Finite-memory digital filters based on polynomial approximation
В. В. Тихомиров · Moscow University Mechanics Bulletin · 2012
Digital filters based on polynomial approximation are commonly used to estimate the low-frequency component and its derivatives for a wideband signal. The simplest digital filter is an arithmetic mean algorithm. The filter properties important for applications are associated with the types of transfer functions. Several formulas are given for the transfer functions of such filters used to estimate the constant component of an input signal and its first and second derivatives on the basis of the second- and third-degree polynomial approximation.