基于FRFT的CSS系统同步设计与实现

Design and Implementation of Synchronization in CSS System Based on Fractional Fourier Transform

基于分数阶傅里叶变换的Chirp扩频是一种新型非相干的线性调频通信系统,其特点在于同步模块简化易实现跳频功能,形成具有更强抗干扰能力的二维扩频抗干扰。通过分析系统的同步需求,设计了一种基于前导序列检测和包络检测的一体化同步方案。该方案在较低信噪比条件下正常工作,收敛时间比BPSK基带信号缩短一半。通过在DSP器件上的系统实现验证了方案的正确性和可行性,该方案对其他非相干系统的同步具有借鉴意义。

CSS based on FRFT is a new type of non-coherent linear frequency modulation communication system featured with simple synchronization and ease implementation of frequency hopping of two-dimensional anti-jamming. Design of an integrative scheme is presented, based on detection of leader character and envelope through the analysis of the system synchronization requirements. Computer simulations indicate that, the synchronization method can work properly under low signal and noise ratio, which converges twice as faster as BPSK base band signal. Finally, the scheme is validated through the implementation on DSP device.