bits per symbol specified in the MCS.

5. The method of claim 1 , wherein a transmitter of the first communication device provides a request to the beamformee circuitry of the first communication device for a first data symbol of the immediate feedback packet to be transmitted to the second communication device; and
wherein the beamformee circuitry of the first communication device, prior to receiving the request, is configured to process a sufficient number of tones of the received data packet to construct at least a number of bits sufficient to enable the transmitter of the first communication device to transmit the first data symbol at a rate specified by the number of data bits per symbol specified in an MCS.

6. The method of claim 1 , wherein constructing the plurality of data symbols of the immediate feedback packet comprises:
estimating a steering matrix based on a Long-Training Field (LTF) training sequence of a preamble of the received data packet; and
performing a compression operation on each tone of the received data packet.

7. The method of claim 1 , wherein a processing duration of each tone of the received data packet is dependent on a dimension of a channel state information (CSI) matrix defined by a number of transmitters of the second communication device and a number of receivers of the first communication device.

8. The method of claim 7 , further comprising:
deriving, at the first communication device, a first intermediate matrix from the CSI matrix by determining a product of the CSI matrix and a Hermitian transpose of the CSI matrix;
finding a maximum diagonal element of the first intermediate matrix based on the number of transmitters of the second communication device;
estimating an upper triangle matrix of the first intermediate matrix based on a number of Long-Training Field (LTF) training symbols of a preamble of the received data packet; and
and scaling the estimated upper triangle matrix of the first intermediate matrix based on the maximum diagonal elements of the first intermedia matrix.

9. The method of claim 8 , further comprising:
deriving, at the first communication device, a second intermediate matrix by determining a product of the first intermediate matrix and a Hermitian transpose of the first intermediate matrix;
finding a maximum diagonal element of the second intermediate matrix based on the number of transmitters of the second communication device; and
iteratively estimating and scaling a single column of the second intermediate matrix corresponding to the maximum diagonal element of the second intermediate matrix, wherein a number of columns to be estimated and scaled depends on a minimum of i) a number of transmitters of the second communication device, ii) a number of receivers of the first communication device, or iii) a predefined number smaller than the number of receivers of the first communication device.

10. The method of claim 9 , further comprising:
compressing the first intermediate matrix using a plurality of Coordinate Rotation Digital Computer (CORDIC) processors, wherein the compression comprises:
for each column of the first intermediate matrix:
selecting at least two active CORDICs to rotate two complex elements of a column of the first intermediate matrix;
estimating a respective angle of rotation for the two complex elements of the column of the first intermediate matrix required to remove an imaginary portion of the two complex elements;
transmitting the estimated angles of rotations for the two complex elements of the column of the first intermediate matrix to a plurality of passive CORDICs;
rotating, using the plurality of passive CORDICs, the remaining complex elements of the rows of the first intermediate matrix by respective angle of rotation estimated by the active CORDICs;
estimating an angle between the respective real portions of the two complex elements; and
rotating, using the plurality of passive CORDICs, the remaining real and imaginary elements of the rows of the first intermediate matrix by the respective estimated angle between the respective real portions of the two complex elements.

11. A first communication device comprising:
a receiver having one or more integrated circuits configured to:
receive a data packet from a second communication device via a communication channel;
process a plurality of tones of the received data packet to generate a compressed steering matrix corresponding to the communication channel;
construct, in parallel to the processing of the plurality of tones, at least a first data symbol of an immediate feedback packet comprising a plurality of data symbols; and

a transmitter having one or more integrated circuits configured to:
transmit the at least flail the first data symbol of the plurality of data symbols of the immediate feedback packet, prior to completing the processing of all the plurality of tones of the received data packet and construction of a remainder of the plurality of data symbols of the immediate feedback packet, from the first communication device to a second communication device, the plurality of data symbols of the immediate feedback packet being for use by the second communication device to steer at least one subsequent transmission to the first communication device and including the compressed steering matrix.

12. The first communication device of claim 11 , wherein a size of each of the plurality of data symbols of the immediate feedback packet depends on a number of data bits per symbol specified in a modul

Assignees

• Nxp Usa Inc

Inventors

• Larionov Nikolaj
• Narravula Sridhar R
• Yu Mao

Classifications

• H04B1/40 Primary

  Circuits · CPC title

• H04B7/0413

  MIMO systems · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04B7/0617 Primary

  for beam forming · CPC title