Closed-form design of variable fractional delay filter using discrete Fourier transform

The design of variable fractional delay filter is investigated. First, the discrete Fourier transform (DFT) interpolation approach is described. Then, the Taylor series expansion and DFT interpolation formula are used to design the variable fractional delay filter which can be implemented by using Farrow structure. Finally, numerical comparison with conventional Lagrange-type variable fractional delay filter is made to demonstrate the effectiveness of this new design approach.