混合SFH/DS扩频信号的跳频频率估计

Hopping Frequencies Estimation of Hybrid SFH and DS Spread Spectrum Signals

针对混合SFH/DS信号跳频频率估计问题,提出了对信号时频脊线进行动态聚类分析,初步确定跳频频率范围的方法;在此基础上根据混合SFH/DS信号的特点,在频率搜索范围内利用高阶循环累积量精确估计跳频频率。以SFH/DS-2、4PSK信号为例,证明了其四阶循环累积量仅在跳频频率处存在的结论,通过检测此循环频率实现了跳频频率的精确估计。该算法无需信号的先验信息,易于通信侦察接收机实现。仿真实验表明,该算法混合FH/DS信号跳频频率估计是十分有效的。

Aiming at the hopping frequencies estimation of hybrid SFH and DS （SFI-UDS） signals, a method was proposed to determine the hopping frequencies range roughly by the dynamic cluster analysis on signals＇time-frequency ridge line, on the basis of which, the hopping frequencies could be estimated by the high-order cyclic cumulants through the frequency seeking range according to the hybrid SFH/DS signals＇characteristics. SFH/DS-2, 4PSK signals were taken for example to prove the fact that the four-order cyclic cumulants existed only at the location of the hopping frequencies, so that whose estimation could be implemented by detecting the cyclo-frequencies. As the proposed method needed no prior information of signals, it was easy to implement for the reconnaissance receiver. And simulation indicates that the method is very effective for the hopping frequencies estimation of hybrid SFH and DS signals.