One Method for Fractional Delay Filter Design with a Multirate Approach

摘要

This paper presents one method for fractional delay filter (FDF) design. The proposal is based on a previously reported FDF design method, where the fractional delay is approximated by two polyphase branches using Lagrange linear interpolation. We make an extension to more than two polyphase branches using higher Lagrange interpolation order. The proposed method presents good results in both magnitude response and group delay. Some design example results are presented and compared with Farrow structure, A complexity analysis is made with the number of operations per output sample. The number of operations required by the proposed method is less than the one required by the Farrow structure.