Coarse frequency estimation in OFDM packet oriented systems

In this paper we derive a fast blind coarse frequency offset estimator for OFDM systems in frequency selective channels. The estimator takes advantage of the strong structure of the OFDM signal. In packet oriented systems, using the method of Schmild and Cox (see IEEE Trans. on Commun. vol.45, no.12, p.1613-21, Dec. 1997) for timing and fine frequency offset estimation, it is possible to obtain very accurate synchronization using only one known OFDM symbol transmitted at the beginning of the burst. In systems using a continuous stream of data this estimator can solve the ambiguity of multiples of the subcarrier spacing that produces a fine estimator based on cyclic extensions