调制信号的识别，可以通过各种调制的功率谱不同来识别，但这种方法在小信噪比下，性能不好，通过循环功率谱来识别，仿真表明在小信噪比下有很好的性能-modulation signal identification, can be modulated through the power spectrum to identify different, but this approach in a small signal to noise ratio, poor performance, cycle po