A Cycle-Slip Detector for Phase-Locked Demodulators

Thresholding in a phase-locked demodulator occurs because of cycle slipping between the received signal and the VCO of the PLD. Measurement of rate of occurrence of slips should be an elegant and sensitive method of determining the threshold of a PLL. It is surely a much simpler procedure than attempting to measure output SNR, particularly if the modulation is anything other than a simple sinewave. This paper describes the principles of a slip detector that was built for laboratory measurements.