On the Deployment of RIS-mounted UAV Networks

TL;DR

This paper presents an optimization method for deploying RIS-mounted UAVs to maximize throughput and fairness in wireless networks, considering both LoS and non-LoS conditions.

Contribution

It introduces a gradient ascent and coordinate search approach for optimal UAV and RIS placement in complex wireless environments.

Findings

Outperforms existing methods in throughput maximization.

Improves user fairness in UAV-RIS networks.

Effectively accounts for signal blockages in deployment strategy.

Abstract

Reconfigurable intelligent surfaces (RIS) enable smart wireless environments by dynamically controlling signal propagation to enhance communication and localization. Unmanned aerial vehicles (UAVs) can act as flying base stations and thus, improve system performance by avoiding signal blockages. In this paper, we propose a gradient ascent and coordinate search based method to determine the optimal location for a system that consists of a UAV and a RIS, where the UAV serves cellular users (CUs) and the RIS serves device-to-device (D2D) pairs. In particular, by optimizing the net throughput for both the D2D pairs and the CUs, the suggested method establishes the ideal location for the RIS-mounted UAV. We consider both line of sight (LoS) and non-LoS paths for the RIS and UAV to calculate the throughput while accounting for blockages in the system. The numerical results show that the proposed method performs better than the existing approaches in terms of both the net throughput and the user fairness.