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  Subjects -> COMPUTER SCIENCE (Total: 2066 journals)
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COMPUTER SCIENCE (1196 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 20)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 27)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 8)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 15)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 5)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 12)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 3)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 15)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 6)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 4)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 19)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 8)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 3)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 9)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 6)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 8)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 9)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Hybrid Journal   (Followers: 29)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Informatica Malaysia     Open Access  
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Ad Hoc Networks     Hybrid Journal   (Followers: 11)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Advanced Engineering Materials     Hybrid Journal   (Followers: 28)
Advanced Science Letters     Full-text available via subscription   (Followers: 10)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 7)
Advances in Artificial Intelligence     Open Access   (Followers: 15)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 3)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 19)
Advances in Computer Engineering     Open Access   (Followers: 4)
Advances in Computer Science : an International Journal     Open Access   (Followers: 14)
Advances in Computing     Open Access   (Followers: 2)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 52)
Advances in Engineering Software     Hybrid Journal   (Followers: 27)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 13)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Human-Computer Interaction     Open Access   (Followers: 20)
Advances in Materials Science     Open Access   (Followers: 14)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 45)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 5)
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 9)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
AI EDAM     Hybrid Journal  
Air, Soil & Water Research     Open Access   (Followers: 11)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 11)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 5)
American Journal of Computational Mathematics     Open Access   (Followers: 4)
American Journal of Information Systems     Open Access   (Followers: 5)
American Journal of Sensor Technology     Open Access   (Followers: 4)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 4)
Annals of Data Science     Hybrid Journal   (Followers: 12)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 12)
Annals of Pure and Applied Logic     Open Access   (Followers: 3)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 1)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 12)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 11)
Applied Computer Systems     Open Access   (Followers: 2)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 33)
Applied Medical Informatics     Open Access   (Followers: 10)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Applied System Innovation     Open Access  
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 5)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 141)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
arq: Architectural Research Quarterly     Hybrid Journal   (Followers: 8)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 7)
Asia Pacific Journal on Computational Engineering     Open Access  
Asia-Pacific Journal of Information Technology and Multimedia     Open Access   (Followers: 1)
Asian Journal of Computer Science and Information Technology     Open Access  
Asian Journal of Control     Hybrid Journal  
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
Australian Educational Computing     Open Access   (Followers: 1)
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 4)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 11)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Basin Research     Hybrid Journal   (Followers: 5)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Big Data and Cognitive Computing     Open Access   (Followers: 2)
Biodiversity Information Science and Standards     Open Access  
Bioinformatics     Hybrid Journal   (Followers: 301)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 21)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 37)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 47)
British Journal of Educational Technology     Hybrid Journal   (Followers: 139)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 1)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal   (Followers: 2)
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 15)
Capturing Intelligence     Full-text available via subscription  
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cell Communication and Signaling     Open Access   (Followers: 2)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
CERN IdeaSquare Journal of Experimental Innovation     Open Access   (Followers: 3)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 11)
Circuits and Systems     Open Access   (Followers: 15)
Clean Air Journal     Full-text available via subscription   (Followers: 1)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combinatorics, Probability and Computing     Hybrid Journal   (Followers: 4)
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Communication Methods and Measures     Hybrid Journal   (Followers: 12)
Communication Theory     Hybrid Journal   (Followers: 21)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
Communications in Computational Physics     Full-text available via subscription   (Followers: 2)
Communications in Information Science and Management Engineering     Open Access   (Followers: 4)
Communications in Partial Differential Equations     Hybrid Journal   (Followers: 3)
Communications of the ACM     Full-text available via subscription   (Followers: 51)
Communications of the Association for Information Systems     Open Access   (Followers: 16)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access   (Followers: 1)
Complex Adaptive Systems Modeling     Open Access  
Complex Analysis and Operator Theory     Hybrid Journal   (Followers: 2)
Complexity     Hybrid Journal   (Followers: 6)
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 8)
Computación y Sistemas     Open Access  
Computation     Open Access   (Followers: 1)
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 9)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 16)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 5)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 14)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 30)
Computer     Full-text available via subscription   (Followers: 97)
Computer Aided Surgery     Open Access   (Followers: 6)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Communications     Hybrid Journal   (Followers: 16)
Computer Journal     Hybrid Journal   (Followers: 9)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 23)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 12)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 2)

        1 2 3 4 5 6 | Last

Journal Cover
AEU - International Journal of Electronics and Communications
Journal Prestige (SJR): 0.42
Citation Impact (citeScore): 2
Number of Followers: 8  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1434-8411
Published by Elsevier Homepage  [3159 journals]
  • Error Performance of Hybrid Wireless-Power Line Communication System
    • Abstract: Publication date: Available online 18 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Neelima Agrawal, Prabhat Kumar SharmaAbstractThis paper considers a hybrid wireless-power line communication system for smart meter and grid interaction. The performance of the considered system is evaluated for different switching schemes such as threshold based switching, random switching, and selection combining. The power line channel is characterized using the log-normal random variable, whereas the channel response for the wireless link is modeled as the Nakagami-m distributed random variable. The expressions for average bit-error-rate (BER) for the considered switching/combining schemes are obtained, and the average BER performances of all the considered combining schemes are compared. The results are verified through simulations.
  • Reduction of Self-Heating Effect Using Selective Buried Oxide (SELBOX)
           Charge Plasma Based Junctionless Transistor
    • Abstract: Publication date: Available online 18 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Amrish Kumar, Abhinav Gupta, Sanjeev RaiAbstractA junctionless transistor (JLT) having high doping concentration of the channel, suffers from the threshold voltage roll-off because of random dopant fluctuation (RDF) effect. RDF has been minimized by using charge plasma based JLT. Charge plasma is same as a workfunction engineering in which work function of the electrode is varied to create hole/electron plasma and induce doping in the intrinsic silicon. N-type doping is induced at the source and drain side due to difference of workfunction of silicon wafer. In this paper, charge plasma based junctionless MOSFET on selective buried oxide (SELBOX-CPJLT) is proposed. This approach is used to reduce the self-heating effect presented in SOI-based devices. The proposed device shows better thermal efficiency as compared to SELBOX-JLT. 2D-Atlas simulation revealed the electrostatics and analog performance of both the devices. The SELBOX-CPJLT exhibits better electrostatic performance as compared to SELBOX-JLT for the same channel length. The analog performance such as intrinsic gain, transconductance generation factor, output conductance and unity gain cut-off frequency are extracted from small signal ac analysis at 1MHz and compared to SELBOX-JLT. The analysis of the thermal circuit model of SELBOX structure is also performed.
