哈工大-信号与系统实验-电气学院

1 。2 原理定义：是带有息随变化物理量或物理象。描述：域和频域。分类：分类很多，可以从不同角度对进行分类。在与系统分析中，根据与自变量性，可分为确定与随机，周期与非周期，与离散，能量与功率，限与频限，物理可。涉及正弦指数单位冲激单位阶跃抽样。内容与参考给出程序并观察产生频率，周期，，相位，，进程与理中。中程序，，并指定。通过对性，自行整程序，以下几种模拟，并得出。(1)

f(t(t

t

(2)

f(tt(t

t(3)

f(t5et5e2t

t

f(tcos2000t取

t=～

0.2(5)

f(t4e0.5tcost取

t=～10在报告中写出整自程序，并给出。(1)

f(t(t

0y=heaviside(t);plot(t,y);axis([-1,10,-0.1,1.2])10.80.60.40.20

1 0 1 2 3 4 5 6 7 8 9 10(3)

f(t5et5e2t

A=5;a=-1;b=-2;t=0:0.001:10;ft=A*exp(a*t)-A*exp(b*t);plot(t,ft)1.41.210.80.60.40.20

0 1 2 3 4 5 6 7 8 9 10(4)

ft)0ts0t,t=A=100;B=2000;t=0:0.001:0.2;ft=cos(A*t)+cos(B*t);plot(t,ft)21.510.500511520 002 004 006 008 0.1 012 014 016 018 0.2。原理级三角形式级指形式非周期涉ururu8u1s内容与周期级利画出下所示周期三角波。要求中输入程序，证结果，并将结果存入指定存储区。在报告中写出完整自编程序，并给出结果。6. N=10;n1=-N:-1;c1=-4*j*sin(n1*pi/2)/pi^2./n1.^2;c0=0;n2=1:N;c2=-4*j*sin(n2*pi/2)/pi^2./n2.^2;cn=[c1c0c2];n=-N:N;subplot211;stem(n,abs(cn));ylabel('Cn的幅度subplot212;stem(n,angle(cn));ylabel('Cn的相位xlabel('\omega/\omega_0')输出频谱0.50.4度 0.3幅的 0.2nC0.1-10-8-6-10-8-6-4-20246810210-1位相的nC-20 2 4 6 8 /0。原理收敛域计算微程s）涉ie 内容与已知

f(t)

(t，求出该，并绘制曲面图。要求中输入程序，证结果，并将结果存入指定存储区。在报告中写出完整自编程序，并给出结果。结果clf;a=-0.5:0.08:0.5;b=-1.99:0.08:1.99;[a,b]=meshgrid(a,b);d=ones(size(a));c=a+i*b;c=c.*c;c=c+d;c=1./c;c=abs(c);mesh(a,b,c);surf(a,b,c);axis([-0.5,0.5,-2,2,0,15]);title('colormap(hsv);单 边 正 弦 信号拉普拉斯变换曲面图101010105020.52 051 2 5 1n, 0n52f0n5，0, 他 ①y1

fnn②y2

fnn]报告写给6. ①f1=[012345];k1=[012345];f2=[111111];k2=[012345];f=conv(f1,f2)k0=k1(1)+k2(1);k3=length(f1)+length(f2)-2;k=k0:k0+k3subplot221stem(k1,f1)title('f1(k)')xlabel('k')ylabel('f1(k)')subplot222stem(k2,f2)title('f2(k)')xlabel('k')ylabel('f2(k)')subplot223stem(k,f)title('f(k)=f1(k)*f2(k)')xlabel('k')ylabel('f(k)')h=get(gca,'position');h(3)=2.3*h(3);set(gca,'position',h)f=0136101515141295k=0123456789106

f2(k)14f 2 f

0.5f(k)f5②f1=[012345];k1=[-5-4-3-2-10];f2=[111111];k2=[012345];f=conv(f1,f2)k0=k1(1)+k2(1);k3=length(f1)+length(f2)-2;k=k0:k0+k3subplot221stem(k1,f1)title('f1(k)')xlabel('k')ylabel('f1(k)')subplot222stem(k2,f2)title('f2(k)')xlabel('k')ylabel('f2(k)')subplot223stem(k,f)title('f(k)=f1(k)*f2(k)')xlabel('k')ylabel('f(k)')h=get(gca,'position');h(3)=2.3*h(3);set(gca,'position',h)f=0 1 3 6 10 15 15 14 12 9 5k=-5 -4 -3 -2 -1 0 1 2 3 4 5f1(k)6

f2(k)4( f 2 f00k

0.5f(k)f500 1 2 3 4 5k①n=[-10:10];00000000001234500000]h=[000000000011111100000]subplot321;stem(n,x,'*k');subplot322;stem(n,h,'k');n1=fliplr(-n);h1=fliplr(h);subplot323;stem(n,x,'*k');holdon;stem(n1,h1,'k');h2=[0,h1];h2(length(h2))=[];n2=n1;subplot324;stem(n,x,'*k');holdon;stem(n2,h2,'k');h3=[0,h2];h3(length(h3))=[];n3=n2;subplot325;stem(n,x,'*k');holdon;stem(n3,h3,'k');n4=-n;nmin=min(n1)-max(n4);nmax=max(n1)-min(n4);n=nmin:nmax;y=conv(x,h)subplot326;stem(n,y,'.k');6 140.520010505101050510664422001050510105051061541025010 5 0 5 10

