cas_filter.cpp

c语言版各种fir滤波器的实现

/**********************************************
* Filename : cas_filter.CPP                   *
* Function : realization of FIR filter with   *
             cas structure                    *
*Parameter : (h) the coefficients of H(z)     *
			 (z) the inner state variables    *
			 (x) the input data               *
			 (y) the output data              *
			 (n) the number of factors of H(z)*
			 (m) the number of input data     *
**********************************************/

void cas_filter(float h[],float z[],float x[],float y[],int n,int m)
{
	int i,j;
	for(i=0;i<m;i++)
	{
		for(j=0;j<n;j++)
		{
			y[i]=h[3*j]*x[i]+z[2*j];
			z[2*j]=h[3*j+1]*x[i]+z[2*j+1];
			z[2*j+1]=h[3*j+2]*x[i];
			x[i]=y[i];
		}
	}
}