双信道光混沌通信系统的理论模型及性能研究

Theoretical model and characteristics investigations of dual-channeloptical chaotic communication system

针对一种新型的双信道光混沌通信系统实验方案,建立了描述其工作特性的理论模型;通过数值模拟结果与报道的实验结果的比较,证实了该理论模型的合理性.利用该模型,基于小信号微扰理论,推导出了激光器传输函数的表达式;研究了信号能在系统中很好传递对系统参量的要求;定量地分析了信道干扰对系统同步性能的影响.对250MHz的调制信号在系统中的传输和解调进行了数值研究,结果表明,信号在传输过程中能得到很好的隐藏,且在输出端易于解调.

A theoretical model characterizing a recent experiment of dual-channel optical chaotic communication has been presented, and is proved to be reasonable by comparing the numerical simulation with the experimental results. After deducing the transmission function of semiconductor laser by small-signal analysis, how to reasonably select the system parameters in order to realize the effective transmission of signal has been specified. Moreover, the cross talk between two channels has been analyzed quantitatively. For a 250MHz modulation message, the numerical simulation shows that it can be hidden efficiently during the transmission in the system and decoded easily.