Frequency synchronization algorithms for OFDM systems suitable for communication over frequency selective fading channels

In this paper, the problem of carrier synchronization of OFDM systems in the presence of a substantial frequency offset is considered. New frequency estimation algorithms for the data aided (DA) mode are presented. The resulting two stage structure is able to cope with frequency offsets in the order of multiples of the spacing between subchannels. Key features of the novel scheme-which are presented in terms of estimation error variances, the required amount of training symbols and the computational load-ensure high speed synchronization with negligible decoder performance degradation at a low implementation effort