Rejection of narrow-band interference in DS spread spectrum systems employing nonlinear interpolation filters

The narrow-band interference (NBI) rejection capability of direct sequence spread spectrum (DS-SS) systems can be further enhanced by employing interference rejection filters. In this paper, the performance of nonlinear interpolation filters is analyzed in the presence of narrow-band interference. Closed-form analytical expression for the signal-to-noise ratio improvement factor is derived. By comparison, we conclude that nonlinear interpolation filters outperform both nonlinear prediction filters and linear filters.