FM-DCSK混沌通信系统的原型设计与研究

文中设计了一个基于调频差分混沌键控通信系统的原型,并实现了部分关键电路。系统发射部分由Lorenz混沌电路和调频电路产生混沌调频载波信号,经采样后在FPGA中实现差分延时和调制;接收部分基于非相干相关法,位同步模块采用相关值与能量比值作为定时测度,通过设置门限和滑动搜索窗口寻找初始同步,而后引入数字锁相环进行相关峰值跟踪和位同步调整。建模验证结果表明,系统非相干解调的误码率指标接近理论分析值,仅相差0.2 dB。

Prototype Design and Research of FM-DCSK Chaotic Communication System

This paper presents a prototype of chaotic communication system based on FM-DCSK modulation scheme and realizes partial key circuits of the prototype. At the transmitter, the FM-DCSK modulator generates wideband FM signal by the Lorenz circuit and frequency modulation circuit. The FM signal is converted to digital signal to implement the delay line and modulation on FPGAs. At the receiver, based on non-coherent correlation demodula- tion, bit synchronization is carried out by the following three steps： first define the ratio of correlation and energy, as timing measure, then set a threshold and slide the integration window to acquire the start time of a bit, and finally track the max of the correlation and correct the timing error via digital PLL. Simulations show that the BER performance of the prototype is close to the thesis, just 0. 2 dB degraded.