An Extraction Method for the Multipath Characteristics of Simulated Tropospheric Propagation Channels

Multipath propagation, resulting from signal reflections, diffractions, scatterings, and atmospheric ducting, poses significant challenges in wireless communication, navigation, and surveillance systems. This study focuses on evaluating the multipath characteristics in tropospheric propagation channels, particularly in air-ground systems. For long-range wave propagation in low-troposphere environments, split-step methods offer both precision and computational efficiency in modeling propagation at specific frequencies. We propose a multipath extraction approach to separate dominant propagation paths and associated multipath components by means of the postprocessing of frequency-domain simulation results. The multipath extraction relies on the Prony’s method, which allows to assess the multipath amplitude, phase, and delay from simulation results at a few frequencies. This research examines the multipath extraction method and validates the proposed models through numerical experiments across various scenarios and parameters. Simulation results are consistent with the two-ray model over flat ground. In this case, the extracted multipath reproduces the simulated channel with a root-mean-square error below –50 dB at all spatial points.