Wavelet-packet-transform-based adaptive predictor to mitigate GNSS jammers

Strong jammers can paralyze the operation of consumer grade Global navigation satellite system (GNSS) receivers. Although conventional time-domain-based anti-jamming techniques can effectively combat the continuous wave interference (CWI), these techniques cannot mitigate the chirp interference. This paper proposes a wavelet-analysis-based anti-jamming architecture to mitigate chirp interferences. By exploiting the excellent time-frequency resolution of wavelet technologies, we can de-noise the received signal to generate reference chirp signals, which are applied to an adaptive predictor. This predictor aims to refine the reference chirp. The refined chirp signals are then subtracted from the received signals. With application of Galileo receiver-s, simulation results have shown that our method can combat the chirp interference with averaged jamming-to-signal power ratio (JSR) of 50 dB, which is superior to some time-domain-based anti-jamming techniques, such as conventional adaptive notch filters.