Improving performance of MLSE in RSOA-based WDM-PON by partial response signaling

Area of Science:

• Optical Communications
• Signal Processing
• Telecommunications Engineering

Background:

• High data-rate upstream transmission in WDM-PON is hindered by inter-symbol interference (ISI) from low-bandwidth transmitters and fiber dispersion.
• Reflective Semiconductor Optical Amplifiers (RSOAs) are commonly used but susceptible to these impairments.

Purpose of the Study:

• To propose and evaluate a novel receiver design for RSOA-based WDM-PON systems.
• To mitigate ISI and reflection impairments for enhanced upstream transmission performance.

Main Methods:

• Implementation of a Partial Response Maximum Likelihood (PRML) equalization technique.
• Combining Partial Response (PR) signaling with Maximum Likelihood Sequence Estimation (MLSE).
• Investigating the impact of discrete reflections on equalization techniques.

Main Results:

• PRML demonstrates superior performance over standard MLSE in suppressing ISI and reflections.
• Achieved 150 km unidirectional uplink at 10 Gb/s.
• Demonstrated bidirectional uplinks of 50 km (10 Gb/s) and 20 km (20 Gb/s).
• PRML shows greater robustness against discrete reflections compared to MLSE.

Conclusions:

• PRML equalization offers a more effective and less complex solution for RSOA-based WDM-PON systems.
• The proposed receiver significantly enhances the reach and data rates for upstream WDM-PON.
• PRML is a promising technique for future high-speed optical access networks.