Patent Document ID: 8204139
Application ID: 12204550
Patent Flag: 1

Claim One:
1. A blind estimation method of at least one temporal modulation parameter of an orthogonal frequency division multiplex (OFDM) signal, said temporal modulation parameter being a useful time, a guard interval, or a repetition period of OFDM symbols of said OFDM signal, wherein: a plurality of demodulation attempts of said OFDM signal are carried out using a plurality of respective values of the temporal parameter, the OFDM signal being demodulated in base band by means of a demodulation frequency, then sampled at a frequency greater than a Nyquist frequency to obtain a sequence of samples; said samples are corrected by a phase offset (Δφ) corresponding to a frequency offset value (Δf) between a carrier frequency of an OFDM multiplex of the OFDM signal and the demodulation frequency; and, for each demodulation attempt, a cost function representative of the entropy of the demodulated signal is calculated, an estimate of said temporal parameter being obtained as a value of this parameter minimising said cost function.