[ns] Wireless CDMA simulation

[Alfredo Todini <a.todini@mclink.it>]

Hello. I am a student at the University of Rome, I am working on my thesis 
for which I should develop a simulation of a wireless CDMA system 
(UMTS-TDD) using NS. I would like to use the NS wireless model, but there 
is nothing specific for CDMA. Has anybody done some work on this ?
I am beginning to consider how to simulate the channel. In TDD-CDMA a 
channel is basically a code/timeslot pair (we are using a single band of 
frequencies). However, channels can have different bandwidths (you can vary 
the spreading factor). Moreover, it should be possible to vary the 
bandwidth assigned to a channel during the simulation. If you use shared 
channels (which is my case) it must be possible to dynamically assign a 
channel to different mobiles on every frame.
Can anybody give me a hint on how to solve this problems ?
Thank you.

Alfredo