Abstract: An improved frequency offset estimation method used in high speed wireless environment is proposed. A training sequence frame is made of Zadoff-Chu sequences with four times repetition. First, the received signal is correlated with local training sequences to eliminate the influence of training sequence. Fine frequency synchronization is achieved by taking two times of frequency offset estimation. The proposed method has good estimation accuracy and large estimation span. All processes of the frequency offset estimation are taken before FFT, leading to a saving of the system synchronization time and reduction of the system complexity. Simulations in AWGN and Rayleigh channels verify validity of the technique.

Key words: frequency offset estimation, Zadoff-Chu sequence
, OFDM