WCDMA simulation with awgn and multipath channel......ask for help....
shirly
I am now doing a final year project in order to complete the degree
study. The project is about the Simulation of WCDMA system.The
objective is study the performance of the system over AWGN and
Multipath Rayleigh Fading. I face some problem during simulation. Hope
anyone will give me an idea and solution. thanks.Below are my
problems:
AWGN:
In this block diagram, i only can run the simulation for single user
only. Between, i also want to run for multiusers such as 10, 40, and
100 users. I had tried to use "varian from mask" in the mode AWGN, but
the graph BER vs SNR show a straight line. I wonder why. Varian
represent the number of users and can be calculated using formula "
varian=(k-1)0.05" where k is number of user. Thus, how i can run
simulation for multiusers. any idea or should add any other block to
represent the users?
Multipath Rayleigh Fading.
Multipath rayleigh is the speed of the mobile /vehicular. The speed i
chose is 5km/h, 60km/h, 90km/h and 120km/h. It is done for single user.
The maximum dopple shift is =[(frequency x speed)/3x10power of 8] like
[(5km/3600s) x 2GHz] / 300 000 000.
For simulation of 5km/h, the graph is When SNR increase the BER will
decrease. but, it is different for graph 60km/h, 90km/h and 120km/h.The
graph obtained were when the SNR increase the BER increase too. This is
not the desired graph. As i know, when the SNR increase the BER will
decrease, am i right.? Although i using same parameter as in 5km/h, i
wonder why the BER is increase. do anyone, got any idea, or what should
i change in the parameter.?
i have attach the awgn and multipath block diagram on the web below:
http://www.esnips.com/web/siatsWebResearch
i hope anyone can give me a help, an idea or solution for the problem.
For your kindness help, i sincerely thanks.
shirly