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Mitigation of Ionospheric Scintillation Effects on GNSS Signals Using Variational Mode Decomposition

This letter addresses the problem of ionospheric scintillation effects on the global navigation satellite system (GNSS) signals. Severe scintillations degrade the signal intensity below the fade margin of the GNSS receiver, resulting in failure of the positioning and navigational services. A robust methodology is needed for the estimation and mitigation of such ionospheric scintillation effects. Hence, in this letter, the application of an adaptive signal decomposition technique based on variational mode decomposition (VMD), in combination with the detrended fluctuation analysis (DFA) method, is reported. VMD-DFA effectively decomposes the GNSS signal affected by ionospheric scintillations into a number of intrinsic mode functions and provides a threshold for the detection and mitigation of scintillations noise. Monte Carlo simulation results demonstrate that the proposed algorithm is superior and reliable for eliminating the amplitude scintillation effects compared to the complementary ensemble empirical mode decomposition method. The application of the proposed algorithm on both synthetic (Cornell scintillation model) and real-time measured GNSS data obtained from GNSS software navigation receiver at Rio de Janeiro, Brazil, has shown its potentiality in mitigating the ionospheric amplitude scintillation effects.