Robust acquisition at GPS receivers in unsafe locations using complex wavelet transform

Abstract

Growing importance of Global Positioning System (GPS) applications in various fields, leads many researches to the security of GPS systems and investigation of eventual perturbations in them. One of the most important intentional interferences is spoofing. This work presents an anti-spoofing method based on complex wavelet transform (CWT). Fake satellites are omitted and then understrength satellites due to spoofing are identified. The results of investigation suggest that the proposed CWT based estimation and extraction method is better than relatively simple wavelet transform. The suggested filter is applied in the Intermediate Frequency signal. Cross-validation technique is used for automatically identifying wavelet signal layers. The proposed method has been implemented on different collected datasets. Software GPS Receiver has been used to implement and validate the developed anti-spoofing technique because it is more flexible and economical compared with usual hardware receivers.