Hi and thanks for the quick reply!
I think Iam just confused about the notation.
When I look at the Matrix forms of rx(k, l) and rx(k) my book says:
Rx(k,l) = Rx(0,0) Rx(0,1)... Rx(0,p)
Rx(1,0) Rx(1,1)... Rx(1,p)
...
Rx(p,0) Rx(p,1)... Rx(p,p)
If x...