Abstract: A method and system for locating an emitter E transmitting a signal toward a receiver A comprising N radio frequency channels (N?1), the characteristics of said signal being unknown to the receiver and said signal being reflected off P reflectors Bi (P?1) of known positions, includes a step of multi-channel joint estimation/detection of the time differences of arrival or TDOA ?i and of the frequency differences of arrival or FDOA fi for each reflected path, a step of angular estimation of the direction ?1 of the direct path of the signal emitted by a goniometry procedure, and a step of location in the plane of the position (x,y) of the emitter E on the basis, at least, of the pairs (?i, fi).

Abstract: A method for jointly determining the azimuth angle ? and the elevation angle ? of the wave vectors of P waves in a system comprising an array of sensors, a number of waves out of the P waves being propagated along coherent or substantially coherent paths between a source and said sensors, includes at least the following steps: selecting a subset of sensors from said sensors to form a linear subarray of sensors; applying, to the signals from the chosen subarray, an algorithm according to a single dimension to decorrelate the sources of the P waves; determining a first component w of said wave vectors by applying, to the signals observed on the sensors of the chosen subarray, a goniometry algorithm according to the single dimension w; determining a second component u of said wave vectors by applying a goniometry algorithm according to the single dimension u to the signals from the entire array of sensors; determining ? and ? from w and u.

Abstract: Disclosed is a method of blind demodulation of signals arising from one or more transmitters, the signals including a mixture of symbols comprising at least one step of separating the transmitters by using the temporal independence of the symbol trains specific to a transmitter and the mutual independence of the transmitters.

Abstract: A method for interpolating steering vectors a(?) of a sensor network, the sensor network receiving signals transmitted by a source, characterized in that, for the interpolation of the steering vectors a(?), use is made of one or more omnidirectional modal functions z(?)k where z(?)=exp(j?) where ? corresponds to an angle sector on which the interpolation of the steering vectors is carried out.

Abstract: Method and system for locating one or more transmitters in the potential presence of obstacles in a network comprising a first receiving station A and a second receiving station B that is asynchronous with A. The method includes the identification of a reference transmitter through an estimation of its direction of arrival AOA-TDOA pair (?ref, ??ref) on the basis of the knowledge of the positions of the reference transmitter and of stations A and B, an estimation of the direction of arrival of the transmitter or transmitters and of the reflectors (or estimation of the AOA) on station A, and the correction of the errors of asynchronism between station A and station B by using the reference transmitter and the location of the various transmitters on the basis of each pair (AOAi, TDOAi).

Abstract: A method and system for locating an emitter E transmitting a signal toward a receiver A comprising N radio frequency channels (N?1), the characteristics of said signal being unknown to the receiver and said signal being reflected off P reflectors Bi (P?1) of known positions, includes a step of multi-channel joint estimation/detection of the time differences of arrival or TDOA ?i and of the frequency differences of arrival or FDOA fi for each reflected path, a step of angular estimation of the direction ?1 of the direct path of the signal emitted by a goniometry procedure, and a step of location in the plane of the position (x,y) of the emitter E on the basis, at least, of the pairs (?i, fi).

Abstract: A method for jointly determining the azimuth angle ? and the elevation angle ? of the wave vectors of P waves in a system comprising an array of sensors, a number of waves out of the P waves being propagated along coherent or substantially coherent paths between a source and said sensors, includes at least the following steps: selecting a subset of sensors from said sensors to form a linear subarray of sensors; applying, to the signals from the chosen subarray, an algorithm according to a single dimension to decorrelate the sources of the P waves; determining a first component w of said wave vectors by applying, to the signals observed on the sensors of the chosen subarray, a goniometry algorithm according to the single dimension w; determining a second component u of said wave vectors by applying a goniometry algorithm according to the single dimension u to the signals from the entire array of sensors; determining ? and ? from w and u.

Abstract: A goniometry method for one or several diffuse (or distributed) sources is disclosed. The sources or sources having one or more give directions and a diffusion cone. The sources are received by an array of several sensors. The method breaks down the diffusion cone into a finite number L of diffusers. A diffuser has the parameters (?mp, ??mpi, ?mp, ??mpi), associated with it. Directing vectors a(?mp+??mpi, ?mp+??mpi) associated with the L diffusers are combined to obtain a vector (D(?, ?, ??, ??) ? or U(?, ?) ?(??, ??, ?)) dependent on at least one of the incidence and deflection parameters (?, ?, ??, ??) and on the combination vector ?. A MUSIC-type criterion or other goniometry algorithm is applied to the vectors D(?, ?, ??, ??) ? or U(?, ?) ?(??, ??, ?) obtained in order to determine at least one of the incidence parameters ?mp, ?mp, ??mp, ??mp of the associated diffusion cone.

Abstract: Method of high-resolution direction finding to an arbitrary even order, 2q (q>2), for an array comprising N narrowband antennas each receiving the contribution from P sources characterized in that the algebraic properties of a matrix of cumulants of order 2q, C2q,x(l), whose coefficients are the circular cumulants of order 2q, Cum[xi1(t), . . . , xig(t), xiq+1(t)*, . . . , xi2q(t)*], of the observations received on each antenna, for cumulant rankings indexed by l, are utilized to define a signal subspace and a noise subspace.

Abstract: Method and system for locating one or more transmitters in the potential presence of obstacles in a network comprising a first receiving station A and a second receiving station B that is asynchronous with A. The method includes the identification of a reference transmitter through an estimation of its direction of arrival AOA-TDOA pair (?ref,??ref) on the basis of the knowledge of the positions of the reference transmitter and of stations A and B, an estimation of the direction of arrival of the transmitter or transmitters and of the reflectors (or estimation of the AOA) on station A, and the correction of the errors of asynchronism between station A and station B by using the reference transmitter and the location of the various transmitters on the basis of each pair (AOAi, TDOAi).

