完整的維納濾波器Matlab源程序

1、精選優(yōu)質(zhì)文檔-傾情為你奉上clear;clc;%輸入信號A=1;                                            

2、0;         %信號的幅值f=1000;                                       &#

3、160;         %信號的頻率fs=105;                                       

4、         %采樣頻率t=(0:999);                                       &#

5、160;      %采樣點Mlag=100;                                          

6、   %相關(guān)函數(shù)長度變量   x=A*cos(2*pi*f*t/fs);                                %輸入正弦波信號xmean=mean(x);   &#

7、160;                                %正弦波信號均值xvar=var(x,1);             

8、0;                           %正弦波信號方差xn=awgn(x,5);                   &

9、#160;                     %給正弦波信號加入信噪比為20dB的高斯白噪聲figure(1)plot(t,xn)                     &

10、#160;                           %繪制輸入信號圖像title('輸入信號圖像') xlabel('x軸單位：t/s','color','b')ylabel('y軸單位：f/HZ','color',

11、9;b')xnmean=mean(xn)                                  %計算輸入信號均值xnms=mean(xn.2)        

12、                          %計算輸入信號均方值xnvar=var(xn,1)                    

13、;                   %計算輸入信號方差Rxn=xcorr(xn,Mlag,'biased');                   %計算輸入信號自相關(guān)函數(shù)figure(2)subpl

14、ot(221)plot(-Mlag:Mlag),Rxn)                             %繪制自相關(guān)函數(shù)圖像title('輸入信號自相關(guān)函數(shù)圖像')f,xi=ksdensity(xn);       

15、0;                          %計算輸入信號的概率密度，f為樣本點xi處的概率密度subplot(222)plot(xi,f)               

16、0;                                   %繪制概率密度圖像title('輸入信號概率密度圖像')X=fft(xn);       

17、                                           %計算輸入信號序列的快速離散傅里葉變換Px=X.*conj(X)/600; 

18、0;                                 %計算信號頻譜subplot(223)semilogy(t,Px)           &

19、#160;                              %繪制在半對數(shù)坐標(biāo)系下頻譜圖像title('輸入信號在半對數(shù)坐標(biāo)系下頻譜圖像')xlabel('x軸單位：w/rad','color','b')ylabel('y軸單位

20、：w/HZ','color','b')pxx=periodogram(xn);                               %計算輸入信號的功率譜密度subplot(224)semilogy(pxx)   

21、0;                                       %繪制在半對數(shù)坐標(biāo)系下功率譜密度圖像title('輸入信號在半對數(shù)坐標(biāo)系下功率譜密度圖像')xlabel('x軸單

22、位：w/rad','color','b')ylabel('y軸單位：w/HZ','color','b')%fir濾波wp=0.4*pi;                               &#

23、160;                %通帶截止頻率ws=0.6*pi;                              

24、60;                 %阻帶截止頻率DB=ws-wp;                              

25、0;                %過渡帶寬度N0=ceil(6.6*pi/DB);                              &#

26、160;     M=N0+mod(N0+1,2);                                %計算fir濾波器階數(shù)wc=(wp+ws)/2/pi;      

27、;                                %計算理想低通濾波器通帶截止頻率（關(guān)于歸一化）hn=fir1(M,wc);           

28、0;                              %調(diào)用fir1計算FIRDF的h(n)y1n=filter(hn,1,xn);             &

29、#160;                     %將輸入信號通過fir濾波器figure(3)plot(y1n)                       

30、;                            %繪制經(jīng)過fir濾波器后信號圖像title('經(jīng)過fir濾波器后信號圖像')xlabel('x軸單位：f/HZ','color','b')ylabel('y軸單位：A/V','colo

31、r','b')y1nmean=mean(y1n)                                %計算經(jīng)過fir濾波器后信號均值y1nms=mean(y1n.2)      

32、60;                         %計算經(jīng)過fir濾波器后信號均方值y1nvar=var(y1n,1)                   

