Performance Analysis of OIRS-Aided Indoor VLC Systems Under Dynamic Human Blockages and Random UE Orientation
Anand Singh, Haythem Bany Salameh, Moussa Ayyash, Hany Elgala
Abstract
Visible light communication (VLC) is a key enabler for high-speed indoor connectivity and the Internet of Things (IoT) devices. Unlike radio frequency (RF) communication systems, the VLC coverage is typically not uniform, which means that the user equipment’s (UEs) orientation and obstacles significantly affect the communication performance. Specifically, the performance of VLC may severely deteriorate when the Line-of-Sight (LoS) link is blocked by other users/obstructions in crowded indoor scenarios, such as shopping malls, airports, factories, and industrial facilities. Further, the received power may also fluctuate due to the random orientation of UE as Non-LoS (NLoS) power varies. This article characterizes the impact of human blockages and random UE orientation when optical intelligent reflecting surfaces (OIRSs) are integrated with VLC systems. We consider a realistic scenario by assuming the presence of multiple human blockages and random UE orientations. Specifically, this article utilizes a random process model to capture the random UE orientations in OIRS-aided indoor VLC systems. The proposed model characterizes the NLoS channel gain, calculates the received signal-to-noise ratio (SNR) statistics, and derives the probability density function (PDF) of the received SNR. Furthermore, the derived SNR statistics determine the optimal light-emitting-diode semi-angle and receiver Field-of-View (FoV) to maximize received power throughout a given indoor area. In addition, the optimal OIRS element size is computed to achieve the highest average received power within the specified indoor space. Finally, the bit error rate (BER), delay spread, and average data rate are analyzed under blockage and nonblockage scenarios. Simulation results demonstrate a 4–8 dB improvement in the required SNR to achieve a minimum BER of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-3}$ </tex-math></inline-formula> with the proposed OIRS-aided VLC system, attributed to its awareness of human blockages and random UE orientation.