Kaiser-滤波器.doc

clear;close all z1,fs,bits=wavread(C:UsersLikfireDesktop录音2.wav);%sound(z1,fs,bits); n=0:8191;y1=z1(1:8192);Y1=fft(y1); %滤波前%Kaiser低通滤波%fp=1000;fc=1200;As=100;Ap=1;Fs=8000; wc=2*pi*fc/Fs; wp=2*pi*fp/Fs; B=wc-wp; %过渡带宽度beta=0.112*(As-8.7); M=ceil(As-8)/2.285/B);wp=(wp+wc)/2/pi;b=fir1(M,wp,kaiser(M+1,beta); figure; h1,w1=freqz(b,1);plot(w1/(2*pi)*Fs,20*log10(abs(h1);xlabel(频率/Hz);ylabel(幅值);x=fftfilt(b,z1); X=fft(x,8192); %滤波后%-%figure; subplot(2,2,1);plot(n,Y1);axis(0 10000 -100 100)title(滤波前信号频谱); subplot(2,2,2);plot(n,X);title(滤波后信号频谱); subplot(2,2,3);plot(z1);title(滤波前信号波形); subplot(2,2,4);plot(x);title(滤波后信号波形);sound(x,fs,bits); %clear;close all z1,fs,bits=wavread(C:UsersLikfireDesktop录音2.wav)%sound(z1,fs,bits); n=0:16383;y1=z1(1:16384);Y1=fft(y1);%Kaiser高通滤波%fp=4800;fc=5000;As=100;Ap=1;Fs=16000;wc=2*pi*fc/Fs; wp=2*pi*fp/Fs;wdel=wc-wp;beta=0.112*(As-8.7);N=ceil(As-8)/2.285/wdel);wn= kaiser(N,beta); ws=(wp+wc)/2/pi;b=fir1(N-1,ws,high,wn); h,w=freqz(b,1);plot(w/(2*pi)*Fs,20*log10(abs(h);xlabel(频率/Hz);ylabel(幅值); x=fftfilt(b,z1);X=fft(x,16384); figure;subplot(2,2,1);plot(n,Y1);title(滤波前信号频谱);subplot(2,2,2);plot(n,X);title(滤波后信号频谱);subplot(2,2,3);plot(z1);title(滤波前信号波形);subplot(2,2,4);plot(x);title(滤波后信号波形);sound(x,fs,bits);clear;close all;z1,fs,bits=wavread(C:UsersLikfireDesktop录音2.wav);%sound(z1,fs,bits);n=(0:8191);y1=z1(1:8192);Y1=fft(y1);%Kaiser带通滤波%fp1=1200;fp2=3000;fc1=1000;fc2=3200;As=100;Ap=1;Fs=8000;wp1=2*pi*fp1/Fs;wc1=2*pi*fc1/Fs; wp2=2*pi*fp2/Fs; wc2=2*pi*fc2/Fs;wdel=wp1-wc1;beta=0.112*(As-8.7);N=ceil(As-8)/2.285/wdel);ws =(wp1+wc1)/2/pi,(wp2+wc2)/2/pi;wn= kaiser(N+1,beta); b=fir1(N,ws,wn); h1,w1=freqz(b,1);plot(w1/(2*pi)*Fs,20*log10(abs(h1);xlabel(频率/Hz);ylabel(幅值); x=fftfilt(b,z1);X=fft(x,8192);figure(2); subplot(2,2,1);plot(n,Y1);title(滤波前信号频谱); subplot(2,2,2);plot(n,X);title(滤波后信号频谱)