Forum: GNU Radio GMSK and Carrier Recovery

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3e0b4883490ac6cd7631dd8edaaf6571?d=identicon&s=25 jjw (Guest)
on 2007-01-29 23:40
(Received via mailing list)
Hello all,

I am doing some work with the GMSK demodulator block that is provided as
part of GNU radio.  I had been noticing some problems where sometimes
demodulator would not be able to lock on to the signal (generated with
agilent signal generator) properly and determined that the problem is
due to
a carrier frequency offset of ~5 kHz.

While I could technically just compensate for the 5 kHz offset, this
wouldn't account for differences with other crystals or signal sources.
know that the mueller and muller timing recovery algorithm that is used
the GMSK block is dependent on carrier tracking so therefore I assume
that I
would need a carrier tracking loop that isn't dependent on timing
in order for it the design to work properly.

Has anybody attempted to add carrier recovery to the GMSK demod or could
offer any pointers on a good possible solution?  Any input into this
be greatly appreciated.

Thanks for all of the help,
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