Iterative code-aided phase noise synchronization based on the LMMSE criterion

In this paper, we examine code-aided synchronization in the presence of carrier frequency uncertainties and phase noise. As code-aided synchronization can only achieve high estimation accuracy if the initial parameter offset is sufficiently small, we employ a data-aided coarse synchronization unit comprising a feed-forward frequency estimator and a LMMSE estimator for pre-compensating frequency offsets and phase noise. Furthermore, we make use of known iterative synchronization techniques for frequency and phase offsets. We here extend the concept of iterative synchronization to iterative phase noise compensation and we show analytically under which circumstances our approach can achieve a worthwhile improvement in terms of estimation accuracy.