Joint Design of Beam Hopping and Multiple Access Based on Cognitive Radio for Integrated Satellite-Terrestrial Network

The integrated satellite-terrestrial communication network (ISTCN) has become an important research direction for future sixth-generation mobile networks to meet the communication demands of seamless global coverage and anytime access. In ISTCN, terrestrial terminals and satellite terminals can share the same spectrum resources, so the spectrum resources available to the satellite system are unevenly distributed and time-varying according to the use of resources by terrestrial terminals. However, existing beam scheduling algorithms usually allocate satellite beams according to the demands of terminals and ignore the dynamic changes of spectrum resources available for satellites, which is not suitable for ISTCN. Moreover, the number of terminals requesting service and the available spectrum resources are time-varying in ISTCN, single multiple access mode cannot make full use of spectrum resources. Motivated by this fact, we jointly design beam hopping and adaptive dynamic multiple access by integrating promising beam hopping, cognitive radio, and non-orthogonal multiple access technologies. The simulations confirm that the joint design scheme can better adapt to the dynamic changes in traffic demands and available spectrum resources of ISTCN and significantly improve spectrum utilization. Finally, we discuss open challenges and future research directions on joint design scheme of beam scheduling and multiple access in ISTCN.