레이트레이싱 시뮬레이션을 이용한 도심환경의 UAV 기반 비지상 통신 LoS 확률 예측 연구

Abstract

This paper presents simulation results for estimating the LoS(Line-of-Sight) probability in UAV(Unmanned Aerial Vehicle)-based non-terrestrial network environments. The existing LoS probability models proposed by the ITU-R(International Telecommunication Union – Radiocommunication sector) have been primarily designed for ground-based scenarios with base stations installed on building rooftops. Therefore, these existing models have limitations when applied to non-terrestrial platforms such as UAVs. In this study, we analyzed the effects of the UAV altitude, 2D distance between the UAV and the UE(User Equipment), and building height distribution on the LoS probability through ray-tracing simulations using real urban map data from Korea. The simulation results showed that the LoS probability increased with UAV altitude. However, the magnitude of this increase significantly depended on the building height distribution within an urban environment. Specifically, in urban areas with lower building height distributions, a sufficient LoS probability was achievable even at relatively low UAV altitudes. Conversely, in areas with densely distributed high-rise buildings, UAVs had to maintain higher altitudes to secure appropriate LoS probabilities. Additionally, based on the ground distances between the UAV and the UEs, we proposed a suitable coverage criterion by comparing our simulation results with that of the conventional ITU-R M.2412 LoS probability model. The results of this study are expected to provide valuable guidelines for designing and optimizing UAV-based non-terrestrial military communication systems in urban environments.