SPTM-10.1

BLOCK-RECURSIVE, MULTIRATE FILTERBANKS WITH ARBITRARY TIME-FREQUENCY PLANE TILING
Unto K. Laine (Helsinki University of Technology, Laboratory of Acoustics and Audio Signal Processing)

A new method to realize arbitrary time-frequency plane tilings together with critical sampling in block-recursive filterbanks is presented. The method leads to pole-zero approximation of the target channel transfer functions. Perfect reconstruction within the limits of the approximation error can be achieved.

SPTM-10.2

Boundary Filters without DC Leakage for Paraunitary Filter Banks
Wolfgang Niehsen (Institut f. Elektrische Nachrichtentechnik, RWTH Aachen)

The construction of boundary filters without DC leakage for two-channel paraunitary FIR filter banks is considered. The design procedure is based on orthogonal boundary filters which are optimal in a weighted mean square error sense in the Fourier domain and on Householder transformation of boundary filter matrices. Simulation results are presented for boundary filters based on minimum-phase Daubechies filters.

SPTM-10.3

Lossless Filter Banks Based on Two Point Transform and Interpolative Prediction
Kunitoshi Komatsu, Kaoru Sezaki (Institute of Industrial Science, University of Tokyo)

In this paper, we present a method for designing lossless versions of two-channel FIR filter banks. We demonstrate that equal length PR FIR filter banks can be decomposed into 2-point transforms and unequal length into interpolative predictions. The lossless versions of the filter banks are obtained by replacing every constituent module by the corresponding lossless version. This method allows construction of the lossless versions of filter banks with arbitrary filter length. Lossless versions of several filter banks are designed and they are found to yield good performance for lossless image compression.

SPTM-10.4

Non-Uniform Filterbank Bandwidth Allocation for System Modeling Subband Adaptive Filters
Jacob D Griesbach, Tamal Bose, Delores M Etter (University of Colorado)

Subband adaptive filters have been used extensively in system modeling configurations to model unknown systems with large impulse responses. This paper will illustrate the advantages of a non-uniform subband adaptive filter over a uniform subband adaptive filter while giving insight to subband bandwidth allocations for system modeling configurations. By implementing small subbands which isolate the transition regions in the unknown system, while using larger subbands for other, more spectrally flat regions, one can minimize convergence time and lower misadjustment.

SPTM-10.5

Eigenfilter Design of Real and Complex Coefficient Prototypes for Uniform and Nonuniform Filter Banks
Fabrizio Argenti, Enrico Del Re (University of Florence - Dept. Electronic Engineering)

In this study we propose a new method to design Pseudo-QMF prototype filters to implement Near Perfect Reconstruction (NPR) cosine-modulated filter banks. The method is based on the eigenfilter approach, that is simple to implement, but, nevertheless, is very efficient in designing high attenuation prototype filters. The method also allows to design complex coefficient prototypes that can be used to build nonuniform filter banks. The effectiveness of the method is demonstrated by means of some examples of design of both uniform and nonuniform filter banks.

SPTM-10.6

Processing Finite Length Signals via Filter Banks without Border Distortions: a Non-Expansionist Solution
Elena Dominguez Jimenez (E.T.S.I. Industriales, Universidad Politecnica de Madrid), Nuria Gonzalez Prelcic (E.T.S.E.Telecomunicacion, Universidade de Vigo)

In this paper we introduce a novel and general matrix formulation of classical signal extension methods for subband processing of finite length signals. Considering a paraunitary 2-channel filter bank as transformation cell, this new characterization makes it possible to show that perfect reconstruction of finite signals can be ensured without resorting to extra subband samples; thus, by using some traditional signal extension methods, non-expansionist transforms can be defined. Some of these transformations are analyzed to illustrate our theoretical results.

SPTM-10.7

A Polyphase and FFT Realization of Modulation Sub-band Adaptive Filter with Minimum Sampling Rate
Kenji Nakayama, Akihiro Hirano, Hiroaki Sakaguchi (Dept. of Electrical and Computer Eng., Faculty of Eng., Kanazawa Univ.)

A sub-band adaptive filter, in which modulation and demodulation are employed, were proposed [1],[2]. The sampling rate can be minimized, while no aliasing occurs. In this paper, a polyphase and FFT realization of this sub-band adaptive filter is proposed. In the polyphase and FFT realization for the transmultiplexer [3], the sampling rate reduction is the same as the number of the sub-bands. In the proposed method, however, they are different, so the conventional method cannot be applied. In the new realization, the polyphase filters are divided into a tapped delay line and an FFT part so as to be shared by all the sub-bands. Computational complexity is well reduced compared with the direct realization.

SPTM-10.8

Optimum Subband Coding of Cyclostationary Signals
Soura Dasgupta (Department of Electrical and Computer Engineering,University of Iowa), Chris W Schwarz (NADS & Simulation Ctr,University of Iowa), Brian D Anderson (Department of Systems Engineering, Australian National University)

We consider the optimal orthonormal subband coding of zero mean cyclostationary signals, with N-periodic second order statistics. A 2-channel uniform filter bank, with N-periodic analysis and synthesis filters, is used as the subband coder. A dynamic scheme involving N-periodic bit allocation is employed. An average variance condition is used to measure the output distortion. The conditions for maximizing the coding gain parallel those for the case when the signals are Wide Sense Stationary (WSS) and the analysis and synthesis filters and the bit allocation time invariant, in that the blocked subband signals must be decorrelated and the subband power spectral densities must obey an ordering. Some additional conditions on this ordering, over and above those required for the WSS case, are needed.

SPTM-10.9

On H_infinity Optimal Signal Reconstruction in Noisy Filter Banks
Haris Vikalo, Babak Hassibi, Thomas Kailath (Stanford University)

We study the design of synthesis filters in noisy filter bank systems using an H-infinity point of view. For unitary analysis polyphase matrices we obtain an explicit expression for the minimum achievable disturbance attenuation. Numerical examples and comparisons with existing methods are also included.

SPTM-10.10

A Variable-Rate Filtering System for Digital Communications
Larry Wasserman, Alan N Willson, Jr. (UCLA)

We propose an efficient programmable transmit-receive digital filter structure consisting of a pulse-shaping filter (PSF) and a cascaded integrator-comb (CIC) filter which is applicable to variable-rate digital communication systems. The CIC structure is a hardware-efficient means of constructing programmable interpolation and decimation filters, but it introduces a large amount of intersymbol interference (ISI). We solve this problem by proposing a filter design method that determines the PSF coefficients such that the cascade of the PSF and CIC filter exhibits the desired frequency response.

SPTM-10.11

New Results and Open Problems on Nonuniform Filter-Banks
Sony J Akkarakaran, P. P Vaidyanathan (California Institute of Technology)

Nonuniform filter-banks (FB's) have traditionally been built either by cascading uniform ones in a tree structure or by direct design methods that lead to near-perfect reconstruction. However many theoretical issues remain unresolved. This paper begins by pointing out a number of these issues, and summarizes the known conditions for existence of nonuniform perfect reconstruction (PR) FB's. As a new contribution, we simplify some of these conditions and make them more explicit. We provide examples that illustrate some hitherto unobserved connections between these conditions.

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Last Update: February 4, 1999 Ingo Höntsch