根据 fir 滤波器的公式 y(n)=∑h(m)x(n—m);(m: 0~(N-1))
利用 MATLAB 产生滤波器系数(h(n))并归一化,下面为一个 LP 滤波算法void filter(void){uint16 i,j;fp32 sum;int16 x1[2030];fp32 h[19]={ -0
0027, -0
0025, 0
0050, 0
0157, —0
0000, —0
0471, -0
0482, 0
0838, 0
2953, 0
4013,0
2953, 0
0838, —0
0482, —0
0471, -0
0000,0
0157, 0
0050, -0
0025, —0
0027};for(i=0;i 15; } }}乘法器使用次数:N*n3
倒序法:(输入输出可以是同一量)void fir(short x[], short h[], short y[]){ int i,j; long long sum; for (j = N; j 〉 0; j——) { sum = 0; for (i = n; i 〉 0; i—-) sum += x[j—i] * h[i]; y[j] = sum >> 15; }}#include #include 〈math
h>#define true 1#define false 0#define n 8#define bufsize 100 /* the buffer size is 100 *//* global declarations */int in_buffer[bufsize]; /* processing data buffers */int o