Interference, Robustness, and Solutions for Multi-GNSS Receivers

Modern society highly depends on Global Navigation Satellite System (GNSS) technology as millions of people everyday make use of applications and services that rely upon accurate and reliable positioning, navigation, and timing information. The use of satellite-based navigation technology is so widespread that it is hard nowadays to find infrastructures or systems that do not benefit from it. A disruption in the GNSS operation could have an impact on communications, transportation, energy, and defense infrastructures, to name a few. The consequences could be severe in case of safety-critical applications, such as aviation, public safety services, and autonomous vehicles.

Despite its essential role, GNSS technology is not immune to errors, since it is vulnerable to a wide range of threats that can degrade its performance or even completely deny the service. Due to the weakness of GNSS signals at the time of reception on Earth, one of the major threats to GNSS operation, and the key driver behind this thesis, is Radio Frequency Interference (RFI). In this context, the thesis aims at understanding the behavior of GNSS receivers in the presence of interference and at investigating solutions to improve their robustness. Standard test procedures that utilize real-world interferences are proposed and put into practice with the intent to help the GNSS community understand the impact of the most frequently encountered interference types and ensure that receivers are robust against them. Moreover, the thesis investigates solutions to the interference problem. It provides an overview of the existing detection and mitigation techniques, assesses the performance of well-known countermeasures, and then focuses on the development of innovative solutions to improve GNSS robustness to interference.