s=tf('s');
wc=1/(1.5*s+1);
wd=c2d(wc,0.01,'tustin');
b(1)=0.003322; b(2)=0.003322;
a(1)=1; a(2)=-0.9934;
Ts=0.01;T=1000;
t=0:Ts:T;
x1=randn(1,length(t)); 
x=0.01*x1;
y=filter(b,a,x);
R=xcorr(y);
tau=-15+Ts:Ts:15;
lt=length(tau);
s1r=round(length(R)/2-lt/2);
s2r=round(length(R)/2+lt/2-1);
plot(tau,R(s1r:s2r)),grid