Alignment in Direct-to-Device Non-Terrestrial Networks

Determine reliable alignment techniques for narrow-beam direct-to-device non-terrestrial network links in the presence of pointing errors and platform or handset motion.

Background

Narrow-beam LEO direct-to-device links are highly sensitive to pointing errors because directional antennas require accurate alignment between the satellite and handheld terminal. The paper places this challenge in the broader context of satellite user terminals and notes that existing work does not fully address rapidly rotating handsets with multiple antenna panels and time-varying hand blockage.

The cited survey identifies alignment in direct-to-device non-terrestrial networks as an unresolved research problem. The present paper addresses a specific part of this challenge through IMU-assisted predictive beam management, but the broader alignment problem remains open.