A Proper Approximation of Filter Transmittance for HFB System Design

A new approach to designing a hybrid filter bank (HFB) system has been demonstrated. The paper shows the relationship between the analogue analysis filter bank and its discrete equivalent counterparts. Equivalence conditions have been determined and a new method of approximation of filter characteristics has been demonstrated. It limits the number of FIR filter coefficients necessary to implement a synthesis filter bank. This is an extremely important aspect from a practical point of view, because it allows the implementation of a synthesis filter bank in programmable VLSI circuits. A rigorous method of testing the HFB system during a design process using dedicated band-pass signals has also been developed.