Multi-layered Multi-constellation GNSS Interference Mitigation

Abstract

Several layers of defense can be implemented in a Global Navigation Satellite System (GNSS) receiver to improve its performance in the presence of interference. These layers include the use of pre-correlation mitigation techniques, post-correlation quality indicators to screen measurements and Fault Detection and Exclusion (FDE) at the position solution level. This paper provides a characterization of the interaction between these layers of interference mitigation and measurement quality check. Data collected in the presence of increasing power jamming levels have been processed using different interference mitigation techniques, including Robust Interference Mitigation (RIM) and the Adaptive Notch Filter (ANF). A Software Defined Radio (SDR) approach has been adopted and measurements were generated considering five interference mitigation techniques. Position solutions were then computed using the Forward-Backward approach for Receiver Autonomous Integrity Monitoring (RAIM). Signals from GPS, Galileo and Beidou were processed and both single and dual constellation solutions were analysed. The analysis shows that interference mitigation allows the receiver to track a higher number of signals, even in the presence of high jamming levels. This increased measurement availability is then effectively exploited by RAIM techniques that provide reliable solutions. Measurements from several constellation further improve the reliable availability of the position solutions.