Newsgroups: comp.speech
Path: pavo.csi.cam.ac.uk!doc.ic.ac.uk!pipex!howland.reston.ans.net!torn!nott!cunews!wilf
From: wilf@sce.carleton.ca (Wilf Leblanc)
Subject: Re: Q: How to get Distortion-Rate Function value of Gaussian Source.
Message-ID: <wilf.751302139@rigel.sce.carleton.ca>
Keywords: Distortion-rate function, Rate-distortion, Gaussian
Sender: news@cunews.carleton.ca (News Administrator)
Organization: Carleton University
References: <sliawati.751257927@bluering.cowan.edu.au>
Date: Fri, 22 Oct 1993 15:02:19 GMT
Lines: 24

sliawati@scorpion.cowan.edu.au (Suryadiputra LIAWATIMENA) writes:

>	Could someone help me to understand how to calcute or get distortion 
>-rate value for Gaussian source. 
>[...]
>... Another interesting conclusion from (D.19b) is that the mse is reduced by
>factor of 4 of each bit additionally spent in the transmission; the SNR in dB
>is 6.02 times the bit rate R."

>Autoregressive Gaussian source is frequently used for modelling the speech, 
>with mean=0 and unit variance (SQR(sigma_x) = 1).

>The question is: Where the 6.02 value comes from?
>	Thank you very much in advance.

>[...]

You already said it yourself.  The mse is reduced by a factor of 4
(2^(-2R) = 1/4), which on a dB scale is:

    10*log10(1/4) = 6.02...

							wilf

