A joint estimation algorithm of symbol timing and carrier offset in OFDM systems

摘要

An adaptive joint estimation algorithm of carrier frequency, carrier phase and symbol timing offset in OFDM systems is proposed. The synchronization can be divided into three steps. Firstly, the carrier frequency is estimated and corrected based on the cyclic prefix before the OFDM demodulation (FFT). Secondly, carrier phase synchronization and the timing acquisition can be implemented simultaneously based on the pilot symbols after OFDM demodulation. Thirdly, the above coarse timing algorithm acquires synchronization alignment to within several samples, then the fine timing algorithm estimates and corrects this residual timing offset. Simulations show the carrier frequency and phase estimator has a good performance, the timing algorithm can acquire the synchronization position and eliminate the effect of residual timing offset completely. The advantage of this algorithm is simple computation and only a little resource loss due to pilot symbols.