Study of EEPN mitigation using modified RF pilot and Viterbi-Viterbi based phase noise compensation

Area of Science:

• Optical Communications
• Signal Processing
• Digital Communication

Background:

• Equalization enhanced phase noise (EEPN) is a significant challenge in high-speed optical systems.
• Existing methods for EEPN mitigation have limitations in performance and applicability.

Purpose of the Study:

• To propose a novel method for mitigating EEPN in n-level PSK optical systems.
• To investigate the effectiveness of balanced phase modulation for EEPN compensation.
• To compare the proposed method with existing EEPN mitigation techniques.

Main Methods:

• A balanced phase modulation scheme is applied to the optical signal's two polarizations.
• Complex conjugation and multiplication are used in the receiver for EEPN compensation and carrier phase extraction.
• System simulations of a single-channel QPSK system at 56 Gb/s are performed.

Main Results:

• The proposed conjugation and multiplication scheme mitigates EEPN by approximately ½ orders of magnitude.
• The Viterbi-Viterbi algorithm demonstrates superior performance, improving sensitivity by over two orders of magnitude.
• Novel insights into the statistical properties of EEPN are presented.

Conclusions:

• Balanced phase modulation offers a viable approach for EEPN mitigation in n-level PSK systems.
• While effective, the proposed method's performance is surpassed by the Viterbi-Viterbi algorithm in sensitivity improvement.
• Further research into EEPN statistical properties can lead to enhanced mitigation strategies.