Chirp-Like Jammer Excision in DSSS Communication Systems using Combined HHT Spectrum and Hough Transform

The Hilbert-Huang transform (HHT) is employed for chirp-like jammer excision in direct sequence spread spectrum (DSSS) communication systems in this paper. The proposed method iteratively decomposes the received signal into intrinsic mode functions (IMFs) and applies Hilbert transform to each IMF to yield Hilbert spectrum, by which the embedded jammer can be well localized in the time-frequency plane. With the Hough transform to the Hilbert spectrum, the parameters of the jammer are estimated and the jammer in time domain is restructed. The restructed jammer is excised from the received signal, and an excised signal goes through the detector for a decision. The performance of the proposed method is evaluated in the presence of chirp-like jammer plus Gaussian noise.