High-speed recursive filter structures composed of identical all-pass subfilters for interpolation, decimation, and QMF banks with perfect magnitude reconstruction
H. Johansson et L. Wanhammar, High-speed recursive filter structures composed of identical all-pass subfilters for interpolation, decimation, and QMF banks with perfect magnitude reconstruction, IEEE CIR-II, 46(1), 1999, pp. 16-28
Citations number
24
Categorie Soggetti
Eletrical & Eletronics Engineeing
Journal title
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-ANALOG AND DIGITAL SIGNAL PROCESSING
High-speed recursive filter structures for interpolation and decimation wit
h factors of two, and quadrature mirror filter (QMF) banks with perfect mag
nitude reconstruction, are proposed. The structures are composed of identic
al all-pass subfilters that are interconnected via extra multipliers, For t
he case of interpolation and decimation filters, the overall transfer funct
ion corresponds in the simplest case to several half-band infinite-impulse
response (IIR) filters in cascade, To achieve a smaller passband ripple tha
n for a cascade design, a design procedure that has been used earlier for s
ingle-rate filters is used. In this approach, the design is split into desi
gns of a prototype finite-impulse response (FIR) filter and a half-band IIR
filter. For the case of QMF banks, the design is again separated into desi
gns of a prototype FIR filter and a half-band IIR filter. One major advanta
ge of the proposed filter structures over the corresponding conventional (h
alf-band filter) structures is that the required coefficient word length fo
r the allpass filters is substantially reduced, implying that the maximal s
ample frequency can be substantially increased for a given VLSI technology.
Further, for interpolation and decimation, the arithmetic complexity may b
e reduced in comparison with both the conventional structures and straightf
orward cascade structures. Simple recurrence formulas for computation of th
e interconnecting multipliers, given the overall transfer function, are der
ived. Several examples are included which compare the proposed structures w
ith the corresponding conventional and straightforward cascade structures.