Thomson-Csf

Thomas-Csf

Gerard Auger

Olivier Bacelon

Pierre A Laurent

Claude Michel

Gilles Michalon

Patrick Mocchi

A dynamic and decentralized self-adaptive method and system including allocation of all time/frequency resources available at a given moment to as many requesting mobile units as are necessary. Transmission between stations is performed by allocation of frequencies. For each frequency allocated, the transmissions are grouped in slots forming frames in a time/frequency space. Each frame includes n slots of a same duration and a same width. The method includes using the allocated transmission frequencies and the frames for each transmission from a station by occupancy of one and the same number of slots according to a modulo p operation. A search is made, during a monitoring procedure, for free slots to determine parameters of occupation of a transmission as a function of the state of occupancy of the frames of the time/frequency space existing before the transmission. With the noted method and system, simultaneous operation of a large number of stations, without planning, initial data or centralized management, while at the same time maintaining compatibility with waveforms of conventional systems and methods, is enabled.

Self-adaptive method for the transmission of data, and implementation

Navigation system allowing real-time coordination of the displacement of

A radiocommunications and localization device of the type comprising an array of antennas coupled respectively to a goniometer device and a radio receiver delivering phonic signals to an operator respectively on two headphones. This device includes a device to identify the position of the operator's head and a device for the generation of phonic signals that is coupled to the goniometer device, the radio receiver and the identifying device for the application, respectively to the headphones, of the mutually phase-shifted phonic signals so as to give the operator the impression that the phonic signal that he hears is coming from the direction of arrival of the radiowaves determined by the goniometer device. The applications of this device relate to the radio-localization of persons moving in groups.

Radiocommunications and localizing device

A method which constructs, in each transmitter/receiver of a mobile body or vehicle, information tables recording the changes undergone by a radio channel by memorizing, during consecutive time intervals of a determined duration dT that are smaller than the period of recurrence T, of the statuses of the radio channel, namely 'in collision', 'busy' or 'free'. The method then sets fixed transmission instants in each transmitter/receiver, these fixed transmission instants being temporally spaced out at intervals equal to the recurrence period T, to predict the status of the channel for each fixed transmission instant as a function of the status of the channel memorized at the instant preceding it with a temporal shift equal to the period T, and in deciding to transmit at this instant if the predicted status of the channel is not a status of collision or to transmit at an instant deferred with respect to the predicted instant if the opposite is the case.

Method for the transmission of data among mobile bodies or autonomous

The continuous phase angular demodulation method disclosed digitally processes the signal in baseband after having over-sampled it with reference to the bit period. The processing consists in routinely demodulating sub-sets of differential phases at the bit period T.sub.b shifted with respect to one another by fractions T.sub.b /q of this period, in correcting them, a priori, by the phase deviations associated with a set of pre-defined d frequency drifts and in computing, for the d.q sets thus obtained, a noise criterion. The set of demodulated bits chosen is the one that reduces this noise criterion to the minimum. The set of bits then enables computation of the phase variation emitted and, using this variation and the measured variation, the real frequency drift. Another demodulation taking this drift into account is done for the q sets of initial differential stages and the set minimizing the noise criterion is then chosen and fixes the synchronization bit by the sampling instants associated with it.

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Champagne sur Oise, France

Gerard Auger