Hi There,
I was wondering if someone could help to define a good choice for digital
FSK demodulation method?
I need to demodulate a coherent FSK signal where fc=135kHz and mark and
space separation is 10kHz. The detector must be able to work in a somewhat
noisy environment but operate at (near) real-time. So a good trade-off
between speed and accuracy as well as complexity since i'm only a
undergraduate student.
I have looked at:
1) zero-crossing - looks a bit simple to me and i think it won't perform
well in a noisy environment.
2) short time DFT - very computationally intense. Think I don't have that
processing power.
3) digital PLL - I actually moved from this theory to the arctan
differentiated method as the part of phase detection is very similar.
4) arctan differentiated (quadrature demodulation) - this one looks
promising.
5) autocorrelation - for what I have read this seems to be the best
method, but also seems very complex and I don't think I want that for now.
So maybe there are more "satisfying" arguments why one doesn't want this?
I have started work on (4), this method comes up a lot on the internet,
but no one really explains why this is a good method.
I'm not asking for anyone to do my homework, i'm just looking for some
pointers and I don't really have the time to thoroughly test al the
options.
To everybody that can help me out, thank you very much!
Regards,
mf