Abstract: A method for generating an encryption key is provided to encrypt data exchanged between a first user and a second user, wherein the key is determined from measurements of the transmission channel.

Abstract: A method for generating an encryption key is provided to encrypt data exchanged between a first user and a second user, wherein the key is determined from measurements of the transmission channel.

Abstract: A system and method for radio frequency tagging a transmitter of a useful first signal Su, by a tagging second signal Ctag, the signals are transmitted simultaneously, comprises at least the following elements: signal generation means adapted: to produce a useful signal Su in a given frequency band B, at a frequency fSu and an amplitude ASu, and to determine, from the values of the band parameter BSu of the useful signal Su and from the amplitude ASu of the useful signal Su, the parameters of the tagging signal Ctag, a transmission antenna adapted to simultaneously transmit said signal Su and said tagging signal, the level of which is X dB lower than the useful signal Su, means for receiving and processing the useful signal and the tagging signal adapted to discriminate the tagging signal from the useful signal.

Abstract: A method for optimizing the jamming of P predefined zones or positions in a communications network of transmitters, jammers and receivers comprising several platforms, uses a local reception situation at the level of each friendly platform, a local jamming situation at the level of each friendly reception platform, and determines for each friendly transmitting platform and each friendly receiving platform, one or more parameters so as to minimize or to eliminate the fratricidal effects on the friendly reception platforms.

Abstract: A system and method for radio frequency tagging a transmitter of a useful first signal Su, by a tagging second signal Ctag, the signals are transmitted simultaneously, comprises at least the following elements: signal generation means adapted: to produce a useful signal Su in a given frequency band B, at a frequency fSu and an amplitude ASu, and to determine, from the values of the band parameter BSu of the useful signal Su and from the amplitude ASu of the useful signal Su, the parameters of the tagging signal Ctag, a transmission antenna adapted to simultaneously transmit said signal Su and said tagging signal, the level of which is X dB lower than the useful signal Su, means for receiving and processing the useful signal and the tagging signal adapted to discriminate the tagging signal from the useful signal.

Abstract: A method is provided for selectively, dynamically and adaptively jamming the third-party radio communications that are external to a radio communication network to be protected, which optimizes the effectiveness of the jamming of P predefined areas or positions in a network of transmitters, and which uses closed-loop control to limit fratricidal effects on certain platforms having telecommunication transmitters/receivers to be preserved.

Abstract: A method for optimizing the jamming of P predefined zones or positions in a communications network of transmitters, jammers and receivers comprising several platforms, uses a local reception situation at the level of each friendly platform, a local jamming situation at the level of each friendly reception platform, and determines for each friendly transmitting platform and each friendly receiving platform, one or more parameters so as to minimize or to eliminate the fratricidal effects on the friendly reception platforms.

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 synchronizing a substantially rectilinear signal being propagated through an unknown channel, in the presence of unknown substantially rectilinear interferences, received by an array of N sensors, in which a known training sequence s(nT) is used comprising K symbols and sampled at the symbol rate T (s(nT), 0?n?{tilde over (K)}1), characterized in that, based on observations x((n+l/p)T) over the duration of the training sequence, where p=T/Te is an integer and Te the sampling period, a virtual observation vector X((n+l/p)T)=[x((n+l/p)T)T, x((n+l/p)T)†]T is defined, as well as a decision criterion or decision statistic taking into account the second-order non-circular nature of the interferences, by using the first and second correlation matrices of the virtual observation vector X((n+l/p)T).

Abstract: The invention relates to a method and system for controlling and analyzing cellular radio communications exchanged between mobile terminals and base stations BTS. The invention is characterized in that a dummy mobile terminals and base stations BTS. The invention is comprising a dummy mobile telephone network RRTM_F comprising a dummy base station BTS_F and a dummy mobile terminal MS_F are inserted into the real network RRTM_R, said dummy network being responsible for the decoding and transparent synchronous relaying of messages exchanged between the real network and the real mobile as well as real mobile access control from the real network or the dummy network.

