信號(hào)分析與處理實(shí)驗(yàn)報(bào)告

試驗(yàn)一%CreateaRectangularwindowNfft=512;fori=1:3switchi;case1Nwin=10;case2Nwin=30;case3Nwin=100;endw=boxcar(Nwin);[y,f]=freqz(w,1,Nfft);mag=abs(y);holdon;plot(f/pi,20*log10(mag/max(mag)));endxlabel('歸一化頻率');ylabel('幅度');grid實(shí)驗(yàn)二>>%DesignaButterworthDigtiallowpassfilter%Desiredperformentsoftkefilterwp=0.2*pi;ws=0.3*pi;Rp=1.5;Rs=12;Fs=100000;Ts=1/Fs;Nn=128;Wp=(2/Ts)*tan(wp/2);Ws=(2/Ts)*tan(ws/2);%ComputerOderandCutofffrequency[N,Wn]=buttord(Wp,Ws,Rp,Rs,'s')%Computertheanalogfilter[z,p,k]=buttap(N);[Bap,Aap]=zp2tf(z,p,k);[b,a]=lp2lp(Bap,Aap,Wn);%Bilineartransformation%foranalogtodigitalfilterconversion.[bz,az]=bilinear(b,a,Fs)freqz(bz,az,Nn,Fs)title('用Bilinear函數(shù)設(shè)計(jì)數(shù)字濾波器')N=4Wn=7.2733e+004Warning:Matrixisclosetosingularorbadlyscaled.Resultsmaybeinaccurate.RCOND=1.299710e-028.>Inbilinearat89Warning:Matrixisclosetosingularorbadlyscaled.Resultsmaybeinaccurate.RCOND=1.299710e-028.>Inbilinearat90bz=0.00690.02750.04120.02750.0069az=1.0000-2.19222.0439-0.89620.1544實(shí)驗(yàn)三%DesignaButterworthDigtiallowpassfilterwithDesiredperformentsoftkefilterwp=2000*2*pi;ws=3000*2*pi;Rp=3;Rs=15;Fs=10000;Nn=128;%ComputerOderandCutofffrequency[N,Wn]=cheblord(Wp,Ws,Rp,Rs,'s')%Computertheanalogfilter[z,p,k]=buttap(N);[Bap,Aap]=zp2tf(z,p,k);[b,a]=lp2lp(Bap,Aap,Wn);%Impulseinvariancemethod[bz,az]=impinvar(b,a,Fs)freqz(bz,az,Nn,Fs)N=18wn=1.2842e+004Warning:Matrixisclosetosingularorbadlyscaled.Resultsmaybeinaccurate.RCOND=7.489236e-138.>Inbilinearat89InUntitled3at19Warning:Matrixisclosetosingularorbadlyscaled.Resultsmaybeinaccurate.RCOND=7.489236e-138.>Inbilinearat90InUntitled3at19bz=1.0e-005*Columns1through140.00000.00010.00050.00280.01050.02950.06380.10940.15050.16720.15050.10940.06380.0295Columns15through190.01050.00280.00050.00010.0000az=1.0e+003*Columns1through140.0010-0.01090.0568-0.18900.4484-0.80471.1309-1.27161.1588-0.86170.5238-0.25950.1040-0.0332Columns15through190.0083-0.00160.0002-0.00000.0000實(shí)驗(yàn)四%ChebyshevIlowpassfilter%Desiredperformentswp=20000*pi;ws=30000*pi;Rp=1;Rs=15;%ComputerOrderNebs=sqrt(10^(Rp/10)-1);A=10^(Rs/20);Wc=wpWr=ws/wp;g=sqrt(A*A-1)/ebs;N1=log10(g+sqrt(g*g-1))/log