Experimental Evaluation of Multi-Antenna Receivers for UAV Communication in Live LTE Networks

Unmanned Aerial Vehicle (UAV) communication is known to suffer from significant interference due to the clearance of the radio paths with ground base stations. Multi-antenna receive combining has the promise of alleviating the impact of interference, translating to improved connectivity performance. In this paper, we evaluate the performance of Conventional Beamforming (CB) and Maximum Ratio Combining (MRC) receivers for UAV communication based on live Long Term Evolution (LTE) networks. Our measurement setup consists of nine Universal Software Radio Peripheral (USRP) boards and a circular antenna array with sixteen elements. The LTE signals are recorded at different UAV flight heights in urban environments, and processed offline. Results show similar Signal-to-Interference-plus-Noise Ratio (SINR) performance by MRC and CB, with CB slightly outperforming MRC provided knowledge of LTE signal structure is used for the beam selection. No significant dependency from the flight height has been observed. The outage probability analysis further emphasizes the benefits of using CB in the studied scenarios.