资源描述:
《信号与信号实验》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、信号与信号实验MATLAB部分实验一:棊本信号在MATLAB屮的表示和运算一、实验目的;1、学会用MATLAB表示常用连续信号的方法;2、学会用MATLAB进行信号基木运算的方法;3、学会用MATLAB实现连续吋间信号的卷积的方法。二、实验闪容:1、绘出下列信号的时域波形(1)f(t)=(2-e-2t)u(t)(2)f(t)=cos(7rt)[u(t)-u(t-1)](3)f(t)=u(-3t+2)(4)f(t)=-(l/2)tu(t+2)解:tl=0:0.01:5;y1=(2-exp(-2*t1)).*(t1>0);subplot(221);plo
2、t(t1,y1);grid;titleCf(t)=(2-e-2t)u(ty);t2=0:0.01:5;y2=cos(pi*t2).*((t2>0)-(t2>1));subplot(222);plot(t2,y2);grid;title(’f(t)=cos(7rt)[u(t)-u(t-1)]’);t3=-2:0.01:5;y3=(-3*t3+2〉0);subplot(223);plot(t3,y3);gridtitleCf(t)=u(-3t+2)’);t4=-3:0.01:5;y4=(-1/2)*t4.*(t4>-2);subplot(224);plo
3、t(t4,y4);grid;title(,f(t)=-(l/2)tu(t+2)t);21.510.501f(t)=(2-e-2t)u(t)图1-1f(t)=u(-3t+2)10.500.5T(t)=COS(TTt)[U(t)-U(t-1)]°2III■5o10图1-2f(t)=-(1/2)tu(t+2)5123-■ii-32、用MATLAB绘出不列信号的卷积积分fKt)*f2⑴的时域波形(1)f1(t)=tu(t),f2(t)=u(t)(2)fl(t)=u(t)-u(t-4),f2(t)=sin(7tt)u(t)(3)fl(t)=e-2tu(t),f
4、2(t)=e-tu(t)(4)fl(t)=e-tu⑴,f2(t)=u(t)解:(1)fs=1000;t=-l:l/fs:4;xl=stepfun(t,O);x2=xl.*t;y=conv(xl,x2)/fs;n=length(yl);tt=(0:n-l)/fs-2;subplot(311),plot(t,x1),grid;title(’fl(t)=tu(t)’);subplot(312),plot(t,x2),grid;titleff2(t)=u(t)t);subplot(313),plot(tt,y),gridon;titleffl(t)*f2(t
5、)');(2)fs=1000;t=-l:l/fs:4;xl=(t>0)-(t>4);x2=sin(pi*t).*(t>0);x=conv(xl,x2)/fs;n=length(x);tt=(0:n-l)/fs-2;subplot(311);plot(t,x1);grid;title(’fl(t)=u(t)-u(t-4))*);subplot(312);plot(t,x2);grid;title(’f2(t)=sin(7rt)u(t)’);subplot(313);plot(tt,x);grid;title(’f1⑴*f2f);(3)t=0:l/fs:
6、4;xl=exp(-2*t).*(t>0);x2=exp(-t).*(t>0);x=conv(x1,x2)/fs;n=length(x);tt=(O:n-l)/fs-O;subplot(311);plot(t,x1);grid;title(*fl(t)=e-2tu(t)!);subplot(312);plot(t,x2);grid;title('f2(t)=e-tu(t)’);subplot(313);plot(tt,x);grid;titleCfl(t)*f2(t)f);(4)t=0:l/fs:2;x1=exp(-2*t).*(t>0);x2=(t
7、>0);x=conv(x1,x2)/fs;n=length(x);tt=(O:n-l)/fs-O;subplot(311);plot(t,x1);grid;titleCf1(t)=e-tu(t))’);subplot(312);plot(t,x2);grid;titleCf2(t)=u(t)*);subplot(313);plot(tt,x);grid;titleCfl(t)*f2(t)’);1O.£f1(t=tu(t)0-1-0.500.511.522.533.54?2-1二f2(t)=u(t)f1(t'f2⑴-——-0.500.511.522.5
8、33.54?2-2%-1012345678?2-3f1(t)=e-(u{t)00.20.40.60.811.