[TowerTalk] My take on small power differences

[Lux, Jim]

On 5/18/22 5:31 PM, Brian Beezley wrote:
> I've been told I should post a link to this writeup I did several 
> years ago:
>
> http://ham-radio.com/k6sti/pileup.htm
>
> As noted in the analysis limitations section, I'm not sure how much it 
> really adds. But I do think a probabilistic approach is needed to 
> tease out the effect of small power differences.
>
> I've thought of recording pileups to try to obtain some realistic 
> signal power distributions. But it's tricky to do that well. I was 
> afraid I didn't know enough to avoid biased data so I've never done it. 


How did you choose log-normal as the "interference power" distribution?

I've just been looking at some modeling codes, and for an individual 
interferer, their power will likely be Rayleigh distributed (multipath 
fading in the ionosphere). I'm not sure what the "sum of Rayleigh" would 
look like (although I'll know shortly because I'm building a model).

( I note that the literature says "/Sums of Rayleigh/random variables 
occur extensively in wireless communications. A closed-form expression 
does not exist for the/sum distribution/." - so a Monte Carlo is where 
it's at.)