Eecient Prototype Filter Realizations for Cosine-modulated Filter Banks

Filter Banks Tanja Karp(1) and Alfred Mertins(2) (1)Lehrstuhl f ur Elektrotechnik, Universit at Mannheim B6/26, D-68131 Mannheim, Germany, [email protected] (2) University of Kiel, Telecommunications Institute Kaiserstr. 2, D-24143 Kiel, Germany, [email protected] r esum e Cet article presente des implantations optimis ees de ltres prototypes de bancs de ltres modul es a reconstruction parfaite, a retard quelconque. Les implantations propos ees sont bas ees sur des "sch emas de liftage". Ici, l'approximation des coe cients "de liftage" est faite de mani ere a ce que le ltrage n'emploie que peu d'operations de d ecalage et addition. Comme le "sch ema de liftage" est robuste aux erreurs de quanti cation ainsi introduites, la propri et e de recontruction parfaite du banc de ltres est conserv ee. Le prototype d'origine et celui obtenu par cette methode sont compar es en terme de complexit e d'implantation et d'att enuation hors-bande. abstract This paper presents e cient realizations of prototype lters for biorthogonal cosine-modulated lter banks with arbitrary overall system delay. The implementation is based on lifting schemes. The lifting coe cients will be approximated such that the lter operations can be realized by a few shift and add operations. Since the lifting scheme is robust against coefcient quantization we do not loose the perfect reconstruction (PR) property of the lter bank when doing this approximation. The original and the approximated prototype lters are compared in terms of complexity and stopband attenuation.