A Novel and Low-Complexity Fine-Timing Synchronization  Method for OFDM Systems

This paper proposes a new fine-timing synchronization method for OFDM systems based on repeated-conjugated-symmetric preamble. The proposed timing method utilizes delayed correlation, delayed product and symmetric correlation to design timing metric 1 and timing metric 2. Firstly, timing metric 2 is used to make initial timing synchronization according to its maximum value, and then timing metric 1 is used to find the first tap of multipah channel. Compared to the conventional timing synchronization method based on the conjugated-symmetric correlation, the proposed method has a low computational load and eliminates the timing ambiguity of conventional synchronization method caused by side peaks of the timing metric. Moreover, the proposed method can decrease efficiently the timing offset in multipath channel. Simulation results in 6-path channel for typical urban show that the proposed method achieves accurate timing performance. The proposed method is adapted to an OFDM system using either a continuous transmission or a burst operation.