10(Wr+sqrt(Wr*Wr-1));N=ceil(N1)Wc=6.2832e+004N=4實(shí)驗(yàn)五（1）%Buttworthlowpassfilterwp=20000*piws=30000*pi;Rp=1;Rs=15;disp('Buttworthlowpassfilter')[N,Wc]=buttord(wp,ws,Rp,Rs,'s')%ChebyshevIIlowpassfilterwp=20000*pi;ws=30000*pi;Rp=1;Rs=15;disp('ChebyshevIIlowpassfilter')[N,Wc]=cheb2ord(wp,ws,Rp,Rs,'s')wp=6.2832e+004ButtworthlowpassfilterN=6Wc=7.0865e+004ChebyshevIIlowpassfilterN=4Wc=8.2364e+004（2）>%DesignaButterworthAnaloglowpassfilterwp=10000*2*piws=15000*2*pi;Rp=1;Rs=15;%ComputerOderandCutofffrequency[N,Wn]=buttord(wp,ws,Rp,Rs,'s')Fc=Wn/(2*pi)%Computerthefilter[b,a]=butter(N,Wn,'s');%Outputw=linspace(1,30000,10000)*2*pi;H=freqs(b,a,w);magH=(abs(H));phaH=unwrap(angle(H));plot(w/(2*pi),20*log10(magH));xlabel('f/Hz');ylabel('Magnidute(dB)');title('巴特沃思模擬低通濾波器')wp=6.2832e+004N=6Wn=7.0865e+004Fc=1.1279e+004實(shí)驗(yàn)六%DesiredperformentsN=5;Rp=3;w1=200*piw2=1000*pi;%Chebyshevanaloglowpassfilterprototype[z,p,k]=cheb1ap(N,Rp);[b,a]=zp2tf(z,p,k);%FindthecenterfrequencyandBandwidthW0=sqrt(w1*w2);Bw=w2-w1;%Dsignanalogbandpassfilterdisp('Dsignedanalogbandpassfilter:')[bt,at]=lp2bp(b,a,W0,Bw);[h,w]=freqs(bt,at);plot(w/pi,20*log10(abs(h)));xlabel('頻率(πrad/s)');ylabel('幅度(dB)');gridonw1=628.3185Dsignedanalogbandpassfilter:實(shí)驗(yàn)七%Exp3-12RC=1num=[10];den=[11/RC];w=0:0.01:5;[mag,phase]=bode(num,den,w);clfsubplot(211)plot(w,mag);xlabel('f(rad/s)')ylabel('幅度')title('Exp3-12')subplot(212),plot(w,phase);xlabel('f(rad/s)')ylabel('相位')實(shí)驗(yàn)八%Exp3-13num=[10];den=[111];w=0:0.01:5;H=freqs(num,den,w);mag=abs(H);phase=angle(H)*180/pi;clfsubplot(211)plot(w,mag);xlabel('f(rads)')ylabel('幅度')title('Exp3-13')subplot(212),plot(w,phase);xlabel('f(rads)')ylabel('相位')實(shí)驗(yàn)九%Exp4-21b=[0.2,0.3,1];a=[1,0.4,1];subplot(2,1,1)zplane(b,a);title('零極點(diǎn)圖')subplot(2,1,2)impz(b,a);title('單位沖擊響應(yīng)')figurefreqz(b,a);實(shí)驗(yàn)十%Exp5-21x1=[1,2,2,1]x2=[1,2,3,4]'x1*x2線(xiàn)性卷積結(jié)果；'y=conv(x1,x2)pause'N=5時(shí)循環(huán)卷積結(jié)果'y=circonvt(x1,x2,5)pause'N=6時(shí)循環(huán)卷積結(jié)果'y=circonvt(x1,x2,6)pause'N=7時(shí)循環(huán)卷積結(jié)果'y=circonvt(x1,x2,7)pause'N=8時(shí)循環(huán)卷積結(jié)果'y=circonvt(x1,x2,8)x1=1221x2=1234ans=x1*x2線(xiàn)性卷積結(jié)果；y=1