Wideband Air-to-Ground Channel Propagation Characterization in Diffuse Multipath Environment

In air-to-ground (A2G) environments, accurately characterizing the multipath channel propagation characteristics is crucial for improving positioning system accuracy. Therefore, this paper presents A2G wideband channel measurement conducted in a rural environment. An autoregressive moving average (ARMA) filter-based space-alternating generalized expectation-maximization (SAGE) channel parameter estimation algorithm combined with a Kalman filter is used to achieve high-precision estimation and tracking of channel parameters. Time-varying multipath parameters, including delay, amplitude and duration time, are then analyzed. This work can further contribute to the development of a geometry-based stochastic channel model (GSCM) for A2G channel multipath propagation in positioning and navigation technologies.