Evaluation of Beamsteering Performance in MultiuserMIMO Unmanned Aerial Base Stations Networks

Future wireless communication networks can benefit from Unmanned Aerial Base Stations (UABSs) to provide enhanced capacity to ground users (GU) in large and remote locations. Connecting UABSs to the terrestrial network presents several challenges, such as the limited gain traditional antennas need to maintain suitable wireless links between the core network, UABS, and GU. A convenient solution is to use MaMIMO (Massive Multiple Input Multiple Output) since it improves spectral and energy efficiency, thus providing high data rates while reducing power consumption. This paper proposes a Multi-user MIMO (MuMIMO) model for UABS aided networks to increase service range and served capacity. It uses hybrid beamforming and beamsteering on Terrestrial Base Stations (TBSs) and UABSs to grant access to mobile GU in a bicycle race scenario. Results show that using the mobile operators' locations will benefit the backhaul network's performance by duplicating the capacity compared to using a private operator. Furthermore, user coverage increases by 400% if MuMIMO is used, compared to a single beam MaMIMO network. The proposed scenario could achieve a channel efficiency of 6.5 bit/s/Hz in the access network and 8.6 bit/s/Hz in the backhaul network. Finally, the average UABS transmitted power is reduced by 2/3, increasing the number of used beams.