A Novel Interference Detection Method Based On Wigner-Hough Transform For Gnss Receivers

Nowadays, the research topic on transformed domain techniques (e.g. time-frequency (TF) transform) has obtained increasing attention in interference detection for Global Navigation Satellite System (GNSS) receivers. Different time-frequency representations (TFRs), such as spectrogram and Wigner-Ville distribution (WVD), have been considered in interference detection for GNSS applications. The spectrogram approach presents the TF resolution trade-off problem according to Heisenberg's uncertainty principle, which provides poor TF localization properties. In order to deal with the TF resolution limitation with the spectrogram approach, the WVD has been adopted in interference detection for GNSS receivers. The WVD has many nice properties and provides nearly the best TF resolution among all the TF analysis techniques, but it presents severe cross interfering terms problem due to interaction of different signal components, which inevitably results in serious estimation error for the instantaneous frequency of the GNSS interfering signal.In this paper, the novel interference detection methods by using Hough transform based time-frequency (TF) analyses such as Wigner-Hough Transform (WHT) and Pseudo Wigner-Ville Distribution Hough Transform (PWHT) have been proposed for Global Navigation Satellite System (GNSS) receivers. The proposed interference detection methods have been examined by experiments on real GPS L1 data collected in the presence of sweep interference (linear-frequency-modulated interference, i.e. linear chirp) in comparison with the conventional TF analysis based interference detection approaches such as spectrogram and Wigner-Ville distribution (WVD).The analysis results have shown that the proposed Hough transform based TF analysis methods can suppress the undesired cross-terms in the bilinear TF distributions and improve the GNSS interference detection performance with respect to the conventional TF analysis approaches, which have been proven to be valid and effective in interference detection for GNSS receivers in jamming environments.