Low Overhead IMU Assisted Predictive Beam Management for Multiband LEO Direct to Device Links

Abstract

Direct to device D2D connectivity from low Earth orbit LEO satellites is moving to Ku band, where a handheld terminal must obtain directional gain from several small phased array panels distributed around the chassis. Beam management then becomes a joint satellite panel beam selection problem with hundreds of candidates, and ordinary hand motion can change the best candidate within one decision interval. This paper proposes a low overhead predictive beam management scheme for a multiband LEO D2D downlink in which a low frequency anchor link carries control signalling and fallback traffic, and a Ku band link carries broadband data. The handset inertial measurement unit IMU reports attitude and angular rate with a known delay; the scheme extrapolates the delayed attitude to the current orientation, scores all satellite panel beam candidates analytically from the satellite ephemeris and panel geometry, and trains only a small candidate set built with a satellite panel diversity rule under a fixed pilot budget. The Ku band link is activated only when its predicted post training rate exceeds the anchor rate by a margin. Trace driven Monte Carlo simulations with a four panel handset and two visible satellites show that, with six pilots 0.3 percent training overhead, the proposed scheme improves mean goodput by 21.2 percent and reduces broadband outage by 57.6 percent at 90 degrees per second relative to an equal budget delayed attitude baseline, and operates within 3.8 percent of a zero overhead oracle.