针对传统定时同步算法的副峰干扰和低信噪比(SNR)下定时不稳定的问题,提出了一种基于伪随机噪声(PN)序列的定时同步算法。根据PN序列良好的延迟相关性和对称相关性,重新设计了训练序列的结构,并优化了定时度量函数的计算方法。仿真结果表明,改进算法的定时度量估计曲线只存在一个峰值,消除了副峰干扰。在循环前缀为四分之一符号长度与低SNR的情况下,仍可实现准确和稳定的定时。

A timing synchronization algorithm based on a pseudo-noise (PN) sequence is proposed aiming at the problems of sub-peak interference and timing instability at low signal-to-noise ratio (SNR) in the traditional timing synchronization algorithms. The structure of the training sequence is reconstructed and the calculation method of the timing measurement function is optimized by utilizing the good delay correlation and symmetric correlation of the PN sequence. The simulation results show that only one peak can be seen in the timing metric estimation curve and the sub-peaks are suppressed by using the proposed algorithm. The algorithm can realize accurate and stable timing synchronization, even when the length of the cyclic prefix is a quarter of the symbol length and the SNR is low.