NOMA-Aided Multi-UAV Communications in Full-Duplex Heterogeneous Networks
Tan Zheng Hui Ernest, A. S. Madhukumar, Rajendra Prasad Sirigina, Anoop Kumar Krishna
Abstract
To address spectrum scarcity in unmanned aerial vehicle (UAV) communications, nonorthogonal multiple access (NOMA) aided multi-UAV communications in full-duplex (FD) heterogeneous networks (HetNets) are investigated in this article. Specifically, an ergodic capacity analysis of NOMA-aided multi-UAV communications in FD-HetNets is conducted through a moment generating function (MGF) approach within a stochastic geometry framework. By employing the MGF approach to evaluate ergodic capacity, exact expressions that are simpler to evaluate are obtained. When compared against half-duplex HetNets, i.e., HD-HetNets, FD-HetNets with effective interference management enable higher ergodic capacity to be obtained by the macro base station and UAVs. Furthermore, we show that it is possible for NOMA-aided multi-UAV communications in FD-HetNets to achieve higher ergodic sum capacity and ergodic capacity gains than HD-HetNets while supporting more UAVs at low altitude due to a stronger desired signal. Even with lower levels of self-interference suppression and strong phase noise, NOMA-aided multi-UAV communications in FD-HetNets is still able to achieve higher ergodic sum capacity over HD-HetNets. Therefore, the attractiveness of NOMA-aided multi-UAV communications in FD-HetNets is highlighted as a promising solution toward improving spectrum utilization in UAV communications.