Enabling Aerial Movable Antenna System with UAV Swarm for Low-Altitude Economy

Unmanned aerial vehicles (UAVs) emerge as a critical platform to support low-altitude economy, due to the advantages of three-dimensional (3D) maneuverability, flexible deployment, and line-of-sight (LoS) air-to-air/ground communication links. This paper proposes a novel UAV swarm enabled aerial movable antenna (AMA) system, by leveraging the intrinsic high mobility of UAVs. Specifically, we consider a multi-user equipment (UE) communication scenario, and aim to maximize the minimum achievable rate over all ground UEs, by jointly optimizing the receive beamforming at the AMA and 3D UAV swarm placement positions. It is firstly shown that for the special case of single UE communication with the optimal maximal-ratio combining (MRC) beamforming, the resulting signal-to-noise ratio (SNR) scales with the number of UAVs, while irrespective of their array geometry. Then, for arbitrary number of UEs, an alternating optimization algorithm is proposed to solve the non-convex optimization problem, where the receive beamforming and each UAV placement position are optimized alternately in an iterative manner. Simulation results demonstrate that benefiting from the UAVs’ intrinsic mobility to create favorable channel conditions for multi-UE communications, the proposed low-altitude UAV swarm enabled AMA system is superior to the benchmark scheme.