  • A hyperchaotic memristor system with exponential and discontinuous
           memductance function
    • Abstract: Publication date: Available online 17 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Karthikeyan Rajagopal, Sundaram Arun, Anitha Karthikeyan, Prakash Duraisamy, Ashokkumar SrinivasanAbstractMost of the memristor chaotic and hyperchaotic oscillators discussed in the literatures use the cubic flux controlled memristor model. The drawback of this model is that in spite of knowing the terminal voltage polarity, one cannot easily determine whether the memductance increase or decrease. Hence we propose new memristor hyperchaotic oscillators derived using exponential memductance and discontinuous memductance functions. Dynamical analysis of the proposed oscillators are conducted using equilibrium points, stability of equilibrium, Eigen values and Lyapunov exponents. Bifurcation plots are derived to understand the parameter dependence of the proposed oscillators. Multistability and coexisting attractors are exhibited by these memristor oscillators.
  • Multi band Multi Polarized Reconfigurable Circularly Polarized Monopole
           Antenna with Simple Biasing Network
    • Abstract: Publication date: Available online 17 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Dinesh Kumar Singh, Binod Kumar Kanaujia, Santanu Dwari, Ganga Prasad PandeyAbstractDesign of a reconfigurable multiband multi polarized monopole antenna with simple bias circuit is presented. The proposed antenna consists of simple radiating truncated rectangular patch with a cross-shaped slit and a ground plane embedded with L-shaped slit. The antenna produces two separate impedance bandwidth with three senses of polarization namely right hand circular polarization, left hand circular polarization and linear polarization. PIN diode is used to reconfigure the L-shape slit in the ground plane. The antenna generates dual band behaviour with multiple circularly and linearly polarized bands. With OFF state of the diode, the impedance bandwidth of the antenna is 10.22% and 83.43% from 3.99 GHz to 4.42 GHz and 5.84 GHz to 14.20 GHz, respectively, while 3-dB axial ratio bandwidths are 9.83% and 13.73% from 5.79 GHz to 6.39GHz and 8.49 GHz to 9.74GHz, respectively. In the ON state, antenna also shows the dual band behaviour with an impedance bandwidth of 49.10% and 21.31% from 7.20 GHz to 11.04 GHz and 12.66 GHz to 15.37 GHz, respectively, while 3-dB axial ratio bandwidth of 6.49%, 8.45% and 2.0% from 7.90 GHz to 8.43 GHz, 10.08 GHz to 10.97 GHz and 12.87 GHz to 13.13 GHz, respectively..
  • Research on detection performance of passive detection system based on
    • Abstract: Publication date: Available online 16 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Zan Liu, Xihong Chen, Chenglong Li, Qiang LiuAbstractElectromagnetic (EM) wave propagated via troposcatter is a valuable candidate for beyond line-of-sight (b-LoS) detection. In this paper, the probability of detection is firstly analyzed. Aiming at acquiring signal-to-noise ratio (SNR), we present two approaches including statistical model and time-varying model. Hopfield model is employed to establish the relationship between SNR and time-varying meteorological parameters. Simulations demonstrate the availability of above models. Finally, a cognitive system is introduced to improve the performance of passive detection system. The uncontrollable factors including meteorological parameters, elevation angle and frequency of EM wave are firstly studied, and then the controllable parameters will be regulated on the basis of conclusions deduced in this paper.
  • Design and Validation of Miniaturize Rat Race Coupler Based Microstrip
    • Abstract: Publication date: Available online 16 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ankita Kumari, Priyansha Bhowmik, Tamasi MoyraAbstractThis work presents a compact Balun with enhanced bandwidth and better isolation between output ports using Interdigital Capacitor (IDC). Firstly, a Rat Race Coupler (RRC) is designed, later Balun is proposed by replacing the isolation port with a 50 Ohm isolation resistor. The proposed Transmission line (TL) is designed using an IDC in parallel with a high impedance TL. Based on a π-equivalent circuit the proposed TL has been investigated and optimized to achieve 70.7 Ohm impedance. The Balun is designed and fabricated. The simulated and fabricated results are in accord. The fractional bandwidth (FBW) of RRC and Balun are 37.5% and 33% respectively at centre frequency 2.4 GHz. The size occupied by the proposed Balun is 0.51λg×0.22λg. The structure is low cost, uniplanar and compact.
  • Joint channel mitigation and side information estimation for GFDM systems
           in indoor environments
    • Abstract: Publication date: Available online 15 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Sivaprasad Valluri, V.V. ManiAbstractGeneralized frequency division multiplexing (GFDM) is the foremost contender for physical layer of 5G communication. The flexible nature of GFDM allows multiple symbols in time domain to superimpose, thereby creating high peak to average power ratio (PAPR). The idea of selective mapping (SLM) is to use a sequence of phase rotation vectors for generating alternatives using original GFDM signal. Among them, signal with lowest PAPR is selected for transmission. This procedure requires mandatory side information (SI) estimation or transmission which in turn decreases data reliability or efficiency. To address these issues, authors present a modified approach of pilot-assisted GFDM SLM system without need of SI transmission and to enable joint PAPR reduction and data recovery. In the proposed approach, we utilize a common modulating phase to modulate all subcarriers in a subsymbol assuming that each subsymbol consists of at least two pilots. This creates an inherent SI cancellation mechanism using the pilots which are employed for channel estimation. For practical validation of proposed concepts, we used software-defined radio (SDR) experimental setup employing universal software radio peripheral USRP) 2953R as hardware and Labview as software. Experimental results show a significant reduction in out-of-band spectral leakage without disturbing the estimated channel response.
