[Freetel-codec2] Questions about FSK modem

[Qasim Chaudhari]

Hi,
I have three questions about an FSK modem.

1. When - and when not - is carrier frequency estimation necessary for FSK
demodulation? When it is required, how should we do that? Note that it's
different than phase recovery that is done for coherent demodulators.

2. For coherent demodulation, how can phase be recovered in FSK case? So
for example, how to design a PLL phase detector in that case? Is there some
feedforward scheme as well?

3. How to implement an equalizer for FSK modulated signals?

Appreciate your help.

Cheers,
Qasim

[David Rowe]

Hi,

1/ We have tone freq estimation in our FSK demod as the modulator used
for balloon telemetry tends to drift.

(2) and (3) are general questions that are not related to the codec 2
project.

- David

Post by Qasim Chaudhari
Hi,
I have three questions about an FSK modem.
1. When - and when not - is carrier frequency estimation necessary for
FSK demodulation? When it is required, how should we do that? Note that
it's different than phase recovery that is done for coherent demodulators.
2. For coherent demodulation, how can phase be recovered in FSK case? So
for example, how to design a PLL phase detector in that case? Is there
some feedforward scheme as well?
3. How to implement an equalizer for FSK modulated signals?
Appreciate your help.
Cheers,
Qasim
------------------------------------------------------------------------------
_______________________________________________
Freetel-codec2 mailing list
https://lists.sourceforge.net/lists/listinfo/freetel-codec2

------------------------------------------------------------------------------