Performance Analysis and EE Optimization in AAV-Assisted Dual-Layer Heterogeneous Communication Network Based on RSMA

This paper investigates a dual-layer heterogeneous communication network assisted by multiple autonomous aerial vehicles (AAVs) based on rate-splitting multiple access (RSMA). Considering the repulsion characteristics between AAVs' positions and terrestrial base stations (BSs), AAVs are deployed in non-hole areas outside the BSs. The positions of AAVs are modeled by Poisson hole process (PHP). Due to the difficulty of directly solving the user association problem under PHP, the nearest neighbor hole approximation method is introduced. Due to the complex interference caused by multiple communication links in the dual-layer heterogeneous network, we adopt the conditional Laplace transform method to represent interference, deriving expressions for coverage probability and area spectral efficiency (ASE). Considering the energy constraints of the AAV network, this paper defines the system-level network energy efficiency (EE) as the ratio of the ASE to the average energy consumption per unit area. Utilizing this framework, we jointly optimize the AAV network density and the RSMA power allocation coefficients to maximize EE. The numerical results ultimately validated the accuracy of the theoretical analysis. Through simulation analysis, this paper explores the impact of network deployment parameters on system performance and provided the AAV network density and RSMA power allocation scheme that maximizes EE.