Thales

Thomson-Csf

Thomson Licensing S.a.

François Pipon

Pascal Chevalier

Antoine Soulie

Jean-Jacques Monot

François Delaveau

Dominique Heurguier

Denis Masse

Gilbert Multedo

David Depierre

Dieudonné Josset

Antonio Cipriano

Philippe Buscailhon

Emmanuel Gross

Fr&eacute;d&eacute;rique Lasnier

Rym Mhiri

Dorin Panaitopol

Renaud MOLIÈRE

Kévin Mille

Bruno Kerjean

Luxmiram Vijayandran

Nathalie Haziza

Rémi Painchault

Sonja Hiltunen

François Turpin

Jérémy Brugier

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.

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

A method for measuring certain parameters of the impulse response of a propagation channel involving emitters and reflectors that are fixed or mobile, and for detecting and determining the parameters regarding the position and kinematics of the emitters and reflectors, or for auto-locating the reception system implementing the invention, in a system comprising N sensors receiving signals from the emitters or from the reflection on the reflectors. The method determines an ambiguity function which couples the spatial analysis and the delay-distance/Doppler-kinematic analysis, and determines at least one sufficient statistic &#x108;(l,m,K) corresponding to the correlation between the known signal s(kTe) corresponding to the complex envelope of the signal emitted and the output of a filter w(l,m) where l corresponds to a temporal assumption and m corresponds to a frequency assumption. The method also determines the values of the pair (l,m) by comparing the value of the statistic for the pair (l,m) with a threshold value.

Methods and devices for determining the impulse response of propagation channels involving emitters, reflectors and sensors that are fixed or mobile

A method of demodulating a signal in a transmission system where the modulation includes several substantially orthogonal subcarriers, and the vector of the propagation channel H[n,k] is known or the received signal includes at least pilot symbols emitting reference data. The method includes at least one step of estimating the symbol a[n,k] emitted on the ksubcarrier of the nsymbol of the modulation using a recombination step weighting the various signals received after synchronization and demodulation x[n,k].

Method of demodulating OFDM type signals in the presence of strong co-channel interference signals

Method of optimizing scheduling in a communications network of CDMA type comprising at least the following steps:

Method of optimizing scheduling in a communications system of CDMA type

A method to detect and/or locate a mobile craft in a reception system making use of transmitters of opportunity, whose signal comprises elements enabling the synchronization of the receiver, wherein certain discriminating sequences are detected of the payload signal. Each transmission present on the carrier frequencies examined by the receiver or receivers is separated by the space/time filtering of the signals in each carrier frequency. The transmitters Ei corresponding to the signals received are identified. The pulse response of the propagation channel for each transmitter Ei and for each detection made on this transmitter are determined by measuring the instant of arrival of the path reflected by the mobile craft is measured and then its delay relative to the instant of transmission from the transmitter. The position of the mobile craft is deduced at the intersection of the ellipsoids defined by the foci constituted by the transmitters Ei from which signals are received and the receiver or receivers Rj. The disclosed method can be applied to the detection of an aircraft.

Method for the multistatic detection and locating of a mobile craft through the use of digital broadcasting transmitters

Process for estimating the correlation matrix of signals of unknown characteristics in an array of N sensor. The process determines the correlation matrix {circumflex over (R)}s of the signals of known characteristics, estimates the correlation matrix {circumflex over (R)}x of the sensor signals, forms a matrix A equal to A={circumflex over (R)}s{circumflex over (R)}x {circumflex over (R)}sand decomposes the matrix A into eigenelements, constructs a matrix B based on the eigenelements of the matrix A, and determines the estimated correlation matrix {circumflex over (R)}b of the interfering signals based on the estimated matrix {circumflex over (R)}s and of the matrix B, such that {circumflex over (R)}b={circumflex over (R)}sB {circumflex over (R)}s. Such a process may find application to antenna processing.

Method for estimating a correlation matrix of interfering signals received through a sensor array

A system for analyzing interference caused by neighboring cells in a cellular communication system. A multipath synchronization is performed on the learning sequences of the beacon frequencies in order to determine the number of base stations using the analysis frequency as a beacon frequency. The identifiers of the base stations which are transmitting the beacon frequencies on which a synchronization has been made are demodulated after spatial filtering. A multipath synchronization is performed on learning sequences of the traffic frequencies so as to determine the number of base stations using the analysis frequency as a traffic frequency.

Method and device for analyzing interference in a cellular radiocommunication system

The method consists in estimating the matrix of correlation R.sub.XX of the signals received on a set of N reception sensors, computing the reverse correlation matrix R.sub.XX.sup.-n, computing vectors of intercorrelation r.sub.Xd between the signals received on the set of the N sensors and a known replica signal d(k), computing a criterion of synchronization in calculating the products of the conjugate, transposed intercorrection vectors R.sub.XX.sup.-n and of the matrix of the intercorrelation vector r.sub.Xdi and comparing the value of the criterion obtained with a determined threshold value 1 to place the synchronization on the sample for which the value of the criteria exceeds the threshold value .eta.. To estimate the Doppler shift the synchronization sequence is subdivided into a determined number of sections of symbols to carry out fast Fourier transform computations on determined intercorrelation vectors in each section.

Method and device enabling a modem to be synchronized with an RF digital

Disclosed is a method enabling the improvement of the multisensor reception of a system of radiocommunications exchanging signals between at least one fixed base station providing for multisensor reception by means of a network of sensors, and the processing of the signals. This method consists, in a transparent manner perceived from the base station, in computing a weighting vector W for the formation of channels at reception. The weighting vector W is estimated by an adaptive algorithm leading to a maximization of the signal-to-noise ratio. Application: mobile radiocommunications. FIG. 1

Multisensor reception method for a fixed base station of a

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Paris, France

François Pipon