Time and frequency dispersion characteristics of the UAS wireless channel in residential and mountainous desert terrains

A Survey of Channel Modeling for UAV Communications

“…However, frequency variance due to Doppler shift is not significant in [46], [47] due to the low velocity of UAVs. In [48], for the mountainous desert scenario, the median RMS delay spread and the Doppler frequency spread were roughly 0.06µs and 28.96 Hz, respectively. For the residential area, the measured median RMS delay spread and the Doppler frequency spread were approximately 0.03µs and 28.06 Hz.…”

“…From the perspective of aeronautical communication, a correlative channel sounder was used in [39] and [40] for measuring multipath effects. In the context of characterizing the UAV propagation channel, the wideband frequency-selective parameters are often measured using the universal software radio peripheral (USRP) hardware platform, for instance, as in [45], [46] and [48]. This platform provides more flexibility in terms of low-power consumption and multiple frequency bands.…”

“…In [48], the measurement campaign was performed in both a residential area and a mountainous desert landscape in Arizona, USA. The software defined radio (SDR) platform was tuned to 5.8 GHz.…”

“…In these works, the stochastic model only provides numerical analysis and lacks in validation by measurement results. On one hand, empirical data have been collected from the measurement campaigns in [45], [47], [48] to study the impact of UAV flight dynamics and environment on the small-scale fading. However, these studies did not consolidate the fading statistics using the TDL model.…”

“…, where Ψ b s and φ b s are, respectively, the azimuth and the elevation angle observed from the base station, l b s, ma x and l b s, mi n are the distance between the base station and, respectively, the farthest and the nearest scatterer point, and V is the volume of the scattering region [20] The von Mises PDF of AOA as a function of azimuth angle: • Path loss model presented as closed-form expressions with correction factors based on environment conditions [47], UAV altitude [62], [64] and elevation angle [65] • Channel characterization depends upon the multipath resolution of the channel sounder, antenna design and propagation environment • Small-scale fading can be characterized by the superposition of all multipath components in the form of channel impulse response [45]- [48] • Size and payload constraints of different UAV types…”