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phase recovery

Started by m September 3, 2008
Hi everybody,

I am implementing a GMSK demodulator. To achieve coherent demodulation, I
recovered the frequency with the power of 4 of the signal. How can I
recover then the phase? Can anybody give me any clue?

Thanks
mj


On Sep 4, 1:10 am, "m" <stuttbr...@hotmail.com> wrote:
> Hi everybody, > > I am implementing a GMSK demodulator. To achieve coherent demodulation, I > recovered the frequency with the power of 4 of the signal. How can I > recover then the phase? Can anybody give me any clue? > > Thanks > mj
I am rusty on this but I think you need a power of 4 and then a phase- locked loop. You then divide down by 4 the recovered frequency. Will be a bit noisy.
>On Sep 4, 1:10 am, "m" <stuttbr...@hotmail.com> wrote: >> Hi everybody, >> >> I am implementing a GMSK demodulator. To achieve coherent demodulation,
I
>> recovered the frequency with the power of 4 of the signal. How can I >> recover then the phase? Can anybody give me any clue? >> >> Thanks >> mj > >I am rusty on this but I think you need a power of 4 and then a phase- >locked loop. You then divide down by 4 the recovered frequency. Will >be a bit noisy. >
Thank you for your answer, I tried what you suggest but the peak that should happen at 4 times the frequency is very weak and, as there is doppler, maybe the PLL could lock to a wrong frequency. Any other ideas? Thansk a lot mj