Dear all,
I am trying to generate a noise channel for a synchronous downlink MC-CDMA
through a zero-mean complex Gaussian process through a designed filter whose
power spectrum density (PSD) is shaped as classic Doppler PSD.
The symbol rate, Rs, which is the chip rate over N subcarriers is set to
3.84Mchip/s. I have considered a normalized Doppler frequency of fdT = 0.001
where T is the duration of a symbol, which is the inverse of Rs. The system
operates a carrier frequency of fc = 2 GHz and vehicle speeds were simulated
with a maximum Doppler frequency of fd,max| = 120 Hz, which corresponds to a
nominal velocity of v = 65 kmph.
The problem is I am not sure on how to generate the noise model (Doppler PSD)
using the Matlab code. Is it right for me to multiply the Doppler PSD with the
AWGN in order to simulate a time-varying channel? Please somebody help me to
clarify this matter and if possible give the right Matlab code or Doppler PSD
algorithm.
Another thing, I need to know is there any correlation between Rayleigh
(distribution) channel with the the Doppler PSD.
Thanks and regards.
Najmy
