Abstract

This paper presents a comprehensive theoretical analysis of light propagation in underground Visible Light Communication (VLC) systems. Focusing on channel model optimization, we explore both Line-of-Sight (LoS) and Non-Line-of-Sight (NLoS) components to elucidate their roles and influences on system performance. Power received by any optical receiver is meticulously modeled, considering factors such as photodetector (PD) responsivity, DC channel gain components, and additive noise. Our findings indicate optimal conditions with received power (P-r) values of -55 dBm and V LCbitrate of 4500 kbps, yielding high Mean Opinion Scores (MOS) of 4.5. Conversely, suboptimal conditions yield P-r of - 75 dBm and V LCbitrate of 2000 kbps, with MOS of 2.8, reflecting the impact of poor alignment and scattering.