Empirical Low-Altitude Air-to-Ground Spatial Channel Characterization for Cellular Networks Connectivity

Cellular-connected unmanned aerial vehicles (UAVs) have recently attracted a surge of interest in both academia and industry. Understanding the air-to-ground (A2G) propagation channels is essential to enable reliable and/or high-throughput communications for UAVs and protect the ground user equipments (UEs). In this contribution, a recently conducted measurement campaign for the A2G channels is introduced. A uniform circular array (UCA) with 16 antenna elements was employed to collect the downlink signals of two different Long Term Evolution (LTE) networks, at the heights of 0-40m in three different, namely rural, urban and industrial scenarios. The channel impulse responses (CIRs) have been extracted from the received data, and the spatial, including angular, parameters of the multipath components in individual channels were estimated according to a high-resolution-parameter-estimation (HRPE) principle. Based on the HRPE results, clusters of multipath components were further identified. Finally, comprehensive spatial channel characteristics were investigated in the composite and cluster levels at different heights in the three scenarios.

Automated summary

This paper introduces a recent measurement campaign for air-to-ground (A2G) propagation channels using a uniform circular array (UCA) with 16 antenna elements to collect downlink signals of two LTE networks at different heights in rural, urban, and industrial scenarios. Channel impulse responses (CIRs) were extracted and spatial parameters of multipath components in individual channels were estimated using a high-resolution-parameter-estimation (HRPE) principle. Clusters of multipath components were identified based on the HRPE results, and comprehensive spatial channel characteristics were investigated in composite and cluster levels at different heights in the three scenarios.