  • Linear Network Coding Using Channel Quantization Combining with SIC Based
           Estimation for Multiple Antenna Systems
    • Abstract: Publication date: Available online 12 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Huu Minh Nguyen, Xuan Nam Tran, Van Bien Pham, Cong Dinh NguyenAbstractThis paper proposes a network coding method with linear mapping and low-complexity estimation for the two-way relay non-reciprocal channel using the M-QAM modulation. The proposed network coding is developed by combining the channel quantization method and linear estimation based on successive interference cancellation. The effect of residual interference due to channel quantization on the signal decision is analyzed in detail in order to understand the system behavior. Analytical and simulation results show that the proposed network coding method can achieve high SER performance and up-link throughput while requiring low computational complexity.
  • Low Sensitivity Complex Image Rejection Filter for GNSS Receivers
    • Abstract: Publication date: Available online 11 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Omer Aydin, Utku Emre AliAbstractIn this paper, a new approach for the design of a low-sensitivity complex-filter is proposed. The approach is based on realising the filter using low-sensitivity allpass sections. The complex filter obtained can be used as image-reject filter in low-IF GNSS receivers. The filter configuration is modular, i.e. is composed of the same subcircuits which simplifies the design of the circuit. A Chebyshev type OTA-C image-reject filter obtained by cascading two third-order allpass based complex filters is presented. Post layout simulation results of the filter using SPECTRE in CADENCE design tool verifying its proper operation are provided.
  • A novel MILP model for timely message delivery in real-time WSNs
    • Abstract: Publication date: Available online 11 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Nassima Ghoul-Bousba, Maher Rebai, Louiza Bouallouche-Medjkoune, Djamil Aissani, Lyes KhoukhiAbstractPacket delivery delay minimization is a critical issue in Wireless Sensor Networks. In mission-critical applications, the sensed information is highly delay-sensitive, and should be transmitted to the sink within a required delay. In this paper, we propose a new mixed integer linear programming model (MILP) to address the problem of end-to-end delay minimization of data transmission in delay-sensitive applications such as healthcare monitoring. The proposed model simultaneously guarantees 1) timely delivery data packets, 2) network reliability, 3) connectivity, and 4) flow preservation.We verify by computational experiments that the developed mixed integer linear model, using Cplex, is able to provide an optimal solution for timely data packet delivery of all our small and medium size problems.
  • Dual-band Polarization and Frequency Reconfigurable Antenna Using Double
           Layer Metasurface
    • Abstract: Publication date: Available online 10 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): XiaoFeng Chen, YongJiu ZhaoAbstractIn this paper, a polarization and frequency reconfigurable antenna with double layer metasurface, responsible for frequency and polarization reconfiguration respectively, is proposed. This antenna could operate in linear polarization in 4GHz and circular polarization in 5GHz band. By rotating the frequency reconfiguration metasurface, the linear polarization(LP) operating frequency can be continuously changed from 4GHz to 4.35GHz (8.4%) with circular polarization operating frequency around 5GHz unchanged. Moreover, polarization of the whole antenna at 5GHz can be reconfigured to linear polarization(LP), right-hand circular polarization(RHCP) and left-hand circular polarization(LHCP) by rotating polarization reconfiguration metasurface, the 3dB axial ratio bandwidth is 5.0-5.2 GHz (4%). In all states, gain of the antenna achieves 5 dBi.
  • Adaptive Neuro-Fuzzy Inference System approach in bandwidth and mutual
           coupling analyses of a novel UWB MIMO antenna with notch bands applicable
           for massive MIMOs
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Mahmood Abbasi Layegh, Changiz Ghobadi, Javad Nourinia, Yousef Samoodi, Shayan Najafi MashhadiAbstractA novel UWB MIMO antenna with band-notched characteristic operating in the frequency range between 3.1 GHz and 10.6 GHz is presented. The designed MIMO antenna has two ports and the size of 32×14 mm2 which is fabricated on an FR-4 printed-circuit-board. The feeding system of the proposed antenna is a microstrip line. The two antennas are positioned face to face but laid reversely upon the substrate in order to have a good isolation, less cross polarization, high gain and good envelope correlation coefficient. S-parameters describe the input-output relationship between ports (or terminals) in a MIMO antenna. The effects of the strip feed line width on the variations in reflection coefficient (S11) and consequently the impedance bandwidth as well as the mutual coupling between the two antennas for various separations are analyzed by Adaptive Neuro-Fuzzy Inference System (ANFIS) approach. This system is trained for different membership functions based on the number of epochs, root-mean-square error and mean absolute percentage error. Then, a comparative study is made between them. It is shown that when fuzzy system is trained by gaussian combination membership function (Gauss2mf), better results in terms of training, testing error and correlation coefficient can be attained.
  • Novel half-mode substrate integrated waveguide bandpass filters using
           semi-hexagonal resonators
    • Abstract: Publication date: Available online 7 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Tahsin Khorand, Mohammad Sajjad BayatiAbstractIn this paper, a novel bandpass filter is presented, designed, and implemented by using a triple mode semi-hexagonal Half-Mode Substrate Integrated Waveguide (HMSIW) cavity, which has the advantages of compact size, low insertion loss, and high selectivity in upper and lower passband. To realize a triple mode filter, the first resonant mode is shifted to near the next two modes using a via hole perturbation. Two microstrip open stubs connected to open edge of HMSIW resonator are introduced to generate two transmission zeros in the lower passband. The position of transmission zeros could be controlled by adjusting the coupling gap between the microstrip open stub resonators. By etching an E-shape slot on the top plate of HMSIW resonator, two other transmission zeros are produced in the upper passband. A wide-band planar six-pole bandpass filter, which has the advantages of wide bandwidth and small size, is also proposed and fabricated by cascading two triple mode resonators. Measured results indicate that 29% and 47% fractional bandwidth, as well as approximately 1 dB and 1.1 dB insertion loss, are achieved for the proposed filters. Measured results of all those filters agree well with the simulated results.
