Beam tracking between LEO satellites for mmWave communications

Beam tracking is a necessary feature of RF based inter-satellite communication for low-Earth orbit (LEO) satellites. However it is not obvious how best to achieve beam tracking given constraints of computational resources and finite antenna size, which limits the precision with which beam tracking can be achieved. Here we consider the Hawkeye 360 satellite constellation [1] as a prototypical LEO constellation with non-trivial relative motion between satellites. We compare two models for predicting angular motion in between, namely single harmonic motion (SHM) and Clohessy-Wiltshire (CW), and we use these approaches to estimate errors in beam tracking for realistic measurement conditions. Our simulation results show that the CW model outperforms the SHM model in terms of tracking accuracy as well as noise reduction without significant additional computational burden.