Joint altitude and beamwidth optimization for LEO satellite-based IoT constellation

Low Earth Orbit (LEO) satellite-based Internet of Things (IoT) has become a hot topic in IoT networks due to the ability of global coverage, especially in remote areas. How to design a commercial LEO satellite-based constellation to meet the IoT traffic requirement remains an open problem. In this paper, we propose a throughput optimization algorithm for LEO satellite-based IoT networks meanwhile reducing the number of LEO satellite. Based on stochastic geometry theory, a closed-form expression is derived for the throughput of a dynamic LEO satellite-based IoT networks when LEO satellite equips with capture effect (CE) receiver and successive interference cancelation (SIC) receiver, respectively. Furthermore, a joint altitude and beamwidth optimization problem is formulated under the constraint of Walker constellation to optimize the throughput and the number of LEO satellites. To solve this multi-objective optimization problem, we design an iterative non-dominated sorting genetic algorithm II (NSGA-II) for the rapid development of IoT traffic. Simulation results show that our proposed algorithm can effectively improve the throughput performance of random access (RA) protocol in LEO satellite-based IoT networks compared to benchmark problems.