It hard to understand what do you need. Usually noise parameters are inserted at the end of the S-parameters file (s2p or snp formats). If you use it with simulator program will do everything automatically.
Below is the part of the text that you may find on **broken link removed**
Noise parameters
It turns out that signal-to-noise ratio of a device is one of those "magic parameters" that are exactly described by circles of constant value on the Smith chart (much like small-signal gain). Contrast this with power amplifier responses such as contours of constant maximum efficiency, which are more generally described as "potatoes".
Once you have the noise parameters in hand using linear CAD software you can mathematically calculate the signal-to-noise response if the device sees impedances other than fifty ohms. Noise parameters are can be very accurate, if they are measured carefully.
There are three things that you are after when you measure noise parameters (four if you consider that gamma opt is a vector and has a real and imaginary part). Remember, the three noise parameters are functions of bias point, frequency and temperature, and of course, device geometry.
Gamma Opt
Gamma opt is the optimum impedance that must be presented to a low noise device to achieve its lowest possible noise figure.
Fmin
Fmin is the minimum noise figure of a device, and it is only achieved at gamma opt.
RN (equivalent noise resistance)
RN gives an indication of how fast the noise figure of a device degrades when it's input is matched to other impedances beside gamma opt. Lower RN is always desirable, it is a measure of the slope of noise figure versus impedance.
I hope it will help.
BR,
RF-OM