Impact of Device Specifications on VLC Path Loss and System Performance: An Empirical Study

Visible light communication (VLC) is a promising technology for sixth-generation (6G) networks due to its unlicensed bands and high transmission rates. In recent years, several studies have explored the physical propagation characteristics of VLC channels. Nevertheless, the existing models are limited by reliance on customized optical devices. In addition, only sporadic studies have investigated the influence of device specifications, yet neglecting the joint effects of the transmitter and receiver specifications. In this paper, we experimentally measure the optical channel taking into account the specifications of light-emitting diode (LED) and photo-diode (PD). Measurement results show that the path loss exponent (PLE) is 2.47 and 1.78 when the angle of departure (AOD) is larger and smaller than the half-power angle (HPA), respectively. Moreover, changing the PD size from 9.7 mm to 2 mm results in a 15.05 dB difference in path loss (PL). We further derive a PL model that can capture the joint effects of LED and PD specifications based on empirical data. The root mean square error (RMSE) of the measured and simulated data is 2.52, thereby demonstrating the accuracy and practicality of the proposed model. Based on the model, we particularly investigate the impact of the device specifications on the bit error rate (BER) performance. Results indicate that the specifications of the device need to be carefully considered for developing VLC systems. Overall, the proposed model accurately characterizes PL under different device specifications and provides a feasible and universal device selection paradigm for the design and optimization of VLC systems.