Time-Variant PDFs of AODs and AOAs for Ground Scattering in Low-Altitude Air-to-Air Communication Over Open Area

Abstract

Distributions of angles of departure (AODs) and angles of arrival (AOAs) are essential for mobile communications since they are the basis of channel modeling, channel estimation, antenna beamforming, precoding, and positioning. However, distributions of AODs and AOAs for air-to-air (A2A) communications have not been presented precisely, not to mention the time-variant probability density functions (PDFs). This letter presents analytical derivations of the time-variant PDFs of AODs and AOAs of ground scattering paths over open area based on uniformly distributed scatterers in maximum delay determined scattering area for low altitude A2A communication, both hundreds-meter scenario and under 60m scenario are simulated to observe the time-variant features of the PDFs due to movements of the aircraft.