Movable Antenna-Aided Energy Efficiency Optimization in LEO Satellite Communication System

Abstract

With the rapid development of direct Satellite-toDevice services, the throughput demand of Low Earth Orbit (LEO) satellite communication (SatCom) has surged. However, deploying large-scale fixed-position antenna (FPA) arrays to enable massive multiple-input multiple-output (MIMO) incurs substantial power consumption, which is unsustainable under stringent on-board power constraints. To address this challenge, this paper investigates a movable antenna (MA)-aided energy efficiency (EE) optimization framework for LEO SatCom systems, where MAs dynamically adjust their physical positions within a prescribed region to reshape channel conditions and mitigate multi-user interference. Specifically, we formulate an EE maximization problem with MA power consumption model that couples precoding design with MA position. The resulting non-convex fractional problem is decomposed into two tractable subproblems and tackled via proposed alternating optimization framework. In particular, precoding is optimized using Dinkelbach’s method combined with the quadratic transform, while MA position is optimized by particle swarm optimization (PSO). Simulation results demonstrate the substantial EE gains over conventional FPA baselines.