Cassidian Sas

Eads Secure Networks

Airbus Ds Slc

Cnam-conservatoire National Des Arts Et Metiers

Airbus Ds Sas

Cnam Conservatoire National Des Arts Des Metiers

Luc Fety

Philippe Mege

Laurent Martinod

Olivier Perrin

Nicolas Gregis

This interference reduction method in a receiver () comprising at least two antennas (), each receiving a signal transmitted through a radio propagation channel, comprises the following steps: &#x2014;weighting () of each of the signals received with a weighting vector associated respectively with a respective antenna of the receiver; &#x2014;combination () of the weighted signals received to obtain a combined received signal; &#x2014;weighting () of a reference signal with another weighting vector; &#x2014;comparison () of the combined received signal and the weighted reference signal to obtain an error; and &#x2014;determination () of the weighting vectors with the help of the maximum a posteriori criterion by maximizing the probability of realization of the said weighting vectors conditionally with the error obtained.

Interference reduction method

This method for the estimation of a channel between an emitter and a receiver, where the said emitter emits a signal comprising symbol frames distributed in time and frequency, among which pilot symbols known to the receiver, is characterized in that it comprises the following steps: &#x2022;&#x2014;computation () of a covariance matrix Mand Mof the channel in the frequency and time domains respectively; &#x2022;&#x2014;decomposition () of the covariance matrices Mand Minto eigenvectors according to the relations M&#x2212;WNWand M&#x2212;WNW; &#x2022;&#x2014;computation () of the Kronecker product of the matrices NVand Wto obtain an eigenvector matrix W; &#x2022;&#x2014;computation () of a diagonal eigenvalue matrixequal to the Kronecker product of the eigenvalue matrices Nand N; and &#x2022;&#x2014;estimation of the channel with the help of pilot symbols and matrices W and N using the maximum a posteriori or quadratic error minimisation criterion.

Method for estimating a radio channel

To reduce interferences in signals received by a receiver through a propagation channel, each including symbols distributed according to frequency and time dimensions and corresponding to a common emitted signal, the receiver weights an estimate of the emitted signal and the received signals by weighting vectors evolving in vector subspaces representing time variations and frequency variations of the channels for propagating the signals between an emitter and the receiver. These vector subspaces are defined by matrices, some columns of which are suppressed as a function of frequency and time constraints of the channel. The receiver minimizes a function of the difference between the sum of weighted received signals and the weighted estimate of the emitted signal in order to estimate the emitted signal as a function of the weighting vectors and the received signals.

Reduction of interference in an OFDM signal with weighting vectors evolving in vector subspaces

Growing community of inventors

Paris, France

Luc Fety