jigesi 发表于 2012-7-20 07:12 
the property of a stationary process ACF-r(l, m)=r(l+t, m+t), not related to t. if the process is n ...
Thanks for your comment. Yes, I see.
I am try to overcome the problems, e.g. the one you stated.
At least, I hope I can derive some properties or something I can say to the ACs