Coherent interference excision using higher order spectra

The bispectrum of a direct sequence spread spectrum communication signal contaminated with coupled multitone jamming provides significant information about the jammer frequencies and thus permits its excision using a bank of notch filters. Jammers that can be modeled as an autoregressive process can also be examined in the bispectral domain and mitigated using a linear FIR filter with temporally changing coefficients. The results indicate that utilizing bispectral analysis in DS spread spectrum communications is an attractive alternative to conventional excision techniques and in some scenarios the only excision option available.