1、數字信號處理上機答案（含程序及圖片）第三版高西全 丁玉美著數字信號處理實驗一內容一a=0.8;ys=0;A=1,-0.9;B=0.05,0.05; xn=1,zeros(1,50);x1n=1 1 1 1 1 1 1 1 zeros(1,50); x2n=ones(1,128); xi=filtic(B,A,ys);hn=filter(B,A,xn,xi)n=0:length(hn)-1;subplot(2,2,1);stem(n,yn,'.')title('(a) 系統單位脈沖響應h(n)');xlabel('n');ylabel(hn);y1

2、n=filter(B,A,x1n,xi); n=0:length(y1n)-1;subplot(2,2,2);y='y1(n)' stem(n,y1n,'.')title('(b) 系統對R8(n)的響應y1(n)');xlabel('n');ylabel(yn);y2n=filter(B,A,x2n,xi); n=0:length(y2n)-1;subplot(2,2,4);y='y2(n)' stem(n,y2n,'.')title('(c) 系統對u(n)的響應y2(n)');

3、xlabel('n');ylabel(yn);內容二x1n=1 1 1 1 1 1 1 1 ;h1n=ones(1,10) zeros(1,10);h2n=1 2.5 2.5 1 zeros(1,10);y21n=conv(h1n,x1n);y22n=conv(h2n,x1n);M1=length(y21n)-1;M2=length(y22n)-1;n1=0:1:M1;n2=0:1:M2;n11=0:length(h1n)-1;n22=0:length(h2n)-1;subplot(2,2,1); tstem(n11,h1n); title('(d) 系統單位脈沖響應h

4、1(n)');xlabel('n');ylabel(h1(n);subplot(2,2,2); stem(n1,y21n,'fill');title('(e) h1(n)與R8(n)的卷積y21(n)');xlabel('n');ylabel(y21(n);subplot(2,2,3); tstem(n22,h2n); title('(f) 系統單位脈沖響應h2(n)');xlabel('n');ylabel(h2(n);subplot(2,2,4); stem(n1,y22n,'f

5、ill');title('(g) h2(n)與R8(n)的卷積y22(n)');xlabel('n');ylabel(y22(n);內容三諧振器對u(n)的響應a=0.8;ys=0;xn=1,zeros(1,250); B=1/100.49,-1/100.49;A=1,-1.8237,0.9801;xi=filtic(B,A,ys);yn=filter(B,A,xn,xi)n=0:length(yn)-1;subplot(1,1,1);stem(n,yn,'.')諧振器對正弦信號的響應a=0.8;ys=0;xsin=sin(0.014*n

6、)+sin(0.4*n); B=1/100.49,-1/100.49;A=1,-1.8237,0.9801;xi=filtic(B,A,ys);yn=filter(B,A,xsin,xi)n=0:length(yn)-1;subplot(1,1,1);stem(n,yn,'.')數字信號處理實驗三實驗（1）x1n=ones(1,4);X1k8=fft(x1n,8);X1k16=fft(x1n,16);N=8;f=2/N*(0:N-1);figure(1);subplot(1,2,1);stem(f,abs(X1k8),'.');title('(la) 8

7、µãDFTx_1(n)');xlabel('omega/pi¡¯);ylabel(¡®|(ejomega)|');N=16;f=2/N*(0:N-1);subplot(1,2,2);stem(f,abs(X1k16),'.');title('(la) 16µãDFTx_1(n)');xlabel('omega/pi');ylabel('|(ejomega)|');實驗（1-2，1-3）M=8;xa=1:(M/2);xb=(M/2

8、):-1:1;x2n=xa,xb;x3n=xb,xa;X2k8=fft(x2n,8);X2k16=fft(x2n,16);X3k8=fft(x3n,8);X3k16=fft(x3n,16);figure(2);N=8;f=2/N*(0:N-1);subplot(2,2,1);stem(f,abs(X2k8),'.');title('(2a) 8µãDFTx_2(n)');xlabel('omega/pi');ylabel('|(ejomega)|');subplot(2,2,3);stem(f,abs(X3k8

9、),'.');title('(3a) 8µãDFTx_3(n)');xlabel('omega/pi');ylabel('|(ejomega)|');N=16;f=2/N*(0:N-1);subplot(2,2,2);stem(f,abs(X2k16),'.');title('(2a) 16µãDFTx_2(n)');xlabel('');ylabel('');subplot(2,2,4);stem(f,abs(X3k16),&

10、#39;.');title('(3a) 16µãDFTx_3(n)');xlabel('omega/pi');ylabel('|(ejomega)|');實驗（2-1，2-2）N=8;n=0:N-1;x4n=cos(pi*n/4);x5n=cos(pi*n/4)+cos(pi*n/8);X4k8=fft(x4n,8);X4k16=fft(x4n,16);X5k8=fft(x5n,8);X5k16=fft(x5n,16);figure(3);N=8;f=2/N*(0:N-1);subplot(2,2,1);stem(f,

11、abs(X4k8),'.');title('(4a) 8µãDFTx_4(n)');xlabel('omega/pi');ylabel('|(ejomega)|');subplot(2,2,3);stem(f,abs(X5k8),'.');title('(5a) 8µãDFTx_5(n)');xlabel('omega/pi');ylabel('|(ejomega)|');N=16;f=2/N*(0:N-1);subplot(2

12、,2,2);stem(f,abs(X4k16),'.');title('(4a) 16µãDFTx_4(n)');xlabel('omega/pi');ylabel('|(ejomega)|');subplot(2,2,4);stem(f,abs(X5k16),'.');title('(5a) 16µãDFTx_5(n)');xlabel('omega/pi');ylabel('|(ejomega)|');實驗（3）Fs=64;

