ICASSP '98 Main Page

General Information

Conference Schedule

Technical Program

    Overview
    50th Annivary Events
    Plenary Sessions
    Special Sessions
    Tutorials
    Technical Sessions

	By Date
		May 12, Tue
		May 13, Wed
		May 14, Thur
		May 15, Fri

By Category
	AE	ANNIV
	COMM	DSP
	IMDSP	MMSP
	NNSP	PLEN
	SP	SPEC
	SSAP	UA
	VLSI

By Author
	A	B	C	D	E
	F	G	H	I	J
	K	L	M	N	O
	P	Q	R	S	T
	U	V	W	X	Y
	Z

Invited Speakers

Registration

Exhibits

Social Events

Coming to Seattle

Satellite Events

Call for Papers/
Author's Kit

Future Conferences

Help

Abstract - DSP6

DSP6.1	Design of Causal IIR Perfect Reconstruction Filter Banks X. Zhang, T. Yoshikawa (Nagaoka University of Technology, Japan) This paper presents a new method for designing two channel biorthogonal IIR filter banks, which satisfy both the perfect reconstruction and causal stable conditions. The proposed method is based on the formulation of a generalized eigenvalue problem by using Remez multiple exchange algorithm. Therefore, the filter coefficients can be computed by solving the eigenvalue problem, and the optimal solution is easily obtained through a few iterations. One example is designed to demonstrate the effectiveness of the proposed method.
DSP6.2	Discrete-Coefficient Linear-Phase Prototypes for PR Cosine-Modulated Filter Banks A. Mertins (University of Western Australia, Australia) In this paper, a method for the design of perfect reconstruction (PR) linear-phase prototypes for cosine-modulated filter banks with discrete coefficients is presented. Such prototypes are of great interest for efficient hardware implementations. The design procedure is based on a subspace approach that allows to linearly combine PR prototype filters in such a way that the resulting filter also is a PR prototype. Within a given subspace the weights of the optimal linear combination can be easily computed via an eigenanalysis. The filter design is carried out iteratively, while the PR property is guaranteed throughout the design process. No non-linear optimization routine is needed.
DSP6.3	Design of Perfect Reconstruction FIR Multifilters C. Kok (University of Wisconsin-Madison, USA) The design of perfect reconstruction FIR multifilters is discussed in this paper. Schur algorithm is applied to factorize the polyphase matrix of multifilters into lattice blocks. The multifilters are characterized by the chain parameters in each lattice block. The complete parameterization of paraunitary multifilters and a class of biorthogonal multifilters are derived. The parameterizations are minimial and result in simple design methods using unconstrainted optimization.
DSP6.4	The Generalized Lapped Biorthogonal Transform T. Tran (University of Wisconsin, USA); R. De Queiroz (Xerox Corporation, USA); T. Nguyen (Boston University, USA) A lattice structure based on the singular value decomposition (SVD) is introduced. The lattice can also be proven to use a minimal number of delay elements and to completely span a large class of M-channel linear phase perfect reconstruction filter bank (LPPRFB): all analysis and synthesis filters have the same FIR length of L=KM, sharing the same center of symmetry. The lattice also structurally enforces both linear phase and perfect reconstruction properties, is capable of providing fast and efficient implementation, and avoids the costly matrix inversion problem in the optimization process. From a block transform perspective, the new lattice represents a family of generalized lapped biorthogonal transform (GLBT) with arbitrary integer overlapping factor K. The relaxation of the orthogonal constraint allows the GLBT to have significantly different analysis and synthesis basis functions which can then be tailored appropriately to fit a particular application. Several design examples are presented along with a high-performance GLBT-based progressive image coder to demonstrate the superiority of the new lapped transforms.
DSP6.5	Cyclic LTI Systems and the Paraunitary Interpolation Problem P. Vaidyanathan, A. Kirac (Caltech, USA) Cyclic signal processing refers to situations where all the time indices are interpreted modulo some integer L. Since the frequency domain is a uniform discrete grid,there is more freedom in theoretical and design aspects. The basics of cyclic(L) multirate systems and filter banks have already appeared in the literature, and important differences between the cyclic and noncyclic cases are known. Since there is a strong connection between paraunitary filter banks and orthonormal wavelets, some deeper questions pertaining to cyclic(L) paraunitary matrices are addressed in this paper. It is shown that cyclic(L) paraunitary matrices do not in general have noncyclic paraunitary FIR interpolants, though IIR interpolants can always be constructed. It is shown, as a consequence, that cyclic paraunitary systems cannot in general be factored into degree one nonrecursive paraunitary building blocks. The connection to unitariness of the cyclic state space realization is also addressed.
