A Novel Postfix Synchronization Method for OFDM Systems

This paper presents a novel synchronization method for OFDM systems that uses preambles containing two identical training parts followed by a flipped postfix (FlP). Specifically, the proposed preamble for AWGN channels consists of a flipped cyclic prefix (FCP) and two identical training parts followed by a FlP The preamble for ISI and fading channels is similar except that the FCP is replaced by a zero padding prefix (ZPP). By using these FlP-based preambles, the accuracy of the timing offset estimator is highly improved without increasing the computation complexity. Performance of the proposed method is evaluated by simulation over AWGN, ISI and fading channels in terms of the mean and variance of the time offset and carrier frequency offset (CFO) estimators. Results show the new time offset estimator has a quite small variance and its mean value is quite close to the exact start point. Comparison to Schmidl-Cox and Minn´s classical synchronization methods illustrates the advantages of the proposed method.