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

Abstract

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.

Performance Evaluation of Multi-Antenna Receivers for Vehicular Communications in Live LTE Networks

“…In this work we use the measurement setup thoroughly described in [12] or [13] and shown on Figure 1. It is composed of sixteen antennas uniform circular array manufactured for 1.8 GHz LTE band 3 and connected to the measurement system built based on Universal Software Radio Peripheral (USRP) boards.…”

“…Scanner information is processed in order to better understand the level of interference in all measured points. The entire process was thoroughly explained in [12], therefore in the next subsection only the summary of processing is outlined.…”

“…Post processing using MRC is very similar to the single antenna receiver but the processed signal is obtained by combining the sixteen recorded data streams. We refer to [12] for further details on the receiver processing.…”

A USRP-Based Multi-Antenna Testbed for Reception of Multi-Site Cellular Signals

“…In the remaining of this section, the potential of using the LTE toolbox is discussed by describing the receive beamforming processing. Although this section is focused only on the receiving beamforming, other multi-antenna combining techniques including Maximum Ratio Combiner (MRC) or even single antenna processing can be achieved by replacing the beamforming block with the desired antenna processing as described in [28]. Figure 7 presents the flowchart of the data processing.…”

“…Finally in [28], similar to the previously described application, the very same snapshots recorded in the air were used to compare the performance of multi-antenna receivers in UAV scenarios. In contrast to the results obtained during the vehicular campaign, in the air the beamforming constantly outperforms MRC receiver.…”