Effect and mitigation of oscillator vibration-induced phase noise on carrier phase tracking

Abstract

The influence of vibration-induced oscillator phase noise on carrier phase tracking of a GNSS receiver is analyzed. We show that when the oscillator is vibrating, the vibration-induced oscillator noise is increased and the carrier phase tracking is affected. In order to mitigate the influence of the vibration-induced oscillator phase noise on carrier phase tracking, a vector tracking structure based on an extended Kalman filter called vector phase tracking loop (VPLL) is proposed. In this method, an individual phase lock loop (PLL) for each channel is used to track the satellite-dependent parameters such as atmospheric delay, and a common vector loop is integrated for common parameters tracking such as the receiver clock. The performance of the conventional PLL and the proposed VPLL under oscillator vibration is compared using data collected from a simulator and from a field test. Different PLL bandwidths are tested in order to consider different operating conditions. The test results show that when similar thermal noise error is present, the proposed method can improve the carrier phase tracking compared to conventional PLL.