Time-frequency interference rejection based on the S-transform for GNSS applications

Interference detection and mitigation are important issues to guarantee the availability and service continuity of Global Navigation Satellite Systems. In this paper, a new method based on a joint spectral and time-frequency (TF) analysis is proposed for jamming excision. It localizes the time-varying energy spectral density of the interfering signal by using the S-transform, then employs a binary mask to filter out the interference power. This approach is not model-driven and is computationally efficient. These features make it a practical add-on for GNSS receivers. We evaluate the effectiveness of the method presented by testing the acquisition of a Galileo signal under jamming attack. Simulation results prove that the performance in terms of code acquisition are significantly enhanced, even under challenging reception conditions.