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.

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.

Abstract: 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 ?(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.

Abstract: Method for measuring certain parameters of the impulse response of a propagation channel involving emitters and reflectors that are fixed or mobile, so as to detect and determine the parameters regarding the position and kinematics of these emitters and reflectors, or to auto-locate the reception system implementing the invention, in a system comprising N sensors receiving signals from said emitters or from the reflection on said reflectors, and comprising at least the following steps: determination of an ambiguity function which couples the spatial analysis and the delay-distance/Doppler-kinematic analysis, determination of at least one sufficient statistic C(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 (delay-distance, temporal ramp, etc.) and m to a frequency assumption (Dopper-kinematic, Doppler ramp, etc.

Abstract: 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 kth subcarrier of the nth symbol of the modulation using a recombination step weighting the various signals received after synchronization and demodulation x[n,k].

Abstract: Method of optimizing scheduling in a communications network of CDMA type comprising at least the following steps: detect the base stations received at a measurement point by means of multisensor synchronization, and for each of them estimate the propagation channel, h(0, s), . . . , h(L?1, s), estimate the received powers Pi, determine the base station or stations of highest levels which define a group of active stations {Gsa}, on the basis of the results obtained in the preceding steps, estimate for each base station of the group of active stations {Gsa}, the reception filter g (0, s, a) implemented by a mobile situated at the measurement point for the reception of the station considered, estimate, for each slot s and each antenna configuration a of the mobile, the ratio Es/I0, on the basis of the estimates of the propagation channel, and deduce therefrom the interference factor IF associated with the mobile placed at the measurement point.

Abstract: Method of optimizing scheduling in a communications network of CDMA type comprising at least the following steps: detect the base stations received at a measurement point by means of multisensor synchronization, and for each of them estimate the propagation channel, h(0, s), . . . , h(L?1, s), estimate the received powers Pi, determine the base station or stations of highest levels which define a group of active stations {Gsa}, on the basis of the results obtained in the preceding steps, estimate for each base station of the group of active stations {Gsa}, the reception filter g (0, s, a) implemented by a mobile situated at the measurement point for the reception of the station considered, estimate, for each slot s and each antenna configuration a of the mobile, the ratio Es/I0, on the basis of the estimates of the propagation channel, and deduce therefrom the interference factor IF associated with the mobile placed at the measurement point.

Abstract: 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.

Abstract: Method of demodulating a signal in a transmission system where the modulation includes several substantially orthogonal subcarriers, the vector of the propagation channel H[n,k] being known, or the received signal including at least pilot symbols emitting reference data. It comprises at least one step of estimating the symbol a[n,k] emitted on the kth subcarrier of the nth symbol of the modulation with the aid of a recombination weighting the various signals received after synchronization and demodulation x[n,k].

Abstract: 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, comprises at least the following steps: a) detecting certain “discriminating” sequences of the payload signal; b) separating each transmission present on the carrier frequencies examined by the receiver or receivers by the space/time filtering of the signals in each carrier frequency; c) identifying the transmitters Ei corresponding to the signals received; d) determining the pulse response of the propagation channel for each transmitter Ei and for each detection made on this transmitter;) measuring the instant of arrival of the path reflected by the mobile craft and then its delay relative to the instant of transmission from the transmitter; h) deducing the position of the mobile craft at the intersection of the ellipsoids defined by the foci constituted by the transmitters Ei from which signals are received and the rece

Abstract: 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?1/2{circumflex over (R)}x {circumflex over (R)}s?1/2 and 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)}s1/2 B {circumflex over (R)}s1/2. Such a process may find application to antenna processing.

Abstract: Process for estimating the correlation matrix of signals of unknown characteristics in an array of N sensors comprising the following steps:

Abstract: 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.

Abstract: A process for calculating on the one hand the coefficients of a spatial filter applied to the signals emanating from the third step and on the other hand the coefficients of a temporal filter applied to the replica signal, made up either of the known symbols for the learning sequences, or from the demodulated symbols for the information sequences, the coefficients of these two filters being calculated so as to minimize, under a specified constraint, a criterion of mean square error between the output signal from the spatial filter and the output signal from the temporal filter, and consisting in filtering the signals emanating from the third step with the aid of the thus calculated coefficients of the spatial filter, thus optimizing the gain of the array of sensors in the direction of the useful signal at the output of the spatial filtering and ensuring rejection of the interference.

Abstract: A process and device related to multisensor radio direction finding receivers usable in radio communication systems including several emission sources. The process and device isolate the contribution of each emission source in sensor signals so as to perform direction finding on a single emission source only, based on learning sequences inserted into waveforms emitted by each of the emission sources. Such a process and device may find particular application to cellular communication networks.

Abstract: A method and apparatus for spatial multiplexing and demultiplexing of radio signals. A multichannel transmitter and receiver is integrated in a base station and coupled to an antenna array. Using digital radio signals containing previously known or non-Gaussian sequences and arranged in frames, the spatial information about each mobile unit is estimated on the basis of the signal received by the receiver for the reception and transmission frequencies. This is done by known sequences or by blind source separation methods. The respective paths of each mobile unit with the power above a predetermined threshold is isolated by spatial filtering in the presence of multiple channel paths in order to provide spatial demultiplexing.

Abstract: 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.

Abstract: 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.