Improving comb alias rejection by exploiting certain class of palindromic polynomials

This paper presents a simple method to improve the alias rejection in comb decimation filters. The method is based on a mathematical result regarding zeros of palindromic polynomials of even degree. Using this result, additional zeros are introduced in comb folding bands (bands around the comb zeros), resulting in an improved alias rejection. Like a comb filter, the proposed decimation filter is also multiplierless. The comparisons with some recent methods for comb alias rejection improvements with a similar complexity are also provided.