Performance analysis of a multi-GNSS receiver in the presence of a commercial jammer

In addition to the two existing Global Navigation Satellite Systems (GNSS) GPS and GLONASS, there are two other emerging GNSS constellations Galileo and BeiDou that will offer global coverage sometime within the end of this decade. These redundant multiple constellations transmitting civilian signals in different frequency bands will offer immense possibilities to improve navigation performance in terms of availability, reliability, accuracy and so on. In this paper, the authors analyze the performance of their implemented multi-frequency multi-GNSS software-defined receiver in two different cases: a good Line-Of-Sight (LOS) condition i) without the presence of any intentional jamming, and ii) in the presence of a commercial L1 jammer. The objective here is to analyze the performance of the multi-GNSS receiver in an ideal LOS condition, so the benefits of multi-GNSS could be straightaway realized. In addition to this, the second objective is to highlight one of the key benefits that a multi-frequency multi-GNSS receiver can offer in the occurrence of jamming in one of its frequency bands. To this end, the authors implemented a modified interference detection method based on the level changing rate of the Running Digital Sum (RDS) of the raw data bins. A simple jamming detection based GNSS signal selection mechanism is implemented. It is shown in the paper that the jamming detection based GNSS signal selection mechanism offers a much improved navigation performance than a straightforward multi-GNSS solution.