IEEE Transactions on Circuits and Systems

In this paper, the open problem regarding the BIBO stability of two-dimensional linear shift invariant filters, in the presence of nonessential singularities of the second kind, is considered. Necessary and sufficient conditions for boundedness, andl_2andl_1stabilities of a functionG(z_1, z_2)= P(z_1, z_2)/[Q(z_1, z_2)]^n, whereP/Qhas simple nonessential... View full abstract»

The coefficients of a polynomial in thes-plane is obtained by evaluating the derivatives of the corresponding polynomial in thez-plane atz = 1orz = - 1, This leads to some necessary coefficient condition be satisfied, if the system is to be stable. View full abstract»

Most of the literature dealing with low-noise realizations for narrow-band recursive digital filters is based on the 2AB structure proposed by Agarwal and Burrus. We show that for poles in the neighborhood of the pointz = 1, i.e., the region where 2AB structures are of interest, it is possible to obtain initial conditions such that any structure based on the 2AB realization will sustain... View full abstract»

The characterization theorems for at-diagnosable analog system model have been proposed by Hakimi and Nakajima [1]. In this paper, a combinatorial covering approach is proposed as the foundation of a decision process to supplement the above findings. View full abstract»

This paper develops a calculus for computing Filippov's differential inclusion which simplifies the analysis of dynamical systems described by differential equations with a discontinuous right-hand side. In particular, when a slightly generalized Lyapunov theory is used, the rigorous stability analysis of variable structure systems is routine. As an example, a variable structure control law for ri... View full abstract»

Two issues concerning alias-free, parallel, quadrature mirror filter (QMF) banks are addressed in this correspondence. First, a property concerning alias-free analysis/synthesis systems is established; second, a scheme is proposed, by which a synthesis bank can be modified in order to take care of aliasing errors caused by linear channel-distortion in a simple manner. Applications of the stated re... View full abstract»

Two methods for the design of two-dimensional (2-D) rotated digital filters proposed by Costa and Venetsanopoulos and Goodman are modified by performing rotation through a somewhat more general transformation. This modification eliminates nonessential singularities of the second kind, which can lead to an unstable 2-D digital filter when finiteprecision arithmetic is used for the implementation. T... View full abstract»

A general statistical analysis is presented for the roundoff error that is generated when a discrete random multiplicand, taking on only integer values, is multiplied by a real coefficient and the result rounded back to the nearest integer. Numerical results are provided for mean, variance, correlation with multiplicand, and correlation between roundoff errors, as functions of multiplier coefficie... View full abstract»

High-precision analog-to-digital converters (ADC's) which periodically sample continuous time waveforms are required in many "signal acquisition" applications such as digital audio and instrumentation. This paper describes a specific topology for an oversampling differential pulse code modulation (DPCM)-type ADC that requires neither an analog anti-aliasing filter nor a sample-and-hold. Dithering ... View full abstract»

A variable-structure-controlled (VSQ Van der Pol oscillator is shown to produce an ideal average response of perfect harmonic nature when its motions are made to slide on a circle defined in the interior of its limit cycle. The sinusoidal responses are robust with respect to parameter perturbations and external disturbances. View full abstract»

A new method of designing linear-phase FIR filters is proposed by minimizing a quadratic measure of the error in the passband and stopband. The method is based on the computation of an eigenvector of an appropriate real, symmetric, and positive-definite matrix. The proposed design procedure is general enough to incorporate both time- and frequency-domain constraints. For example, Nyquist filters c... View full abstract»

The problem of characterizing lossless electrical networks composed of either capacitors or inductors and imaginary-valued resistors whose resistance is of one sign is solved. The impedance (and admittance) singularities are all on one-half the imaginary-frequency axis. The results are related to analogous results for RC and LC networks. These results are of significance in fields using such netwo... View full abstract»

It will be shown how dissipation can be introduced in a class of wave digital filters involving two-port adaptors without necessarily increasing the number of adders and multipliers. The dissipation introduced this way represent an alternative method to magnitude truncation. View full abstract»

This paper presents the time-domain Pade approximation and modal-Pade method for single and multivariable systems. In the first part of the paper, Pade equations are derived for SISO and MIMO systems by assuming a state-space description of the higher order system and its reduced order model. For a SISO system, it is shown that these Pade equations are the same as the Pade equations obtained by a ... View full abstract»

We investigate the properties of a special class of recursive polyphase filters whose subfilters are distinct allpass filters. On the basis of the discovered properties, a Remez-type algorithm is constructed for designing these filters. The proposed algorithm is faster and gives higher filter selectivities than other existing methods. Better understanding of the filter properties allows us to sele... View full abstract»

In a companion paper [1], an efficient procedure was given for the design of recursive polyphase filters whose subfilters are distinct allpass filters, and the properties of these filters were considered in detail. Both nonlinear-phase and approximately linear-phase filters were discussed. In this paper, we show how these filters can be used for constructing efficient single-stage and multistage d... View full abstract»