Method and receiver device for estimating a frequency offset and a frequency drift of a useful signal

A method for estimating a frequency shift and a frequency drift affecting a useful signal received by a receiving device, said useful signal including a code word formed by a channel encoder from useful data, wherein said method includes:

• an analysis phase including:
• for each of two analysis frequency drifts, compensating for the analysis frequency drift on the useful signal to generate a compensated useful signal,
• estimating a frequency shift on each of the compensated useful signals, so as to obtain analysis of frequency shifts each associated respectively with one of the two analysis frequency drifts, to define two analysis points in a frequency drift/frequency shift plane,
• selecting frequency hypotheses on a straight line determined from the two analysis points, and
• an estimation phase including:
• for each frequency hypothesis among the selected frequency hypotheses, performing a frequency recalibration of the useful signal depending on the frequency hypothesis, to obtain a sample sequence associated with the frequency hypothesis,
• for each of the sample sequences, evaluating a probability of the sample sequence being the code word of said channel encoder,
• estimating a frequency shift and a frequency drift affecting the useful signal depending on the frequency hypothesis associated with one of the sample sequences having a highest probability of being the code word of the channel encoder.