  • A Bandwidth Allocation and Energy-Optimal Transmission Rate Scheduling
           Scheme in Multi-Services Wireless Networks
    • Abstract: Publication date: Available online 7 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Su Pan, Yuqing ChenAbstractThe energy-saving of mobile devices during their application offloading process has always been the research hotspot in the field of mobile cloud computing (MCC). In this paper, we focus on the scenario where multiple mobile devices with MCC and non-MCC services coexist. A bandwidth allocation and the corresponding transmission rate scheduling schemes are proposed with the objectives of simultaneously maximizing the overall system throughput and minimizing the energy consumption of individual mobile device with MCC service. To allocate the bandwidth to all mobile devices, two different algorithms are proposed, i.e., 0-1 integer programming algorithm and Lagrange dual algorithm. The transmission rate scheduling scheme for mobile device with MCC service is presented based on reverse order iteration method. The numerical results suggest that energy consumed by individual mobile device with MCC service can be remarkably saved while the overall system throughput can also be maximized. Moreover, the results show that 0-1 integer programming algorithm can get greater system throughput but has higher computational complexity, which means the algorithm is more suitable for small-scale systems, whereas Lagrange dual algorithm can achieve a good balance between the performance and computational complexity.
  • Design of a Vivaldi Antenna With Wideband Reduced Radar Cross Section
    • Abstract: Publication date: Available online 7 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Tayyab A. Khan, Jianxing Li, Zhiyuan Li, Muhammad Abdullah, Juan Chen, Anxue ZhangAbstractIn this paper, a low radar cross section (RCS) Vivaldi antenna is proposed. The main objective of this work is to achieve a reasonable RCS reduction without affecting the radiation performance of the antenna. With carefully inspecting the surface current distributions at different frequencies and realizing the critical role of the structural mode in reducing RCS, a simple and efficient object shaping method is employed by introducing a number of circular slots in the surface of the radiator to achieve the RCS reduction. These circular slots along the inner circular profile of the Vivaldi antenna can minimize the scattering along the surface of the radiator, which hence leads to a reduction in the monostatic RCS. Comparing the measured results between the reference antenna and the proposed antenna, a significant 11 dB RCS reduction is obtained while maintaining good radiation performance. Simulated and measured results including S-parameters, gain, RCS of the reference antenna and the proposed antenna are presented.
  • Power Tunable Inductor Based on Active Capacitor with Negative Resistance
    • Abstract: Publication date: Available online 7 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohammad Beigizadeh, Rasoul Dehghani, Abdolreza NabaviAbstractA method to provide a low power tunable inductor is presented in which the inductance and its equivalent series resistance can be independently tuned. This equivalent series resistance can be also set to negative or zero value that is corresponding to inductor with ideal quality factor. In this method, a varactor is placed in parallel with a passive inductor and then, an active capacitor is placed in series with them. To this end, a low power Tunable Active Capacitor (TAC) is proposed which is capable of generating tunable capacitor and large negative resistance to compensate the loss of tunable inductor circuit. Also, the power consumption is low because of using a diode-connected transistor. A prototype of the proposed circuit is designed and simulated at 4 GHz. The electromagnetic simulation results show the inductance tuning range of 0.48nH - 2.3nH with zero or even negative equivalent series resistance is obtained while the power dissipation is less than 3mW. Moreover, noise analysis shows that higher inductance translates to lower noise while there is a weak correlation between noise and quality factor of the obtained inductances.
  • Synthesis and Design of an LPF with Wide-Stop Band and High Rejection
    • Abstract: Publication date: Available online 7 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ali Vaezi, Fatemeh Geran GharakhiliAbstractIn this paper, a compact microstrip lowpass filter (LPF) is designed, analyzed, simulated, and tested. The proposed design that consists of a basic part in the central section of the structure and two parts of suppression of harmonics that are inserted in the first and last sections of the basic part, have wide-stop band, high suppression factor (-38 dB attenuation level from 2.4GHz up to 27.4 GHz), low normalized size and sharp roll-off. The proposed LPF has a -3 dB cut-off frequency of 2.4 GHz, a wide stopband bandwidth around 11th harmonic suppression and an insertion loss less than 0.1 dB at passband. This filter has been fabricated and tested and good agreement is observed between the simulated and measured results.
  • Bandwidth-enhanced Differential VCO and varactor-coupled Quadrature VCO
           for mmWave applications
    • Abstract: Publication date: Available online 7 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Farman Ullah, Yu Liu, Xiaosong Wang, Muhammad Masood Sarfraz, Haiying ZhangAbstractThis paper presents a bandwidth-enhanced differential LC-Voltage Controlled Oscillator (LC-VCO) and varactor-coupled Quadrature VCO (QVCO) designed and simulated in high-performance SiGe HBTs of the GlobalFoundries (GFs) 130nm SiGe BiCMOS8HP process for mmWave applications. Using the proposed varactor circuit, the designed VCO is operated in wideband and also the two-identical free-running differential VCOs (DVCOs) are coupled through the proposed varactor to oscillate in quadrature. The device sizes in the coupling network are properly set to achieve low I/Q errors. In addition, all the VCOs are designed in class-C to further improve their performances both in term of low power and low phase noise. The post-simulation results show that the differential oscillator is tunable from 20.3- to 31.3-GHz as the tuning voltage is varied from 0 to 1.2V, while consuming only 10mA from 1.2V supply, presenting the best state-of-the-art figure-of-merit (FoMT) of -188 dBc/Hz. Similarly, the QVCO can cover 40.2% oscillation bandwidth around 25.5GHz oscillating frequency which is significantly wider than other state-of-the-art VCOs operating at comparable frequencies.
