applications of neural networks in design of digital filters5 5.1 APPLICATION OF NEURAL NETWORK IN DESIGN OF DIGITAL FILTERS Dali Wang and Ali Zilouchian INTRODUCTION Any action on a signal that modifies the spectral content of the signal is called filtering. This includes the enhancement or suppression of certain features of the signal and is usually achieved by the use of linear time invariant systems. There are situations where the system may change with time in a particular manner; such systems are called adaptive filters. In this section, we describe fixed filters only. There are two broad classes of digital filters. The first class is called finite impulse response (FIR) filters, since their response to an impulse dies away in a finite number of samples. FIR filters are developed as non-recursive structures and are inherently simpler to des……