Rotatable Antenna-Enabled Satellite Communication: Joint Design of Boresight Alignment and Beam Tracking
2026-06-01 • Information Theory
Information Theory
AI summaryⓘ
The authors address the problem of signal misalignment in low Earth orbit satellites caused by their fast movement. They propose using antennas that can rotate to keep signals properly aligned between satellites and ground stations. This approach allows better communication by adjusting the antenna direction dynamically, improving signal strength without heavy computation. They also design a method to track and update antenna positions efficiently as the satellite moves. Simulations show this method works better than fixed antenna setups, especially when angles change quickly.
Low Earth Orbit (LEO)rotatable antennabeamformingline-of-sight (LoS) channelantenna boresightbeam trackingarray gainspatial degree of freedomchannel estimation
Authors
Tiantian Ma, Beixiong Zheng, Changsheng You, Ruiqi Liu, Robert Schober
Abstract
Low Earth orbit (LEO) satellite links experience rapid angular variation due to high orbital velocities, which causes severe beam misalignment and array gain degradation under conventional fixed-antenna architectures. In this letter, we propose a rotatable antenna (RA)-enabled LEO communication framework, where RA arrays are deployed at both the satellite and the ground node (GN) to exploit antenna boresight reconfiguration as an additional spatial degree-of-freedom (DoF) for maintaining directional alignment under high mobility. By leveraging the rank-one line-of-sight (LoS) channel structure inherent to satellite links, we derive closed-form solutions for the joint design of the transmit/receive beamforming and antenna boresight directions, revealing that optimal performance can be achieved via decoupled alignment across antennas with low computational complexity. To enable practical operation under dynamic conditions, we further develop a channel estimation and beam tracking protocol that exploits the predictable satellite orbit to continuously update boresight directions with low training overhead. Simulation results demonstrate that the proposed RA-enabled design significantly outperforms fixed and random boresight baselines in terms of achievable rate and robustness to angular variations, highlighting the effectiveness of rotational spatial reconfiguration in high-mobility satellite communications.