  • A Modified Non-negative LMS Algorithm for Online System Identification
    • Abstract: Publication date: Available online 6 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Azam KhaliliAbstractAdaptive filters are useful solutions for system identification problem where an optimization problem is used to formulated the estimation of the unknown model coefficients. The nonnegativity constraint is one of the most frequently used constraint which can be imposed to avoid physically unreasonable solutions and to comply with physical characteristics. In this letter, we propose a new variant of non-negative least mean square (NNLMS) that has a less mean square error (MSE) value and faster convergence rate. We provide both mean weight behavior and transient excess mean-square error analysis for proposed algorithm. Simulation results validate the theoretical analysis and show the effectiveness of our proposed algorithm.
  • Compact dual-wideband bandpass filter for wireless applications
    • Abstract: Publication date: Available online 6 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Solunke Yogesh Shriram, Kanaparthi V. Phani Kumar, S.S. KarthikeyanAbstractIn this paper, a compact dual-wideband bandpass filter with two reflection zeros in both passbands and two transmission zeros in the stopband, based on a signal interference technique is presented. The proposed filter is formed by a transmission line connected in parallel with a series connection of transmission lines and a short circuited edge coupled line. A simple lossless transmission line model is used to derive the condition for transmission zeros. To validate the theoretical predictions, a compact dual-wideband bandpass filter has been fabricated to operate at GPS and INSAT Satellite bands. The measured 3 dB passband fractional bandwidths are 82.16% and 41.52%, respectively.
  • Gradient-oriented Directional Predictor for HEVC Planar and Angular Intra
           Prediction Modes to Enhance Lossless Compression
    • Abstract: Publication date: Available online 4 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): S. Shilpa Kamath, P. Aparna, Abhilash AntonyAbstractRecent advancements in the capture and display technologies motivated the ITU-T Video Coding Experts Group and ISO/IEC Moving Picture Experts Group to jointly develop the High-Efficiency Video Coding (HEVC), a state-of-the-art video coding standard for efficient compression. The compression applications that essentially require lossless compression scenarios include medical imaging, video analytics, video surveillance, video streaming etc., where the content reconstruction should be flawless. In the proposed work, we present a gradient-oriented directional prediction (GDP) strategy at the pixel level to enhance the compression efficiency of the conventional block-based planar and angular intra prediction in the HEVC lossless mode. The detailed experimental analysis demonstrates that the proposed method outperforms the lossless mode of HEVC anchor in terms of bit-rate savings by 8.29%, 1.65%, 1.94% and 2.21% for Main-AI, LD, LDP and RA configurations respectively, without impairing the computational complexity. The experimental results also illustrates that the proposed predictor performs superior to the existing state-of-the-art techniques in the literature.
  • Electronically Tunable High Gain Current-Mode Instrumentation Amplifier
    • Abstract: Publication date: Available online 31 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Sirish Oruganti, Neeta Pandey, Rajeshwari PandeyAbstractA new design for electronically tunable current mode (CM) instrumentation amplifier (IA) is presented in this paper. It employs Modified Z copy Current Differencing Transconductance Amplifier (MZC-CDTA) along with a resistor. The gain of the proposed CM IA is controlled by a single resistor and can theoretically approach infinite value. Electronic tuning feature is augmented by using a MOS based resistor. The functionality is verified through simulations on Cadence Virtuoso using TowerJazz’s 180nm Technology Node and performance against PVT variations is also examined. Feasibility of on-chip implementation is confirmed by the post-layout simulations carried out.
  • Design and Fabrication of Compact 2x2 Dual Linear Polarized Wideband and
           High Gain Array for Ku-Band Satellite Communication Application
    • Abstract: Publication date: Available online 31 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Parya Fathi, Javad AliasgariAbstractIn this paper, the design of a planar array antenna for two-way satellite communication is presented. The antenna unit consists of four elements and two waveguide feeding networks used to connect the elements. The radiating elements are small horn apertures. Each element of the array includes two separate ports to radiate vertical and horizontal polarization, respectively. The feeding networks consist of power dividers and bends to connect the vertical and horizontal polarization ports of horns, separately. Radiating elements and feeding networks are designed to cover receive band (10.5 to 12.75 GHz) and transmit band (13.75 to 14.5 GHz) within Ku-band. The maximum gain for this type of antenna is 21 dBi.
  • Pulse Shape Optimization for Physical layer UWB Communication and
           Performance Evaluation in Saleh – Valenzuela Channel IEEE 802.15.3a
    • Abstract: Publication date: Available online 31 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Abhishek Sharma, Sanjay Kumar SharmaAbstractUltra-Wideband communication faces constraints on radiated power from regulatory bodies to minimize the co-existing interference with the narrowband communication. These limitations cause sacrifices in terms of data rate. In this paper, a new methodology of pulse shaping is proposed to meet the spectrum mask given by Federal Communication Commission (FCC). This methodology acutely reduces the undesired ringing effect in the time domain which in turn reduces the required power per unit bandwidth of the signal. We select 7th order derivative of Gaussian monocycle as a base pulse and modulate this pulse with Gaussian window in the time domain to achieve the proposed pulse shape. The power spectral density (PSD) of the proposed pulse is perfectly fitted for spectral mask provided by FCC, in comparison of PSD of the base pulse, which in turn simultaneously provides better antenna power resolution due to the reduced ringing effect in the time domain for the proposed pulse. We also analyse the behaviour of the pulse in multi-user Time Hopped (TH) UWB environment for Saleh Valenzuela IEEE 802.15.3a multipath fading channel to find the suitability of the pulse for UWB communication.
