Enhanced Blind Adaptive Narrowband Interference Suppression in DSSS

This paper addresses blind adaptive suppression of a digital narrowband interferer in direct sequence spread spectrum (DSSS) communications.. We apply an adaptive suppression method for wideband interference proposed by Honig, Madhow and Verdd [1] to a narrowband interferer. We identify the eigenspaces of the system dynamics to: 1) significantly decrease convergence times via a new constraint on step size, 2) introduce a simple parameterization of the mean output energy and signal-to-interference ratio, and 3) identify modes of operation where the algorithm ceases to effectively cancel interference. We propose a new adaptive receiver that avoids the convergence anomalies, while capitalizing on the new step size for faster convergence.