Y.C. Lim

A weighted least squares algorithm for the design of lattice-type perfect reconstruction cosine modulated filter banks

This paper presents a weighted least squares (WLS) algorithm for the design of lattice-type perfect reconstruction (PR) cosine modulated filter banks. The design of such a filter bank is formulated as a WLS problem with respect to the lattice coefficients, incorporating the condition that a number of the zeros of the prototype filter must be at specific locations in the stopband. Our iterative algorithm needs only a few iterations to derive a set of lattice coefficients which optimizes this WLS problem, while providing flexible control of the prototype filters stopband ripples. By specifying appropriate zeros of the prototype filter in the stop band, good designs with no DC leakage can be easily obtained.

Design of discrete coefficient FIR filters using LMS algorithm

Two design techniques are proposed that can be used to design high-order discrete coefficient (FIR finite impulse response) filters. Both techniques are stochastic, in the sense that they randomly search in the discrete space of the filter coefficients for more optimal solutions than an existing one. The LMS algorithm is used to confine the search to those points that have a higher chance of being a good solution. The unique feature of the proposed techniques is their computing time, which increases only proportionally to the square of the filter length, as opposed to the other existing techniques, whose computer time increases exponentially with the length of the filter.<<ETX>>

A WLS algorithm for the design of low-delay quadrature mirror filter banks

This paper presents a weighted lease squares (WLS) algorithm for the design of low-delay quadrature mirror filter (QMF) banks with a prescribed number of zeros of the low-pass filter at /spl omega/=/spl pi/: this is desirable when the filter bank is used for the wavelet decomposition of a signal. The algorithm needs only a few iterations to obtain a solution which optimizes the filter bank design problem in the weighted minimax sense. A design example is provided for illustration.

Speed-independent circuit design using net-theoretic techniques

The authors propose the design of an asynchronous circuit using a new Petri net model called the signal transition net (STN) where no structural restriction needs to be imposed. The partial relations used for the specification and the important properties of the STN are described axiomatically and then analyzed based on the new notions of finiteness and completeness of the unfolding (see M. Nielsen et al., 1981) of the STN. Unfolding is a partial order semantic of Petri nets.<<ETX>>