  • Self-Start-Up Fully Integrated DC-DC Step-Up Converter Using Body Biasing
           Technique for Energy Harvesting Applications
    • Abstract: Publication date: Available online 31 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): N. Cheraghi Shirazi, A. Jannesari, P. TorkzadehAbstractAn ultra-low power, self-start-up switched-capacitor Two Branch Charge Pump (TBCP) circuit for low power, low voltage, and battery-less implantable applications is proposed. In order to make feasible the low voltage operation, the proposed charge pump along with Non-Overlapped Clock generator (NOC) are designed working in sub-threshold region by using body biasing technique. A four-stage TBCP circuit is implemented with both NMOS and PMOS transistors to provide a direct load flow. This leads to a significant drop in reverse charge sharing and switching loss and accordingly improves pumping efficiency. A post-layout simulation of designed four-stage TBCP has been performed by using an auxiliary body biasing technique. Consequently, a low start-up voltage of 300mV with a pumping efficiency of 95% for 1pF load capacitance is achieved. The output voltage can rise up-to 1.88V within 40μs with 0.2% output voltage ripple in case of using 400mV power supply. The designed circuit is implemented by 180-nm standard CMOS technology with an effective chip area of 130.5μm×141.8μm while the whole circuit consumes just 3.2μW.
  • Design of a Self-Diplexing Antenna Using SIW Technique with High Isolation
    • Abstract: Publication date: Available online 30 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Arvind Kumar, Divya Chaturvedi, Singaravelu RaghavanAbstractIn this paper, a novel and small substrate integrated waveguide (SIW) based self-diplexing antenna is presented. The proposed antenna exploits two quarter-mode SIW cavity resonators for radiation, which are realized by splitting a half-mode SIW cavity with the help of one open-ended slot. Each quarter-mode cavity resonator is excited separately by microstrip feedlines. By properly adjusting the corresponding dimensions of the antenna, a very high isolation of better than -30 dB is obtained between the input ports that helps to realize a self-diplexing phenomenon. The antenna exhibits two resonant frequencies of 6.44 and 7.09 GHz, with the corresponding gain values of 3.2 and 4.8 dBi, respectively. Moreover, the antenna shows unidirectional and stable radiation patterns at both operating frequencies, while it maintains a planar and simple configuration, which can be rescaled for any other desired frequency.
  • A Closed-Form Sum-Rate Lower Bound for Amplify-and-Forward Multi-Way Relay
    • Abstract: Publication date: Available online 30 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Yingzhi Lu, Zhaoxi FangAbstractIn this letter, we investigate the sum-rate performance of the multi-way relay network (MWRN) with amplify-and-forward (AF) relaying, where multiple users exchange information with the help of a relay node. We consider a full exchange scenario where each user has to decode messages form all the other users. We analyze the sum-rate lower and upper bounds of the AF MWRN, and derive a closed-form expression for the average sum-rate low bound when the number of users is sufficient large. Numerical results show that the derived bound is tight.
  • (3.1-20) GHz MIMO Antennas
    • Abstract: Publication date: Available online 26 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Bazil Taha Ahmed, Pablo Sanchez Olivares, José Luis Masa Campos, Fernando Moreno VázquezAbstractIn this paper, a super-wideband (SWB) printed monopole antenna has been designed and manufactured. The measured frequency band in terms of reflection coefficient is from 3.1 to 20 GHz under a -10 dB criteria, thanks to the inclusion of a taper impedance adapter. This single antenna has been used to implement and analyze several MIMO antenna configurations, where the isolation between the compounding elements has been checked and optimized to improve the Envelope Correlation Coefficient. Two elements MIMO configurations (parallel ports or orthogonal diversity), as well as four element MIMO antennas with parallel ports are presented. Non continuous ground planes of the MIMO antenna elements with the inclusion of L shaped thin strips are proposed as valid structures to significantly improve the side by side mutual coupling from an initial peak value of 15 dB to better than 24 dB within the entire frequency band. In all the presented MIMO antenna structures, the measured values demonstrate good performance up to 20 GHz, both in reflection and isolation. Nevertheless, the influence of the mutual coupling effects has been checked as more significant in the lower part of the frequency band, especially in the 4 element MIMO configuration. The inclusion of the L shaped strips in the ground plane significantly mitigates this effect. Although the antennas have only been measured up to 20 GHz (upper frequency limit of the laboratory Vector Network Analyzer), simulations show satisfactory antennas’ performance up to 50 GHz.
  • Analysis of Modified Square Sierpinski Gasket fractal microstrip antenna
           for Wireless communications
    • Abstract: Publication date: Available online 26 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Devesh, J.A. Ansari, Mohd. Gulman Siddiqui, A.K. SarojAbstractIn this paper, the slot loaded microstrip antenna has been developed with Sierpinski gasket technique. The proposed Modified Square Sierpinski Gasket (MSSG) fractal antenna involves a square patch utilizing Sierpinski gasket (triangular) structure. Four triangular slots are loaded at each iteration. The structure is then simulated using commercially available Ansoft HFSS simulator. The multi-band operation has been achieved by the proposed antenna at 15.915 GHz, 20.045 GHz, 23.077 GHz, 27.77 GHz frequencies with -20 dB, -25 dB, -22 dB, -28 dB return loss respectively which works well for Ku (12-18 GHz) and K (18-27GHz) band. The consistent result is obtained after simulation and the validity of fabricated design is checked by the measured result. The designed antenna is an attractive candidate for applications like wireless multi-band communication systems.
  • Soft computing-based synthesis model for equilateral triangular ring
           printed antenna
    • Abstract: Publication date: Available online 26 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ahmet KayabasiAbstractA soft computing-based synthesis model is proposed for the design of equilateral triangular ring printed antennas (ETRPAs) that operate at ultrahigh band applications. The synthesis of printed antennas having irregular shapes needs great efforts and time. Soft computing models eliminates complex, lengthy and time consuming mathematical procedures for synthesis and analysis of the printed antennas. In this paper, a soft computing model based on artificial neural network (ANN) is constructed for synthesis of ETRPAs. To generate training and testing data set, number of 100 ETRPAs with various geometrical and electrical parameters are simulated in terms of resonant frequency with the aid of a 3D full wave simulator. Soft computing model based ANN is designed to obtain the patch physical dimensions of ETRPAs simultaneously. The soft computing model is trained with simulated data set of 75 ETRPAs and tested with remainders 25 ETRPAs. A prototype of ETRPA is then fabricated to verify the proposed model. The testing results of the soft computing model are found in close agreement with simulated and experimental data. The presented model is simply/fast predicting the patch dimensions of ETRPAs and it is extremely useful to antenna engineers for the design of the ETRPAs.
