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Related papers: A Highly Robust Sparse Fractal Array

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Sparse arrays are popular for performance optimization while keeping the hardware and computational costs down. In this paper, we consider sparse arrays design method for wideband source operating in a wideband jamming environment.…

Signal Processing · Electrical Eng. & Systems 2019-12-09 Syed A. Hamza , Moeness G. Amin

In the first section we review recent results on the harmonic analysis of fractals generated by iterated function systems with emphasis on spectral duality. Classical harmonic analysis is typically based on groups whereas the fractals are…

Classical Analysis and ODEs · Mathematics 2007-05-23 Palle E. T. Jorgensen , Steen Pedersen

Planar Fourier capture arrays (PFCAs) are optical sensors built entirely in standard microchip manufacturing flows. PFCAs are composed of ensembles of angle sensitive pixels (ASPs) that each report a single coefficient of the Fourier…

The FFT algorithm that implements the discrete Fourier transform is considered one of the top ten algorithms of the $20$th century. Its main strengths are the low computational cost of $\mathcal{O}(n \log n$) and its stability. It is one of…

Numerical Analysis · Mathematics 2017-06-15 Matteo Briani , Annie Cuyt , Wen-shin Lee

The ability to resolve detail in the object that is being imaged, named by resolution, is the core parameter of an imaging system. Super-resolution is a class of techniques that can enhance the resolution of an imaging system and even…

Data Structures and Algorithms · Computer Science 2022-10-13 Yaonan Jin , Daogao Liu , Zhao Song

Telescope arrays allow high-performance wide-field imaging systems to be built more quickly and at lower cost than conventional telescopes. Distributed aperture telescopes (the premier example of which is the Dragonfly Telephoto Array) are…

Instrumentation and Methods for Astrophysics · Physics 2022-09-16 Roberto G. Abraham , Pieter G. van Dokkum , Deborah M. Lokhorst , Seery Chen , Qing Liu , Michael L. Rice , E. Lynn Rice

The fractal or Hausdorff dimension is a measure of roughness (or smoothness) for time series and spatial data. The graph of a smooth, differentiable surface indexed in $\mathbb{R}^d$ has topological and fractal dimension $d$. If the surface…

Methodology · Statistics 2015-03-17 Tilmann Gneiting , Hana Ševčíková , Donald B. Percival

The design and experimental implementation of a waveform for high-accuracy inter-node ranging in a coherent distributed antenna array is presented. Based on a spectrally-sparse high-accuracy ranging waveform, the presented multi-frequency…

Signal Processing · Electrical Eng. & Systems 2020-02-10 Sean Ellison , Jeffrey Nanzer

We develop a new definition of fractals which can be considered as an abstraction of the fractals determined through self-similarity. The definition is formulated through imposing conditions which are governed the relation between the…

Metric Geometry · Mathematics 2019-08-13 Marat Akhmet , Ejaily Milad Alejaily

Fractal behaviour, i.e. scale invariance in spatio-temporal dynamics, have been found to describe and model many systems in nature, in particular fluid mechanics and geophysical related geometrical objects, like the convective boundary…

Solar and Stellar Astrophysics · Physics 2018-09-19 S. de Franciscis , J. Pascual-Granado , J. C. Suárez , A. García Hernández , R. Garrido

Co-prime sensing is a sub-Nyquist technique for signal acquisition. Several modifications to the prototype co-prime array have been proposed in the literature. Researchers have also demonstrated low latency estimation. This paper describes…

Signal Processing · Electrical Eng. & Systems 2020-11-24 Usham V. Dias

Let a measurement consist of a linear combination of damped complex exponential modes, plus noise. The problem is to estimate the parameters of these modes, as in line spectrum estimation, vibration analysis, speech processing, system…

Information Theory · Computer Science 2016-05-04 Pooria Pakrooh , Louis L. Scharf , Ali Pezeshki

This letter investigates the non-coherent Direction of Arrival (DOA) estimation problem dealing with the DOA estimation from magnitude only measurements of the array output. The magnitude squared of the array output is expanded as a…

Applications · Statistics 2016-06-22 Hadi Zayyani , Mehdi Korki

Random stepped frequency (RSF) radar, which transmits random-frequency pulses, can suppress the range ambiguity, improve convert detection, and possess excellent electronic counter-countermeasures (ECCM) ability [1]. In this paper, we apply…

Signal Processing · Electrical Eng. & Systems 2018-08-30 Tianyao Huang , Yimin Liu , Huadong Meng , Xiqin Wang

Sparse array (SA) geometries, such as coprime and nested arrays, can be regarded as a concatenation of two uniform linear arrays (ULAs). Such arrays lead to a significant increase of the number of degrees of freedom (DOF) when the…

Signal Processing · Electrical Eng. & Systems 2022-01-05 Wanlu Shi , Sergiy A. Vorobyov , Yingsong Li

Sampling theory in fractional Fourier Transform (FrFT) domain has been studied extensively in the last decades. This interest stems from the ability of the FrFT to generalize the traditional Fourier Transform, broadening the traditional…

Information Theory · Computer Science 2024-04-30 Václav Pavlíček , Ayush Bhandari

A steerable parametric loudspeaker array is known for its directivity and narrow beam width. However, it often suffers from the grating lobes due to periodic array distributions. Here we propose the array configuration of hyperuniform…

Audio and Speech Processing · Electrical Eng. & Systems 2023-04-14 Kun Tang , Yuqi Wang , Shaobo Wang , Da Gao , Haojie Li , Xindong Liang , Patrick Sebbah , Yibin Li , Jin Zhang , Junhui Shi

This paper proposes a novel multi-antenna architecture, termed ray antenna array (RAA), which aims to enhance wireless communication performance in a cost-effective manner. RAA is composed of massive cheap antenna elements and a few radio…

Signal Processing · Electrical Eng. & Systems 2025-05-27 Zhenjun Dong , Zhiwen Zhou , Yong Zeng

A method is proposed for generating compact fractal disordered media, by generalizing the random midpoint displacement algorithm. The obtained structures are invasive stochastic fractals, with the Hurst exponent varying as a continuous…

Statistical Mechanics · Physics 2011-01-04 Christian Turk , Anna Carbone , Bernardino M. Chiaia

We study the convergence of certain subseries of the harmonic series corresponding to increasing sequences of integers whose digits in a certain base are not uniformly distributed. We also discuss the case of irregular sequences, where the…

Number Theory · Mathematics 2009-03-13 Gabor Korvin