信号系统实验第8章作业

第8章作业

8.1.2

a=[1,4,2];

b=[1,0,3];

sys=tf(b,a);

t=0:0.01:10;

f=exp(-t);

y=lsim(sys,f,t);

y_1=(6-3*2^(0.5)).*exp((-2+2^(0.5)).*t)+(3*2^(0.5)-2).*exp((-2-

2^(0.5)).*t)-4.*exp(-1.*t);

subplot(2,1,1),lsim(sys,f,t);

grid on

text(0.5,0.7,'\fontsize{30}\fontname{方正硬笔行书简体}\bf\leftarrow输入信号') text(4.3,0.2,'\fontsize{30}\fontname{方正硬笔行书简体}\bf\leftarrow输出信号') subplot(2,1,2),plot(t,y_1),grid on

title('\fontsize{30}\fontname{方正硬笔行书简体}\bf用经典方法求解出来的结果')

8.3.3

a=[1,4,5];

b=[1,0];

congjixuangying=impulse(b,a,0:10)

jieyuexiangying=step(b,a,0:10)

hold on

subplot(2,1,1),impulse(b,a,0:0.1:10);grid on

title('\fontsize{30}\fontname{方正硬笔行书简体}冲激响应') subplot(2,1,2),step(b,a,0:0.1:10);grid on

title('\fontsize{30}\fontname{方正硬笔行书简体}阶跃响应') congjixuangying =

1.0000

-0.1546

-0.0409

-0.0032

0.0003

0.0001

0.0000

-0.0000

-0.0000

-0.0000

0.0000

jieyuexiangying =

0.1139

0.0167

0.0003

-0.0003

-0.0000

-0.0000

0.0000

0.0000

0.0000

8.4.2

a=[1,1/2];

b=[1,2];

n=0:20;

xn=2.*cos(n.*pi./3);

yn=filter(b,a,xn)

hold on

yy=stem(n,yn,'filled');

set(yy,'Color','m','LineWidth',4)

grid on

title('\fontsize{30}\fontname{华文行楷}系统零状态响应时域波形')

xlabel('\fontsize{30}\fontname{华文行楷}n')

ylabel('\fontsize{30}\fontname{华文行楷}y(n)')

yn =

Columns 1 through 8

2.0000 4.0000 -1.0000 -

3.5000 -3.2500 0.6250 3.6875

3.1563

Columns 9 through 16

-0.5781 -3.7109 -3.1445 0.5723 3.7139 3.1431 -0.5715 -3.7142

Columns 17 through 21

8.6.3

a=[1,1,1/4];

b=1;

n=0:20;

hn=impz(b,a,0:20)

jieyuexiangying=filter(b,a,heavisidez(n))

hold on

subplot(2,1,1),impz(b,a,0:20)

title('\fontsize{30}\fontname{华文楷体}单位序列响应')

xlabel('\fontsize{30}\fontname{华文楷体}n')

ylabel('\fontsize{30}\fontname{华文楷体}hn'),grid on

subplot(2,1,2),zz=stem(n,jieyuexiangying,'filled');

set(zz,'Color','g','LineWidth',4),grid on

title('\fontsize{30}\fontname{华文楷体}阶跃响应')

xlabel('\fontsize{30}\fontname{华文楷体}n')

ylabel('jieyuexiangying')

hn =

1.0000

-1.0000

0.7500

-0.5000

0.3125

-0.1875

0.1094

-0.0625

0.0352

-0.0195

0.0107

-0.0059

0.0032

-0.0017

0.0009

-0.0005

0.0003

-0.0001

0.0001

-0.0000

0.0000

f =

Columns 1 through 13

1 1 1 1 1 1 1 1 1 1 1 1 1

Columns 14 through 21

1 1 1 1 1 1 1 1

jieyuexiangying =

Columns 1 through 8

1.0000 0 0.7500 0.2500 0.5625 0.3750 0.4844

0.4219

Columns 9 through 16

0.4570 0.4375 0.4482 0.4424 0.4456 0.4438 0.4448

0.4443

Columns 17 through 21

0.4445 0.4444 0.4445 0.4444 0.4445