13、T=1/Fs;N=16;n=0:N-1;nT=n*T;x8n=cos(8*pi*nT)+cos(16*pi*nT)+cos(20*pi*nT);X8k16=fft(x8n,16);N=16;f=2/N*(0:N-1);figure(4);subplot(2,2,1);stem(f,abs(X8k16),'.');title('(8a) 16µãDFTx_8(n)');xlabel('omega/pi');ylabel('|(ejomega)|');N=32;n=0:N-1;nT=n*T;x8n=cos(8*pi

14、*nT)+cos(16*pi*nT)+cos(20*pi*nT);X8k32=fft(x8n,32);N=32;f=2/N*(0:N-1);figure(4);subplot(2,2,2);stem(f,abs(X8k32),'.');title('(8a) 32µãDFTx_8(n)');xlabel('omega/pi');ylabel('|(ejomega)|');N=64;n=0:N-1;nT=n*T;x8n=cos(8*pi*nT)+cos(16*pi*nT)+cos(20*pi*nT);X8k64=

15、fft(x8n,64);N=64;f=2/N*(0:N-1);figure(4);subplot(2,2,3);stem(f,abs(X8k64),'.');title('(8a) 64µãDFTx_8(n)');xlabel('omega/pi');ylabel('|(ejomega)|');數字信號處理實驗四內容一function st=mstgN=800 Fs=10000;T=1/Fs;Tp=N*T; t=0:T:(N-1)*T;k=0:N-1;f=k/Tp;fc1=Fs/10;fm1=fc1/10; f

16、c2=Fs/20; fm2=fc2/10; fc3=Fs/40;fm3=fc3/10; xt1=cos(2*pi*fm1*t).*cos(2*pi*fc1*t); xt2=cos(2*pi*fm2*t).*cos(2*pi*fc2*t); xt3=cos(2*pi*fm3*t).*cos(2*pi*fc3*t); st=xt1+xt2+xt3; fxt=fft(st,N); subplot(3,1,1)plot(t,st);grid;xlabel('t/s');ylabel('s(t)');axis(0,Tp/8,min(st),max(st);title(&#

17、39;(a) s(t)的波形')subplot(3,1,2)stem(f,abs(fxt)/max(abs(fxt),'.');grid;title('(b) s(t)的頻譜')axis(0,Fs/5,0,1.2);xlabel('f/Hz');ylabel('幅度')內容二Fs=10000;T=1/Fs; st=mstg;%低通濾波器設計與實現fp=280;fs=450;wp=2*fp/Fs;ws=2*fs/Fs;rp=0.1;rs=60; N,wp=ellipord(wp,ws,rp,rs);B,A=ellip(N,r

18、p,rs,wp); y1t=filter(B,A,st); figure(2);subplot(3,1,1);H,w=freqz(B,A,1000);m=abs(H);plot(w/pi,20*log(m/max(m);grid on;title('低通濾波損耗函數曲線');xlabel('w/pi ');ylabel('幅度'); axis(0,1,0,1.2*max(H)yt='y1(t)'subplot(3,1,2); plot(t,y1t);title('低通濾波后的波形');xlabel(

19、9;t/s');ylabel(y1(t);%帶通濾波器設計與實現fpl=440;fpu=560;fsl=275;fsu=900;wp=2*fpl/Fs,2*fpu/Fs;ws=2*fsl/Fs,2*fsu/Fs;rp=0.1;rs=60; N,wp=ellipord(wp,ws,rp,rs); B,A=ellip(N,rp,rs,wp); y2t=filter(B,A,st); figure(3);subplot(3,1,1);H,w=freqz(B,A,1000);m=abs(H);plot(w/pi,20*log(m/max(m);grid on;title('帶

20、通濾波損耗函數曲線');xlabel('w/pi ');ylabel('幅度'); axis(0,1,0,1.2*max(H)yt='y2(t)'subplot(3,1,2); plot(t,y2t);title('帶通濾波后的波形');xlabel('t/s');ylabel(y2(t);%高通濾波器設計與實現fp=890;fs=600;wp=2*fp/Fs;ws=2*fs/Fs;rp=0.1;rs=60; N,wp=ellipord(wp,ws,rp,rs); B,A=ellip(N,rp,rs,wp,

21、'high');y3t=filter(B,A,st); figure(4);subplot(3,1,1);H,w=freqz(B,A,1000);m=abs(H);plot(w/pi,20*log(m/max(m);grid on;title('高通濾波損耗函數曲線');xlabel('w/pi ');ylabel('幅度'); axis(0,1,0,1.2*max(H)yt='y3(t)'subplot(3,1,2); plot(t,y3t);title('高通濾波后的波形');xlab

22、el('t/s');ylabel(y3(t);低通濾波器損耗函數及其分離出的調幅信號y1(t)帶通濾波器損耗函數及其分離出的調幅信號y2(t)高通濾波器損耗函數及其分離出的調幅信號y3(t)數字信號處理實驗五1、function xt=xtg(N)Fs=1000;T=1/Fs;Tp=N*T;t=0:T:(N-1)*T;fc=Fs/10;f0=fc/10;mt=cos(2*pi*f0*t); ct=cos(2*pi*fc*t); xt=mt.*ct; nt=2*rand(1,N)-1; fp=150; fs=200;Rp=0.1;As=60;fb=fp,fs;m=0,1; dev=10(-As/20),(10(Rp/20)-1)/(10(Rp/20)+1);n,fo,mo,W=remezord(fb,m,dev,Fs);hn=remez(n,fo,mo,W); yt=filter(hn,1,10*nt); xt=xt+yt; fst=fft(xt,N);k=0:N-1;f=k/Tp;su