110 Hits in 6.1 sec

Techniques for High-Performance DAB and DVB-T On-Channel Repeaters

Peter Moss, Adam Wiewiorka
2011 International Journal of Sensors Wireless Communications and Control  
For effective operation, systems must incorporate excellent RF design and high-performance signal processing in order to remain stable and reradiate a clean, decodable signal.  ...  On-channel repeaters are able to receive and re-transmit a broadcast signal on the same frequency and thus can facilitate network expansion, particularly in an SFN, and network repair following the introduction  ...  As well as the IIR equaliser discussed above, an FIR equaliser structure can be used for correcting the response of a single-ended input in the time domain, where the input has suffered linear distortion  ... 
doi:10.2174/2210327911101010033 fatcat:aolo7pmdfjcfncjvwbkennahl4

Robust Channel Estimation Methods for Spectrally Efficient FDM Systems

Hedaia Ghannam, Izzat Darwazeh
2018 2018 IEEE 87th Vehicular Technology Conference (VTC Spring)  
This paper proposes and explores a novel channel estimation scheme for non-orthogonal multi-carrier signals and systems; spectrally efficient frequency division multiplexing (SEFDM), in which higher spectral  ...  efficiency is achieved by violating the orthogonality of its subcarriers.  ...  Recently, a joint iterative channel estimation and equalisation scheme in the frequency domain is proposed for singlecarrier non-orthogonal faster-than-Nyquist (FTN) systems, where a trace (trellis) operation  ... 
doi:10.1109/vtcspring.2018.8417823 dblp:conf/vtc/GhannamD18 fatcat:accug74uf5bgbdbtx2ap77df3i

Chromatic Aberration Recovery on Arbitrary Images [article]

Daniel J. Blueman
2021 arXiv   pre-print
Digital imaging sensor technology has continued to outpace development in optical technology in modern imaging systems.  ...  The goals of higher-performance and lighter lens systems drive a recent need to find new ways to overcome resulting image quality limitations.  ...  Additionally, I would like to thank all my friends and colleagues at the University of Bristol for their guidance and support in the Computer Graphics and Computer Vision labs, including Timo Kunkel.  ... 
arXiv:2110.04030v1 fatcat:j5paakqflvbuxgt3itniylkjz4

The First 15 Years of SEFDM: A Brief Survey

Izzat Darwazeh, Hedaia Ghannam, Tongyang Xu
2018 2018 11th International Symposium on Communication Systems, Networks & Digital Signal Processing (CSNDSP)  
Spectrally efficient frequency division multiplexing (SEFDM) is a multi-carrier signal waveform, which achieves higher spectral efficiency, relative to conventional orthogonal frequency division multiplexing  ...  This survey provides the history of SEFDM development since its inception in 2003, covering fundamentals and concepts, wireless and optical communications applications, circuit design and experimental  ...  Furthermore, a technique, termed multistream faster than Nyquist (FTN), redeveloped from a paper published in 1975 [10] , was presented both theoretically and experimentally in [11] .  ... 
doi:10.1109/csndsp.2018.8471886 dblp:conf/csndsp/DarwazehGX18 fatcat:fa2rbifejjhpbidkqzyh2rmkqq

Reconfigurable Structures for Direct Equalisation in Mobile Receivers [article]

Felip Riera-Palou
2014 arXiv   pre-print
In mobile systems, the equaliser is made adaptable in order to be able to respond to the channel variations.  ...  Simulations show that, in realistic scenarios, making the equaliser longer than a certain (undetermined) number of taps will not yield any benefit. Moreover, computation and power will be wasted.  ...  Here, only the final result is presented, which in the frequency domain is given by: 0 N ) f ( S 1 ) f ( W + = (2.7) where W(f) represents the equaliser response in the frequency domain, that is, the discretetime  ... 
arXiv:1401.7216v1 fatcat:z653f7gqavgltehsby4bhtb5cu

Implementation of Sparse Techniques for MIMO Channel Estimation

S. Ramith
2021 International Journal for Research in Applied Science and Engineering Technology  
Compressed Sensing (CS) algorithms are beneficial in addressing these limitations in the system to increase the spectral efficiency can help free up resources and prevent additional taxing on the hardware  ...  MSE performance is increased with increase in sparsity level. CoSaMP performs better than SP and OMP at low SNRs.  ...  Computational requirements grow only slightly faster than linearly with data rate or bandwidth.  ... 
doi:10.22214/ijraset.2021.35288 fatcat:6q4ttbzf3ffrbpzfuaaf6emg2i

Dual-polarisation Non-linear Frequency-division Multiplexed Transmission with b-Modulation [article]

Xianhe Yangzhang, Vahid Aref, Son Thai Le, Henning Buelow, Domanic Lavery, Polina Bayvel
2019 arXiv   pre-print
There has been much interest in the non-linear frequency-division multiplexing (NFDM) transmission scheme in the optical fibre communication system.  ...  Second, the q_c- and b-modulation for dual-polarisation were compared in terms of Q-factor, spectral efficiency (SE), and correlation of sub-carriers.  ...  In an NFDM system, information is encoded on nonlinear frequencies, which is defined by the non-linear Fourier transform (NFT) of a time-domain signal.  ... 
arXiv:1902.07619v1 fatcat:w3qftjmusvcgpe4ywdjap3ecqe

An iterative pilot-data-aided estimator for SFBC relay-assisted OFDM-based systems

