UAV-Mounted Movable Antenna: Joint Optimization of UAV Placement and Antenna Configuration

TL;DR

This paper proposes a joint optimization framework for UAV-mounted movable antennas, enhancing spectrum sharing by optimizing UAV height, antenna configuration, and position to maximize secondary user gains while limiting interference.

Contribution

It introduces a novel joint optimization approach for UAV-mounted movable antennas, including a practical alternating optimization algorithm for near-optimal solutions.

Findings

Proposed scheme outperforms existing methods in beamforming gain.

Achieved full beamforming gain for secondary users.

Reduced computational complexity compared to traditional optimization methods.

Abstract

Recently, movable antennas (MAs) have garnered immense attention due to their capability to favorably alter channel conditions through agile movement. In this letter, we delve into a spectrum sharing system enabled by unmanned aerial vehicle (UAV) mounted MAs, thereby introducing a new degree of freedom vertically alongside the horizontal local mobility for MAs. Our objective is to maximize the minimum beamforming gain for secondary users (SUs) while ensuring that interference to the primary users (PUs) remains below a predefined threshold, which necessitates a joint optimization involving the UAV's height, the antenna weight vector (AWV), and the antenna position vector (APV). However, the formulated optimization problem is non-convex and challenging to solve optimally. To tackle this issue, we propose an alternating optimization algorithm that optimizes the UAV's height, APV and AWV in an iterative manner, thus yielding a near-optimal solution. Numerical results demonstrate the superiority of the proposed scheme as well as its ability to deliver full beamforming gain to SUs with reduced computational complexity.