FFT实现信号的检测与同步，使用FFT做相关运算，大大缩短了了同步的复杂度和时间，这里是主代码，其他模块QUARTUS中自带有IP核，直接调用就是了-FFT signal detection and synchronization, do the relevant calculations using FFT, greatly reducing the complexity and time synchronization, here is the main code IP core comes