Statistical modeling for the low Earth orbit small satellite channel

The number of small satellites is increasing as well as their capabilities to perform complex missions in the Low Earth Orbit (LEO), and beyond the Earth, that were only possible to accomplish with larger satellites in the past. Most of those satellites are being integrated into the 5G and Internet of things (IoT) as communication platforms, and those offer several advantages that are most achievable with spacecraft at higher orbits. Among the most remarkable advantages of LEO operation is the shorter distance to the Earth’s surface, which reduces the propagation time from the satellite to an Earth station (ES) compared with higher orbits. However, operating at LEO also exhibit several challenges that need to be addressed in order to exploit the distance advantage. The challenges of operating at LEO comes from the fact that satellites at this orbit are not synchronized with the Earth rotation, causing an uncoordinated movement between a satellite and an ES. LEO spacecraft completes an orbit revolution in less than two hours, causing an intermittent satellite visibility from the Earth’s surface. Additionally, LEO satellites are seen from a fixed ES as moving transceivers at very high speed, with varying distance, and with different azimuthal trajectories from one satellite pass to another. The challenges introduced by the satellite mobility cause a varying channel that is a major problem for communication. The LEO satellite channel as been costly and time consuming to characterize in the past, and the available models in the literature were not made for small satellites as the ones being deployed now. Furthermore, it was never completely characterized, and the developed models were made for specific operational frequencies and places that have evolved in the last decades. This work it is introduced a new methodology to analyze and characterize the LEO small satellite channel and keep track of its variations using theoretical approaches and computational analysis. The land mobile satellite channel was selected as the case of interest to be modeled for different transmission conditions and receiver environments.

https://orcid.org/0000-0003-1770-471X