Signal-level integrity and metrics based on the application of quickest detection theory to interference detection

In this paper, we will concentrate on interferences as one of the major impairments that can threat the integrity of mass-market GNSS receivers. While the topic of interference detection has already been covered in the existing GNSS literature, the purpose of this work is to focus on the fast and reliable detection of interferences, using the tools of the so-called “quickest detection” theory. To do so, time plays a relevant role, since we are often interested in minimizing the time for detecting a given threat. This is in contrast to classical detection techniques, where the goal is to maximize the detection probability subject to some probability of false alarm, but where “time” is not explicitly considered. Theoretical results on quickest detectors are complemented in this work with experimental tests using real signals, obtained in the framework of the EC funded iGNSSrx project. The effects of different types of interferences onto the proposed quickest detection techniques are shown and the performance of the designed detection algorithms working in real conditions is presented. The results show how the behavior of the proposed algorithms is satisfactory for being used in integrity monitoring applications.