Weak GNSS signal acquisition based on wavelet de-noising through lifting scheme and heuristic threshold optimization

Signals of Global Navigation Satellite System suffer heavy fading after long distance transmission. However, the signal receiver demands both efficiency and accuracy. This paper employs DWT (discrete wavelet transformation) and lifting scheme in wavelet de-noising post-processing after the signal is detected by differential coherent integration methods. At the same time, a lifting wavelet de-noising through double threshold optimization based on Tabu Search(TS) is proposed to be applied in the post-processing. The complexity of lifting scheme for de-noising is analyzed in the paper. Also, the selection of the wavelet base and the decomposition level are discussed as well. The result of the simulation reveals that the lifting wavelet de-noising through double threshold optimization based on TS shows much better performance in the de-noising accuracy than DWT or the lifting scheme separately. Moreover, the lifting scheme applied in the double threshold optimization based on TS reduces the de-noising calculation amount to lower the difficulty for acquisition.