Abstract: A method of synchronizing a substantially rectilinear signal being propagated through an unknown channel, in the presence of unknown substantially rectilinear interferences, received by an array of N sensors, in which a known training sequence s(nT) is used comprising K symbols and sampled at the symbol rate T (s(nT), 0?n?{tilde over (K)}1), characterized in that, based on observations x((n+l/p)T) over the duration of the training sequence, where p=T/Te is an integer and Te the sampling period, a virtual observation vector X((n+l/p)T)=[x((n+l/p)T)T, x((n+l/p)T)†]T is defined, as well as a decision criterion or decision statistic taking into account the second-order non-circular nature of the interferences, by using the first and second correlation matrices of the virtual observation vector X((n+l/p)T).

Abstract: The invention relates to a method and system for controlling and analysing cellular radio communications exchanged between mobile terminals and base stations BTS. The invention is characterised in that a dummy mobile terminals and base stations BTS. The invention is comprising a dummy mobile telephone network RRTM_F comprising a dummy base station BTS_F and a dummy mobile terminal MS_F are inserted into the real network RRTM_R, said dummy network being responsible for the decoding and transparent synchronous relaying of messages exchanged between the real network and the real mobile as well as real mobile access control from the real network or the dummy network.

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: A method for the detection of M0 sources common to several observations u(t) and v(t) within a single array of sensors, the observations having different lengths N1 and N2, comprises at least the following steps: defining a law of likelihood Vuv([M=M0]/M0) substantially equal to the chi-2 law with 2(N1?M0)(N2?M0) degrees of freedom with N1?N2, dim{u(t)}=N1×1 and dim{v(t)}=N2×1; determining a detection threshold ?M in order to obtain a low probability of false alarms and a number of degrees of freedom that takes account of the lengths N1 and N2 and of the number of sources M0; determining the presence and/or the number of the sources M0 in applying the law of likelihood and the threshold ?M. The method and device can be applied to the determining of the presence and/or the number of sources common to at least two observations having different lengths in a GSM type radiocommunications system.

Abstract: Method and device for the detection of one or more mobiles within a communications network, the method comprising at least one step for the “acquisition” of at least one RACH type signal exchanged between a mobile and a base station of the network and a step to measure the angle of arrival of the signal, the measurement step being synchronized with a parameter of the exchanged signal. Application to the GSM network.

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: In a method of co-operative radio direction-finding in transmission in a system of radio direction-finding for a radiocommunications system comprising one or more transmission sources or transmitters, the transmitted signal comprises a reference sequence formed by a sequence of symbols {Sk}, the receiver comprising at least one array of several sensors coupled to a radio direction-finder. The method comprises the following steps: a) determining the reference signal or signals di(t) associated with a transmitter m from the reference symbols {Sk} and from the modulation defined by the format of the signals; b) defining the instant of arrival tk of one or more reference signals; c) from the signal x(t) received at the sensors, the instants of arrival tk and the reference signal or signals di(t) derived from the step a), determining the value or values of incidence of the signals for a given transmitter. The method can be applied to GSM or UMTS signals.

Abstract: In a method of co-operative radio direction-finding in transmission in a system of radio direction-finding for a radiocommunications system comprising one or more transmission sources or transmitters, the transmitted signal comprises a reference sequence formed by a sequence of symbols {Sk}, the receiver comprising at least one array of several sensors coupled to a radio direction-finder.

Abstract: A method for the detection of M0 sources common to several observations u(t) and v(t) within a single array of sensors, the observations having different lengths N1 and N2, comprises at least the following steps: defining a law of likelihood Vuv([M=M0]/M0) substantially equal to the chi-2 law with 2(N1−M0)(N2−M0) degrees of freedom with N1≦N2, dim{u(t)}=N1×1 and dim{v(t)}=N2×1; determining a detection threshold &agr;M in order to obtain a low probability of false alarms and a number of degrees of freedom that takes account of the lengths N1 and N2 and of the number of sources M0; determining the presence and/or the number of the sources M0 in applying the law of likelihood and the threshold &agr;M. The method and device can be applied to the determining of the presence and/or the number of sources common to at least two observations having different lengths in a GSM type radiocommunications system.