MATLAB數(shù)字濾波器程序 Hamming窗帶通濾波器

ID:679278 · 發(fā)表于 2020-1-2 00:48

Hamming窗帶通濾波器

%Hamming窗帶通濾波器的設(shè)計(jì)

fp1=200;fc1=100;

fpu=8000;fcu=10000;

wlp=2*pi*fp1/FS;wls=2*pi*fc1/FS;

wup=2*pi*fpu/FS;wus=2*pi*fcu/FS;

Bt=wlp-wls;

N0=ceil(6.6*pi/Bt);

N=N0+mod(N0+1,2);

wc=[(wls+wlp)/2/pi,(wus+wup)/2/pi];

hn=fir1(N-1,wc,hamming(N));

[h1,w1] = freqz(hn,1,512,FS);

figure(4);

subplot(2,1,1);plot(hn);axis ([700 900 -0.5 1]);xlabel('n');ylabel('幅度');title('hamming窗帶通時(shí)域圖');

subplot(2,1,2);plot(w1,abs(h1));title('hamming窗帶通頻譜圖');axis tight;xlabel('f/Hz');ylabel('耗損(dB)');

pause(1)；

%對(duì)濾波后的信號(hào)進(jìn)行分析變換

X=conv(hn,x);

n2=length(X);

n2=2^nextpow2(n2);

f=FS*(0:n2/2-1)/n2;

figure(5);subplot(2,1,1);plot(X);title('濾波后的信號(hào)時(shí)域圖');axis tight;xlabel('f/Hz');ylabel('幅度');

X1=fft(X,n2);subplot(2,1,2);plot(f,abs(X1(1:n2/2))); axis tight;xlabel('f/Hz');ylabel('幅度');title('濾波后的信號(hào)頻譜');

sound(X,FS);

圖1 語(yǔ)音信號(hào)

圖2 加噪信號(hào)

圖3 濾波信號(hào)

Hamming窗帶通濾波器程序

%hamming帶通
%產(chǎn)生語(yǔ)音信號(hào)
clc;
Fs=48000;
[x,FS]=audioread('C:\Users\SDHH\Documents\錄音\luyin.m4a');
x=x(:,1);
sound(x,FS);
%頻譜分析
n=length(x);
n=2^nextpow2(n); %選取變換的點(diǎn)數(shù)
t=(0:(n-1))/FS;%計(jì)算音頻信號(hào)的長(zhǎng)度
x=[x',zeros(1,n-length(x))]';
figure(1);
subplot(2,1,1); plot(t,x); axis tight; title('語(yǔ)音信號(hào)時(shí)域圖'); xlabel('t/s');ylabel('幅度')
y=fft(x,n); %對(duì)n點(diǎn)進(jìn)行傅里葉變換到頻域
f=FS*(0:n/2-1)/n; % 對(duì)應(yīng)點(diǎn)的頻率
subplot(2,1,2);
plot(f,abs(y(1:n/2)));axis tight;xlabel('f/Hz');ylabel('幅度');title('語(yǔ)音信號(hào)頻域圖');
pause(2.5);
%###########################################################################################################
%產(chǎn)生噪聲信號(hào)
noise=1*sin(2*pi*20000*t)+1*sin(2*pi*200*t);
Noise=fft(noise,n);%對(duì)n點(diǎn)進(jìn)行傅里葉變換到頻域
figure(2);
subplot(2,1,1);plot(t,noise);axis tight;xlabel('t/s');ylabel('幅度');title('加噪聲信號(hào)時(shí)域圖');
subplot(2,1,2)
plot(f,abs(Noise(1:n/2))); %加噪語(yǔ)音信號(hào)的頻譜圖
axis axis([1 40000 1 50000] );xlabel('f/Hz');ylabel('幅度');title('加噪語(yǔ)音信號(hào)頻譜圖');
pause(1);
%#############################################################################################################
x1=x+noise'; %將兩個(gè)信號(hào)疊加成一個(gè)新的信號(hào)——加噪聲處理
sound(x1,FS);
%加噪后頻譜分析
noise_1=fft(x1,n);%對(duì)n點(diǎn)進(jìn)行傅里葉變換到頻域
figure(3);
subplot(2,1,1)
plot(t,x1);axis tight;xlabel('t/s');ylabel('幅度');title('加噪聲信號(hào)時(shí)域圖');
subplot(2,1,2)
plot(f,abs(noise_1(1:n/2))); %加噪語(yǔ)音信號(hào)的頻譜圖
axis ([1 30000 1 4000] ;xlabel('f/Hz');ylabel('幅度');title('加噪語(yǔ)音信號(hào)頻譜圖');
pause(2.5);
%#################################################################################################################
%hamming窗帶通濾波器設(shè)計(jì)
fp1=200;fc1=100;
fpu=8000;fcu=10000;
wlp=2*pi*fp1/FS;wls=2*pi*fc1/FS;
wup=2*pi*fpu/FS;wus=2*pi*fcu/FS;
Bt=wlp-wls;
N0=ceil(6.6*pi/Bt);
N=N0+mod(N0+1,2);
wc=[(wls+wlp)/2/pi,(wus+wup)/2/pi];
hn=fir1(N-1,wc,hamming(N));
[h1,w1] = freqz(hn,1,512,FS);
figure(4);
subplot(2,1,1);plot(hn);axis tight;xlabel('n');ylabel('幅度');title('hamming窗帶通時(shí)域圖');
subplot(2,1,2);plot(w1,abs(h1));title('hamming窗帶通頻譜圖');axis ([700 900 -0.5 1]);xlabel('f/Hz');ylabel('耗損(dB)');
pause(1);
%#################################################################################################################
%對(duì)濾波后的信號(hào)進(jìn)行分析變換
X=conv(hn,x);
n2=length(X);
n2=2^nextpow2(n2);
f=FS*(0:n2/2-1)/n2;
figure(5);subplot(2,1,1);plot(X);title('濾波后的信號(hào)時(shí)域圖');axis tight;xlabel('f/Hz');ylabel('幅度');
X1=fft(X,n2);subplot(2,1,2);plot(f,abs(X1(1:n2/2))); axis tight;xlabel('f/Hz');ylabel('幅度');title('濾波后的信號(hào)頻譜');
sound(X,FS);

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MATLAB數(shù)字濾波器程序 Hamming窗帶通濾波器

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