33、;                  %計算經(jīng)過fir濾波器后信號方差Ry1n=xcorr(y1n,Mlag,'biased');                 %計算經(jīng)過fir濾波器后信號自相關(guān)函數(shù)figure(4)subplot

34、(221)plot(-Mlag:Mlag),Ry1n)                             %繪制自相關(guān)函數(shù)圖像title('經(jīng)過fir濾波器后信號自相關(guān)函數(shù)圖像')f,y1i=ksdensity(y1n);     

35、60;                          %計算經(jīng)過fir濾波器后信號的概率密度，f為樣本點xi處的概率密度subplot(222)plot(y1i,f)              &

36、#160;                                     %繪制概率密度圖像title('經(jīng)過fir濾波器后信號概率密度圖像')Y1=fft(y1n);    

37、;                                            %計算經(jīng)過fir濾波器后信號序列的快速離散傅里葉變換Py1=Y1.*conj(Y

38、1)/600;                               %計算信號頻譜subplot(223)semilogy(t,Py1)            &

39、#160;                             %繪制在半對數(shù)坐標(biāo)系下頻譜圖像title('經(jīng)過fir濾波器后信號在半對數(shù)坐標(biāo)系下頻譜圖像')xlabel('x軸單位：w/rad','color','b')ylabel('y軸單

40、位：w/HZ','color','b')py1n=periodogram(y1n);                           %計算經(jīng)過fir濾波器后信號的功率譜密度subplot(224)semilogy(py1n)     

41、                                     %繪制在半對數(shù)坐標(biāo)系下功率譜密度圖像title('經(jīng)過fir濾波器后信號在半對數(shù)坐標(biāo)系下功率譜密度圖像')xlabel('x軸單位：w/rad

42、','color','b')ylabel('y軸單位：w/HZ','color','b')%維納濾波N=100;                                 &#

43、160;                      %維納濾波器長度Rxnx=xcorr(xn,x,Mlag,'biased');                   %產(chǎn)生輸入信號與原始信號的

44、互相關(guān)函數(shù)rxnx=zeros(N,1);                                       rxnx(:)=Rxnx(101:101+N-1);Rxx=zeros(N,N);

45、0;                                         %產(chǎn)生輸入信號自相關(guān)矩陣Rxx=diag(Rxn(101)*ones(1,N);for i=2:N &#

46、160;  c=Rxn(101+i)*ones(1,N+1-i);    Rxx=Rxx+diag(c,i-1)+diag(c,-i+1);endRxx;h=zeros(N,1);h=inv(Rxx)*rxnx;                             

47、             %計算維納濾波器的h(n)yn=filter(h,1,xn);                                

48、0;        %將輸入信號通過維納濾波器figure(5)plot(yn)                                     

49、60;                %繪制經(jīng)過維納濾波器后信號圖像title('經(jīng)過維納濾波器后信號信號圖像')xlabel('x軸單位：f/HZ','color','b')ylabel('y軸單位：A/V','color','b')ynmean=mean(yn)     &

50、#160;                               %計算經(jīng)過維納濾波器后信號均值ynms=mean(yn.2)             &

51、#160;                       %計算經(jīng)過維納濾波器后信號均方值ynvar=var(yn,1)                     

52、                    %計算經(jīng)過維納濾波器后信號方差Ryn=xcorr(yn,Mlag,'biased');                     %計算

53、經(jīng)過維納濾波器后信號自相關(guān)函數(shù)figure(6)subplot(221)plot(-Mlag:Mlag),Ryn)                               %繪制自相關(guān)函數(shù)圖像title('經(jīng)過維納濾波器后信號自相關(guān)函數(shù)圖像')f,yi=ksdensit

54、y(yn);                                    %計算經(jīng)過維納濾波器后信號的概率密度，f為樣本點xi處的概率密度subplot(222)plot(yi,f)