A method for OFDM synchronizations using cyclic differential PN sequences

A new method of OFDM synchronizations is presented. The proposed method is based on two training PN symbols that are cyclic differential in time domain and frequency domain, with which we can not only obtain symbol-timing estimation, carrier frequency-offset estimation and channel estimation, but also the uncertainty caused by plateau in S&C method be removed. The point is that the time symbol-timing estimation can be kept even though the SNR is specially low, so the merit makes the proposed method useful for OFDM synchronizations in bad communications environment.