Research on Carrier Recovery Algorithm in Coherent Optical Communication System

Abstract

In coherent optical communication system, the random deviation of optical phase which is caused by the spontaneous emission of laser leads to phase noise, resulting in a random rotation of signal constellation. In order to ensure the reliability of the communication system, carrier phase estimation and recovery are required at the receiver. In this paper, we investigate two traditional carrier phase recovery (CPR) algorithms, including Viterbi&Viterbi phase estimation (VVPE) and blind phase search (BPS) algorithm. On this basis, we also discuss seven improved algorithms. Then we compare and analyze the hardware complexities of eight different CPR algorithms. In addition, the cause of equalization enhanced phase noise (EEPN) and its impact on the carrier phase recovery algorithm are also discussed.