随着电子侦察技术的快速发展,传统跳频体制通信系统易被截获和监听,如何提升系统的保密性和安全性成为通信系统的研究热点。为提高跳频调制信号的抗窃听性,提出了一种基于跳频体制的分数域调制方法,该方法分别将同步序列和数据序列进行加权分数阶傅里叶变换(WFRFT)调制,并通过跳频序列发生器产生跳频频率,实现同步信号和数据信号的跳频体制分数域调制。仿真结果表明,分数域调制信号的时频分布和功率谱特性与传统跳频信号相类似,时域特性为传统信号时频域的叠加,星座图特性发生旋转和裂变,可有效提高抗扫描性和抗窃听性。

With the rapid development of the electronic reconnaissance technology, the traditional frequency hopping communication system (FHSS) was easy to be intercepted and monitored. How to improve the confidentiality and security of the communication system has been the research hotspot. In order to improve the anti-eavesdropping performance of FHSS, a fractional domain modulation method based on frequency hopping system was proposed. In this method, the synchronization sequence and data sequence are modulated through weighted fractional Fourier transform (WFRFT) respectively, meanwhile the FHSS frequency is generated by the frequency hopping sequence generator to realize the fractional domain modulation of synchronization signal and data signal. The simulation results show that the time-frequency distribution and power spectrum density characteristics of the fractional domain modulation FHSS signal is similarly with the traditional FHSS signal, and the time domain characteristics are the superposition of the time domain signal and the frequency domain signal, the constellation characteristics are rotated and fissioned, which can effectively improve the anti-scanning and anti-eavesdropping performance of the signal.