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Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
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ExtraTrees-hidden Markov model based equalizer for mode division multiplexing ring-core fiber communication with
Optics Express
|June 11, 2024
Summary
This study introduces an advanced equalizer for orbital angular momentum mode division multiplexing (OAM-MDM) systems. The new method significantly enhances receiver sensitivity and reduces computational complexity for high-capacity optical communications.
Area of Science:
- Optical Communications
- Signal Processing
Background:
- Orbital Angular Momentum Mode Division Multiplexing (OAM-MDM) is crucial for increasing fiber optic communication capacity.
- Non-orthogonal multiband carrierless amplitude and phase (NMCAP) modulation offers high spectral efficiency.
- Nonlinear channel impairments degrade signal quality in high-speed optical systems.
Purpose of the Study:
- To develop and evaluate a novel equalizer for OAM-MDM systems utilizing NMCAP modulation.
- To improve receiver sensitivity and reduce computational complexity compared to existing methods.
- To assess the feasibility of the proposed equalizer for ultra-high-capacity inter-data-center interconnections.
Main Methods:
- Implementation of an Extremely Randomized Trees-Hidden Markov Model (ExtraTrees-HMM) based equalizer.
- Modeling the nonlinear channel using statistical characteristics of received distorted signals.
- Experimental validation in a 216 Gbit/s OAM-MDM NMCAP optical fiber communication system over 2 km of ring-core fiber.
Main Results:
- The ExtraTrees-HMM equalizer improved receiver sensitivity by 1 dB for OAM mode l=+2 and 0.6 dB for OAM mode l=+3 compared to a conventional Volterra nonlinear equalizer (VNE).
- A reduction in computational complexity of 43.94% was achieved with the ExtraTrees-HMM equalizer compared to the VNE.
- The proposed method effectively mitigates nonlinear channel distortions.
Conclusions:
- The ExtraTrees-HMM equalizer is a highly effective solution for OAM-MDM systems with NMCAP modulation.
- This approach offers significant improvements in receiver sensitivity and computational efficiency.
- The ExtraTrees-HMM equalizer shows strong potential for future ultra-high-capacity optical communication networks.
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