020 10 0 10 20②n=[-10:10];x=[000000123450000000000]h=[000000000011111100000]subplot321;stem(n,x,'*k');subplot322;stem(n,h,'k');n1=fliplr(-n);h1=fliplr(h);subplot323;stem(n,x,'*k');holdon;stem(n1,h1,'k');h2=[0,h1];h2(length(h2))=[];n2=n1;subplot324;stem(n,x,'*k');holdon;stem(n2,h2,'k');h3=[0,h2];h3(length(h3))=[];n3=n2;subplot325;stem(n,x,'*k');holdon;stem(n3,h3,'k');n4=-n;nmin=min(n1)-max(n4);nmax=max(n1)-min(n4);n=nmin:nmax;y=conv(x,h)subplot326;stem(n,y,'.k');6 140.520010505101050510664422001050510105051061541025010 5 0 5 10

020 10 0 10 20;zfilterh[n](0.9)n[n]

f[n[n[n10]

出y[nf[nh[n。②设可由表示：y[n]y[ny[n

f[n]n[20:100①如下k1=0:30f1=0.9.^k1;k2=k1;f=conv(f1,f2)k0=k1(1)+k2(1);k3=length(f1)+length(f2)-2;k=k0:k0+k3subplot221stem(k1,f1)title('h(n)')xlabel('k')ylabel('f1(k)')subplot222stem(k2,f2)title('f(n)')xlabel('k')ylabel('f2(k)')subplot223stem(k,f)title('y(n)=f(n)*h(n)')xlabel('k')ylabel('f(k)')h=get(gca,'position');h(3)=2.3*h(3);set(gca,'position',h)②程序如下（1）冲击响应程序如下a=[1-10.9];b=[1];k=-20:100;stem(k,x)subplot211stem(k,x)title('输入序列')xlabel('k')ylabel('y(k)')subplot212stem(k,y)title('响应序列')xlabel('k')结果如下输 入序列10.5(y00 k响应序列10.5010.500.5-10 k2a=[1-10.9];b=[1];k=-20:101;stem(k,x)subplot211stem(k,x)title('')xlabel('k')ylabel('y(k)')subplot212stem(k,y)title('')xlabel('k')ZZZZZZsszzeZZZ①列各f[n]。F

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2z1①1.1num=[216445632];den=[33-1518-12];[r,p,k]=residuez(num,den)r=-0.01779.4914-3.0702+2.3398i-3.0702-2.3398ip=-3.23611.23610.5000+0.8660i0.5000-0.8660ik=-2.66671.2num=[4-8.86-17.9826.74-8.04];den=[1-210665];[r,p,k]=residuez(num,den)r=1.0849+1.3745i1.0849-1.3745i0.9769-1.2503i0.9769+1.2503ip=2.0000+3.0000i2.0000-3.0000i-1.0000+2.0000i-1.0000-2.0000ik=-0.1237②2.1零输入响应下num=[2-1-3];den=[2-1];y0=[1,3];N=50;n=[0;N-1]';x=0;zi=filtic(num,den,y0);[y,zf]=filter(num,den,x,zi);plot(n,x,n,y,'b--');title('零输入响应');xlabel('n');ylabel('x(n)-y(n)');legend('输入x','输出y',1);grid;结果下零 输 入响应输 入输 入x输 出y0.450.40.350.3y 0.20.150.10.0500 5 n2.1零状态响应下num=[2-1-3];den=[2-1];y0=[0,0];N=50;n=[0;N-1]';x=0.5.^n;zi=filtic(num,den,y0);[y,zf]=filter(num,den,x,zi);plot(n,x,n,y,'b--');legend('x','y',1);grid下零 状 态 响 应输 入输 入x输 出y0.90.80.7

0.60.50.40.30.20.100 5 n2.3全程序下num=[2-1-3];den=[2-1];y0=[1,3];N=50;x=0.8.^n;zi=filtic(num,den,y0);[y,zf]=filter(num,den,x,zi);title('xlable('n');ylable('x(n)-y(n)');legend('x','y',1);grid全响应1.510.500 5 10 15 20 25 30 35 40 45 50③程序a=[200-1];b=[1-2-1];p=roots(a);q=roots(b);p=p'q=q';x=max(abs([pq1]));x=x+0.1;y=x;clfholdonaxis([-xx-yy]);axis([-xx-yy]);t=exp(i*w)plot(t)axis('square');plot([-x,x],[0,0]);text(0.1,x,'jim[z]');text(y,0.1,'Re[z]');plot(real(p),imag(p),'x');plot(real(q),imag(q),'o');title('pole-zerodiagramfordiscretesystem')holdoffp=-0.3969-0.6874i -0.3969+0.6874i q=-0.4142 2.4142zomrey2.5 jim[z]21.510.50

Re[z]-0.5-1.5-2.5

0 1 2num=[1-2-1];den=[200-1];[H,w]=freqz(num,den)plot(w,H,'*')32.521.510.50051152

0 0.5 1 1.5 2 2.5