Generalized filter-bank equalizer for noise reduction with reduced signal delay

Abstract

An efficient realization of a low delay filter-bank, termed as generalized filter-bank equalizer (FBE), will be proposed for noise reduction with low signal delay. The FBE is equivalent to a time-domain filter with coefficients adapted in the frequencydomain. This filter-bank structure ensures perfect signal reconstruction for a variety of spectral transforms with less restrictions than for an analysis-synthesis filter-bank (AS FB). A non-uniform frequency resolution can be achieved by an allpass transformation. In this case, the FBE has not only a lower signal delay than the AS FB, but also a lower algorithmic complexity for most parameter configurations. Another advantage of the FBE is the lower number of required delay elements (memory) compared to the AS FB. The noise reduction achieved by means of the AS FB and the FBE is approximately equal.