Alcatel

France Telecom

Alcatel Espace

Thales

Eric Belis

Jean-Didier Gayrard

Ivar Mortensen

Henri Favaro

Marie-Laure Boucheret

Andre Marguinaud

Christian Rigal

Luc Delamotte

Muriel Aveline

Jean Bouin

R&eacute;gis Lenormand

Daniel Rousset

Frédéric Michard

Claudine Flament

Chantal Lesthievent

Patrick Oudart

A device (D) is dedicated to transmitting and/or receiving signals representative of data in a communication satellite (SAT) having a fixed frequency bandwidth. This device (D) comprises transmission and/or reception means (MER) responsible for sending and/or receiving signals in multiple beams, and control means (MC) responsible for defining a chosen number of cells of chosen dimensions and positions, and configuring the transmission and/or reception means (MER) so as to define beams each associated with at least one of the defined cells, with a chosen carrier frequency based on the requirements of each of the cells and taking into account the frequency bandwidth available on the satellite (SAT).

Device for transmitting and/or receiving signals with frequency re-use by assignment of a cell for each terminal, for a communication satellite

Equipment () includes at least one electronic module () for the payload or the platform of a satellite (50) adapted to be supported by a structure () of the satellite, the satellite structure including a heat transfer system () for transporting dissipated heat to a radiator (). The equipment includes at least transfer devices () for transferring heat dissipated by the electronic module and connectors () for connecting the transfer devices to the heat transfer system () of the structure in such a manner as to enable the supply of heat exchange fluid () to the transfer devices and the transfer of heat dissipated by the electronic module to the radiator. A satellite structure includes an arrangement of equipments and a communication system for satellites, with particular application to the new generation of satellites with electrical propulsion.

Modular architecture for thermal control in a spacecraft

A satellite for a satellite telecommunication system transmits signals at different powers on the downlink connection. The powers are chosen to limit the relative dynamic range of signals received on the downlink connection. The relative dynamic range of signals received on the downlink connection is advantageously less than 5 dB and preferably less than 2 dB. A digital processor circuit is used, together with an analog-digital converter, a circuit taking the fast Fourier transform of the converted signals, a circuit for monitoring the gain of the signals, a circuit for switching the signals to at least two amplifier subsystems each including an inverse fast Fourier transform circuit, a digital-analog converter and a power amplifier.

Dynamic compensation of signals for space telecommunication repeaters

A digital filter method comprising the following steps: input signal data x(n) is sampled at sampling frequency Fe and shared between and stored in Q memories of shift register of FIFO type associated with the Q branches of the filter. The filter coefficients g.sub.m (p) are stored in at least one other memory referred to as a 'coefficient' memory. Interpolation by L followed by decimation by M makes it possible to reduce the working frequency of the filter to the output frequency Fs=(L/M)Fe with L/M&lt;1. Data samples x(n) are multiplied by the coefficients g.sub.m (p) at the rate Fs. According to the invention, the data samples x(n) in each branch remain present for a plurality of multiplications .apprxeq.Fe/Q, and the coefficients are rotated in each branch by address permutation in the coefficient memory at each clock period. The invention proposes various devices implementing the method. Applications in radar and in telecommunications.

Broad-band digital filtering method and a filter implementing the method

In order to detect the error on the frequency of an M-PSK phase-modulated carrier, the phase .psi.(n) of the samples is restored to the interval �-.pi., +.pi.�; .phi.(n)=mod(.psi.(n), 2.pi./M) is calculated; d(n)=mod(.phi.(n)-.phi.(n-1), 2.pi./M) is calculated; p'(n)=mod(d(n)+p(n-1), 2.pi./M) is calculated, where p(n)=mod(p*(n), 2.pi./M), where p*(n) is obtained by subtracting the current output from p'(n); d'(n)=p'(n)-p(n-1) is calculated; a parameter 'tri' is defined by tri=1 if .vertline.d'(n).vertline.&lt;S and tri=.beta. if .vertline.d'(n).vertline..gtoreq.S, where S is a threshold; det.sub.-- tri(n)=.alpha..p'(n).tri is calculated, det.sub.-- tri(n) constituting the current output, representative of the error on the frequency of the carrier.

Method and device for detecting the error on the frequency of a carrier

The method makes it possible digitally to evaluate the phase of any carrier that has been subjected to rPSK modulation subsequent to clock recovery, sampling, and digitizing the in-phase and quadrature components of the samples, by processing that is performed in polar coordinates and that comprises reducing the range over which the phase of each sample is defined to a range of +.pi./r to -.pi./r and then seeking the center of gravity over 2.sup.N successive samples (N being an integer) by performing successive averaging calculations, each time on two values, in application of an N-stage tree structure. Each average of two values is associated with an index indicative of the degree of reliability of the average, and those averages which are associated with a small reliability index are ignored while calculating subsequent averages in the tree structure.

Method and apparatus for digitally evaluating the phase of a modulated

A high-throughput filtering method and corresponding apparatus in which each output sample sn is determined by weighting N input samples xi by multiplying the input samples by N coefficients, where the N coefficients are each decomposed into a set of coordinates, each coordinate corresponding to P bits of the coefficient. Essentially, input samples are multiplied by the coordinates of each of the coefficients in a pre-processing operation where the output signals corresponding to the resulting products for a coefficient are added in an adding block. A plurality of adding blocks are provided corresponding respectively to the coefficients such that each block includes the summation result of the products for a corresponding coefficient. The summation result from a previous adding block is added to the summation result of a current block, and the result of this addition is supplied to the next adding block. The output signal is obtained in this manner.

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Toulouse, France

Eric Belis