Visible Light Communication: Principles, Architectures, and Emerging Applications

Visible Light Communication (VLC) is an emerging wireless communication technology that utilizes the visible light spectrum (380–780 nm) for simultaneous illumination and high-speed data transmission. By modulating the intensity of Light Emitting Diodes (LEDs) at rates imperceptible to the human eye, VLC offers a transformative solution to the congested radio frequency (RF) spectrum. This paper presents a comprehensive review of VLC principles, system architectures, modulation techniques, channel characteristics, and diverse applications. We examine transmitter and receiver designs, including advanced multi-channel RGB configurations and MIMO architectures. The paper analyzes channel-modeling approaches for both indoor and underwater environments, evaluates key modulation schemes including OFDM and Color Shift Keying, and discusses critical challenges such as ambient light interference, non-line-of-sight propagation, and uplink implementation. We conclude by exploring future directions, including Li-Fi integration with 5G/6G networks, underwater optical wireless communication, and intelligent reflecting surfaces. Our analysis indicates that VLC technology, with its abundant unlicensed spectrum and inherent security advantages, is positioned to play a pivotal role in next-generation wireless networks