Adaptive Bandwidth Tracking for GNSS Satellites Signal with Dynamic Stress Upper Bound Estimation

The positioning performance of Global Navigation Satellite System(GNSS) relies greatly on the accuracy of phase tracking, which is carried out by Phase Lock Loop (PLL). Traditional PLLs work employs a constant noise bandwidth. There may be problems with accuracy or robustness with loop in different scenarios. Variable bandwidth PLL adjusts the noise bandwidth to get better phase tracking results. The working principle is to estimate the dynamic stress according to the statistical magnitude of the phase discriminator output. But the influence of dynamic change reflected in the statistical magnitude delay for a certain time, which may cause the response of bandwidth adjustment not in time. In severe cases, the PLL may lose lock for carrier phase. An adaptive bandwidth algorithm for third order PLL based on estimation of dynamic stress upper bound is proposed. The experiment results show that it can response rapidly for change of dynamic stress. At the same time, it maintains the ability to distinct phase jitter noise from dynamic stress error.