GNSS Carrier Phase Tracking With Discrete Wavelet Transform Filtering Under Ionospheric Scintillation

In this letter, we propose the phase-locked loop with discrete wavelet transform filtering and redesigned Kalman filters (KFs) to enhance the global navigation satellite system signal carrier tracking robustness under ionospheric scintillation, being of the paramount importance in safety critical applications and advanced receivers. By normalizing the discriminator in the loop using the signal amplitude estimated with the discrete wavelet transform filtering, the phase variation due to scintillation is well estimated. The adaptive KF is modified with an additional amplitude state to copy with the scintillation-induced disturbance so as to stably track the fluctuated phases. Simulations are offered to verify the performance improvement of the proposed method versus the previous ones in the case of ionospheric scintillation.