The rapid proliferation of unmanned aerial vehicle (UAV) applications imposes stringent requirements on continuous and reliable communication coverage in low-altitude airspace. Conventional cellular systems built upon fixed-position antennas (FPAs) are inherently constrained by static array geometries and limited mechanical degrees of freedom, which severely restrict their ability to adapt to highly dynamic three-dimensional (3D) propagation environments. Movable antenna (MA) technology has recently emerged as a promising paradigm to overcome these limitations by actively reconfiguring electromagnetic radiation characteristics through controllable antenna positioning and array orientation, thereby enabling flexible spatial coverage adaptation. To systematically quantify the airspace coverage capability of MA-enabled systems, this paper formulates a spatial coverage maximization problem over a discretized 3D voxel space. For each voxel, the received signal-to-noise ratio (SNR) is maximized via joint optimization of the MA's 3D positions and beamforming matrices. To efficiently solve the resulting non-convex problem, a hybrid particle swarm optimization and simulated annealing framework is developed to search for high-quality antenna configurations. Simulation results demonstrate that the proposed MA design framework substantially outperforms conventional FPA-based schemes in terms of spatial coverage, achieving coverage rates of 26.8% and 29.65% for airspace below 300m and 600m, respectively. Moreover, further coverage enhancement can be attained by incorporating mechanical tilt adjustment, highlighting the strong potential of MA technology for reliable low-altitude communication coverage.

翻译：无人机应用的迅速普及对低空空域连续可靠的通信覆盖提出了严格要求。基于固定位置天线的传统蜂窝系统受限于静态阵列几何结构和有限的机械自由度，严重制约了其适应高度动态三维传播环境的能力。可移动天线技术作为一种新兴范式，通过可控天线定位和阵列方向主动重构电磁辐射特性，从而实现了灵活的空间覆盖适配。为系统量化MA赋能系统的空域覆盖能力，本文在离散化三维体素空间上构建了空间覆盖最大化问题。针对每个体素，通过联合优化MA的三维位置和波束成形矩阵，最大化接收信噪比。为高效求解所得非凸问题，开发了一种混合粒子群优化与模拟退火框架以搜索高质量天线配置。仿真结果表明，所提出的MA设计框架在空间覆盖方面显著优于传统基于FPA的方案，在300米和600米以下空域分别实现了26.8%和29.65%的覆盖率。此外，通过结合机械倾角调整可进一步获得覆盖增强，这凸显了MA技术在实现可靠低空通信覆盖方面的巨大潜力。