无信号间干扰的相关延迟-差分混沌移位键控混沌通信方案

Correlation delay-DCSK chaotic communication scheme without inter-signal interference

现有的差分混沌移位键控(DCSK)通信系统主要的缺陷是传输速率较低,为此提出了一种无信号间干扰的相关延迟差分混沌移位键控(CD-DCSK)通信方案。在发送端,由正交信号发生器产生两路正交混沌信号,并经符号函数归一化以保持发送信号的能量恒定,然后,这两路混沌信号与其延迟不同时间间隔后的混沌信号分别调制1 bit数据信息形成一帧发送信号。在解调端,采用相关解调提取数据信息,通过检测相关器输出结果的符号恢复信息比特。利用高斯近似(GA)法分析了系统在加性高斯白噪声(AWGN)信道下的理论误码率(BER)性能,并与经典的混沌通信系统进行了比较。分析及实验结果表明:与DCSK系统相比,无信号间干扰的CD-DCSK系统的传输速率提升了50个百分点,且其误码性能优于相关延迟移位键控(CDSK)系统。

The major drawback of existing Differential Chaos Shift Keying (DCSK) communication system is low transmission rate. To solve the problem,a Correlation Delay-Differential Chaos Shift Keying (CD-DCSK) communication scheme without inter-signal interference was proposed. At the transmitting side,two orthogonal chaotic signals were generated by an orthogonal signal generator and normalized by the sign function to keep the energy of the transmitted signal constant. Then,two chaotic signals and their chaotic signals with different delay time intervals were respectively modulated by 1 bit data information to form a frame of transmission signal. At the demodulation side,correlation demodulation was used to extract data information and the information bits were recovered by detecting the sign of correlator output. The theoretical Bit Error Rate (BER) performance of system under Additive White Gaussian Noise (AWGN) channel was analyzed by using Gaussian Approximation (GA) method,and was compared with classical chaotic communication systems. The performance analysis and experimental results indicate that,compared with DCSK system,the transmission rate of CD-DCSK system without inter-signal interference increases by 50 percentage points,and the BER performance of the proposed system is better than that of Correlation Delay Shift Keying (CDSK) system.