Enhanced Acquisition and Tracking in All Digital Phase-Locked Loops

Abstract

This paper presents a technique to substantially mitigate the tracking jitter of all digital phase-locked loops and, hence, enhance the overall performance of the loop. This has been achieved by a structure utilizing a notch filter in a cascade arrangement with the loop filter to suppress the undesired frequency components and preserve the DC value at the output of the loop filter, which represents the trial value of the carrier phase error. A rapid acquisition of the error and a bit error rate (BER) performance close to theoretical results have been achieved.