kaushalparikh@yahoo.com wrote:

> Can I implement a MSK demodulator using PLL? Basically I want to
> demodulate MSK using FM demodulator IC. The IC uses a PLL for FM
> demodulation.

If you can do FM demodulation then you can probably do MSK -- you'd 
really want a chip that is designed for FSK demodulation, but as long as 
you can recover DC from your PLL you'll be all right as far as it goes.
> 
> What are the drawbacks in using PLL ( if I can use one ) as compared to
> coherent demodulator with carrier recovery?
> 
Noncoherent demodulation of MSK loses you a whole bunch of effective 
power.  Just how much you'd lose probably depends on the error rate that 
you're aiming for and how you implement your detector.  For a realistic 
system with Gaussian noise I'll bet that you couldn't do better than 6dB 
loss; in something that's just thrown together the loss could easily be 
as bad as 20dB.

For information on coherent detection of MSK see my Master's thesis: 
http://www.wescottdesign.com/articles/MSK/mskTop.html.  It probably 
isn't the best possible exposition on MSK, but it's the best one I can 
point to on the web (other links would be welcome).

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

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See details at http://www.wescottdesign.com/actfes/actfes.html

Can I implement a MSK demodulator using PLL? Basically I want to
demodulate MSK using FM demodulator IC. The IC uses a PLL for FM
demodulation.

What are the drawbacks in using PLL ( if I can use one ) as compared to
coherent demodulator with carrier recovery?

Thanks

~ Kaushal