Thomson-Csf

Gilbert Multedo

Jean-Jacques Monot

Pascal Chevalier

Robert Berranger

Fran&ccedil;ois Pipon

Jo&euml;l Thibault

Jean-Claude Balin

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. Simultaneously, the intended signal is transmitted in the direction of the main path of each mobile unit while protecting each mobile unit from signals transmitted in the direction of other mobile units by spatial filtering with cancelling constraints in order to provide spatial multiplexing.

Method and device for space division multiplexing of radio signals transmitted in cellular radio communications

A process which adjusts the transmission and reception chains of the paths formed by a base station of a system for radio communication between mobiles which after calibration of the antenna base adjusts the reception chains relating to each path by distributing a first specified adjustment signal synchronously over each of the reception chains and calculating an equalization filter which inverts the transfer functions related to each reception chain. The process next adjusts the transmission chains related to each path by distributing a second specified adjustment signal synchronously over each of the transmission chains, by extracting from each of the paths a part of a transmission signal before the transmission signal is sent to the antenna base so as to re-inject that part of the transmission signal into the reception chains, and by calculating an equalization filter which inverts the transfer functions related to each transmission chain. Finally, the process receives via the equalization filters previously calculated for the reception chains reception signals originating from the antenna base, or transmits via the equalization filters previously calculated for the transmission chains the transmission signals originating from the multipath transmission/reception device.

Process for adjusting the transmission and reception chains of the paths by a base station of a system for radio communication between mobiles

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. 1

Multisensor reception method for a fixed base station of a

The method consists in the step of masking the energy influence of the aliased spectrum of a jammer received in the useful band of each of the reception channels of a radio station during a determined time interval surrounding the change-over instant of each antenna. The masking is done either by means of attenuators with diodes placed at the input of each of the reception channels and controlled during the determined time interval or by memorizing, at least during the time interval, the gain of the intermediate frequency amplifiers before the change over takes place, by opening the automatic gain control loop of the intermediate frequency amplifiers to stabilize the gain of each amplifier, during the change over, at its memorized gain value.

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Vaureal Cergy, France

Gilbert Multedo