Alternative Wireless Positioning Based on LEO-PNT for Low-Cost High-Accessibility Solutions in Africa

Low-cost and high-accessibility solutions for wireless positioning in Africa require access to affordable infrastructure, low-power receivers that can operate with solar-cell batteries, and low-cost chipsets to process data from satellites. With the fast-paced progress in the design of CubeSats and SmallSats, launching and maintaining satellites in Low Earth Orbit (LEO) is becoming in-creasingly affordable. While LEO signals have historically been used for communications and Earth-sensing purposes, recent research has also focused on LEO for Positioning, Navigation, and Timing (PNT) purposes, known as LEO-PNT. Our paper focuses on LEO-PNT design and addresses several parameter-design issues in LEO- PNT, such as orbital altitudes and carrier-frequency choices, with positioning metrics in mind. A comprehensive in-house Matlab-based simulator is used with user-track data collected from Togo, and a performance analysis is conducted under two outdoor Quadriga-based channel models and a free-space path loss model. We find that LEO constellations up to 1300 km orbits and with signals operating below 7 G Hz carrier frequency can be viable solutions for LEO- PNT in Africa, yet further studies are needed to reduce the size of future LEO constellations.