Patent ID: 8023596

Claim:
A system of estimating and tracking the frequency offset for a transmission system whose bandwidth is not insignificant with respect to the central frequency, the system transmitting a waveform including fixed carriers whose level is substantially greater than that of the carriers transporting the information, the carriers having frequencies F 0 . . . F N-1 , and the payload signal carrying the information, comprising: N banks of band-pass filters, each bank comprising P filters, suitable for covering all of the values that the frequencies F 0 . . . F N-1 may take after Doppler offset, a filter output is connected to a quadratic envelope detector, P adders suitable for adding the corresponding outputs of the N banks of filters, a first system for detecting the position of the two largest maxima from the P sums and for validating the position of the larges maximum, a second system for storing the positions of the two larges maxima and their weight and for predicting the current value, a third system for validating/replacing the position found, and a fourth system converting the positions into estimated Doppler and filtering the latter through a low pass filter.