matlab上机实验一 二,信号与系统上机实验-matlab(第一第二次实验课)

信号与系统上机实验-matlab(第一第二次实验课)

实验一 典型连续时间信号描述及运算一、典型连续时间信号绘制1、单边指数衰减t=0:1:500; f1=200*exp(-1.*t./62.5);f2=200*exp(-1.*t./125.0);f3=200*exp(-1.*t./250.0);plot(t,f1, - ,t,f2, -- ,t,f3, -. )0 50 100 150 200 250 300 350 400 450 5000204060801001201401601802002、正弦信号t=-250:1:250; pi=3.1415926f1=150*sin(2*pi*t/100);f2=150*sin(2*pi*t/200);f3=150*sin(2*pi*t/200+pi/5);plot(t,f1, - ,t,f2, -- ,t,f3, - )-250 -200 -150 -100 -50 0 50 100 150 200 250-150-100-500501001503、正弦衰减信号t=0:1:500;f1=200*sin(((2*pi*t)/100)).*exp(-t/250);plot(t,f1) 0 50 100 150 200 250 300 350 400 450 500-150-100-500501001502004、钟形信号t=-250:1:250;f1=400*exp((-t.*t)./(100*100));f2=400*exp((-t.*t)./(150*150));f3=400*exp((-t.*t)./(250*250));plot(t,f1, - ,t,f2, -- ,t,f3, -. )-250 -200 -150 -100 -50 0 50 100 150 200 2500501001502002503003504005、符号信号t=-5:0.001:5;f1=sign(t);plot(t,f1)-5 -4 -3 -2 -1 0 1 2 3 4 5-1-0.8-0.6-0.4-0.200.20.40.60.816、阶跃信号t=-5:0.001:5;f1=0.5+0.5*sign(t);plot(t,f1)-5 -4 -3 -2 -1 0 1 2 3 4 500.10.20.30.40.50.60.70.80.91二、连续时间信号的运算已知 及信号 ，用 MATLAB 绘出满足下列要)]4()[()1 tutf )sin()2ttf求的信号波形。(1 ) (2))()(113tfft )](2([)(114 tfftf(3 ) (4)325216(5 ) )(()267 tftf(1):syms tf1=sym( (-t+4)*(heaviside(t)-heaviside(t-4)) );subplot(1,2,1);ezplot(f1);y1=subs(f1,t,-t);f3=f1+y1;subplot(1,2,2);ezplot(f3);0 0.5 1 1.5 2 2.5 3 3.5 400.511.522.533.54t(-t+4) (u(t)-u(t-4))-4 -3 -2 -1 0 1 2 3 400.511.522.533.54t(-t+4) (u(t)-u(t-4))+(t+4) (u(-t)-u(-t-4))(2) syms tf1=sym( (-t+4)*(heaviside(t)-heaviside(t-4)) );subplot(1,2,1);ezplot(f1);y2=subs(f1,-2*t);f4=-(y2+f1);subplot(1,2,2);ezplot(f4);0 0.5 1 1.5 2 2.5 3 3.5 400.511.522.533.54t(-t+4) (u(t)-u(t-4)-2 -1 0 1 2 3 4-4-3.5-3-2.5-2-1.5-1-0.50t-(2 t+4) (u(-2 t)-u(-2 t-4)-(-t+4) (u(t)-u(t-4)(3)syms tf2=sym( sin(2*pi*t) );subplot(1,3,1);ezplot(f2);subplot(1,3,2);ezplot(f3);f5=f2*f3;subplot(1,3,3);-6 -4 -2 0 2 4 6-1-0.500.51tsin(2  t)-4 -2 0 2 400.511.522.533.54t(-t+4) (u(t)-u(t-4)+(t+4) (u(-t)-u(-t-4)-4 -2 0 2 4-4-3-2-101234tsin(2  t) (-t+4) (u(t)-u(t-4)+(t+4) (u(-t)-u(-t-4))(4) syms tsubplot(1,3,1);ezplot(f1);subplot(1,3,2);ezplot(f2);f6=f1*f2;subplot(1,3,3);ezplot(f6)0 1 2 3 400.511.522.533.54t(-t+4) (u(t)-u(t-4)-6 -4 -2 0 2 4 6-1-0.500.51tsin(2  t)0 1 2 3 4-3-2-101234t(-t+4) (u(t)-u(t-4) sin(2  t)(5) syms ty3=subs(f6,t-2);f7=y3*f2;subplot(1,1,1);ezplot(f7)2 2.5 3 3.5 4 4.5 5 5.500.511.522.533.54t(-t+6) (u(t-2)-u(t-6) sin(2  (t-2) sin(2  t)程序随堂测试：以 f(t)为三角信号为例，求 f(2t) , f(2-2t) t=-3:0.001:3;ft=tripuls(t,4,0.5); subplot(3,1,1); plot(t,ft); grid on;title ( f(t) );ft1= tripuls(2*t,4,0.5);subplot(3,1,2); plot(t,ft1); grid on;title ( f(2t) );ft2= tripuls(2-2*t,4,0.5);subplot(3,1,3); plot(t,ft2); grid on;实验二 线性系统时域分析一、连续时间信号卷积利用 MATLAB 实现下述两个信号的卷积积分：p=0.01;k1=-0.5:p:1;f1=1;k2=0:p:2;f2=0.5*k2;[f,k]=sconv(f1,f2,k1