UAV-Assisted Wireless Communications: An Experimental Analysis of Air-to-Ground and Ground-to-Air Channels in Open Environments

Unmanned Aerial Vehicles (UAVs) offer promising potential as communications node carriers, providing on-demand wireless connectivity to users. While existing literature presents various channel models, they often overlook the impact of UAV heading. This paper experimentally characterizes Air-to-Ground (A2G) and Ground-to-Air (G2A) wireless channels in obstacle-free, interference-free open environments, accounting for distance and UAV heading. We analyze the Received Signal Strength Indicator (RSSI) and TCP throughput between ground users and UAVs, covering distances between 50 m and 500 m, and considering different UAV headings. Our study offers a more accurate channel model characterization compared to deterministic models such as Friis and two-ray. Additionally, we characterize the antenna's radiation pattern based on UAV headings.