# Finding the Wiener filter transfer function

I am trying to understand the mechanism of finding the transfer function for a Wiener function.

|Rxx(0)   Rxx(-1) ...... Rxx(1-N)| | h(0) |   | Ryx(0) |
|Rxx(1)   Rxx(0)  ...... Rxx(2-N)| | h(1) | = | Ryx(1) |
|......   ......  ......  ...... | | .....|   |....... |
|Rxx(N-1) Rxx(N-2) ...... Rxx(0) | |h(N-1)|   |Ryx(N-1)|


Rxx is the autocorrelation of my input signal h is filter transfer function and Ryx is crosscorrelation of the input and output signal. My question is how to come up with the h. I mean i have two unknowns in this equation cause i dont know h and I dont know the y output signal therefore i cant calculate the crosscorelation Ryx.

Is there something that I need to assume in order to get the h??

Thanks in advance for the help.