GNSS interference detection with the SWAN fully configurable SW receiver platform

The SWAN project aims at promoting the development of a new generation of GNSS receivers based on SDR, the most flexible and reconfigurable, able to manage multiple GNSS signals and to incorporate future updates of the same signals. The project is part of an Italian initiative, financed by the Italian Space Agency with the purpose of triggering further research and development of architectures and algorithms for the implementation of GNSS receivers, based on the SDR technique. This paper describes how the multiple receiver architectures have been implemented in a fully operational model called Base Model and its possible application in the field of the interference detection. In particular the possibility of gathering samples of the received signal at intermediate frequency in real time with a selectable bandwidth makes easier to study the incoming signals in terms of time-frequency spectral analysis for the interference detection. The focus here is on a power spectral density fluctuation detection technique, in which statistical inference is used to detect different types of interferences in the GNSS signals band after being captured by the RF front-end. The implemented technique is based on a Welch periodogram computation and then on the Short Term Fourier Transform. The algorithm description is backed up by the results of a preliminary test campaign.