Enabling Panoramic Full-Angle Reflection via Aerial Intelligent Reflecting Surface

TL;DR

This paper introduces a 3D aerial intelligent reflecting surface (AIRS) architecture that enables panoramic full-angle signal reflection, enhancing wireless coverage and performance with flexible deployment and fewer reflections.

Contribution

It presents a novel AIRS-based 3D networking architecture and develops optimization methods for maximizing worst-case SNR, including a closed-form solution for single-location and a suboptimal approach for area coverage.

Findings

Significant SNR improvement over heuristic schemes

Aerial IRS achieves 360° panoramic reflection

Efficient optimization algorithms for AIRS deployment

Abstract

This paper proposes a new three dimensional (3D) networking architecture enabled by aerial intelligent reflecting surface (AIRS) to achieve panoramic signal reflection from the sky. Compared to the conventional terrestrial IRS, AIRS not only enjoys higher deployment flexibility, but also is able to achieve 360$^\circ$ panoramic full-angle reflection and requires fewer reflections in general due to its higher likelihood of having line of sight (LoS) links with the ground nodes. We focus on the problem to maximize the worst-case signal-to-noise ratio (SNR) in a given coverage area by jointly optimizing the transmit beamforming, AIRS placement and phase shifts. The formulated problem is non-convex and the optimization variables are coupled with each other in an intricate manner. To tackle this problem, we first consider the special case of single-location SNR maximization to gain useful insights, for which the optimal solution is obtained in closed-form. Then for the general case of area coverage, an efficient suboptimal solution is proposed by exploiting the similarity between phase shifts optimization for IRS and analog beamforming for the conventional phase array. Numerical results show that the proposed design can achieve significant performance gain than heuristic AIRS deployment schemes.