On Tue, 06 May 2008 07:31:39 -0500, benpeterson wrote:

> Hi all,
> 
> I have a question,
> 
> I have a wav.file, which is a FM modulated signal. It has 3 channels. I
> want to demodulate them, in Signal Processing Toolbox of Matlab. (but
> just the first and second channel (not the third one))
> 
> I used "demod" function, but it functions very bad and the problem is
> that, i need to demodulate both channels at the same time (mixed), in
> order to have both of them together at the end too.
> 
> I don't know how to do it.
> As is said, "demod" function returns an unclear plot.
> 
> Do you have any idea, how i can demodulate both channels at the same
> time?
> 
> 
>  
> thanx in advance,
> benpeterson

How are the three channels modulated?  Is it like FM broadcast radio, 
with several channels that are frequency division multiplexed at 
baseband, then FM modulated onto a carrier?  Is it three FM carriers each 
with it's own modulation?  What?

I'm sure that Matlab's 'demod' function is designed to work with one FM 
signal, so presumably you'd be able to demodulate the FM broadcast case 
and do post-processing.  If you've got three carriers in your .wav file 
then you'll have to separate them out and then demodulate.

-- 
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

Hi all, 

I have a question,

I have a wav.file, which is a FM modulated signal. It has 3 channels.
I want to demodulate them, in Signal Processing Toolbox of Matlab. (but
just the first and second channel (not the third one))

I used "demod" function, but it functions very bad and the problem is
that, i need to demodulate both channels at the same time (mixed), in order
to have both of them together at the end too.

I don't know how to do it.
As is said, "demod" function returns an unclear plot. 

Do you have any idea, how i can demodulate both channels at the same time?

 

thanx in advance,
benpeterson