OIRS-enhanced NOMA-VLC systems: optimization and experimental validation of sum data rate and user fairness

Area of Science:

• Wireless communication
• Optical networking
• Signal processing

Background:

• Visible Light Communication (VLC) systems offer high bandwidth but face challenges with signal strength and interference.
• Non-Orthogonal Multiple Access (NOMA) technology aims to improve spectral efficiency and user capacity in wireless systems.
• Optical Intelligent Reflecting Surfaces (OIRS) can dynamically control signal propagation, enhancing VLC performance.

Purpose of the Study:

• To develop and evaluate an OIRS-assisted NOMA-VLC system that optimizes both sum data rate and user fairness.
• To address the non-convex optimization problem of resource allocation in OIRS-assisted NOMA-VLC systems.
• To provide the first experimental validation of OIRS-assisted NOMA-VLC systems.

Main Methods:

• A mathematical model was formulated considering OIRS configuration, successive interference cancellation (SIC), and Quality of Service (QoS) requirements.
• The problem was decomposed into two subproblems solved using an alternating optimization algorithm.
• Advanced evolutionary algorithms, including NSGA-SACM and MOEAD-HCANW, were employed for OIRS and LED power allocation optimization.

Main Results:

• The proposed OIRS-assisted NOMA-VLC system significantly outperformed baseline methods in numerical simulations.
• The system demonstrated substantial improvements in both bit rate and user fairness, particularly in indoor environments.
• Experimental validation confirmed the simulation results, showing good agreement and highlighting the effectiveness of OIRS.

Conclusions:

• OIRS effectively enhances the performance of NOMA-VLC systems by improving signal strength and reducing interference.
• The proposed resource allocation algorithms successfully balance data rate and user fairness, addressing QoS requirements.
• The integration of OIRS with NOMA-VLC presents a promising approach for future high-performance wireless communication systems.