发生在时变系统中所展示的频谱扩展。待仿真系统是一个简单系统，其中系统的代桶输入是一个形为x(t)=cos[2π(f0+f1)t]的“音频”。-Occurred in the time-varying system in spread spectrum display. Subject to the simulation system is a simple system in which the generation of the system input is a bucket-shaped