Air-to-Ground Channel Model for Pedestrian and Vehicle Users in General Urban Environments

Precise channel modeling is crucial for analyzing the potential of autonomous aerial vehicles (AAVs) as aerial base stations (ABS) for communication in complex urban environments. Traditional air-to-ground (A2G) channel models, such as probability of line-of-sight (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$P_{\text{LoS}}$</tex-math></inline-formula>) and path loss (PL) models, typically assume uniform free space between buildings, neglecting the distinction between roads and sidewalks. This work addresses this gap by proposing a geometry-based 3-D PL model for urban AAV communication, explicitly considering both roads and sidewalks. The proposed model extends the city layout defined by International Telecommunication Union parameters to account for the distinct geometries of these two areas, catering to different users, including fast-moving vehicles and slow-paced pedestrians. The model accurately predicts <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$P_{\text{LoS}}$</tex-math></inline-formula> and PL variations between roads and sidewalks for ABS operating at various altitudes, distances, inclinations, and azimuth angles. The model's accuracy is validated through a custom-made simulator.