Abstract: Method and antenna system used to point at least an antenna with respect to one or more other antennas, one of the antennas being a transmission antenna with an opening beam &thgr;e associated with a rotation speed Re, to cover an angular sector Se transmitting a signal every Tb seconds and another antenna being a reception antenna with an opening beam &thgr;r associated with a rotation speed Rr to cover an angular sector Sr, comprising at least the following steps

Abstract: 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.

Abstract: A navigation system having a terminal provided at each mobile station. Each terminal includes a locator for locating a mobile station, a display for displaying its travel relative to the reference direction, an indicator to indicate a common reference direction to both mobile stations with the indicator being coupled to the display, a travel data communicator and a processor to process data from the indicator, the locator and the communicator and display it on the display. At least one of the two mobile stations further includes a display for displaying the travel of the second mobile station relative to the first and an input unit for inputting a predetermined angle for defining how the direction of travel of the second mobile station should be corrected relative to the new direction of travel of the first mobile station. The correction is transmitted to the second mobile station by the travel data communicator of the first and second mobile stations.

Abstract: 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.

Abstract: 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.

Abstract: 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.