Novel Transformation Functions for the Stability Guarantee of Recursive Variable Digital Filters
Tian–Bo Deng · 2022 IEEE 11th Global Conference on Consumer Electronics (GCCE) · 2022
Digital filtering is one of the most important signal processing techniques, and it requires a digital filter to perform filtering operations. Some signal-processing applications require the digital filter being in use to change its frequency-domain response (called frequency response) during filtering operations. In such a case, a variable digital filter (VDF) with tunable frequency response is extremely useful. As far as a recursive VDF is concerned, its stability must be guaranteed. This paper presents an effective method for the stability guarantee. The proposed scheme is based on parameter transformations, and it requires a function for carrying out the parameter transformations. This paper presents several such explicitly defined functions that have a particular feature and are suitable for the stability-guarantee purpose. Exploiting those functions yields a recursive VDF with definitely guaranteed stability.