Impact of Time-Varying Dynamic Human Blockages on Indoor Visible Light Communication System

Visible light communication (VLC) has enabled the inception of a novel communication technique due to its high bandwidth and resistance to interference from various electromagnetic sources. However, in an indoor VLC system, other users (static as well as dynamic) can act as blockages to the communication link for the desired user. In this paper, we analyze the performance of an indoor VLC system with dynamic human blockages. Specifically, we use the random waypoint (RWP) model to characterize the movement of the blockages. The system performance is analyzed for a 4-LED configuration, where the blockages can pause during the movement for a specific pause time. Further, we developed a model to calculate the blockage probability in a typical indoor space, which is consequently used to calculate the power at the VLC receiver. Additionally, the analysis is extended for multiple blockage scenarios with different pause times. The second-order statistics such as level crossing rate (LCR) and average fade duration (AFD) have been examined to demonstrate the impact of both pause time and the number of blockages on this dynamic time-varying indoor VLC channel. It is observed that a blockage with a longer pause time will have a longer average outage duration (AOD). Finally, the effect of the velocity of blockages on LCR and AFD is also analyzed. We believe that the insights obtained in this paper will be useful to the operator while deploying an indoor VLC communication system in the presence of dynamic blockages.