FFT实现的是一种卷积运算，该运算实现的方法由DSP通过编程实现，可以直接用的源代码，经过就行，通过软件实现，通过软件实现-The realization of FFT is a kind of convolution computation, the method to realize the operation by the DSP through programming, can be directly in the source code, through it, through the