Chaotic Secure Communication Based on Single Feedback Phase Modulation and Channel Transmission

In this paper, a chaotic secure communication system based on single feedback phase modulation is designed, in which phase modulation of feedback light is carried out by using random square wave as communication key, and chaotic light with wide spectrum and no delay signature is generated. Message is modulated into chaotic carrier at transmitter end, through chaotic synchronization and comparison, original message is successfully demodulated at receiver end. In addition, two kinds of message encryption methods, chaos modulation and chaos masking, are studied by comparing synchronization and bit error rate under different channel signal-to-noise rate.