A Dynamic Beam Shut Off Algorithm for LEO Multibeam Satellite Constellation Network

With the rapid development of low earth orbit (LEO) satellite and onboard multibeam antennas, the low earth orbit multibeam satellite constellation network (LEO-MSCN) is developing rapidly. However, there exists a mount of overlap for some coverage as the satellites progress from the equator to polar regions, which may cause heavy inter-beam interference (IBI). To solve this problem, the beam shut off technique is needed to shut off the unnecessary beams to avoid IBI and save onboard power. In this letter, the dynamic beam shut off (DBSO) optimization problem of LEO-MSCN is formulated to minimize the number of active beams. The formulated optimization problem is equivalent to Set Cover Problem (SCP) which is known as NP-Complete. A heuristic beam shut off algorithm is adopted to achieve the sub-optimal solution with fast convergence, considering the time-varying characteristics of LEO-MSCN topology. The Oneweb constellation network is used as the simulation scenario. It turns out that average number of 7062 beams are required with 38.7% beam resource reduction.