MATLAB实验报告第二章Word下载.docx
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(3)xt=10exp(-t)-5exp(-2t)
A=10;
a=-1;
t=0:
x1t=A*exp(a*t);
A=5;
a=-2;
x2t=A*exp(a*t);
xt=x1t-x2t;
(4)xt=tu(t)
t=-10:
xt=t.*heaviside(t);
(5)xt=2|sin(10pit+pi/3)|
A=2;
w0=10*pi;
phi=pi/3;
1;
xt=A*abs(sin(w0*t+phi));
axis([0,1,-4,4])
Xt=cost+sin(2pit)
A=1;
w0=1;
phi=0;
0.002:
x1t=A*cos(w0*t+phi);
w0=2*pi;
x2t=A*sin(w0*t+phi);
xt=x1t+x2t;
(7)xt=4exp(-0.5t)cos(2pit)
a=-0.5;
x2t=A*cos(w0*t+phi);
xt=x1t.*x2t;
(8)Sa(pit)cos(30t)
A=1;
w0=30;
3;
x2t=sinc(t);
plot(t,xt)
M2-3,写出书中图示波形函数,并画出xt,x0.5t,x(2-0.5t)的图像
functionyt=x2_3(t)
yt=t.*(t>
=0&
t<
2)+2*(t>
=2&
3)+(-1)*(t>
=3&
=5);
5;
xt=x2_3(t);
title('
x(t)'
);
axis([0,6,-2,3])
xt=x2_3(0.5*t);
x(0.5t)'
)
axis([0,10,-2,3])
xt=x2_3(2-0.5*t);
x(2-0.5t)'
axis([-10,10,-2,3])
M2-4画出图示的奇分量和偶分量。
解,因为偶分量:
x1t=1/2*(xt+x(-t)
奇怪量:
x2t=1/2*xt-x(-t)
functionyt=x2_4(t)
=(-1)&
=0);
t=-2:
2;
xt=0.5*(x2_4(t)+x2_4(-t));
jifenliang'
axis([-2,2,-1,1])
t=-2:
xt=0.5*(x2_4(t)-x2_4(-t));
oufenliang'
M2-5利用MATLB实现下列离散时间信号。
(1)xk=daltak
k=-50:
50;
delta=[zeros(1,50),1,zeros(1,50)];
stem(k,delta)
(2)xk=uk
uk=[zeros(1,50),ones(1,51)];
stem(k,uk)
(3)10*(0.5)^k*uk;
a=1/2;
x1k=A*a.^k;
x2k=uk;
xk=x1k.*x2k;
stem(k,xk)
(4)xk=u(k+2)-u(k-5);
(5)xk=ku(k);
xk=[zeros(1,50),ones(1,51)];
x1k=k.*xk;
stem(k,x1k)
(6)xk=5(0.8)^k+=*cos(0.9piK);
k=-10:
a=0.8;
w0=0.9*pi;
x2k=cos(w0*k);
M2-7已知连续信号x1t=cos(6pit)、x2t=cos(14pit)、x3t=cos(26pit)抽fs=10hz,对这三个抽样的离散序列x1k、x2k,x3k,在同一图上画出连续信号及其对应的离散系列图。
解:
x1k=cos(6pit)|t=0.1k=cos(0.6pik)
X2k=cos(14pit)|0.1k=cos(1.4pik);
X3k=cos(26pit)|t=0.1k=cos(2.6pik);
(1):
w0=6*pi;
subplot(1,2,1);
xt=A*cos(w0*t);
axis([-1,1,-1,1])
w0=0.6*pi;
subplot(1,2,2);
xk=A*cos(w0*k);
(2)t=-1:
w0=14*pi;
axis([-1,1,-2,2])
w0=1.4*pi;
(3)>
t=-1:
w0=26*pi;
w0=2.6*pi;
M2-8分别用square函数和sawtooth画出图示离散周期序列。
(1)>
k=0:
40;
T=10;
w0=2*pi/T;
xk=A*square(w0*k,50);
(2)
T=20;
xk=A*sawtooth(w0*k,0.2);
M2-9(1画出xk[-3,-2,3,1,-2,-3,-4,2,-1.4.1]的波形,
(2)画出3倍抽取和3倍内插的波形。
(3)画出想x(k+2)和x(k-4)的波形。
(4)利用fliplr函数实现序列x[-k],并画出波形。
>
k=-4:
6;
x=[-3,-2,3,1,-2,-3,-4,2,-1,4,1];
stem(k,x)
x[k]'
k=-1:
x=[-2,-2,2,1];
x[k]d的3倍抽取'
k=-12:
18;
x=[-3,0,0,-2,0,0,3,0,0,1,0,0,-2,0,0,-3,0,0,-4,0,0,2,0,0,-1,0,0,4,0,0,1];
x[k]d的3倍内插'
k=-6:
4;
x=[-3,-2,3,1,-2,-3,-4,2,-1,4,1];
x[k+2]'
x[k-4]'