北邮通信工程MATLAB实验一-离散时间信号与系统..docx

MATLAB实验一一、常用离散信号的MATLAB产生和图形显示1、单位抽样序列 n=-5:15; zeros(1,20); x=(n==0); stem(n,x,.); 2、单位阶跃序列 n=-5:15; zeros(1,20); x=(n=0); stem(n,x,.);3、正弦序列 n=0:20; f=10; Fs=100; fai=pi/4; x=5*sin(2*pi*f*n/Fs+fai); stem(n,x,.);4、复正弦序列 x=exp(i*0.1*pi*n); stem(n,x);5、指数序列 n=0:10; x=2.^n; stem(n,x,.);二、离散系统的差分方程、冲击响应和卷积分析1、y[n]+0.75y[n-1]+0.125y[n-2]=x[n]-x[n-1]冲激响应： n=0:20; x=(n==0); y=filter([1,-1],[1,0.75,0.125],x); stem(n,y,.);阶跃响应： n=0:20; x=(n=0); y=filter([1,-1],[1,0.75,0.125],x); stem(n,y,.);2、y[n]=0.25{x[n-1]+x[n-2]+x[n-3]+x[n-4]}冲激响应： n=0:20; x=(n==0); y=filter([0,0.25,0.25,0.25,0.25],[1],x); stem(n,y,.);阶跃响应： n=0:20; x=(n=0); y=filter([0,0.25,0.25,0.25,0.25],[1],x); stem(n,y,.);三、离散系统的频率响应分析和零、极点分布 num=[0.0528,0.0797,0.1295,0.797,0.0528]; den=[1,-1,2.4947,-1.88,0.9537,-0.2336]; zplane(num,den); [H,w]=freqz(num,den); Hf=abs(H); plot(w,Hf);