LAUSR

The collision of ranging signals in the process of massive concurrent access ranging seriously affects the networking speed of satellite communication networks. Random access schemes are usually used to reduce the collision probability, but their effects are limited due to the limitation of ranging access rules and the network size. To further improve the performance of access ranging, the idea of optimal access ranging parameters is introduced in this article. A multiobjective anti-collision algorithm (MOACA) is proposed to optimize the concurrent access ranging process of high-capacity nodes of Internet of Things (IoT) to multifrequency time-division multiple-access (MF-TDMA) satellite communication systems. The model of the ranging measurement process is put forward and the expressions of ranging measurement time, collision probability, and the number of ranging channels are derived. On this basis, a multiobjective optimization problem (MOP) of the access ranging process is established. In MOACA, an ideal point database is formed based on the solutions of the MOP problem with typical inputs, and the negotiation curves of objectives are introduced to obtain the most appropriate ideal point from the database under certain requirements and system states. Besides, MOACA also contains a single-objective problem (SOP) for achieving the ideal point in the situation where no matching pattern can be found in the database. The simulation result shows that MOACA can improve the performance of the concurrent access ranging process.