Carrier recovery algorithms and real-time DSP implementation for coherent receivers

Phase noise is the most dynamic distortion in coherent optical transmission systems. In the development of carrier recovery algorithms hardware implementation constraints have to be taken into account. The choice between blind and pilot-based carrier recovery is not obvious. - Blind carrier recovery requires no overhead and achieves maximum phase noise tolerance, but requires differential coding and complex processing. - Pilot-based carrier recovery enables absolute phase detection and simple processing at the cost of additional signal overhead. The optimal choice can be different depending on system constraints, e.g. long-haul vs. metro, power consumption vs. performance...