IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing

New solutions to the issue of designing transmitter and receiver filters for data transmission are proposed. In this design issue, good frequency selectivity, matched filter pairs, transmit, and receive filters with a linear phase characteristic and zero intersymhol interference (ISI) are desired. As these properties cannot be-simultaneously achieved, most of the previously known algorithms relax ... View full abstract»

For the original paper see ibid., vol. 44, no. 3, p. 188-96 (1997). In the aforementioned paper, Spina and Upadhyaya presented a method for the fault diagnosis of analog linear circuits. The method, which is based on a white noise generator and an artificial neural network for response analysis, has been applied to circuits of reasonable dimensions, taking into account the effect of the component ... View full abstract»

In this work, a technique for synchronizing hyperchaotic systems is presented. The basic idea is to make the driven system a linear observer for the state of the drive system. By developing this approach, a linear time-invariant synchronization error system is obtained, for which a necessary and sufficient condition is given in order to asymptotically stabilize its dynamics at the origin. The sugg... View full abstract»

The author explores the connections between nonuniform sampling of a certain function and the almost periodic extension of its Fourier transform. It is shown that the Fourier transform of a bandlimited function can be extended (as a weighted sum of translates) as a Stepanoff almost periodic function, to the whole frequency axis. This result leads to a generalized nonuniform sampling theorem which,... View full abstract»

The simple polynomial set is introduced as a mathematical tool for representing and generating discrete-time signals. Two benefits result. A signal derived from a simple polynomial set comes with an expression for its z-transform and a recurrence relation for its rapid computation. Two examples are presented. The purpose of these examples is to show that simple sets of polynomials can give rise to... View full abstract»

New second-generation current conveyor negative (CCII-) realization suitable for very large scale implementation is described. The proposed architecture provides a very low impedance level at the N terminal and a wide dynamic voltage range, as well as a high current tracking accuracy. Simulations show that the CCII- current follower bandwidth extends beyond 100 MHz. Two compensation methods are di... View full abstract»

Analog filters are important building blocks of many communication and instrumentation systems. However, similar to other analog circuits, testing an analog filter is a difficult problem. In recent years, this problem has become even more difficult because of the increase of circuit complexity. Operational transconductance amplifier-capacitor (OTA-C) filters are especially useful in video applicat... View full abstract»

This brief presents computationally efficient block-adaptive algorithms for quadratic filters employing parallel-cascade realizations of the system model. Parallel-cascade realizations implement higher order Volterra systems using a parallel connection of multiplicative combinations of lower order systems. Such realizations are modular and therefore well-suited for very large scale integrate circu... View full abstract»

The optimal synthesis of a single input single output separable-in-denominator 2-D digital filter with fixed-point arithmetic is investigated. In the first phase, a general partial fraction expansion for this class of filter is presented. In sequel, a parallel block-optimal realization is proposed in order to minimize the round-off noise under L2 scaling. A novel criterion for the absence of limit... View full abstract»

Motivated by the possibility of extensions to two-dimensions, we address the problem constructing a linear-phase multiband perfect reconstruction finite impulse response filter bank by constructing the polyphase matrix associated with it. The equivalent problem of construction of linear phase, i.e., symmetric or antisymmetric compactly supported wavelets are, thus, also considered. Our approach re... View full abstract»

The design of fully differential high-frequency continuous-time current-mode filters is presented. A universal biquad is constructed from two basic building blocks, lossless and lossy differential current-mode integrators, Pole frequency ω0 and quality factor Q are tuned orthogonally by means of a translinear circuit. The design is illustrated on a 200-MHz fifth-order cascade low-... View full abstract»

Digital signal processing (DSP) techniques have been proposed in recent years to adaptively track the control parameters of a power amplifier (PA) feedforward linearizer. In most of the propositions, gradient-based searching algorithms are applied to the parameter tracking. In this paper, we propose an optimal recursive least square (RLS) parameter tracking algorithm, which significantly accelerat... View full abstract»

An understanding of the three-dimensional (3-D) nature of a television signal and its spectrum has been commonly used as an aid in visualizing and developing new analog coding techniques. Determining the actual 3-D (spatio-temporal) characteristics of a television system is, however, more difficult. This paper introduces a mathematical representation for the spatio-temporal characteristics of a te... View full abstract»

Estimating the position or amplitude of a pulse is a common problem in radar and seismic signal processing. In this paper an approximation to the Cramer-Rao bound for estimation of positions and amplitudes of multiple pulses is derived. It is shown that a vector can be associated with each parameter and the effect of a parameter on the estimation of another parameter is expressed as the normalized... View full abstract»

We report the study of a second-order Σ-Δ modulator for audio applications with a nine-levels quantizer. The feedback digital-to-analog has been implemented with four capacitors and two voltage references, taking the structure typical of fully differential system. We first discuss the performance achievable with the most popular dynamic element-matching techniques, namely the data-weig... View full abstract»

In this paper, we address three issues related to the design of op amps for oversampled converters: the theoretical minimum-power bound for an ideal op amp, the best op amp choice in terms of power dissipation, and the best design strategy to reduce power dissipation. To be able to do so, we develop a model that captures the dynamics of the integrator inside the modulator. Based on this model, pow... View full abstract»

SPICE macro models for magnetic MOSFET (MAGFET) devices in the saturation region are presented. By using the proposed models, the performance of several readout circuits using MAGFET devices could be predictable. In this paper, the magnetic field-to-voltage converter, the magnetically controlled operational-transconductance amplifier, and the magnetically controlled filter and magnetic-operational... View full abstract»

Continuous-time (CT) delta-sigma modulators (ΔΣM's) suffer from a problem not seen in discrete-time (DT) designs, that of excess loop delay: nonzero delay between the quantizer clock edge and the time when a change in output bit is seen at the feedback point in the modulator. This paper analytically shows how such delay affects the equivalence between the CT modulator loop filter and i... View full abstract»