ABSTRACT Low Earth Orbit (LEO) satellite constellations offer unprecedented opportunities for global broadband connectivity but pose significant beamforming challenges due to rapid platform motion and stringent onboard hardware constraints. Fully digital architectures, while optimal in theory, remain impractical for satellite payloads, motivating hybrid analog‐digital designs that combine a reduced set of RF chains with analog phase shifter networks. In this work, we first quantify the required update rate for analog beam steering weights as a function of orbital altitude and array aperture size. We show that it is sufficient to update the analog beam steering vectors on the scale of seconds, even for larger arrays at lower altitudes. We then introduce a threshold‐based algorithm that adaptively triggers analog beam steering updates, further reducing the frequency of steering events for a negligible sum‐rate degradation. Finally, we propose an adaptive digital precoding (ADP) scheme that recomputes regularized zero‐forcing (RZF)‐based digital precoder only when interference leakage exceeds a tunable threshold, halving onboard matrix inversions for around a 6% average system sum‐rate penalty. Monte Carlo simulations validate that these techniques jointly achieve near‐optimal sum‐rate performance while dramatically lowering both hardware and computational burdens, paving the way for practical, energy‐efficient beamforming in next‐generation LEO constellations.
Momani et al. (Thu,) studied this question.