France Telecom

France Telecom Sa

Jean-Pierre Cances

Regis Lenormand

Gerard Maral

Bernard Coulomb

Jean-Michel Dumas

Vahid Meghdadi

Fran&ccedil;ois-Ren&eacute; Chevallier

A method for the simulation of responses of a nonlinear amplifier provides for measuring characteristics of nonlinearity of amplitude and of amplitude/phase-shift conversion of the amplifier, each measurement being made at an amplitude that is constant in input. The method further includes measuring the characteristics at different frequencies, developing the characteristics in sequences of direct transfer functions, computing frequency correctors for the direct transfer functions, measuring characteristics of distortion of amplitude modulation, each measurement being performed by modulating the input amplitude, computing modulation transfer functions reproducing the distortion amplitudes at output according to the input modulation amplitudes and correcting the direct transfer functions when the input amplitude is modulated in order to simulate the envelope memory effect. There is a direct application of the invention to the field of the simulation of high efficiency microwave amplification.

Method for the simulation of a nonlinear amplifier with envelope memory effect

The invention concerns a method of allocating a respective free radio beam channel to calling and called stations of a satellite telecommunication network. If there is no free channel on a beam forming the coverage including one given station, the method of the invention looks for free channels in each beam adjacent said beam, and allocates one of the adjacent beam free channels to the given station as soon as in an optimal subset of beams comprising all beams using the same channel as the free channel each level of isolation equal to the ratio of an antenna gain of a main lobe of a respective one of the beams of the optimal subset to the sum of the maximal antenna gains of secondary lobes of the other beams is greater than a given threshold.

Method of allocating a communication channel in a satellite network

A earth station calling another station sends a link setting-up a request to a control station. The control station memorizes in a transformed reference system the contour of a global geographical coverage including all the earth stations together with the earth positions of the latter. Subsequent to the request, the control station simulates the optimum evolution of the radioelectric coverages of the satellite so as to include, both on emitting and receiving, the calling and called stations in respective coverages with guaranteed minimum antenna gains. The total power of the satellite and the positions of the stations are notably considered in this simulation. If the result of simulation is positive, an emission authorization is sent by the control station to the calling station, and satellite antennae are reconfigured by phase shift and power control values emitted by the control station.

Antenna beam coverage reconfiguration

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Toulouse, France

Jean-Pierre Cances