A New Method for Timing Synchronization in OFDM Systems Based on Polyphase Sequences

This paper proposes a synchronization method with a preamble for IEEE 802.16 and other systems that use Orthogonal Frequency Division Multiplexing (OFDM). The preamble for synchronization is composed of two identical periods, which are polyphase codes, and have an autocorrelation function with one main peak and very small sub peaks. Using this signal repetition and autocorrelation, the correlation for symbol timing detection is calculated with a new metric. The proposed metric uses a filtering structure to find the accurate start point. Proposed method drastically improves the performance of timing synchronization, even with a very low SNR, in both AWGN and multipath fading Rayleigh channels.