Generalized ionospheric dispersion simulation method for wideband satellite-ground-link radio systems

A generalized ionospheric dispersion simulation method is presented to verify and test wideband satellite-ground-link radio systems for dispersion robustness. In the method, ionospheric dispersive effects on wideband radio waves are modeled as an allpass nonlinear phase system, thus greatly decreasing the need for signal priori information. To accurately simulate the ionospheric dispersion and reduce the implementation complexity, the system is decomposed into three new allpass subsystems: with a linear phase passing through zero frequency, a constant phase, and a nonlinear phase with zero-offset and quasi-parabolic form respectively. The three subsystems are implemented respectively by the combination of integer-interval delay and fractional delay filter, digital shifting phase and the complex-coefficient finite impulse response (FIR) filter. The ionospheric dispersion simulation can be achieved by cascading the three subsystems in a complex baseband and converting the frequency to a radio frequency. Simulation results show that the method has the ability to accurately simulate the ionospheric dispersion characteristics without knowing the signal priori information and has a low implementation complexity.