Method of combatting interference by spatial filtering or spatio-temporal filtering in a multi-channel receiver

Patent metadata

Field	Value
Publication number	US-10243593-B2
Application number	US-201715853148-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Dec 29, 2016
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A method for receiving a signal and for rejecting interference in a multichannel receiver, comprises the steps of: reception, transposition and discretization of the signal received on each of the channels of the receiver, so as to obtain a discretized multichannel signal, synchronization of the discretized multichannel signal, computation, on the basis of the discretized and synchronized multichannel signal, of a matrix {circumflex over (R)} of correlation of the total noise, computation, on the basis of the matrix {circumflex over (R)} of correlation of the total noise, of a vector w comprising amplitude phase weighting coefficients of a multichannel filter, and application, to the discretized and synchronized multichannel signal, of a multichannel filtering processing on the basis of the vector w, and then of a single-channel equalization processing to the filtered signal.

First claim

The invention claimed is:

1. A method for receiving a signal and for rejecting interference in a multichannel receiver, the said method comprising the steps of:
reception, transposition and discretization of the said signal received on each of the channels of a receiver, so as to obtain a discretized multichannel signal,
synchronization of the discretized multichannel signal,
and further comprising the steps of:
computation, on the basis of the discretized and synchronized multichannel signal, of a matrix {circumflex over (R)} of correlation of the total noise,
computation of a matrix {circumflex over (R)} XD of intercorrelation between a training sequence and the discretized and synchronized multichannel signal received,
computation, on the basis of the matrix {circumflex over (R)} XD , of an estimate of a director vector associated to one path,
computation, on the basis of the said matrix {circumflex over (R)} of correlation of the total noise and of the estimate of the director vector associated to one path, of a vector w comprising amplitude phase weighting coefficients of a multichannel filter, and
application, to the discretized and synchronized multichannel signal, of a multichannel filtering processing on the basis of the said vector w, and then of a single-channel equalization processing to the filtered signal.

2. The method for receiving a signal and for rejecting interference according to claim 1 , wherein the computation of the matrix {circumflex over (R)} of correlation of the total noise received on the set of channels of the receiver is carried out on the basis:
of a matrix {circumflex over (R)} XX of autocorrelation of the discretized and synchronized multichannel signal received,
of a matrix {circumflex over (R)} DD of autocorrelation of the said training sequence,
according to the formula:
{circumflex over (R)}={circumflex over (R)} XX −{circumflex over (R)} XD H {circumflex over (R)} DD −1 {circumflex over (R)} DX .

3. The method for receiving a signal and for rejecting interference according to claim 2 , wherein the inverse of the matrix {circumflex over (R)} DD is pre-computed and stored in a memory of the multichannel receiver.

4. The method for receiving a signal and for rejecting interference according to claim 1 , wherein the computation of the vector w comprising amplitude phase weighting coefficients to be applied to each of the channels in the multichannel filtering part ( 201 ) comprises:
the computation of r xd (i 0 ), r xd (i 0 ) being the mathematical expectation of the correlation between a training sequence and the multichannel signal received affected with a delay i 0 ,
the computation of ŵ according to the formula ŵ={circumflex over (R)} −1 r xd (i 0 ).

5. The method for receiving a signal and for rejecting interference according to claim 4 , wherein the delay i 0 is determined with respect to the position of the path of strongest power.

6. The method for receiving a signal and for rejecting interference according to claim 4 , wherein the delay i 0 is determined with respect to the position which maximizes the signal-to-noise plus interference ratio at the output of the multichannel filtering.

7. The method for receiving a signal and for rejecting interference according to claim 6 , wherein the position which maximizes the signal-to-noise plus interference ratio is obtained through the formula:
i 0 =ArgMax i {SNIR( i )= {circumflex over (r)} xd ( i ) H {circumflex over (R)} −1 {circumflex over (r)} ( i )}.

8. The method for receiving a signal and for rejecting interference according to claim 1 , wherein the said single-channel equalization is carried out on the basis of an estimation of the single-channel propagation pathway g given by the formula g=w H Ĥ where Ĥ is a multisensor pathway matrix estimated according to the formula Ĥ={circumflex over (R)} XD R DD −1 .

9. The method for receiving a signal and for rejecting interference according to claim 1 , wherein the said multichannel filtering is a spatial filtering.

10. The method for receiving a signal and for rejecting interference according to claim 1 , wherein the said multichannel filtering is a spatio-temporal filtering, the method furthermore comprising a step of determining at least one delay τ j associated with a multiple path of the signal received, and a step of forming a spatio-temporal multichannel signal vector on the basis of the said discretized and synchronized signal and of the said discretized and synchronized signal delayed by the said delay or delays τ j , steps of computing a matrix {circumflex over (R)} of correlation of the total noise, and of applying a multichannel filtering processing taking the said spatio-temporal multichannel signal as synchronized and discretized multichannel signal.

11. A multichannel receiver configured to receive a signal on a plurality of channels and to reject interference, comprising:
at least two radio chains, for the reception, transposition and discretization of the said signal received on each of the channels of a receiver, so as to obtain a discretized multichannel signal, and
computation circuits configured to synchronize the said discretized multichannel signal, wherein the computation circuits are further configured to:
compute, on the basis of the discretized and synchronized multichannel signal, a matrix {circumflex over (R)} of correlation of the total noise,
compute a matrix {circumflex over (R)} XD of intercorrelation between a training sequence and the discretized and synchronized multichannel signal received,
compute, on the basis of the matrix {circumflex over (R)} XD , of an estimate of a director vector associated to one path,
compute, on the basis of the said matrix {circumflex over (R)} of correlation of the total noise and of the estimate of the director vector associated to one path, a vector w comprising amplitude phase weighting coefficients of a multichannel filter, and
apply, to the discretized and synchronized multichannel signal, a multichannel filtering processing on the basis of the said vector a and of a single-channel equalization processing to the filtered signal.

Assignees

• Thales Sa

Inventors

• Pipon François

Classifications

• H04B7/086

  using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming · CPC title

• H04B1/1081 Primary

  Reduction of multipath noise (by equalising H04B7/005) · CPC title

• H04L25/022

  of frequency response · CPC title

• H04L2025/03477

  not time-recursive · CPC title

• H04L25/03031

  using only passive components (H04L25/03025 takes precedence) · CPC title