Programmable fractional sample delay filters with flatness compromise between magnitude response and group delay

In this paper, a new design of fractional sample delay filter is presented. This method is based on the Stancu polynomial, which possesses an extra parameter α. Under special choice of this parameter, the results obtained are identical to previous ones based on Lagrange interpolation formula. Much more flatness of group-delay response can be achieved at the sacrifice of the filter magnitude response. Thus, this method provides designers with more flexibility for trading between these two performance criteria