Spectral-Efficient Aircraft Pairing for Massive MIMO NOMA in Aeronautical Communication

Abstract

—As air traffic volumes rise, enhancing the spectral efficiency of aeronautical communication systems is crucial. International Civil Aviation Organization (ICAO) proposes using the L-Band Digital Aeronautical Communication System (LDACS) to meet future demands, but its implementation faces legal and interference challenges with existing L-band systems like Joint Tactical Information Distribution System (JTIDS), Military Tactical Air Navigation (TACAN), and Distance Measurement Equipment (DME). To address this, we propose employing Non-Orthogonal Multiple Access (NOMA) in Very High Frequency (VHF) digital systems, aiming to boost capacity without introducing new bands. Our study focuses on maximizing spectral efficiency using NOMA-based massive Multi-Input Multi-Output (mMIMO) for aeronautical communications. We evaluate different pairing algorithms (Gale Shapley, Hungarian, and correlation-based) and beamforming techniques Zero Forcing and Maximum Ratio (ZF and MR), finding that GS pairing with ZF beamforming yields the optimal solution. Results show that all three algorithms outperform fixed pairing NOMA, with GS being the least complex, followed by Hungarian and correlation-based. Additionally, ZF beamforming outperforms MR in achieving spectral efficiency. This integrated approach offers a promising strategy for enhancing aeronautical communication systems amidst growing air traffic demands.