Joint Turbo Frequency Domain Equalization and Carrier Synchronization

In this paper we investigate the effect of frequency offset and phase noise on a turbo frequency domain equalization system. We propose a joint synchronization and equalization method which is based on maximum a priori estimation of the phase error caused by frequency offset and phase noise. This estimation is generated using the log likelihood ratios of the bits provided by the decoder during iterations. This estimator has the form of a decision directed phase lock loop which can compensate for the effect of the phase error after a few iterations.