浙江农林大学信号与系统实验3

一、验证性实验1）实现两个连续时间信号的相加clear allt=0:0.0001:3;b=3;t0=1;u=stepfun(t,t0);n=length(t);for i=1:nu(i)=b*u(i)*(t(i)-t0);endy=sin(2*pi*t);f=u+y;subplot(3,1,1);plot(t,u);title(斜坡信号 u(t);xlabel(时间 t);ylabel(幅值 u(t);subplot(3,1,2);plot(t,y);title(正弦信号 y(t);xlabel(时间 t);ylabel(幅值 y(t);subplot(3,1,3);plot(t,f);title(连续时间信号的相加);xlabel(时间 t);ylabel(幅值 f(t);0 1 2 30510 乘乘乘乘u(t)乘乘t乘乘u(t)0 1 2 3-101 乘乘乘乘y(t)乘乘t乘乘y(t)0 1 2 3-10010 乘乘乘乘乘乘乘乘乘乘乘t乘乘f(t)2）实现两个连续时间信号的相乘clear allt=0:0.0001:5;b=3;t0=1;u=stepfun(t,t0);n=length(t);for i=1:nu(i)=b*u(i)*(t(i)-t0);endy=sin(2*pi*t);f=u.*y;subplot(3,1,1);plot(t,u);title(斜坡信号u(t);xlabel(时间t);ylabel(幅值u(t);subplot(3,1,2);plot(t,y);title(正弦信号y(t);xlabel(时间t);ylabel(幅值y(t);subplot(3,1,3);plot(t,f);title(连续时间信号的相乘);xlabel(时间t);ylabel(幅值f(t);0 1 2 3 4 501020 乘乘乘乘u(t)乘乘t乘乘u(t)0 1 2 3 4 5-101 乘乘乘乘y(t)乘乘t乘乘y(t)0 1 2 3 4 5-20020 乘乘乘乘乘乘乘乘乘乘乘t乘乘f(t)3）实现连续时间信号的移位clear allt=0:0.0001:2;y=sin(2*pi*(t);y1=sin(2*pi*(t-0.2);plot(t,y,-,t,y1,-);title(f(t);xlabel(t);ylabel(f(t);0 0.5 1 1.5 2-1-0.500.51 f(t)tf(t)4）连续时间信号的翻转clear allt=0:0.02:1;t1=-1:0.02:0;g1=3*t;g2=3*(-t1);grid on;plot(t,g1,-,t1,g2);title(连续时间信号反折);xlabel(t);ylabel(g(t);-1 -0.5 0 0.5 100.511.522.53 乘乘乘乘乘乘乘乘tg(t)5）连续时间信号的倒相clear allt=-1:0.02:1;g1=3.*t.*t;g2=-3.*t.*t;grid on;plot(t,g1,-,t,g2,-);title(连续时间信号倒相);xlabel(t);ylabel(g(t);-1 0 1-4-2024 乘 乘 乘 乘 乘 乘 乘 乘tg(t)6）连续时间信号的尺度变换clear allt=0:0.001:1;a=2;y=sin(2*pi*t);y1=sin(2*a*pi*t);subplot(2,1,1);plot(t,y);title(尺度变换);xlabel(t);ylabel(y(t);subplot(2,1,2);plot(t,y1);xlabel(t);ylabel(y1(t);0 0.5 1-101 乘 乘 乘 乘ty(t)0 0.5 1-101ty1(t)7）综合变换funtion x,n=Heaviside(n0,n1,n2)n=n1:n2;x=(n-n0)=0;clear allsyms tf=sym(t/2+1)*(heaviside(t+2)-heaviside(t-2);subplot(2,3,1);ezplot(f,-3,3);y1=subs(f,t,t+2);subplot(2,3,2);ezplot(y1,-5,1);y2=subs(f,t,t-浙江林学院信息工程学院信号与系统实验（三）2);subplot(2,3,3);ezplot(y2,1,-5);y3=subs(f,t,-t);subplot(2,3,4);ezplot(y3,-3,3);y4=subs(f,t,2*t);subplot(2,3,5);ezplot(y4,-2,2);y5=-f;subplot(2,3,6);ezplot(y5,-3,3);-2 0 200.511.52t(t/2+1) (heaviside(t+2)-heaviside(t-2)-4 -2 000.511.52t(1/2 t+2) (heaviside(t+4)-heaviside(t)-4 -2 000.050.10.150.2t1/2 t (heaviside(t)-heaviside(t-4)-2 0 200.511.52t(-1/2 t+1) (heaviside(-t+2)-heaviside(-t-2)-2 -1 0 1 200.511.52t(t+1) (heaviside(t+1)-heaviside(t-1)-2 0 2-2-1.5-1-0.50t-(1/2 t+1) (heaviside(t+2)-heaviside(t-2)二、程序设计实验1）funtion x,n=Heaviside(n0,n1,n2)n=n1:n2;x=(n-n0)=0;clear allsyms tf=sym(-t+4)*(heaviside(t+2)-heaviside(t-2);f1=subs(f,t,-t);f2=sin(2*pi*t);f3=f1+f2;ezplot(f3,-3,3)-2 0 2-10123456t(t+4) (heaviside(-t+2)-heaviside(-t-2)+sin(2 t)2）funtion x,n=Heaviside(n0,n1,n2)n=n1:n2;x=(n-n0)=0;clear allsyms tf=sym(-t+4)*(heaviside(t+2)-heaviside(t-2);f1=sin(2*pi*t);f2=f*f1;ezplot(f2,-3,3)-2 0 2-4-20246t(-t+4) (heaviside(t+2)-heaviside(t-2) sin(2 t)3）clear allx1=2,3,1,2,3,4,3,1;k1=-3:4;k0=2;k=k1+k0;f=x1;subplot(2,1,1);stem(k1,f,filled);axis(min(k1)-1,max(k)+1,min(f)-0.5,max(f)+0.5);title(信号图);xlabel(时间t);ylabel(幅值f(t);subplot(2,1,2);stem(k,f,filled);axis(min(k1)-1,max(k)+1,min(f)-0.5,max(f)+0.5);title(信号图);xlabel(时间t);ylabel(幅值f(t);-4 -2 0 2 4 61234乘乘乘乘乘t乘乘f(t)-4 -2 0 2 4 61234乘乘乘乘乘t乘乘f(t)4）clear allx1=2,3,1,2,3,4,3,1;k1=-3:4;k0=1;k=k1-k0;f=x1;subplot(2,1,1);stem(k1,f,filled);axis(min(k1)-1,max(k)+1,min(f)-0.5,max(f)+0.5);title(信号图 );xlabel(时间t);ylabel(幅值f(t);subplot(2,1,2);stem(k,f,filled);axis(min(k1)-1,max(k)+1,min(f)-0.5,max(f)+0.5);title(信号图 );xlabel(时间t);ylabel(幅值f(t);-4 -2 0 2 41234乘乘乘乘乘t乘乘f(t)-4 -2 0 2 41234乘乘乘乘乘t乘乘f(t)5）clear allx1=2,3,1,2,3,4,3,1;k1=-