首先研究了非相干光反馈同步系统内部参数失配对系统同步性能的影响,并与相干光反馈的完全同步系统以及广义同步系统进行了比较,其次研究了非相干光反馈采用三种不同的信号调制解调方式(CSK,CMS,ACM),对三种不同频率(250MHz,2.5GHz和12.5GHz)的信号进行了调制解调。通过MATLAB仿真实验可知,非相干光反馈混沌同步系统相对于相干光反馈完全同步系统更易于实现,同时保留了一定的对参数失配的敏感特性,从而确保了该系统比相干光反馈广义同步具有更高的安全性;在信号解调时,CSK只能解调出250MHz信号,CMS能解调出2.5GHz信号,ACM能够解调出高达12.5GHz的信号。
Based on the theoretical model of the synchronization system with incoherent optical feedback, the effects of the internal parameter mismatch on the synchronized characteristics and message encoding and decoding of the chaotic system have been investigated. The results show that the chaotic system with incoherent optical feedback can be realized more easily than the completely synchronized system, and has higher security than the injection locking synchronization system, When the message bit rate is 250 Mbit/s,chaos shift keying (CSK) and chaos masking (CMS) can decode the message easily in the receiver, when the bit rate increases to 2.5 Gbit/s, CSK can not decode the message and the quality of decoding message for CMS becomes bad,and finally when the frequency increases to 12.5 GHz,both CSK and CMS can not decode the message,but additive chaos modulation (ACM) can decode the message easily even at this high bit rate.