DSP6.6	Factorization of Nonuniform Block Orthogonal Transforms T. Nagai, S. Obata, M. Ikehara (Keio University, Japan) Block orthogonal transforms (BOT's) are commonly used for lots of applications. Conventional BOT's are based on uniform filter banks, however, nonuniform BOT's are often superior to uniform ones. In this research, we investigate the factorization of nonuniform BOT's which does not involve the tree structure. Therefore, optimal nonuniform BOT's are available in the sense of transform coding gain. Some design examples are included to confirm our theory. We also apply the nonuniform BOT to the transform image coding.
DSP6.7	Design of Biorthogonal Filter Banks Composed of Linear Phase IIR Filters M. Okuda, M. Ikehara, S. Takahashi (Keio University, Japan) Since IIR filters have lower computational complexity than FIR filters, some design methods for IIR filter banks have been presented in the recent literatures. Smith et al. have proposed a class of linear phase IIR filter banks. However this method restricts the order of the numerator to be odd and ,moreover ,has some drawbacks. In this paper we present two design methods for linear phase IIR filter banks. One is based on Lagrange-Multiplier method , in which optimal IIR filter banks in least squares sense are obtained. In the other approach , IIR filter banks with the maximum number of zeros are derived analytically.
DSP6.8	Biorthogonal Cosine-Modulated Filter Banks without DC Leakage T. Karp (University of Mannheim, Germany); A. Mertins (University of Western Australia, Australia) In this paper, we present a structure for implementing the polyphase filters of biorthogonal modulated filter banks that automatically guarantees perfect reconstruction of the filter bank and furthermore allows to specifiy the values of the filters' frequency responses at certain frequencies. Thus, modulated filter banks without DC leakage can be designed. The new stucture is based on lifting schemes for the polyphase filters. DC leakage can be avoided very easily by reducing the number of lifting coefficients that can be freely chosen and used for filter optimization. The great advantage of the new method is that we do not have to take constraints into consideration when optimizing the prototype filter, but PR and specified zeros are structure inherent.
DSP6.9	Performance Measures and Lagrange Multiplier Methods to Two-Band PR LP Filter Bank Design T. Wang, B. Wah (University of Illinois - Coordinated Science Lab, USA) In this paper, we apply a new adaptive Lagrangian method for designing QMF (quadrature-mirror-filter) filter banks. We formulate the design problem as a nonlinear constrained optimization problem, using the reconstruction error as the objective, and other performance metrics as constraints. This formulation allows us to search for designs that improve over the best existing designs. We propose to solve the design problem using Lagrangian methods, and study methods to improve the convergence speed of Lagrangian methods without affecting their solution quality. This is done by adjusting dynamically the relative weights between the objective and the Lagrangian part. We show that our adaptive method is able to find better designs within a reasonable amount of time that would not be possible otherwise.
DSP6.10	A New Implementation of Arbitrary-Length Cosine-Modulated Filter Bank X. Gao, Z. He (Southeast University, P R China); X. Xia (University of Delaware, USA) In this paper, the fast implementation of cosine-modulated filter bank (CMFB) is revisited. A class of paraunitary CMFBs with arbitrary length is considered. By further reorganizing of the polyphase component matrix and using the linear-phase property of the prototype filter, we obtain a more efficient implementation structure for the CMFB, in which we use 22 lossless matrices instead of 21 ones. In the new implementation, the number of two-channel lossless lattices is reduced by a factor of two.

< Previous Abstract - DSP5

DSP7 - Next Abstract >