Improved acquisition in phase-locked loops with sawtooth phase detectors
Abstract
Phase-locked loops are frequently used to estimate bit timing in baseband digital transmission systems. The investigation reported here examines the applicability of a frequency-sensitive phase detector to timing estimation of randomized data. A new edge-triggered sawtooth phase detector is described. The reduced magnitude of circuit-induced imperfections made possible by the new detector, in conjunction with the little-known frequency discrimination characteristic of the sawtooth detector, is shown to allow significant improvements to acquisition performance. A potential problem with this and other phase-locked loops, false-lock, is studied experimentally, and techniques for avoiding it are discussed.
- Publication:
-
IEEE Transactions on Communications
- Pub Date:
- October 1982
- Bibcode:
- 1982ITCom..30.2364H
- Keywords:
-
- Digital Systems;
- Frequency Discriminators;
- Phase Detectors;
- Phase Locked Systems;
- Sawtooth Waveforms;
- Tracking Problem;
- Feedback Control;
- Performance Prediction;
- Phase Error;
- Pulse Communication;
- Random Noise;
- Electronics and Electrical Engineering