【摘要】 利用Oppenheim的混沌伪装方案对混沌系统的频率特性进行了分析.以Lorenz混沌系统为例,进行了频率特性的数值模拟,得到了系统的同步效率-频率特性、放大系数-频率特性和相位-频率特性的关系曲线及输入信号幅度与同步效率的关系.研究发现,混沌系统频率特性的变化主要发生在输入信号的频率位于混沌系统频带内的情况下;输入信号幅度的大小,不影响输出信号的失真.这一研究结果表明,Oppenheim的混沌伪装方案不适用于保密通信.该混沌系统频率特性的分析方法不仅对Lorenz混沌系统适用,而且也适用于其他非线性系统.更多还原

【Abstract】 The frequency characteristics of chaotic system are studied by using Oppenheim’s chaotic masking. The characteristics about the synchronous efficiencyfrequency, the phasefrequency, the amplification coefficientfrequency, and the synchronous efficiencyamplitude are obtained through the frequency characteristic simulation of Lorenz chaotic system. It is found that the change of the frequency characteristics of chaotic system occurs mainly at the frequency band of the chaotic system, in which the intput signal exists. The amplitude of the input signal doesn’t influence the distortion of the output signal when masking signal is extracted by Oppenheim’s chaotic masking. It is concluded that Oppenheim’s chaotic masking is not suitable for secure communication. This analyzing method of the frequency characteristics of chaotic system is applicable to Lorenz chaotic system as well as other nonlinear systems.更多还原