Signal Processing - Special issue on acoustic echo and noise control
Multirate Digital Signal Processing
Multirate Digital Signal Processing
Signal Processing with Lapped Transforms
Signal Processing with Lapped Transforms
IEEE Transactions on Signal Processing
Hi-index | 35.68 |
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.