Re: Rayleigh and Ricean Distribution.

Ed Casas (edc@ece.ubc.ca) Thu, 2 Mar 2000 15:48:59 -0800 

Date: Thu, 2 Mar 2000 15:48:59 -0800
From: Ed Casas <edc@ece.ubc.ca>
Subject: Re: Rayleigh and Ricean Distribution.



On Wed, Mar 01, 2000 at 10:13:22AM -0800, Titus Cheung wrote:

> 1) "state whether the envelope or the envelope squared is so
> distributed and convert to/from dB" Do we attempt this by
> finding the sigma=RMS value of given envelope and see if the
> mean variance and median calculated with sigma are the same
> with the ones calculated directly?  Example: Are we trying to
> see if the value 0.43*sigma = second central moment of given
> envelope?
...
> 2) "state whether the envelope or the envelope squared is so
> distributed and convert to/from dB" What exactly does it mean
> by "convert to/from dB"?  Are we talking about the same thing
> listed under subtopic Basic Concepts of Review Lecture

Actually, I meant just that you should know that it's the
envelope (not the power) that is Rayleigh or Ricean and you
should be able convert to these voltage values to dB using
20log() (instead of 10log()).

> 3) As for "compute a probability that a Rayleigh or Ricean
> distributed variable is below a threshold ....."  This is just
> the CDF?

Yes.

> Someone know of the CDF for Ricean though?

I don't know what it is in closed form.  It won't be on the exam
except perhaps as an expression involving the integral of the
pdf.

-- 
Ed Casas   edc@ece.ubc.ca   http://casas.ece.ubc.ca   +1 604 822-2592