Patent ID: 7173983
Filing Date: 2007-02-06
Classification: H04L

Abstract:
1. A COFDM demodulator, comprising: a fast Fourier transform circuit for analyzing a received signal in a window corresponding to one symbol, each symbol carrying several phase and amplitude modulated carriers, some of which, shifted in frequency in a predetermined way from one symbol to the next one, form pilots, each symbol having a guard interval; a bidimensional filter for interpolating from anchors corresponding to the pilots received from several consecutive symbols the distortion undergone by each carrier; means for correcting a temporal window shifting with respect to an optimal position, in which two successive windows can be temporally shifted up to the guard interval duration; and means for correcting each distortion according to temporal window shifting corrections performed respectively for the symbol associated with the distortion and for the symbols associated with the anchors used to interpolate the distortion.