On the performance of estimators for burst-mode offset QPSK

Abstract

The Cramér-Rao bound for the joint estimator of carrier frequency offset, carrier phase offset, and symbol timing offset for offset QPSK is derived and used to identify “good” training sequences. Conveniently, sequences that repeat a single OQPSK constellation point are found to be the “best” for all three estimators when half-sine pulse shaping is used.