Cascaded multiplierless realizations of low sensitivities allpass based fractional delay filters

Abstract

A new method of design of fractional delay IIR filters based on cascade realization of allpass structures is proposed in this paper. Closed-form design expressions are derived and the sensitivity of the individual sections is minimized. The advantages of the method are demonstrated by comparative study. Efficient multiplierless implementations are discussed and the robustness in limited wordlength environment is firmly demonstrated.