7.m

已知一个LTI系统的差分方程为： y[n]-1.143*y[n-1]+0.4128*y[n-2]=0.0675*x[n]+0.1349*x[n-1]+0.0675*x[n-2] 初始条件y(-1

N=11;
n=0:N-1
b=[0.03571,0.1428,0.2143,0.1428,0.03571];a=[1,-1.035,0.8264,-0.2605,0.04033];
x=[1,zeros(1,N-1)];
h=filter(b,a,x)
x=1+cos(pi/4*n)+cos(pi/2*n)
y=filter(b,a,x)
stem(n,y)