INVESTIGATION OF VISIBLE LIGHT COMMUNICATION (VLC) SYSTEMS FOR INDOOR WIRELESS COMMUNICATION

Abstract Visible Light Communication (VLC) has emerged as a promising solution for high-speed indoor wireless communication, leveraging existing lighting infrastructure to transmit data. However, its performance is challenged by several factors, including rapid signal attenuation, multipath interference, ambient light noise, and modulation inefficiencies. This study aims to design and evaluate a robust VLC system architecture that addresses these limitations while optimizing data rates, coverage, and power efficiency for practical indoor applications. The research employs a quantitative experimental approach using MATLAB simulations to model key VLC components, including transmitter characteristics, channel propagation, and receiver performance. The Lambertian radiation pattern is analyzed for different LED semi-angles (30°–80°), revealing that a 60° beam (m=1) provides uniform coverage, while a 30° beam (m=10) enhances data rates by 20% but requires precise positioning. The received power is found to decline sharply with distance, dropping from 0.12 μW at 1m to 0.004 μW at 5m, necessitating multi-LED deployments in large spaces. Modulation schemes are rigorously compared, with Discrete Multitone (DMT) outperforming Pulse Position Modulation (PPM) and On-Off Keying (OOK), achieving a bit error rate (BER) of 0.0001% at 24 dB SNR—10× better than PPM and 1000× better than OOK.Channel modeling highlights multipath-induced inter-symbol interference (ISI), with delay spreads reaching 0.8 ns in highly reflective environments (80% reflectivity), reducing data rates by 50%. Noise analysis shows ambient light dominates at low SNR (2 pW), but thermal noise becomes limiting above 15 dB. Power consumption varies significantly, with DMT requiring 3W for 1 Gbps, while PPM offers a balanced 1.5W for 500 Mbps.Policy recommendations include optimizing LED placement for coverage, adopting hybrid modulation schemes, and using optical filters to mitigate ambient noise. These findings provide actionable insights for deploying efficient VLC systems in offices, smart homes, and retail environments, ensuring reliable high-speed communication alongside energy-efficient operation.