Hybrid anti-jamming algorithm for Indian Regional Navigation Satellite System receivers using variational mode decomposition and wavelet packet transform

摘要

Continuous wave interference has found to be one of the major menaces that deter the performance of the Indian Regional Navigation Satellite System (IRNSS) receivers for seamless positioning and navigation. In this paper, a novel hybrid jamming mitigation method based on variational mode decomposition (VMD) and wavelet packet transform (WPT) has been proposed. VMD is used to decompose the received signal into various components referred to as intrinsic mode functions (IMFs). To have an optimum decomposition of the signal, the mode decomposition number of VMD is determined by employing the kurtosis principle. Then, a threshold based on the mutual information index is constructed to differentiate the information dominant and interference dominant modes. The information dominant modes are then processed by the wavelet packet filter to eliminate the remaining effects of jamming and noise present. Finally, the filtered modes and the retained modes are used to reconstruct the desired signal. The performance of the technique is analyzed in the presence of single-tone, multitone, and chirp jamming scenarios with different levels of jamming power. The proposed method has been tested by simulations in comparison with the standard algorithms. Results show that the proposed hybrid algorithm outperforms the standard algorithms in reducing the jamming signal effectively.