Re: [Discuss-gnuradio] anyone implement the Raleigh fading model/multi-path?

[Tom Rondeau]

Richard Clarke wrote:
> Hi George,
>
> I have had a Summer student doing some work on this (a year ago now). 
> He implemented a GNU Radio module that can do Rayleigh channel 
> simulation. He based it on a particular paper (I'd have to look it up) 
> for the implementation. He verified the statistical performance of his 
> implementation against the Matlab Rayleigh channel model and against 
> theory and found it to be a close match. I'm not entirely convinced of 
> the delayed multiple path aspects of the design/implementation but 
> haven't had time to look into it further. In fact as it stands I 
> believe the GNU Radio module (at C++ level) only handles a single flat 
> fading path and doing multiple delayed paths is done at the python 
> module level and which invokes multiple instances of the Flat fading 
> Rayleigh C++ GNU Radio module.
>
> I'd welcome another set of eyes and someone more experienced than I am 
> with GNU Radio to help finish off this potentially very useful 
> addition to the GNU Radio code base.
>
> Cheers
> Richard

Richard,

That sounds great; please let us contribute it. We have a basic channel 
model in Python that implements an AWGN channel, but has a filter, which 
you can set the taps to do fading. It'd be nice if we could enhance this 
to implement a Rayleigh, and even Rician channel (Nakagami, too, for 
those of you who really care about this stuff).

Sounds like your student did some version of Jakes' model. At least, 
that's where I'd start. I have this in Matlab from an old class project 
that I was going to see about resurrecting, but it'd be great to have it 
already implemented in GNU Radio.

Thanks!
Tom