Numerically stable filter design with derivative constraints at three frequencies
Peng‐Hua Wang · 2016
Design of the finite impulse response (FIR) filters by three-point Taylor interpolation is studied in this paper. It is shown that the filter can be constructed by sum of weighted sub-filters which weighting gains are exactly the derivatives at interpolating frequencies. Recursive relations among the coefficients of the sub-filters are derived and used for designing the maximally flat fractional delay filters as an illustrating example. It shows that the proposed solution leads to numerical stable implementation in terms of the normalized root mean squared error.