Wideband Channel Measurements and First Findings for Low Altitude Drone-to-Drone Links in an Urban Scenario

In order to prevent collisions between unmanned aerial vehicles (UAVs), Drone-to-Drone (D2D) communication is a promising technology for enabling reliable collision avoidance systems. For a high reliable communication system accurate channel models, specifically designed for UAVs in typical environments, are needed. Especially, the urban environment for small sized UAVs in very low level (VLL) airspace is challenging due to rich multipath propagation and non line-ofsight (NLOS) conditions. In order to model the real world propagation behavior, channel measurements with small UAVs in different urban scenarios are mandatory. So far, no wideband channel model based on measurements for D2D communication has been proposed. Therefore we conducted channel measurements with our MEDAV RUSK-DLR channel sounder with a 100 MHz bandwidth sounding signal at 5.2 GHz and two flying hexacopters. A key feature in our D2D wideband channel measurement campaign was the use of optical fibers. In this paper, we present the scenarios of our campaign and show first findings. By applying a geometrical signal path simulation we identify multipath component (MPC) sources. The measurements reveal that the D2D MPC scenario is clearly three-dimensional.