User Capacity Analysis of Space-Based Internet of Things with Multibeam Techniques

Space-based Internet of Things (S-IoT) utilizes the characteristics of satellite network coverage, strong antidestructiveness, and full-time work to realize large-scale sensing and interconnection of everything in the sky, land, sea, and air. The user capacity of S-IoT satellites is mainly determined by beam design, communication schemes, satellite-to-earth links, and communication protocols, which directly affect the system capacity and operational capabilities of S-IoT. This paper proposes an S-IoT satellite user capacity analysis model with multibeam and spread spectrum technology. Taking into account the randomness of user distribution, the difference in transmit power, and different spreading sequences, the user capacity of S-IoT satellites was simulated and compared in different scenarios. Based on these results, this article analyzes the key factors affecting user capacity, which will provide a valuable reference for S-IoT design, link optimization, and power selection.