Patent ID: 7366256

Claim:
A method of demodulating a signal in a packet communications system, the signal including at least one burst representing data samples pertaining to one or more users, the method comprising the steps of: (a) phase estimation and tracking during at least the duration of the burst by using a frequency assumption test; (b) for a sample k of the received signal generating a correction and tracking signal Scp(i) by using a value of frequency deviation idF and a residual phase value dφ; (c) correcting an input signal Rk by multiplying it by a correction and tracking signal Scp(i); (d) transmitting the frequency-corrected and phase-corrected signal; (e) at a step of computation of the residual phase value dφ, using a reference constellation signal Dk and the frequency-corrected and phase-corrected signal to estimate the value SNR(i) for index; (f) integrating the residual phase value dφ and transmitting the residual phase value dφ during step (b); (g) determining a variation in the value of index i and reiterating steps (a) to (f); (h) for each assumption, taking the sum of the local SNR(i) values per sample, and determining a variation in the value of k; and (i) extracting the frequency deviation value indexed i for which the value of the SNR is optimum; wherein the generation of correction and tracking signal is given by: ψ k+1 =ψ k +G.F(φ k , ρ k ).dφ k +dF where F(φ,ρ) is a weighting function; ψ k is an estimated phase; G is the loop gain; F is the weighting function; dφ k is the phase error; and dF is the frequency deviation assumption.