Efficient Time and Frequency Offset Estimation for OFDM Based MSS Systems

We consider efficient time and frequency synchronization using one training symbol with a constant envelop for orthogonal frequency division multiplexing (OFDM) based mobile satellite service (MSS) systems over Rician fading channel. We propose a new preamble corresponding to only one OFDM symbol, where multiplication of a value of one sample and a conjugated value of its neighboring sample becomes CAZAC sequence in time domain, and present joint frame/symbol timing and frequency synchronization method through only time domain processing based on this preamble. By the proposed method, the accuracy of the frame/symbol timing synchronization is obviously improved and an estimation range of the frequency offset normalized by the carrier spacing is extremely extended to one half of the total signal bandwidth with only one preamble symbol which has lower peak to average power ratio (PAPR) than those in conventional schemes. The performance of the proposed method is shown by simulation.