  • Distributed cooperative spectrum sensing based on reinforcement learning
           in cognitive radio networks
    • Abstract: Publication date: Available online 26 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mengbo Zhang, Lunwen Wang, Yanqing FengAbstractSpectrum sensing is an initial task for the successful operation of cognitive radio networks (CRN). During cooperative spectrum sensing, malicious secondary user (SU) may report false sensing data which would degrade the final aggregated sensing outcome. In this paper, we propose a distributed cooperative spectrum sensing (CSS) method based on reinforcement learning (RL) to remove data fusion between users with different reputations in CRN. This method regards each SU as an agent, which is selected from the adjacent nodes of CRN participating in CSS. The reputation value is used as reward to ensure that the agent tends to merge with high reputation nodes. The conformance fusion is adopted to promote consensus of the whole network, while it’s also compared with the decision threshold to complete CSS. Simulation results show that the proposed method can identify malicious users effectively. As a result, the whole CRN based on RL is more intelligent and stable.
  • Fault Tolerant Adaptive Write Schemes for Improving Endurance and
           Reliability of Memristor Memories
    • Abstract: Publication date: Available online 25 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): V. Ravi, S.R.S. PrabaharanThe non-deterministic nature of memristor and its unreliable behavior are the two major concerns hampering its growth and industrial manufacturability. The endurance and reliability of memristor memories are affected not only by the process variations (intrinsic), but also due to the electrical stress created by interfacing peripheral circuits (extrinsic). Concerning the intrinsic faults in transition metal oxide (TMO) memristors, drifting of oxygen vacancies across the device is responsible for SET/RESET operation. It is likely that such drifting might induce switching faults during the device operation, for instance endurance of the memory. Thus, the application of a fixed write pulse may not suffice to achieve successful write operations under these circumstances. To circumvent the above pitfall, we propose here a new technique by designing a fault tolerant adaptable write scheme which can adapt by itself based on the behavior and switching faults. Accordingly, the proposed write scheme identifies the optimal amplitude and the width for write pulse. The proposed write scheme under various memristor faults is found to enhancing the reliability of memristors efficiently. Further, the results are validated by means of Monte-Carlo analysis by infusing the random variations of internal parameters of memristors as well.Graphical abstractGraphical abstract for this article
  • Application of optical frequency comb generation with controlled delay
           circuit for managing the high capacity network system
    • Abstract: Publication date: Available online 25 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rahat Ullah, Liu Bo, Mao Yaya, Feng Tian, Amjad Ali, Ibrar Ahmad, Muhammad Saad Khan, Xin XinagjunAbstractThe generation of optical frequency comb (OFC) with novel controlled delay circuit is presented in this study. The proposed OFC is based on a single laser source which is cascadingly connected with three modulators; all the modulators are tailored by RF signal while incorporating no phase shifter or electrical/optical amplifier. The proposed OFC is used as a source at optical line terminal (OLT) of WDM-PON setup, which serves multiple users with a single laser source making OLT side very cost effective. 41 comb lines with over 40dB tone to noise ratio and high side mode suppression ratio, least amplitude difference of under 0.3dB, with cost effective setup is an attractive source for WDM-PON system. The frequency spacing is 32GHz between OFCG lines which provides enough bandwidth for data transmission, the overall bandwidth provided by this scheme is 1.2THz. Using DPSK modulation technique across each frequency of OFCG, the controlled delay circuit increases the capacity by factor two, whereas by deploying DQPSK modulation technique, it quadrupled the overall capacity in downlink transmission. Thus, the system offers four times increased capacity∼1.6Tbps by deploying state of the art technique for modulation and generating OFC with controlled delay. The average power penalty in the downlink and uplink transmission is 2.5dBm and 3.13dBm.
  • Symmetric Sum Coarray Based Co-Prime MIMO Configuration for Direction of
           Arrival Estimation
    • Abstract: Publication date: Available online 23 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Junpeng Shi, Guoping Hu, Xiaofei Zhang, Yu XiaoAbstractThis paper proposes a symmetric co-prime multiple input multiple output (MIMO) configuration for direction of arrival (DOA) estimation, where the transmitter has 4M-1 sensors with spacing of N units and the receiver has 2N-1 sensors with spacing of M units. By separating the transmitter and receiver into two subarrays respectively, the symmetric sum coarray (SSC) exploits four sum coarrays based on the received signal model, and the difference coarray of SSC (DSSC) is developed by vectorizing the sample covariance matrix. The analytical expressions for the coarray aperture, the maximum consecutive integers and the attainable number of unique lags are derived carefully. Compared with the existing configurations, SSC and DSSC can obtain larger number of degrees of freedom (DOFs). Then, the DOA estimation of mutually coherent and uncorrelated targets is employed for illustration. Simulation results demonstrate the effectiveness of proposed configuration.
  • Design and FPGA implementation of a new approximation for PAPR reduction
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Abdelhamid Louliej, Younes Jabrane, Wei-Ping ZhuAbstractOne of the main drawbacks of orthogonal frequency division multiplexing (OFDM) is its sensitivity to the peak-to-average power ratio (PAPR). To address this issue, a novel and efficient scheme based on multilayer perceptron (MLP) neural networks (NN) using radial basis function is proposed and implemented on FPGA. The proposed solution offers good performance as compared to previous algorithms in iterations, much lower complexity and low error rate. For a precise and less complex implementation of radial basis function, a novel approximation of the exponential function using Taylor series is proposed, implemented on FPGA and compared with Altera intellectual property core (IP core). It is shown that, the proposed approximation offers minimal resource consumption. In particular, we note a reduction of 9% and 6% in the use of lookup tables and DSP blocs.
