Research on Communication Delay Optimization in LEO Beam Hopping Systems

The beam hopping (BH) technique in low earth orbit (LEO) satellite communication, which flexibly allocates system resources to enhance resource utilization, has garnered significant attention in recent years. However, due to the highly uneven distribution of user locations and demands within the LEO satellite coverage area, fixed multi-beam positions severely limit satellite service efficiency, leading to substantial communication delays and impacting the quality of user service. To reduce communication delays for users, this paper proposes a dynamic beam position(BP) arrangement and beam illumination strategy. Initially, the paper theoretically analyzes the LEO satellite BH communication system, concluding that reducing the number of BPs, optimizing their placement, and designing illumination strategies can effectively decrease packet queueing delays. Subsequently, we introduce a low-complexity, high-precision strategy for minimizing BPs, the distance-weighted p-center improvement (DWPCI) strategy. Then, considering the relationship between antenna gain and user location, we develop an optimized BP plan, the user demand-driven beam relocation (UDBR) strategy, to increase beam communication capacity. Finally, we present an interference-free integrated priority queueing (IPQ) strategy, that comprehensively considers communication capacity, queue length, and BP hotspot areas. Simulation results demonstrate that the dynamic BP scheme proposed in this paper improves resource utilization and reduces queueing delays, while the beam illumination strategy further shortens these delays.