Aerial Booster-Cell Enabled Inter-Cell Interference Coordination for 5G NR Networks

TL;DR

This paper proposes an inter-cell interference coordination framework for 5G NR networks to enhance UAV connectivity by jointly optimizing antenna tilt and scheduling, improving worst-case UAV SIR.

Contribution

It introduces a novel ICIC approach combining antenna tilt optimization and NR-compliant scheduling, formulated as a multi-cell deployment problem solved with bio-inspired algorithms.

Findings

Significant improvement in worst-case UAV SIR with the proposed method.

Enhanced downlink reliability for aerial users in dense macro deployments.

Effective joint optimization approach for multi-cell 5G NR networks.

Abstract

Cellular-connected unmanned aerial vehicles (UAVs) operating in 5G New Radio (NR) macro networks experience severe and spatially non-uniform downlink interference. This is primarily caused by the interference from the sidelobes of downtilted base station (BS) antennas serving terrestrial users, which limits the ability of the network to provide uniform and high-quality coverage to aerial users. Supporting aerial users requires boosting the coverage of certain cells or sectors, which can further exacerbate inter-cell interference in dense macro deployments. This motivates the need for inter-cell interference coordination (ICIC) in multi-cell 5G NR networks serving both aerial and terrestrial users. In this work, we propose an ICIC framework that jointly optimizes antenna-domain coordination through BS uptilt angle optimization and time-domain interference coordination (TDIC) through NR-compliant scheduling. The framework is formulated as a multi-cell NR macro deployment problem that maximizes the minimum UAV signal-to-interference ratio (SIR) over a spatial grid of UAV locations while maintaining acceptable performance for ground user equipment (GUEs). The resulting optimization problem is non-convex and is solved using bio-inspired optimization techniques, including particle swarm optimization (PSO) and genetic algorithm (GA). Simulation results demonstrate that coordinated uptilt optimization with the booster-cell architecture significantly improves worst-case UAV SIR and downlink reliability in multi-cell 5G NR networks. booster-cell architecture significantly improves worst-case UAV SIR and downlink reliability in multi-cell 5G NR networks.