ELECTRONIC ARTICLE SURVEILLANCE SYSTEM WITH COMB FILTERING BY POLYPHASE DECOMPOSITION AND NONLINEAR FILTERING OF SUBSEQUENCES

摘要

A signal received in an electronic article surveillance system is subjected to a nonlinear comb filtering function to remove interference. The nonlinear comb filtering is provided by performing a polyphase decomposition of an input digital signal, nonlinear filtering of the resulting subsequences, and then synthesizing the nonlinear- filtered subsequences. A median filter may be used as the subsequence filtering function. A linear comb filtering function may be provided downstream from the nonlinear comb filter to provide additional attenuation of interference.