Abstract: A new residual carrier frequency offset(RCFO) estimation method is proposed for orthogonal frequency division multiplexing(OFDM) systems in wireless fading channel. In the method, the SNRs on all the sub-carriers are estimated and used to select high quality sub-channels. And then the hard decision data on the high quality sub-channels are combined with the pilot data to estimate the RCFO. The new method has the advantages of both pilot tone assisted(PTA) and decision directed(DD) methods. Simulation results show that the estimation accuracy of the proposed method has an improvement at least 4 times better than that of the PTA method, and at least 21 times better than that of the DD method when the SNR is more than 10dB.

Key words: orthogonal frequency division multiplexing(OFDM), residual carrier frequency offset(RCFO), pilot tone assisted(PTA) method, decision directed(DD) method