Spot Beam Power Optimization for an Energy Efficient Multi-LEO Satellite Network

This paper proposes a spot beam power control method for downlink non-terrestrial networks consisting of multiple low Earth orbit (LEO) satellites. Each designated ground access point (GAP) is continuously served by a steering beam from LEO satellites during their visibility period. We address the global energy efficiency (GEE) maximization task to determine the optimal tradeoff between the sum-rate and total power consumption of LEO satellites. The GEE maximization problem is formulated by taking the inter-beam, inter-carrier, and terrestrial network interference into account. To ease the complexity of the problem, we further simplify the expressions of the GEE and interference and then propose a successive convex approximation (SCA)-based spot beam power optimization method. Numerical results validate its effectiveness over baseline algorithms in different system setups.