Compressive sensing is a methodology for the reconstruction of sparse or compressible signals using far fewer samples than required by the Nyquist criterion. However, many of the results in compressive sensing concern random sampling matrices such as Gaussian and Bernoulli matrices. In common physically feasible signal acquisition and reconstruction scenarios such as super-resolution of images,...

Frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion is a promising equalization technique for the broadband single-carrier (SC) transmission. However, the presence of timing offset produces the inter-symbol interference (ISI) and degrades the bit error rate (BER) performance. In this paper, we discuss the mechanism of the BER performance degradation in the pr...

In this paper we present a prototype continuous time Σ∆-modulator in a 0.35 μm technology. The circuit has a 6-bit internal quantizer. Through the combination of a modified architecture and comparator interpolation this high quantizer resolution is achieved with only 15 comparators. However, it turns out that this approach imposes a severe speed constraint on the analog adder circuit. The modul...

We prove explicit lower bounds for the smallest singular value and upper condition number of rectangular, multivariate Vandermonde matrices with scattered nodes on complex unit circle. Analogously to Shannon-Nyquist criterion, are assumed be separated by a constant divided used polynomial degree. If this grows linearly spatial dimension, is uniformly bounded. it only logarithmically can, in wor...

Although gratings beyond the Nyquist limit of the peripheral retina are visible as aliased percepts when presented in isolation, the reported lack of aliasing for targets with complex spectra (edges, lines, letters) suggests that aliased frequency components are invisible in the presence of sub-Nyquist image components. We tested this hypothesis by systematically exploring a range of stimulus p...

Virtual synchronous machine (VSM) based high voltage dc systems enhance the inertia of power system. However, dynamic interactions between VSM-based rectifier station, inverter and grid could induce system oscillation, which has been investigated in this article. At first, hybrid ac–dc impedance models VSMs considering coupling ac dynamics are established. Then, relationships impedance, <italic...

In this paper we introduce a figure of merit for the robustness of continuous-time Σ∆ modulators. It is based on the Nyquist criterion for the equivalent discrete-time (DT) loop filter. We show how continuous-time modulators can be designed by optimizing this figure of merit. This way we obtain modulators with increased robustness against variations in the noise-transfer-function (NTF) paramete...

Recently, sub-Nyquist sampling of wideband signals has gained much attention in wireless communications. One of the main reasons for this popularity is the reduction in energy consumption in the ADCs. In this paper, we present an overview of the best known non-uniform sub-Nyquist sampling techniques and the associated spectral analysis. Spectral analysis using sub-Nyquist samples can be done in...

The instability phenomena caused by converter–grid interactions can be prevented designing controllers with adequate stability margins. Yet, the multiple-input–multiple-output (MIMO) dynamics of grid-connected voltage-source converters (VSCs) complicate analysis for controller design. To tackle this challenge, article presents a loop-at-a-time VSCs, which not only shows close correlations gener...

In peripheral vision, high-frequency gratings beyond the Nyquist limit are visible as aliased patterns but, as shown previously, their visibility can be masked by superimposed sub-Nyquist gratings. Is the converse also true? Can supra-Nyquist gratings affect the detectability of sub-Nyquist gratings? In this study, we investigated the masking effect of high contrast, supra-Nyquist components of...