NOMA coordinated beam hopping improves very low Earth orbit satellite links
NOMA Assisted Coordinated Beam Hopping for VLEO Satellite Communication Systems
Information Theory
Summary
Communicating with satellites very close to Earth faces challenges like signal fading and delays. The authors introduce a way for multiple satellites to work together, sharing beams and using a technique called non-orthogonal multiple access (NOMA), to serve ground users more efficiently. They develop models that consider real-world issues like atmospheric interference and satellite movement, then design a method to schedule beams and allocate power better. Their approach improves data rates and reduces communication outages compared to traditional methods.
What this means in practice
- •For satellite network operators: Optimize beam scheduling and power use in VLEO satellite constellations to increase throughput and reduce communication outages.
- •For wireless communication engineers: Design ground station and user equipment to better handle coordinated beams and NOMA from multiple satellites improving link reliability.
Authors
Jiayang Kang, Xinwei Yue, Xuyang Zhang, Tian Li, Peng Yang, Chunyu Pan, Shaoli Kang
Abstract
This paper investigates a non-orthogonal multiple access assisted coordinated beam hopping (NOMA-CBH) scheme in multidimensional very low Earth orbit (VLEO) satellite communication systems, where multiple satellites employ CBH and coordinated beams jointly serve ground users and a dedicated ground station (GS). To characterize the VLEO-specific propagation environment, we develop a channel model that incorporates atmospheric attenuation, Doppler effects, and pointing perturbations. Building upon this architecture and channel model, a low-complexity decoupled (LCD) algorithm is designed to optimize beam scheduling and power allocation. We further derive closed-form outage probability expressions for the ground users and the GS, perform asymptotic analysis to characterize their diversity orders, and evaluate the delay-limited throughput. Simulation results demonstrate that: i) The NOMA-CBH with LCD algorithm achieves an enhanced system sum rate relative to orthogonal multiple access with coordinated beam hopping (OMA-CBH); ii) Across the considered heterogeneous traffic-demand operating points, the NOMA-CBH scheme achieves higher aggregate delivered traffic than the benchmark schemes; and iii) The outage performance of NOMA-CBH is better than that of OMA-CBH.