用周期循环检测算法检测频谱：

首先运行a.m程序，通过此程序运算得出循环频率a值；

再运行zhouqi.m程序，对a值进行确定，通过周期循环算法对信号进行检测；

-Cycle detection algorithm to detect:

First run the am program cycle frequency a value obtained through this program operations　

Then run zhouqi.m program to a value determined by the cycle algorithm of signal detection