To provide coverage to the network devices distributed all over the globe, non-terrestrial networks (NTNs) have been recognized to complement and extend the terrestrial network to remote areas. The Low Earth Orbit (LEO) NTNs face several unprecedented challenges over 5G-NR protocol due to high differential delay and Doppler shifts which drastically impacts the performance of NR-NTN users. In this work, we investigate the impact of large differential delay and Doppler shifts within a NTN cell on the 5G-NR resource allocation and medium access control (MAC) protocol. We then propose an uplink zone-based scheduling technique to address the high differential delay and Doppler shifts for LEO satellites for LEO satellite-based NTNs. Finally, we validate the performance of the proposed strategy by comparing it with the conventional 5G-NR protocol through numerical simulations over the recently developed Samsung’s NR-NTN System Level Simulator.

https://ieeexplore.ieee.org/document/9771894