A Cooperative NOMA-Aided Multi-Dimensional Beam Hopping Method in Satellite Communication Systems

Beam hopping has been widely considered in multibeam satellite communication systems to meet the time-varying requirement of different cells. To mitigate the interbeam interference, adjacent beams are usually allocated in orthogonal frequency band or illuminated in different time-slots. However, this strategy cannot fully exploit the resource on satellites. In this paper, by using non-orthogonal multiple access between adjacent beams, we propose a multi-dimensional beam hopping approach where the beam pattern is designed in transmission, time, and space dimension. In order to improve the resource utilization of the satellite, a two-step optimization scheme is further studied in detail. Simulation results show that the novel approach is capable of achieving better performance on the aspect of system capacity.

I. Introduction

With the advantage of long distance wireless link, satellite communication has been widely used to provide global information services [1]. Recently, it was furthermore recognized as an efficient supplement for beyond 5G or 6G to support users on the sea or in remote areas [2]–[5]. Since the satellite platform is far away from the Earth, signals arrived at user equipments (UEs) would be extremely weak. In this case, multi-beam transmission technology has drawn significant interest [6]. By deploying a phased array antenna on the satellite, multiple signals are enabled to be transmitted simultaneously with high power gain.