ABSTRACT

This paper deals with the concept of filter banks. Filter banks are a group of band-pass filters connected in parallel. Each parallel connection forms a channel for different frequency-bands present in the input signal. The output of the filter bank is formed by merging these channels. The main theme behind the use of filter banks is to boost or attenuate different individual bands of frequencies present in a signal, without affecting other bands. There are several ways of realizing an filter bank and one such way is the Cosine Modulated filter bank. Instead of designing band-pass filters for different bands, the cosine modulated filter banks, modulates a lowpass filter. In simple words, it simply shifts the pass band of the low pass filter towards higher frequencies, and there by covering the entire band of frequencies of the input signal. Filter banks have many applications in the field of signal processing. Perhaps one of the biggest applications is Graphic Equalizer, where in, the user can ‘graphically’ modify different bands. The design and implementation of a filter bank as M-Band Graphic Equalizer is covered in this paper.