Trellis-based feed-forward carrier recovery for coherent optical systems

Area of Science:

• Optical communications
• Signal processing
• Information theory

Background:

• Coherent optical systems face performance limitations due to phase noise from laser linewidth, fiber non-linearity, and phase-locked loops.
• High-order modulation formats are particularly sensitive to phase noise, impacting data rates and system reliability.

Purpose of the Study:

• To propose an efficient trellis-based algorithm for phase noise mitigation in coherent transmission systems.
• To enhance the performance of systems employing high-order modulation formats.

Main Methods:

• Development of a trellis-based phase noise mitigation algorithm.
• Utilization of a hardware-efficient parallelized and pipelined architecture for ultra-high data rate processing.
• Experimental validation using 200 Gb/s dual-polarization 16-quadrature amplitude modulation (DP-16QAM) signals.

Main Results:

• The proposed algorithm demonstrates significant performance improvement in coherent optical systems.
• Effective mitigation of phase noise from various sources, including laser linewidth, fiber non-linearity, and phase-locked loop.
• Experimental results show superior performance compared to existing phase noise mitigation methods.

Conclusions:

• The developed trellis-based algorithm offers an efficient solution for phase noise mitigation in coherent optical systems.
• The hardware-efficient architecture enables practical implementation for ultra-high data rate processing.
• The method shows particular benefit for high-order modulation formats, improving overall system performance.