Performance Analysis of Cooperative Nonorthogonal Multiple Access Scheme in Two-Layer GEO/LEO Satellite Network

Multilayer satellite networks (MLSNs) are viewed as a promising framework of the future satellite communication networks by realizing cooperative communication among satellites in different orbits. In this article, we introduce the cooperative nonorthogonal multiple access (C-NOMA) scheme into a two-layer geostationary Earth orbit/low Earth orbit satellite network in a frequency coexistence scenario and investigate the performance of the considered network. Taking into account the dynamic properties and channel characteristic of the satellite nodes, we first establish the generic architecture and then obtain the equivalent end-to-end signal-to-interference-plus-noise ratios along with the feasible region of power allocation coefficients based on the C-NOMA principle. Furthermore, the analytical expressions of the system ergodic capacity and outage probability are derived and approximated using Meijer-G functions to evaluate the system performance efficiently. Finally, simulation results are provided to attest the validity of the theoretical results as well as show the superiority of the C-NOMA scheme and the impact of various parameters on the system performance.