CCS FIR 滤波器设计
一、FIR滤波器设计
二、Matlab生成信号
fs = 4096;
N = 1024;
n = 0:N-1;
t = n/fs;
f1 = 50;
f2 = 500;
x1 = sin(2*pi*f1*t);
x2 = sin(2*pi*f2*t);
x = x1 + x2;
plot(t,x)
三、CCS编写滤波程序
#include <stdio.h>
#include <math.h>
#define pi 3.1415926
#define wLow 2*pi*fLow/fs
#define wHight 2*pi*fHight/fs
int fs=4096;
int fLow = 50;
int fHight = 1000;
short x[1024], h[16], y[1024];
const int BL = 16;
const double B[16] = {
-0.0001494509574467, 0.002115953581256,-0.007992452353463, 0.006817529310208,
0.02881270922583, -0.0839591788376, 0.0279713225981, 0.5263836313841,
0.5263836313841, 0.0279713225981, -0.0839591788376, 0.02881270922583,
0.006817529310208,-0.007992452353463, 0.002115953581256,-0.0001494509574467
};
void fir(const short x[restrict], const double h[restrict], short y[restrict],int n, int m)
{
int i, j;
int y0;
for (j = 0; j < m; j++)
{
for (i = 0; i < n; i++)
y0 += x[i + j] * h[i];
y[j] = y0;
}
}
int main(void)
{
int i;
for(i=0;i<1024;i++)
{
x[i] = 1024*sin(wLow*i) + 1024*sin(wHight*i);
}
fir(x,B,y,16,1000);
return 0;
}
四、滤波结果
1、滤波前的波形
2、滤波后的波形
