A fast and accurate anti-jamming system based on wavelet packet transform for GPS receivers

Interference mitigation is an important issue for global positioning system receivers. An anti-jamming system is proposed, which employs two wavelet packet transform (WPT)-based interference mitigation blocks. The proposed pre-/post-correlation mitigation technique employs lower decomposition levels for the WPT-based denoising algorithms because it shares the responsibility of the interference mitigation between two blocks. Moreover, the first block can be deactivated in low-power jamming situations. The performance of the anti-jamming system is evaluated for the cases of single-tone continuous wave interference and linear chirp interference. Experiments and theory prove that the computational cost of the proposed method is significantly less than similar WPT-based mitigation methods and thus it is a fast interference mitigation technique. Experiments also show that it has a considerable decrease in terms of positioning error and thus it is an accurate suppression method.