Robust Interference Mitigation in GNSS Snapshot Receivers

<h3>Abstract</h3> The robust interference mitigation (RIM) framework offers a promising solution to jamming attacks on global navigation satellite system (GNSS) receivers. By identifying interfered samples as outliers in the selected transform domain, RIM operates without relying on jamming waveform assumptions. This paper adapts RIM for GNSS snapshot architectures, assessing the impact of low-bit quantization on receiver performance under continuous wave (CW) and chirp interference. Using simulated data, snapshot RIM demonstrates significant improvements, achieving gains of 10, 20, and 35 dB in detected satellites for 2-, 4-, and 8-bit quantization in the presence of CW jamming. We also analyze the effect of quantization on the effective jammer-to-noise ratio, waveform distortion, and robust variance estimation. An experiment with realistic recordings shows that snapshot RIM achieves a 20-dB gain in the carrier-to-noise ratio over a professional receiver. Finally, a 24-h specifications test supports the feasibility of RIM integration in snapshot receivers with a maximum time-to-first-fix increase of 0.31 s.