Resource Allocation and Trajectory Optimization for NOMA-based and UAV-Assisted Satellite IoT

With the rapid advancement of wireless communication technologies and the widespread commercialization of 5G, the exponential growth of IoT devices has led to increasing scarcity of communication channel resources. This paper focuses on satellite Internet of Things (IoT) scenarios, addressing the challenge that terrestrial IoT devices, often power-constrained, cannot directly transmit signals to satellites. We propose an unmanned aerial vehicle (UAV)-assisted relay scheme for satellite IoT communication, developing a corresponding system model to analyze device access, power allocation factor setting, and UAV trajectory optimization in the uplink transmission. To solve the formulated optimization problem, we first decompose it into three sub-problems. Through techniques such as Taylor series approximation, these sub-problems are transformed into convex optimization problems, enabling efficient solution. Simulation results compare the communication performance under various conditions, demonstrating the effectiveness and superiority of the proposed algorithm in enhancing satellite IoT communication efficiency and reliability.