Dynamic Beam Hopping and Resource Allocation for Non-Uniform Traffic Demand in NGSO Satellite Communication Systems

In this paper, we investigate a dynamic beam hopping and resource allocation problem in non-geostationary orbit (NGSO) satellite communication systems for terrestrial cells with non-uniform traffic demands. To obtain an efficient beam hopping and resource allocation policy for accommodating the stochastic traffic data arrival and the dynamic topology of NGSO satellites, we first formulate a stochastic optimization problem with the objective of minimizing the long-term system cost given the queue stability constraints. Due to the complicated coupling among decisions and the lack of future network state information, the formulated stochastic optimization problem cannot be directly solved. Therefore, we leverage Lyapunov optimization to transform the stochastic optimization problem into a deterministic one to minimize the system cost and the capacity-demand gap. Moreover, an online beam hopping and resource allocation algorithm is proposed to solve the deterministic problem, and thereby dynamically determining the beam hopping, bandwidth allocation, and power control solutions. The theoretical analysis shows that there is an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ [ {{\mathcal O}({{1 / V}}),{\mathcal O}(V)} ]$</tex-math></inline-formula> trade-off between the system cost and the system data backlog with control parameter <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V$</tex-math></inline-formula>. The simulation results demonstrate that the proposed algorithm can effectively match the non-uniform demands. Compared with the benchmarks, the proposed algorithm can effectively reduce the backlog of data queues and the energy consumption of satellites.