频谱校正与滤波器设计matlab程序

1、频谱校正与滤波器设计matlab程序1、数字滤波器Matlab程序代码如下：wc=(400/1000)*pi; w1=boxcar(81); w2=hamming(81);w3=hanning(81);n=1:1:81;hd=sin(wc*(n-41)./(pi*(n-41); hd(41)=wc/pi;h1=hd.*w1; h2=hd.*w2;h3=hd.*w3;mag1,rad=freqz(h1); mag2,rad=freqz(h2);mag3,rad=freqz(h3);figure(1); plot(rad,20*log10(abs(mag1);xlabel(Normalized F

2、requency(rad);ylabel(Normaliaed Magnitude(dB);axis(0,3,-80,0);title(矩形窗滤波器);grid on;figure(2);plot(rad,20*log10(abs(mag2);xlabel(Normalized Frequency(rad);ylabel(Normaliaed Magnitude(dB);axis(0,3,-80,0);title(hamming窗滤波器);grid on;figure(3);plot(rad,20*log10(abs(mag3);xlabel(Normalized Frequency(rad)

3、;ylabel(Normaliaed Magnitude(dB);axis(0,3,-80,0);title(hanning窗滤波器);grid on;输出结果如下：2、频谱校正（比值校正法）Matlab程序如下：functionZ=bizhi(x,fs,N,nx1,nx2,method)nx,mx=size(x);if mx=1, x=x;endnx,mx=size(x);if mxA(index+1); df=indsecL.*A(index-1)./(Amax+A(index-1)-(1-indsecL).*A(index+1)./(Amax+A(index+1); Z(1)=(inde

4、x-1-df)*ddf; Z(2)=Amax/sinc(df); Z(3)=(phmax+pi*df); end if (WindowType=2) indsecL=A(index-1)A(index+1); df=indsecL.*(2*A(index-1)-Amax)./(Amax+A(index-1)-(1-indsecL).*( 2*A(index+1)-Amax)./(Amax+A(index+1); Z(1)=(index-1-df)*ddf; Z(2)=(1-df2)*Amax/sinc(df); Z(3)=(phmax+pi*df); end Z(3)=mod(Z(3),2*p

5、i); Z(3)=Z(3)-(Z(3)pi)*pi;设计例子如下：Fs=1000;n=0:1/Fs:1;xn=10+15*sin(10*2*pi*n)+randn(size(n);nfft=1024;Xn = fftshift(fft(xn,nfft);Xn(513)=Xn(513)/2;A=2*abs(Xn)/Fs;subplot(2,1,1),plot(xn)subplot(2,1,2)stem(-nfft/2:nfft/2 - 1*Fs/nfft,A)xlabel(频率),ylabel(幅值)P=Xn.*conj(Xn)/nfft;xlim(0 500)Z=bizhi(xn,Fs,nfft,8,12,2)输出结果如下这样得到Z为10.00