Automatic suppression of narrow-band interference in direct-sequence spread-spectrum systems

This paper addresses the problem of narrow-band interference (NBI) cancella tion in direct-sequence spread-spectrum systems. The proposed procedure amo unts to a preliminary nonlinear processing, wherein, upon projection of the received signal onto a Fourier basis, a number of samples having the large st modula are excluded from further processing, The structure of the optimu m detector operating on censored observations is obtained, showing that the optimum detector performs matched filtering on the censored data. The perf ormance assessment demonstrates that this receiver is able to suppress narr ow-band interferers, no matter what their structure, provided that the cens oring depth is properly chosen, A blind version of such a receiver is prese nted also, and a comparative performance assessment demonstrates that, unli ke other suppression procedures, the proposed system allows suppression of NBI with no prior knowledge on its structure.