France Telecom

Alcatel

Centre National De La Recherche Scientifique

Thales

Institut National Polytechnique De Toulouse

Institut Superieur De L'aeronautique Et De L'espace

Marie-Laure Boucheret

Benjamin Gadat

Ivar Mortensen

Eric Belis

Jérôme Lacan

Henri Favaro

Charly Poulliat

Bilel Raddadi

Herv&eacute; Legay

C&eacute;cile Guiraud

Nathalie Thomas

Huyen Chi Bui

Method of repointing a reflector array antenna

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

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Goyrans, France

Marie-Laure Boucheret