Design and performance evaluation of a green LED OFDM LiFi system for an electromagnetic interference sensitive hospital network

Abstract

Light Fidelity (LiFi) is an alternative technology to Wireless Fidelity (WiFi) for secure, high-speed hospital communication. The main objective of this study is to design a Four-Quadrature Amplitude Modulation-Orthogonal Frequency Division Multiplexing (4QAM-OFDM) LiFi system that overcomes electromagnetic interference (EMI), ensures biological safety, guarantees secure medical data transmission, and delivers high-speed, low-latency connectivity for hospital networks. The core contribution is a holistic 4QAM-OFDM LiFi design that offers superior spectral efficiency, significantly reduced Bit Error Rate (BER), and compliance with healthcare safety standards compared to existing LiFi systems, as demonstrated by its simulation using OptiSystem 21 and MATLAB R2024b. Using a 500 nm Light-Emitting Diode (LED) compliant with photobiological safety standards safeguards biological safety, while utilizing 1024-subcarrier OFDM decreases ISI. The receiver's Positive-Intrinsic-Negative (PIN) photodetector converts optical signals to electrical form, while the quadrature demodulator minimizes phase distortion, achieving a BER of 4.25E-3 at 30 dBm-further reducible to E-9 with error correction for reliable hospital communication. This performance demonstrates the system's suitability for mission-critical applications such as AI-assisted diagnostics, robotic surgery, and real-time medical imaging. The proposed system maintained excellent tolerance to both multipath distortion and external EMI, resolving EMI-related device interference, improving energy efficiency through reduced power consumption, and enhancing security via optical confinement that prevents signal leakage beyond hospital rooms. This enables a practical and scalable pathway for replacing WiFi in hospital environments, ensuring uninterrupted, high-speed, and safe communication for both routine and life-critical healthcare applications. The system reduces power consumption, diminishes CO₂ emissions, and improves hospital energy efficiency by promoting sustainable and eco-friendly LiFi technology. This study confirms LiFi as a secure, high-performance WiFi alternative for hospitals, meeting healthcare standards.