On the Optimal Assignment of Mirror Element in UAV and OIRS-Assisted OWC based Architecture

Optical intelligent reflective surface (OIRS) is one of the promising solutions to address the 'skip-zone' problem between the base stations and the mobile users. The performance of OIRS can be further complemented by mounting them on unmanned aerial vehicles (UAVs), which are known for their flexibility and maneuverability. The proposed work aims to utilize the OIRS-assisted UAV to improve the performance of optical wireless communication (OWC) systems. In this work, multiple mirror elements of the OIRS are grouped and assigned to the user. Specifically, a novel mirror element assignment scheme is proposed, namely a signal-to-noise ratio (SNR) based mirror assignment (SMA) to achieve maximum user throughput with proportional fairness for each user. The performance of the proposed SMA scheme is compared against the equal mirror assignment (EMA) scheme and well-known conventional benchmark approaches, e.g., time-division multiple-access (TDMA) and non-orthogonal multiple access (NOMA). The results are reported in terms of average sum rate, fairness, and capacity outage probability. The obtained results show that the proposed SMA scheme outperforms EMA, TDMA, and NOMA schemes.