Impact of Base Station Antenna Tilt Angle on UAV Communications

Abstract

Different from a terrestrial network, novel unmanned aerial vehicle (UAV) networks arc necessary to efficiently serve aerial users (AUs) as well as ground users (GUs). In this paper, we model a base station (BS) antenna power gain, which is determined by the BS antenna tilt angle and the horizontal distance between BS and user (GU or AU). In order to efficiently serve both GUs and AUs, we propose two BS service schemes, inclusive-service base station (IS-BS) and exclusive-service base station (ES-BS) schemes. For each BS service scheme, we derive a network outage probability by taking into account the characteristics of the BS antenna power gain and channel components for line-of-sight (LoS) and non-line-of-sight (NLoS) environments. Finally, we show that the effect of the total BS density, the interfering BS density, and the user density on the optimal BS tilt angle and our proposed scheme.