Verification of satellite-channel simulators with scintillation, terrestrial multipath, and shadowing effects

In the UHF (200-400 MHz) frequency band, satellite transmissions are affected by scintillation (caused by nonuniform electrical charge distributions in the ionosphere), terrestrial multipath (caused by diffuse reflections, scattering, and diffusion) and shadowing. A satellite channel model, which accounts for all these phenomena, has been developed to accurately assess link and system performance for the mobile user objective system (MUOS) program. The MUOS channel model is mathematically complex and difficult to implement because it has to account for the various UHF propagation effects. In this paper, a methodology for verifying implementations of the channel model, called channel simulators, is presented. Since the MUOS channel model is described by a wide-sense stationary uncorrelated scattering (WSSUS) process, it can be completely characterized by first and second order statistics, represented by a probability density function (pdf) and bi-variate correlation function, respectively. From the pdf and bi-variate correlation functions, three theoretical functions (i.e. exceedance, normalized power spectral density and multipath intensity profile) are derived and used as validation metrics. To verify a channel simulator, the theoretically derived metrics are compared to measured statistics from the simulator. Verification results are presented for a variety of channels including those that model aeronautical, maritime, land-forest, and land-urban environments