A Novel Joint Algorithm of Timing and Carrier Frequency Acquisition for Burst OFDM System

This paper describes a novel joint acquisition algorithm of timing and carrier frequency for burst orthogonal frequency division multiplexing (OFDM) transmission system. Only one training symbol is used for symbol timing recovery and carrier frequency acquisition, the overhead is small, and so the proposed method is suitable for burst OFDM transmission system. The realization of timing recovery and carrier frequency acquisition is achieved in time domain, and the timing offset of frame and symbol can be estimated simultaneously, thus the complexity of synchronization is reduced. As autocorrelation is used, timing recovery of the proposed algorithm is robust against carrier frequency offsets. Comparing to the OFDM system timing recovery algorithm proposed at foretime, authors’ method avoid the phenomenon of plateau or multi-peak in timing metric. Ever for very low single-to-noise ratio, a dominant peak could be present in timing metric while the proposed algorithm is used. Moreover, the repetition of the reference symbols in training symbol extends the range of carrier frequency acquisition, and so the operation rang completely satisfy the requirement of the bust OFDM transmission system. In order to improve the frequency estimation, averaging is applied. Simulations show that the proposed algorithm can estimate the timing offset quickly and exactly and the coarse frequency offset estimator operating range can fulfill a worst-case scenario of carrier frequency offset for bust OFDM transmission system even for a frequency selective fading channels.