firbfilt.m

使用Matlab实现了FIR与IIR滤波器

function [ output_args ] = Untitled1( input_args )
%UNTITLED1 Summary of this function goes here
%  Detailed explanation goes here
[y,ft,bits]=wavread('hello.wav');
subplot(2,2,1);
plot(y);
xlabel('Time Index t');
ylabel('Amplitude');
title('原始时域图象');grid;
subplot(2,2,2);
plot(abs(fft(y)));
xlabel('Frequence Index w');
ylabel('Amplitude');
title('原始频域图象');grid;
fcutsb=[1000 1200 3000 3200];
magsb = [0 1 0];
devsb = [10^(-100/20),(1-10^(-1/20)),10^(-100/20)];
[Nb,Wnb,betab,ftypeb] = kaiserord(fcutsb,magsb,devsb,ft);
kwb = kaiser(Nb+1,betab);
bb = fir1(Nb,Wnb,kwb);
vb=fftfilt(bb,y);
subplot(2,2,3);
plot(vb);
xlabel('Time Index t');
ylabel('Amplitude');
title('FIR带通滤波时域图象');grid;
subplot(2,2,4);
plot(abs(fft(vb)));
xlabel('Frequence Index w');
ylabel('Amplitude');
title('带通滤波后频域图象');grid;
sound(vb,ft,bits);