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

Area of Science:

• Biomedical Engineering
• Optical Communications
• Wireless Networking

Background:

• Wireless Fidelity (WiFi) faces challenges in hospital environments including electromagnetic interference (EMI) and security vulnerabilities.
• Existing Light Fidelity (LiFi) systems require optimization for healthcare applications to ensure safety, security, and high performance.
• There is a need for a robust communication system that supports critical healthcare applications like AI diagnostics and robotic surgery.

Purpose of the Study:

• To design and simulate a Four-Quadrature Amplitude Modulation-Orthogonal Frequency Division Multiplexing (4QAM-OFDM) LiFi system tailored for secure, high-speed hospital communication.
• To address challenges such as electromagnetic interference (EMI), ensure biological safety, and guarantee secure medical data transmission.
• To achieve high-speed, low-latency connectivity for hospital networks, positioning LiFi as a viable WiFi alternative.

Main Methods:

• Designed a 4QAM-OFDM LiFi system incorporating a 500 nm Light-Emitting Diode (LED) compliant with photobiological safety standards.
• Utilized a 1024-subcarrier Orthogonal Frequency Division Multiplexing (OFDM) scheme to mitigate inter-symbol interference (ISI).
• Simulated the system using OptiSystem 21 and MATLAB R2024b, employing a Positive-Intrinsic-Negative (PIN) photodetector and quadrature demodulator for signal reception and processing.

Main Results:

• Achieved superior spectral efficiency and a significantly reduced Bit Error Rate (BER) of 4.25E-3 at 30 dBm, reducible to E-9 with error correction.
• Demonstrated excellent tolerance to multipath distortion and external EMI, resolving interference issues and enhancing security through optical confinement.
• Validated the system's biological safety compliance and improved energy efficiency, with reduced power consumption and CO₂ emissions.

Conclusions:

• The designed 4QAM-OFDM LiFi system offers a secure, high-performance, and biologically safe alternative to WiFi for hospital networks.
• The system's robustness against interference and its high data rates make it suitable for mission-critical healthcare applications.
• This LiFi technology presents a practical, scalable, and sustainable solution for modernizing hospital communication infrastructure.