Multiplier-free structures for IIR half-band filter by multiple use of short subfilter

This paper proposes a novel synthesis scheme for sharpening IIR half-band filters. Starting from a short IIR half-band subfilter, the scheme utilizes algebraic composition of several subfilters to construct a composite IIR half-band filter. The IIR half-band filter has a low-complexity structure with good numerical properties like small dynamic range and low round-off error sensitivity. When the subfilter is multiplier-free, the proposed scheme is completely multiplier-free and also not subject to wordlength