Abstract: Method of multi-parameter direction finding of several sources in an array of N sensors, comprising at least the following steps: a) choosing a parameter to be determined, or parameter of interest, b) expressing the direction vector in the form of a linear relation between the parameter of interest chosen and the secondary parameters b0(?, ?0)=U0(?) ?0(?0), c) applying a MUSIC-type direction finding step by factorizing the criterion serving for the determination of the angles of incidence so as to determine at least the incidence parameter, d) on the basis of the incidence value, determining the vector representative of the secondary parameters and expressing this vector in the form of a linear relation between a chosen parameter to be determined and the other secondary parameters, e) applying a MUSIC-type direction finding step by factorizing the criterion serving in the determination of the chosen parameter, f) repeating steps d) to e) so as to determine the majority or the whole set of secondary parameters

Abstract: Method of locating one or more transmitters on the basis of an array of sensors moving with respect to the transmitters comprising at least the following steps: determining the direction vectors âk corresponding to the response of the array of sensors to a source with incidence (?, ?) as a function of the incidence parameters ?, ?, and of the parameter ? related to the distortion of the phases on the sensors, transforming this vector âk so as to eliminate the unknown parameter ?, into a vector ?km, ??km, using the transformed vector to obtain the position of the transmitter using a maximized locating criterion.

Abstract: A method for interpolating steering vectors a(?) of a sensor network, the sensor network receiving signals transmitted by a source, characterized in that, for the interpolation of the steering vectors a(?), use is made of one or more omnidirectional modal functions z(?)k where z(?)=exp(j?) where ? corresponds to an angle sector on which the interpolation of the steering vectors is carried out.

Abstract: Method of using one or more transmitters and/or one or more parameters associated with a transmitter by using a reception station comprising a device suitable for measuring over time a set of K parameters dependent on the transmitters associated with vectors {circumflex over (?)}k representative of the transmitters for 1?k?K. The method includes a step of extracting the parameter or parameters consisting in grouping together by transmitter the parameters which are associated therewith by means of a technique of independent component analysis.

Abstract: Process for the blind demodulation of a linear waveform source or transmitter in a system comprising one or more sources and an array of sensors and a propagation channel. The process comprises at least the following steps: the symbol period T is determined and sampled to Te such that T=ITe (I being an integer); a spatio-temporal observation z(t), the mixed sources of which are symbol trains from the transmitter, is constructed from the observations x(kTe); an ICA-type method is applied to the observation vector z(t) in order to estimate the Lc symbol trains {am-i} that are associated with the channel vectors ?z,j=?z(kj); the Lc outputs (âm,j, ?z,j) are arranged in the same order as the inputs (am-i,hz(i)) so as to obtain the propagation channel vectors ?z,j=?z(kj); and the phase ?imax associated with the outputs is determined.

Abstract: Method of using one or more transmitters and/or one or more parameters associated with a transmitter by using a reception station comprising a device suitable for measuring over time a set of K parameters dependent on the transmitters associated with vectors {circumflex over (?)}k representative of the transmitters for 1?k?K. The method includes a step of extracting the parameter or parameters consisting in grouping together by transmitter the parameters which are associated therewith by means of a technique of independent component analysis.

Abstract: Disclosed is a method of blind demodulation of signals arising from one or more transmitters, the signals including a mixture of symbols comprising at least one step of separating the transmitters by using the temporal independence of the symbol trains specific to a transmitter and the mutual independence of the transmitters.

Abstract: A goniometry method for one or several diffuse (or distributed) sources is disclosed. The sources or sources having one or more give directions and a diffusion cone. The sources are received by an array of several sensors. The method breaks down the diffusion cone into a finite number L of diffusers. A diffuser has the parameters (?mp, ??mpi, ?mp, ??mpi), associated with it. Directing vectors a(?mp+??mpi, ?mp+??mpi) associated with the L diffusers are combined to obtain a vector (D(?, ?, ??, ??) ? or U(?, ?) ?(??, ??, ?)) dependent on at least one of the incidence and deflection parameters (?, ?, ??, ??) and on the combination vector ?. A MUSIC-type criterion or other goniometry algorithm is applied to the vectors D(?, ?, ??, ??) ? or U(?, ?) ?(??, ??, ?) obtained in order to determine at least one of the incidence parameters ?mp, ?mp, ??mp, ??mp of the associated diffusion cone.

Abstract: The invention concerns digital signal transmission. In particular, it concerns high speed transmission using layered space-time encoding architecture adapted to all types of propagation channels. The invention therefore proposes a digital signal transmission system comprising: a space-time encoder (1) receiving a flow of data to be transmitted d[i], formatting this data d[i] as symbol vectors v[k] of dimension P(P>1) and generating said symbol vectors v[k], and modulator-transmitters {2p}(1?p?P), each receiving one component of the symbol vector m[k] output from the space-time encoder (1), applying the constellation of a predetermined modulation to said symbol mp[k], and converting the symbol obtained ap[k] into a signal sp(t) presenting time diversity transmitted on said antenna (24p) connected to said transmitter (2p).

Abstract: An antenna processing method for centered or potentially non-centered cyclostationary signals, comprises at least one step in which one or more nth order estimators are obtained from r-order statistics, with r=1 to n?1, and for one or more values of r, it comprises a step for the correction of the estimator by means of r-order detected cyclic frequencies. The method can be applied to the separation of the emitter sources of the signals received by using the estimator or estimators.