一种改进的跳频抗干扰定时同步算法

An Improved Frequency Hopping Anti-jamming Timing Synchronization Algorithm

跳频系统是抗干扰通信中一种常用的手段,定时同步方案设计需要考虑到系统特点,并且在干扰条件下具有良好性能;在对干扰条件下系统定时性能分析的基础上,针对传统CME检测算法计算复杂的问题,提出一种基于能量排序检测的平方定时同步算法;该算法首先对解跳后的信号进行能量检测,利用检测结果通过排序去除干扰后进行定时误差检测,最后通过内插恢复用于解调,无需多次迭代确定检测门限;仿真结果表明,改进算法与使用传统CME算法定时估计性能相当且能满足系统解调性能要求,使得计算量下降1/2;在不同干信比和不同干扰带宽下,归一化定时方差小于1×10^(-3),解调性能损失小于0.5 dB。

Frequency hopping system is a common means of anti-jamming communication.The design of timing synchronization scheme needs to consider the characteristics of the system and has good performance under interference conditions.Based on the timing performance analysis of the system under interference conditions,a square timing synchronization algorithm based on energy ordering detection is proposed to solve the computational complexity of traditional continuous mean excision(CME)detection method.The algorithm first detects the energy of the signal after de hopping,uses the detection results to remove the interference by sorting,and then performs the timing error detection.Finally,it is used for demodulation by interpolation recovery,which does not need multiple iterations to determine the detection threshold.The simulation results show that compared with traditional CME method,the improved algorithm has the same timing estimation performance,and can meet the demodulation performance requirements of the system,resulting in a 1/2 reduction in the computational effort;Under different interference signal ratios and interference bandwidths,the normalized timing variance is less than 1×10^(-3),and the demodulation performance loss is less than 0.5 dB.