coef_3.m

关于用matlab实现滤滤器中输入波形的采样点数

clear all;
close all;
Fp=15000;Fs=20000;Rp=0.5;Rs=40;
Fsample=50000;
Wp=2*Fp/Fsample;
Ws=2*Fs/Fsample;
[N,Wn]=ellipord(Wp,Ws,Rp,Rs);
N=2*ceil(N/2);
[b,a]=ellip(N,Rp,Rs,Wn);
[h,omega]=freqz(b,a,1024);
figure(10);
hh=plot(Fsample*omega/pi/2,2*log10(abs(h)+eps));
set(hh,'linewidth',3);
grid on;
kk=2^fix(15-log2(max(a)))-1;
A=round(a*kk);
B=round(b*kk);
[H,OMEGA]=freqz(B,A,1024);
HH=20*log10(abs(H)+eps);
hold on;
figure;
%plot(Fsample*OMEGA/pi/2,HH,'green');
hh=plot(Fsample*OMEGA/pi/2,HH-max(HH),'red');
set(hh,'linewidth',2);
hold off
streamr = fopen('C:\tic2xx\myprojects\IIR3\coef.h','w' );
fprintf(streamr ,  '        \n');
fprintf(streamr,'coefb4:     .sect    "coefb4" \n'  );
for j=0:4
    fprintf(streamr, '        .word   ');
    fprintf(streamr,'%d',B(5-j));
    fprintf(streamr, '        \n')
end;
for j=0:2
    fprintf(streamr, '        .word   ');
    fprintf(streamr,'    %d',A(5-j));
    fprintf(streamr, '        \n');
end;
fprintf(streamr, '        .word   ');
fprintf(streamr,'    %d',A(2));
fclose (streamr);