Abs t rac t For a clipped channel with a Gaussian input, a predistortionlrestoration technique to reduce clipping-induced nonlinear distortion is proposed and analyzed. The input signal is processed by a nonlinear predistorter circuit, reducing the probability of clipping. The receiver output signal passes through a restorer having the inverse transfer characteristic, which yields the original ...

A systematic technique for designing a continuous-time sigma-delta modulator @AhI) is presented. The continuous-time m open-loop transfer function is obtained by the pulse-invariant transformation of its discrete-time equivalent. This method results in an inherently stable XAM and does not need any loss factor to make the modulator stable, and so provides the maximum achievable signal-to-noise ...

The paper considers the so-called dynamic phasor model as a basis for harmonic analysis of a class of switching systems. The dynamic phasor model is a powerful tool for exploring cyclic properties of dynamic systems. It is shown that there is a connection between the dynamic phasor model and the harmonic transfer function of a linear time periodic system and this connection is used to extend th...

A methodology for the design of Continuous-Time (CT) Sigma-Delta (Σ∆) modulators with VCO-based quantizer is proposed. The coefficients of the CT Σ∆ modulator are accurately calculated such that the noise transfer function of the modulator is exactly the same as a Discrete-Time (DT) Σ∆ modulator of the same order. Several design examples for different modulator orders and feedback DAC signal sh...

Accurate measurement of spatial resolution in terms modulation transfer function (MTF) is essential computed tomography (CT) images. The purpose this study was to developed a computational phantom that can be used evaluate the effect noise on MTF CT Our phantoms for measuring were with MATLAB software. image blurred by point spread certain standard deviation. Subsequently, different levels adde...