4.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
x=[n>=0]
x3=cos((7*pi/10)*n)
b=[0.0675,0.1349,0.0675];a=[1,-1.143,0.4128];
%x=ones(1,N);
zi=filtic(b,a,[1,2]);
y=filter(b,a,x3,zi)
stem(n,y)