Communication Channel Modelling of Unmanned Aerial Vehicles

Wireless communication channel characterization for unmanned aerial vehicles (UAVs) is essential for reliable control, data transmission, and mission performance in civil, industrial, and defence applications. Channel behaviour is examined using a measurement-based approach that captures both large-scale propagation effects, represented by path loss, and small-scale characteristics, represented by the channel impulse response (CIR) and power delay profile (PDP). An SDR-based channel sounding system is employed to collect and process in-phase and quadrature (IQ) data, enabling the extraction of key channel parameters. Following system verification, measurements are conducted in ground-to-ground (G2G), air-to-ground (A2G), and air-to-air (A2A) scenarios. The results demonstrate that path loss alone is insufficient to describe UAV communication channels, as CIR and PDP provide additional insight into multipath propagation and delay-domain behaviour. The findings indicate that realistic UAV channel models should incorporate both large-scale and small-scale channel statistics. Further improvements may be achieved through increased sounding bandwidth, enhanced synchronization, measurements in a wider range of environments, and more detailed analysis of Doppler effects.