I was wondering how to do carrier synchronization for CPFSK signals?
I want to decode the CPFSK signal by computing the phase difference. The
shape of the phase difference is similar to the following plot
|---| |---| fc+fd/2
- - -|- -| - | - | - - - fc
---| |---| |--- fc-fd/2
where fc is the carrier, fd is the peak frequency deviation.
Before send this demodulated data into the soft slicer, I have to build the
sample clock and recover the carrier frequency.
I plan to use the Gardner (or similar) detector to do the timing
synchronization. The input to the TED is just the phase difference as shown
above.
But I am not sure how to do the carrier synchronication. Can
anyone point me a method how to do this?
Thanks a lot!