Efficiency Enhancement of RF-Pilot-Based Phase Noise Compensation for Coherent Optical OFDM Systems

Phase noise effects must be taken into account when studying the performance of coherent optical orthogonal frequency division multiplexing (CO-OFDM) transmission systems. One drawback of CO-OFDM is the high sensitivity to phase noise. In this paper, we explain different kinds of phase noise effects on the OFDM signals and analyze the phase noise effect induced by transmitter laser and receiver local oscillator. We review the pilot-aided and the standard RF-pilot (RFP) based phase noise compensation methods and explain its drawbacks. We provide two extended RFP schemes that overcome the drawbacks of the standard RFP scheme and enhance the performance of CO-OFDM systems. A simulation results of a CO-OFDM transmission system with 4-QAM is simulated. Furthermore, the phase noise effects for various laser linewidths on the system performance is presented.