時域離散信號的產生與基本運算

1、實驗一時域離散信號的產生與基本運算一、實驗目的1、了解常用的時域離散信號及其特點。2、掌握MATLAET生常用時域離散信號的方法。3、掌握時域離散信號簡單的基本運算方法。二、實驗內容1、自己設定參數(shù)，分別表示并繪制單位抽樣序列、單位階躍序列、正弦序列、實指數(shù)序列、隨機序列。2、自己設定參數(shù)，分別表示并繪制信號移位、信號相加、信號相乘、信號翻轉、信號和、信號積、信號能量。3、已知信號(1)描繪x(n)序列的波形。(2)用延遲的單位脈沖序列及其加權和表示x(n)序列。(3)描繪以下序列的波形：xi(n)=2x(n-2),X2(n)=2x(n+2),X3(n)=x(2-n)三、實現(xiàn)步驟1、自己設定參

2、數(shù)，分別表示并繪制單位抽樣序列、單位階躍序列、正弦序列、實指數(shù)序列、隨機序列。(1)單位抽樣序列程序：x=zeros(1,10);012345678910x(2)=1;stem(x,'filled')axis(0,10,-0.2,1);title('?3e?uDod);D'單位抽樣序列0.80.60.40.20-0.2(2)單位階躍序列程序：N=10;u=ones(1,N);stem(u,'filled')axis(-10,10,0,1);title('心¥?x?D6&D'單位階躍序列(3)正弦序列程序：x=-2

3、0:1:20;y=sin(0.2*pi.*x+0.5*pi);stem(x,y,'filled');axis(-20,20,-2,2);title('?y?oD)oaD);正弦序列1.5-20-15-10-505101520(4)實指數(shù)序列a=1/2程序：n=0:10;a1=1/2;y1=a1.An;stem(n,y1,'filled');axis(0,10,0,1);title('eii?eyDoaD£?a=1/?;圖45實指數(shù)序列a=2程序：n=0:10;a2=2;y2=a2.An;stem(n,y2,'filled'

4、;);e?eyDoaD,a=2'實指數(shù)序列，a=2120010008006004002000106隨機序列程序:y=rand(1,20);stem(y,'filled'）；title('?uD6aD);隨機序列2、自己設定參數(shù)，分別表示并繪制信號移位、信號相加、信號相乘、信號翻轉、信號和、信號積、信號能量。信號的移位:(1)信號移位程序：n=-3:10;k0=3;k1=-3;x=cos(2*pi*n/10);x1=cos(2*pi*(n-k0)/10);x2=cos(2*pi*(n-k1)/10);subplot(3,1,1),stem(n,x,ylabel(&

5、#39;x(n)');subplot(3,1,2),stem(n,x1,ylabel('x(n-2)');subplot(3,1,3),stem(n,x2,%6心？D?o?心？6?'filled');'filled');'filled');ylabel('x(n+2)');2信號相加、信號相乘程序：n=-3:20;x1=cos(2*pi*n/10);subplot(2,2,1);stem(n,x1,'filled');title('x(1)');axis(-4,20,-2,2

6、);x2=cos(2*pi*n/10);subplot(2,2,2);stem(n,x2,'filled');title('x(2)');axis(-4,20,-2,2);y=x1+x2;subplot(2,2,3);stem(n,y,'filled');title('D?o?d?。/);axis(-4,20,-2,2);y=x1.*x2;subplot(2,2,4);stem(n,y,'filled');title('D?o?a3?');axis(-4,20,-2,2);n=-5:5;x=exp(-0.4

7、*n);x1=fliplr(x);n1=-fliplr(n);subplot(2,1,1),stem(n,x,'filled');title('x(n)'subplot(2,1,2),stem(n1,x1,'filled');title('x(-n)'）；信號和、信號積、信號能量：程序：x=1,2,3,4,5,6,7,8,9;y1=sum(x)y2=prod(x)E1=sum(x.*conj(x)得到：y1=45y2=362880E1=2853、已知信號(1)描繪x(n)序列的波形；(2)用延遲的單位脈沖序列及其加權和表示x(n)

8、序列;(3)描繪一下序列的波形functionf=u(t)f=(t>=0);subplot(2,1,1)n=-10:10;y1=(2*n+5).*(u(n+4)-u(n)+6.*(u(n)-u(n-5);stem(n,y1,'filled')axis(-10,10,-3,6);title('序列波形)；t=-10:10;subplot(2,1,2)y=(-3)*(u(t+4)-u(t+3)+(-1)*(u(t+3)-u(t+2)+(u(t+2)-u(t+1)+3*(u(t+1)-u)+6*(u-u(t-1)+6*(u(t-1)-u(t-2)+6*(u(t-2)-u

9、(t-3)+6*(u(t-3)-u(t-4)+6*(u(t-4)-u(t-5)；stem(t,y,'filled')axis(-10,10,-3,6);title('用單位脈沖序列及其加權和表示序列波形);subplot(2,2,1)t=-10:10;y=(-3)*(u(t+4)-u(t+3)+(-1)*(u(t+3)-u(t+2)+(u(t+2)-u(t+1)+3*(u(t+1)-u(t)+6*(u(t)-u(t-1)+6*(u(t-1)-u(t-2)+6*(u(t-2)-u(t-3)+6*(u(t-3)-u(t-4)+6*(u(t-4)-u(t-5);stem(t,

10、y,'filled')axis(-10,10,-6,12);title('x(n)');subplot(2,2,2)t=-10:10;y=(-3)*(u(t+4)-u(t+3)+(-1)*(u(t+3)-u(t+2)+(u(t+2)-u(t+1)+3*(u(t+1)-u(t)+6*(u(t)-u(t-1)+6*(u(t-1)-u(t-2)+6*(u(t-2)-u(t-3)+6*(u(t-3)-u(t-4)+6*(u(t-4)-u(t-5);stem(t+2,2*y,'filled')axis(-10,10,-6,12);title('2x

11、(n-2)');subplot(2,2,3)t=-10:10;y=(-3)*(u(t+4)-u(t+3)+(-1)*(u(t+3)-u(t+2)+(u(t+2)-u(t+1)+3*(u(t+1)-u(t)+6*(u(t)-u(t-1)+6*(u(t-1)-u(t-2)+6*(u(t-2)-u(t-3)+6*(u(t-3)-u(t-4)+6*(u(t-4)-u(t-5)；stem(t-2,2*y,'filled')axis(-10,10,-6,12);title('2x(n+2)');subplot(2,2,4)t=-10:10;y=(-3)*(u(t+4)-u(t+3)+(-1)*(u(t+3)-u(t+2)+(u(t+2)-u(t+1)+3*(u(t+1)-u(t)+6*(u(t)-u(t-1)+6*(u(t-1)-u(t-2)+6*(u(t-2)-u(t-3)+6*(u(t-3)-u(t-4)+6*(u(t-4)-u(t-5