A simple algorithm I have used in the pastis to measure phase offset.
in short intervals starting with an interval in which under worst case errors phase changes of less than 180 deg can happen. correct the frequency error for that. lengthen the interval, rinse and repeat. until your phase offset is constant. measure phase error from there. then compute a frequency offset you need to apply to have the phase change over this error in a given timeframe or compute a time you have to shift frequency by a given amount. after the time has elapsed switch back to your previously measured offset. You should now have about zero frequency and phase error. you will now have to fix the small errors in f and p continuously. I have used this ages ago (~1989) for a positioning system that had to lock on the Stereo Pilot Tone or the RDS carrier of multiple FM Broadcast transmitter ( that ran in lockstep). uwe _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
