DocumentCode :
1377293
Title :
Least-Squares Design of DFT Filter-Banks Based on Allpass Transformation of Higher Order
Author :
Löllmann, Heinrich W. ; Vary, Peter
Author_Institution :
Inst. of Commun. Syst. & Data Process. (IND), RWTH Aachen Univ., Aachen, Germany
Volume :
58
Issue :
4
fYear :
2010
fDate :
4/1/2010 12:00:00 AM
Firstpage :
2393
Lastpage :
2398
Abstract :
The allpass transformation of higher order is a very general concept to construct a frequency warped analysis-synthesis filter bank (AS FB) with nonuniform time-frequency resolution. In contrast to the more common allpass transformation of first order, the delay elements of the analysis filter bank are substituted by allpass filters of higher order to achieve a more flexible control over its frequency selectivity. Known analytical closed-form designs for the synthesis filter bank can ensure perfect reconstruction (PR), but the synthesis subband filters are not necessarily stable and exhibit no distinctive bandpass characteristic. These problems are addressed by a new least-squares error (LSE) filter bank design. The coefficients of the finite-impulse-response (FIR) synthesis filters are determined simply by a linear set of equations where the signal delay is an adjustable design parameter. This approach can achieve a perfect signal reconstruction with synthesis filters which are inherently stable and feature a bandpass characteristic. The proposed filter bank is of interest for various subband processing systems requiring nonuniform frequency bands.
Keywords :
FIR filters; all-pass filters; discrete Fourier transforms; least squares approximations; signal reconstruction; time-frequency analysis; AS-FB; DFT filter-banks least-squares design; FIR filters; LSE filter bank; finite-impulse-response synthesis filters; frequency warped analysis-synthesis filter bank; higher order allpass transformation; least-squares error filter bank; nonuniform time-frequency resolution; perfect reconstruction; signal reconstruction; synthesis subband filters; Allpass transformation; frequency warping; least squares; nonuniform filter banks; perfect reconstruction;
fLanguage :
English
Journal_Title :
Signal Processing, IEEE Transactions on
Publisher :
ieee
ISSN :
1053-587X
Type :
jour
DOI :
10.1109/TSP.2009.2039838
Filename :
5373847
Link To Document :
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