Thales

Merlet, Eric

Jean-Luc Rogier

Anne Ferreol

Eric Merlet

Jean-Christophe Mesnage

Arnaud Lecca

Catherine Lamy-Bergot

Dominique Heurguier

Sylvain Traverso

Jean-Yves Bernier

Gilbert Multedo

François Jolec

A method for reducing the peak factor of a signal transmitted in a frequency band comprising several channels, the signal using a plurality of channels in the band comprises: a step of clipping the signal, a step of subtracting the clipped signal from the signal, so as to obtain a peak signal, a step of filtering the peak signal with the aid of a multichannel filter configured to comply with a predetermined spectral mask for each of the channels used by the signal, and a step of subtracting the filtered peak signal from the signal. A device for emitting a multichannel signal implementing the method for reducing the peak factor is also provided.

Method for reducing the peak factor of a multichannel emission by adaptive and intelligent clipping/filtering

A method for managing the HF frequencies in a broadband communication network, comprises the following steps: determining the range of passing frequencies for a user for a given link and SLA service; establishing the set of authorized frequencies S&#x2033; in the transmission range of the user with the different power and modulation configurations for each frequency; analyzing the received spectrum in order to determine the frequency or frequencies already used and deciding, on the basis of their associated usage type, whether they must be excluded; for each possible frequency fl of the set S'&#x2033;, determining the necessary power, i=1 . . . N, j=1 . . . m for each of the m possible rate/waveform configurations, taking into account the power limit on each frequency fl; allocating the frequencies fl of the set S&#x2032;&#x2033; to the different users, their modulation and their power, by taking account of multi-carrier constraints.

Method for managing HF frequencies in broadband use

A method is provided for estimating the polarization ellipticity of an antenna response signal to an incident electromagnetic wave received on a crossed-loop antenna or an Adcock antenna array. The method comprises at least the following steps: measuring the phase offset &#x394;&#x3c6; between the signals acquired respectively on the cosine and sine path of the antenna; measuring the ratio R between the amplitudes of the signals acquired respectively on the cosine and sine path of the antenna; determining the ellipticity angle &#x3c4; based on the phase offset &#x394;&#x3c6; and on the ratio R. The invention applies notably to the discrimination of ionospheric waves from ground and/or sea waves, in particular for a surveillance, eavesdropping, or goniometry system using HF band signals.

Method for estimating the polarization ellipticity of an antenna response signal to an incident electromagnetic wave

A method of measuring the direction of arrival &#x3b8; of radio signals in the HF band received by a crossed loop antenna includes, in a preparatory calibration phase, acquiring and recording the measurements made by the antenna of a calibration signal which varies in its frequency and bearing angle; and in a measurement phase in which the bearing angle or angles of arrival of signals detected by the antenna is or are determined, acquiring the signals detected in at least one frequency channel, and then, for each frequency channel f, correlating the acquired signals with the recordings having frequencies close to f, resulting from the calibration, and determining the direction of arrival of the signals by finding the bearing angle &#x3b8; for which the maximum correlation is reached.

Method of determining the direction of arrival of a high-frequency electromagnetic wave

Growing community of inventors

Gennevilliers, France

Jean-Luc Rogier