Li-Fi System Reliability in Real-World Deployments: SimulationBased Evaluation of QPSK Modulation and Adaptive Optimization for Noise Resilience

Optical wireless advancements positioned Light Fidelity (Li-Fi) as a robust alternative to radio-frequency technologies. This study evaluated Li-Fi reliability under real-world conditions using MATLAB and OptiSystem simulations, analyzing critical metrics including Q factor and Bit Error Rate (BER). A basic unmodulated configuration achieved a peak Q factor of 4.61 (BER: 1.13 × 10⁻⁶), but ambient noise degraded performance to � = 1.33 (BER: 0.091). Quadrature Phase Shift Keying (QPSK) mitigated degradation, yielding a Q factor of 21.52 (���: 5.42 × 10⁻¹⁰³), outperforming On-Off Keying (OOK) in spectral efficiency and noise resilience. Findings emphasized modulation selection and adaptive filtering to optimize signal integrity, validating Li-Fi’s viability for high-speed applications in smart homes, industrial IoT, and vehicular networks. Future work should prioritize hybrid modulation and environmental adaptability to expand Li-Fi’s utility in complex wireless ecosystems