Model consists of two users (transmitters) who send bursts of data to a base station (receiver). Channel is clear, and no correction coding is used, for the sake of simplicity. Transmission is in base band, and is considered synchronized. Bursts of data are raw, without control bits. All of these: AWGN noise or fading, correction coding, transmission in bandpass channel, and control bits can be added easily. For the simulation of asynchronus link, i don't know.
For more talk about the model and technique, i recommend to visit the facebook page of the model, since i am there more available for help and explanation. URL is:
I am not sure if sfun (mexw32) file is uploaded. If not, contact me via facebook so i can send it to you.
Any suggestions, ideas, or discussion are welcome. :)