Darlene Neves, Carlos Ribeiro, Adão Silva, Atílio Gameiro
2012 EURASIP Journal on Advances in Signal Processing  
In this article, we propose and assess an iterative pilot-data-aided channel estimation scheme for space frequency block coding relay-assisted OFDM-based systems.  ...  The relay node (RN) employs the equalise-and-forward protocol, and both the base station (BS) and the RN are equipped with antenna arrays, whereas the user terminal (UT) is a single-antenna device.  ...  System model The indices n and k denote time and frequency domain variables, respectively.  ... 
doi:10.1186/1687-6180-2012-74 fatcat:m5wyjxgvv5gyldofilu245gtqy

On the Implementation of Carrierless Amplitude and Phase Modulation in Visible Light Communication

Kabiru O. Akande, Paul Anthony Haigh, Wasiu O. Popoola
2018 IEEE Access  
This paper presents an in-depth study of the implementation of CAP in LED-based VLC systems, highlighting the unique features that make it specially suited for VLC applications.  ...  Carrierless amplitude and phase modulation (CAP) is one of the spectrally efficient schemes that has been proposed to tackle the limited modulation bandwidth challenge in visible light communication (VLC  ...  An example of this is the new sets of two-dimensional (2D) CAP pulses and a set of frequency domain (FD) 3D CAP pulses that are proposed in [51] .  ... 
doi:10.1109/access.2018.2876001 fatcat:3cl3erqqcjg4xk6tuijd3rox6a

Distributed Control Strategies for Microgrids: An Overview

Enrique Espina, Jacqueline Llanos, Claudio Burgos-Mellado, Roberto Cardenas-Dobson, Manuel Martinez-Gomez, Doris Saez
2020 IEEE Access  
, total harmonic distortion regulation, are also reviewed and discussed in this survey.  ...  Protocols for cooperative control such as linear consensus, heterogeneous consensus and finitetime consensus are discussed and reviewed in this paper.  ...  designed with finite-time convergence can achieve a faster dynamic performance than that achieved by using linear consensus, and relatively good disturbance rejection capabilities.  ... 
doi:10.1109/access.2020.3032378 fatcat:u6bbfgnf2vchtbp7a4qsjtsvq4

The Altes Family of Log-Periodic Chirplets and the Hyperbolic Chirplet Transform

Donnacha Daly, Didier Sornette
2021 Symmetry  
are often the signature of critical failure in complex systems.  ...  As they are self-similar, these "Altes chirplets" allow efficient implementation of the scale-invariant hyperbolic chirplet transform (HCT), whose basis functions form hyperbolic curves in the time-frequency  ...  In fact, this work shows that even a linear chirp is seen to perform better than a hyperbolic narrowband chirp.  ... 
doi:10.3390/sym13101922 fatcat:l73hwhhdurdvzjl5m6ut2dosti

On QAM Speech Transmission Schemes for Microcellular Mobile PCNs

Lajos Hanzo, William Webb, Raymond Steele, Redwan A. Salami
1993 Transactions on Emerging Telecommunications Technologies  
contrast to the presently suggested system.  ...  Section 2 gives a brief overview of QAM research for both Gaussian and Rayleigh fiiding channels and highlights the key features of two previously proposed QAM-based mobile communication schemes for PCN in  ...  1.5 times the Nyquist frequency.  ... 
doi:10.1002/ett.4460040504 fatcat:3qswqxpiubel3gv4hrlhttc73e

Roadmap on all-optical processing

Paolo Minzioni, Cosimo Lacava, Takasumi Tanabe, Jianji Dong, Xiaoyong Hu, Gyorgy Csaba, Wolfgang Porod, Ghanshyam Singh, Alan E Willner, Ahmed Almaiman, Victor Torres-Company, Jochen Schröder (+20 others)
2019 Journal of Optics  
This work was supported in part from a grant from the John Templeton Foundation (JTF #60478).  ...  The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation.  ...  The challenge of maintaining faster switching in this design has been achieved by appropriate switching the contrast with high conversion frequency [86] .  ... 
doi:10.1088/2040-8986/ab0e66 fatcat:6zg52wqctvgldeddmehkezzjnq

Doppler Shift Estimation and Compensation in High Speed MIMO-OFDM VANETs

2018 Journal of Computing and Information Technology  
Motions in vehicular ad hoc networks (VANETs) cause Doppler Frequency Shifts (DFSs) which are described by frequency dispersions in the received signals.  ...  The proposed method realizes a low computational complexity DFS estimator and compensator in the linear order of the Fast Fourier Transform (FFT) size as compared to the DFS uncompensated MIMO-OFDM systems  ...  For time-invariant (TI) fading channels, the channel matrix in the frequency domain would be diagonal such that each sub carrier in the orthogonal frequency division multiplexed (OFDM) system is simply  ... 
doi:10.20532/cit.2018.1003823 fatcat:roueedglsramnfnsmn266sbwqi

Space-Filling X-Ray Source Trajectories for Efficient Scanning in Large-Angle Cone-Beam Computed Tomography

Andrew M. Kingston, Glenn R. Myers, Shane J. Latham, Benoit Recur, Heyang Li, Adrian P. Sheppard
2018 IEEE Transactions on Computational Imaging  
We show that the SFT provides greater data acquisition efficiency, and reduced reconstruction artifacts when compared with helical trajectory.  ...  The practical implications of these properties in tomography are also illustrated by simulation.  ...  To maximise tomographic resolution, the Nyquist sampling theorem dictates that the source points sample the z-direction with a minimum frequency of L/Rp.  ... 
doi:10.1109/tci.2018.2841202 fatcat:7djwewskrnfl3gmtxgz7ktmhju
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