跳频通信中一种结合干扰预处理的平方定时同步算法

为了提高跳频通信中定时同步算法的准确性，设计了一种结合干扰预处理的跳频信号定时同步算法。首先对解跳后信号在时域完成基于能量的自适应门限的干扰检测，并根据检测结果将受干扰信号进行置零预处理；其次对预处理后的信号采用平方法进行定时误差估计；最后根据估计结果内插完成定时恢复。结果表明，提出的改进算法选取长度为200跳的符号，在干扰相对带宽为30%、干信比为10 dB、信噪比为5 dB、时钟稳定度为1×10^-6的条件下，进行干扰预处理后定时，归一化定时误差的方差为0.000 75，满足跳频系统解调性能损失小于0.5 dB的要求。设计方法提高了干扰条件下平方法定时的准确性，在跳频通信抗干扰应用中有一定的参考价值。

A square timing synchronization algorithm combined with interference preprocessing in frequency hopping communication

In order to improve the accuracy of timing synchronization algorithm in FH communication, a timing synchronization algorithm of FH signal combined with interference preprocessing was designed. Firstly, the interference detection based on the adaptive threshold of energy was completed in the time domain, and the interfered signal was preprocessed according to the detection results. Secondly, the square method was used to estimate the timing error of the pretreated signal. Finally, the timing recovery was completed by interpolation according to the estimation results. The results show that the proposed improved algorithm selects symbols with a length of 200 hops is timed after interference preprocessing, with the relative interference bandwidth of 30%, the signal to interference ratio of 10 dB, the signal to noise ratio of 5 dB, and the clock stability of 1×10-6, and the variance of normalized timing error is 0000 75, which meets the requirement that the demodulation performance loss of frequency hopping system is less than 05 dB. The design method improves the accuracy of squared timing under interference conditions, and has certain reference value in the application of frequency hopping communication anti-interference.