Hello Dear, I'm looking for a accurate and simple way to model Rayleigh distributed sequences for modeling a wireless communication channel. I've already made a model by filtering white noise sequence but it doesn't work well and it is not accurate. Thanks.

# Modeling of Rayleigh Fading Channel

Started by ●January 4, 2008

Reply by ●January 4, 20082008-01-04

Rayleigh distribution can be generated from uniform distribution using the following formula. Z = a + sqrt(b*log[1 - U]); % log is natural log. where U is uniformly distributed random number in the range [0 <= U < 1]; In matlab rand function can be used to generate pseudo random numbers. In hardware we use LFSR to generate pseudo random numbers. mean of generated rayleigh distribution is given by m = a + sqrt(pi*b/4); ...... eq 2 and variance is given by var = b*(4-pi)/4; ...... eq 3 you can reverse calculate parameters a and b using eq 2 and 3, based on the desired mean and variance of rayleigh distribution. Regards Bharat Pathak Founder and CEO Arithos Designs www.arithos.com>Hello Dear, > >I'm looking for a accurate and simple way to model Rayleigh distributed >sequences for modeling a wireless communication channel. I've alreadymade>a model by filtering white noise sequence but it doesn't work well andit>is not accurate. > >Thanks. >

Reply by ●January 5, 20082008-01-05

On Jan 4, 4:32 pm, "zohreh" <zand2...@gmail.com> wrote:> Hello Dear, > > I'm looking for a accurate and simple way to model Rayleigh distributed > sequences for modeling a wireless communication channel. I've already made > a model by filtering white noise sequence but it doesn't work well and it > is not accurate. > > Thanks.If you have Matlab's Communications Toolbox, you can use its Rayleigh channel function. Darol Klawetter

Reply by ●January 7, 20082008-01-07

Thanks a lot. Now I have another problem. How the Doppler spread can affect the mean and variance of that? I mean how I can generate Rayleigh sequence by given Doppler spread and the variance (from Jakes's model)? >Rayleigh distribution can be generated from uniform distribution>using the following formula. > >Z = a + sqrt(b*log[1 - U]); % log is natural log. > >where U is uniformly distributed random number in the range >[0 <= U < 1]; In matlab rand function can be used to generate >pseudo random numbers. In hardware we use LFSR to generate >pseudo random numbers. > >mean of generated rayleigh distribution is given by > >m = a + sqrt(pi*b/4); ...... eq 2 > >and variance is given by > >var = b*(4-pi)/4; ...... eq 3 > >you can reverse calculate parameters a and b using eq 2 and 3, >based on the desired mean and variance of rayleigh distribution. > >Regards >Bharat Pathak >Founder and CEO >Arithos Designs >www.arithos.com > > >>Hello Dear, >> >>I'm looking for a accurate and simple way to model Rayleigh distributed >>sequences for modeling a wireless communication channel. I've already >made >>a model by filtering white noise sequence but it doesn't work well and >it >>is not accurate. >> >>Thanks. >> >