# Ewa MatusiakUniversity of Vienna | UniWien

Ewa Matusiak

## About

11

Publications

739

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145

Citations

Citations since 2016

Introduction

**Skills and Expertise**

## Publications

Publications (11)

A method for signal processing includes accepting an analog signal, which consists of a sequence of pulses confined to a finite time interval. The analog signal is sampled at a sampling rate that is lower than a Nyquist rate of the analog signal and with samples taken at sample times that are independent of respective pulse shapes of the pulses and...

We consider perturbation of frames and frame sequences in a Hilbert space H. It is
known that small perturbations of a frame give rise to another frame. We show that
the canonical dual of the perturbed sequence is a perturbation of the canonical dual
of the original one and estimate the error in the approximation of functions belonging
to the pertu...

We develop sub-Nyquist sampling systems for analog signals comprised of
several, possibly overlapping, finite duration pulses with unknown shapes and
time positions. Efficient sampling schemes when either the pulse shape or the
locations of the pulses are known have been previously developed. To the best
of our knowledge, stable and low-rate sampli...

Time-frequency analysis, such as the Gabor transform, plays an important role in many signal processing applications. The redundancy of such representations is often directly related to the computational load of any algorithm operating in the transform domain. To reduce complexity, it may be desirable to increase the time and frequency sampling int...

Time-frequency analysis, such as the Gabor transform, plays an important role in many signal processing applications. The redundancy of such representations is often directly related to the computational load of any algorithm operating in the transform domain. To reduce complexity, it may be desirable to increase the time and frequency sampling int...

We study a sampling setup where a continuous-time signal is mapped by a memoryless, invertible and nonlinear transformation, and then sampled in a nonideal manner. Such scenarios appear, for example, in acquisition systems where a sensor introduces static nonlinearity, before the signal is sampled by a practical analog-to-digital converter. We deve...

In this paper, we describe a new method for studying the invertibility of Gabor frame operators. Our approach can be applied to both the continuous (on) and the finite discrete setting. In the latter case, we obtain algorithms for directly computing the inverse of Gabor frame-type matrices equivalent to those known in the literature. The framework...

In this paper we develop constructive invertibility conditions for the twisted convolution. Our approach is based on splitting the twisted convolution with rational parameters into a finite number of weighted convolutions, which can be interpreted as another twisted convolution on a finite cyclic group. In analogy with the twisted convolution of fi...

We develop sub-Nyquist sampling systems for signals comprised of several, possibly overlapping, finite duration pulses with unknown shapes and time positions. To the best of our knowledge, stable and low-rate sampling strategies for a superposition of unknown pulses without knowledge of the pulse locations have not been derived. We propose a multic...

In this work we consider the following setup, which is valid in several engineering applications; available are the generalized samples (1) of a sig- nal x. This signal is related to a function y, through a known mapping T ; y = T(x). additionally, we have the prior y 2 A , where A is a known sub- space of some Hilbert space H. Our purpose is to fi...

The metaplectic representation describes a class of automorphisms of the Heisenberg group H = H(G) , defined for a locally compact abelian group G . For G =ℝ d , H is the usual Heisenberg group. For the case when G is the finite cyclic group ℤ n , only partial constructions are known. Here we present new results for this case and we obtai...