Air-to-Air Channel Characterization for UAV Communications at 3.4 GHz

TL;DR

This paper presents initial 3.4 GHz air-to-air channel measurements for UAVs using a custom open-source sounder, providing insights into channel behavior over various flight conditions.

Contribution

It introduces a lightweight, reconfigurable channel sounder and offers the first detailed A2A channel characterization at 3.4 GHz for UAV networks.

Findings

Channel impulse responses were extracted and analyzed.

Fading behavior modeled as a function of link geometry.

Fading statistics including RMS delay spread characterized.

Abstract

Uncrewed Aerial Vehicle (UAV) networks require accurate Air-to-Air (A2A) channel models, but most existing work focuses on Air-to-Ground links and leaves the sub-6 GHz A2A channel poorly characterized. We present preliminary 3.4 GHz A2A channel measurements collected with a lightweight, reconfigurable, open-source channel sounder built from USRP B210 software-defined radios and a high-precision GNSS-disciplined oscillator mounted on two UAVs. Measurements were conducted at the AERPAW Lake Wheeler testbed using a spherical flight trajectory around a second drone to capture channel behavior over varying altitudes, elevation angles, and relative headings. From these data, we analyze fundamental channel properties, extract channel impulse responses, model fading behavior as a function of link geometry, and characterize fading statistics including RMS delay spread. The resulting dataset and analysis provide a more realistic basis for the design, emulation, and evaluation of physical-layer and MAC protocols for next-generation UAV communication networks.