基于重发机制的PI-DCSK调制技术的设计

针对在DCSK（Differential Chaos Shift Keying）混沌通信系统中因信道加性噪声而引起的失真问题，在DCSK系统的基础上，提出一种改进的混沌键控系统方案——PI-DCSK（PhaseInversion Differential ChaosShift Keying）混沌通信系统。根据DCSK系统的调制信息信号和参考信号的延时重发机制，PI-DCSK系统接收端在半码元周期内对接收信号进行相位倒置相关解调，降低了码元周期内重相关性相邻噪声的干扰，在相同信噪比情况下可有效降低DCSK调制系统的误码率。仿真结果表明，在码元周期内相邻噪声相关系数较大、信噪比较低的情况下，PI-DCSK调制系统误码率明显低于DCSK系统。

Design of PI-DCSK Modulation Technology Based on Retransmission Mechanism

To reduce distortion due to AWGN （Additive White Gaussian Noise） in transmission channel of DCSK （Differential Chaos Shift Keying） chaotic communication system, an improved system scheme was proposed Which is called PI-DCSK （Phase Inversion Differential Chaos Shift Keying ） chaotic communication system based on DCSK modulation system. According to the delay retransmission mechanism of information signal and reference signal had a half-symbol period delay at the transmitter in the DCSK system; then at the PI-DCSK receiver the phase inversion correlated demodulation during half-symbol period for received signal was exploited. By the fact that the adjacent noises within a symbol period in the channel was correlated, the proposed scheme could reduce the adjacent noise interference obviously and further decrease the bit error rate of DCSK modulation system with the same SNR （Signal to Noise Ratio）. Simulation results show that PI-DCSK system performance is better than DCSK system, especially in larger correlation coefficient, and the lower SNR condition.