Narrowband interference suppression in DSSS system based on frequency shift wavelet packet transform

Abstract

A narrowband interference suppression algorithm which combined wavelet packet transform with frequency shift is proposed. It first confined the interference in the center of a subband. Then, the signal is decomposed by wavelet packet transform, and interference is suppressed under subband power ratio rule. Finally, the signal is de-noised by soft-thresholding before signal reconstructed. Both analysis and simulation demonstrate that the interference is completely suppressed by frequency shift wavelet packet transform, the signal-to-noise ratio is improved by soft threshold signal de-noising, the single dwell time of acquisition is reduced and the acquisition performance is improved.