An highly-effective time and frequency synchronization scheme for OFDM wireless communication system

A time and frequency synchronization scheme for OFDM wireless communication system based on a novel training sequence is proposed. The training sequence includes only one OFDM symbol. It is centro-symmetric and only modulated on even sub-carriers, the second half of which is duplicate of the first half. So, timing metric can avoid peak plateau, and frequency offset estimator can effectively resist multi-path fading. Besides, through conjugate correlation operation between every two adjacent even sub-carriers, one cycle m-sequence can be obtained. Taking advantage of real-value and two-value correlation characteristics of m-sequence, integer frequency offset estimator can show impulse feature with largely decreased computational complexity. Computer simulation shows, compared with the classic synchronization scheme, the proposed one can realize precise timing capture and the whole base-band frequency offset estimation under multi-path fading environment with only one symbol. It's of high efficiency, low complexity, and fits low SNR environment.