一种基于叠加弱能量训练序列的OFDM时间同步算法

针对正交频分复用(orthogonal frequency division multiplexing,OFDM)系统对定时误差敏感,从叠加训练序列结构出发,提出了一种弱能量训练序列.该训练序列只叠加在循环前缀上,且比普通的重复结构训练序列能量要低,能降低由于叠加训练序列对系统误码率的影响,还能利用训练序列的结构特点降低相关峰值旁瓣对同步判决的影响,提高了时间同步的准确率.在低信噪比时采用该训练序列结构,同步准确率高于采用普通重复结构训练序列的同步方法,最后通过计算机仿真验证了该方法的有效性.

A timing synchronization algorithm based on superimposed weak power training sequence in OFDM systems

Timing error sensitivity is the characteristic of orthogonal frequency division multiplexing (OFDM) system. Using superimposed training sequence, a novel weak power training sequence was proposed. The training sequence, superimposed on the cyclic prefix, has lower power than the reduplicate structure training sequence. The method can reduce the bit error rate of the system affected by the superimposed training sequence. It can make the sidelobe of the correlation lower and improve the timing synchronization accuracy by using the structural characteristic. The timing synchronization accuracy using the structure proposed at the low SNR is higher than that of the reduplicate structure. The performance of the method is checked by simulation.