  • A Unified Performance Analysis of Energy Detector over α-η-μ/Lognormal
           and α-κ-μ/Lognormal Composite Fading Channels with Diversity and
           Cooperative Spectrum Sensing
    • Abstract: Publication date: Available online 21 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Manisha Bhatt, Sanjay Kumar SoniAbstractIn this paper, our objective is to formulate a generalized composite distribution which includes both α-η-μ and the α-κ-μ distributions for modelling small scale fading while shadowing effect is captured by the lognormal distribution. An approximate closed-form of generalized/lognormal (GL) distribution is derived using Gauss-Hermite (GH) integration. Subsequently, the distribution is utilized to formulate analytical expressions for the average probability of energy detection (PD) as well as average area under the receiver operating characteristic curve (AUC) with and without maximal ratio combining (MRC) diversity reception technique. The proposed solutions are expressed in terms of single and bivariate Fox’s H functions, which are currently being used in open literature. Further, the derived average PD is utilized for analysing the performance of energy detector (ED) over square-law selection (SLS) and square-law combining (SLC) diversity schemes. Optimization of detection threshold and number of cooperative sensing nodes to minimize the total error rate has been discussed for CSS network with erroneous feedback channels. Finally, the simplified closed-form asymptotic expressions of the average PD and AUC are also derived. The analytical expressions are validated by comparing them with the exact numerical results and Monte Carlo simulation.
  • Toward an Unsupervised Blind Stereoscopic 3D Image Quality Assessment
           Using Joint Spatial and Frequency Representations
    • Abstract: Publication date: Available online 21 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Meixin Fang, Wujie ZhouAbstractExisting blind stereoscopic 3D (S3D) image quality assessment (IQA) metrics usually require supervised learning methods to predict S3D image quality, which limits their applicability in practice. In this paper, we propose an unsupervised blind S3D IQA metric that utilizes the joint spatial and frequency representations of visual perception. The metric proposed in this work was inspired by the binocular visual mechanism; furthermore, it is unsupervised and does not require subject-rated samples for training. To be more specific, first, the various binocular quality-aware features in spatial and frequency domains are extracted from the monocular and cyclopean views of natural S3D image patches. Subsequently, these features are utilized to establish a pristine multivariate Gaussian (MVG) model to characterize natural S3D image regularities. Finally, with the learned MVG model, the final quality score for a distorted S3D image can be yielded using a Bhattacharyya-like distance. Our experimental results illustrate that, compared to related existing metrics, the devised metric achieves competitive prediction performance.
  • Optimal Components Selection for Active Filter Design with Average
           Differential Evolution Algorithm
    • Abstract: Publication date: Available online 20 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Burhanettin DurmuşAbstractComponent selection in electronic circuit design is an important issue to achieve a targeted performance and quality level. Particularly in filter circuits, changes in gain and phase response of the circuit are directly dependent on the component values of the filter. Therefore, the selection of component values must be done carefully. In this article, a differential evolution (DE) algorithm with a new mutation strategy, named as average DE (ADE), is introduced for analog active filter design. The ADE algorithm minimizes the total design error of the state variable filter (SVF) for the optimal selection of component values. Simulation results indicate that the proposed algorithm reduces the design error when compared to other methods.
  • Supplementary Single Active Device Based Grounded Immittance Function
    • Abstract: Publication date: Available online 20 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mehmet Dogan, Erkan YuceAbstractNew five grounded immittance function simulators are proposed in this paper. The first one is a positive lossless grounded inductor simulator which employs just one inverting buffer plus-type second-generation current conveyor while the other four proposed circuits include only one non-inverting current feedback operational amplifier. The second and third ones are negative lossless grounded inductor simulators. The fourth one is a positive inductor with a series positive resistor while the last one is a negative capacitance multiplier. All of the proposed circuits except the first one consist of only grounded capacitor(s). However, all of the proposed circuits need a single passive component matching condition. A band-pass filter composed of the first proposed circuit is given as an example. Also, frequency dependent non-ideal gain effects on the performance of all the circuits are given. The results of a lot of SPICE simulations are carried out by using 0.13 µm IBM technology parameters where ± 0.75 V DC symmetrical power supply voltages are utilized. In order to demonstrate the performance of the first proposed circuit, an experimental result is given as an example.
  • Corrigendum to “Modified DVCC based quadrature oscillator and lossless
           grounded inductor simulator using grounded capacitor(s)” [AEU – Int.
           J. Electron. Commun. 76 (2017) 86–96]
    • Abstract: Publication date: Available online 19 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ahmet Abaci, Erkan Yuce
  • InP high electron mobility transistors for submillimetre wave and
           terahertz frequency applications: A review
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): J. Ajayan, D. Nirmal, T. Ravichandran, P. Mohankumar, P. Prajoon, L. Arivazhagan, Chandan Kumar SarkarAbstractThis paper reviews the rapid advancements being made in the development of high electron mobility transistors (HEMTs) on InP substrates for future sub-millimetre wave (30–300 GHz) and terahertz (300 GHz to 3.5 THz) frequency applications. The InP HEMTs exhibits outstanding 2-DEG properties in InAlAs/InGaAs heterostructure. This paper highlights the rapid growths in the developments of enhancement mode (E-Mode) and depletion mode (D-Mode) InP HEMTs over the last 40 years, the use of InP HEMTs for cryogenic applications, reliability issues and kink effects in InP HEMTs in detail and it also highlights the impact of geometrical dimensions and their scaling on the performance of InP HEMTs. Their uniqueness in terms of low noise, low power dissipation, high gain and high frequency of operation has fuelled the incorporation of InP HEMTs in a wide variety of applications such as high speed wireless and optical communication systems, sub-millimetre wave (S-MMW) and THz receivers and transmitters, radio astronomy and radiometry, flight communications and sensing applications, material spectroscopy, active and passive imaging applications, biomedical instrumentation applications and high speed ICs such as low noise amplifiers (LNAs), multiplier chains, switches, multiplexers and flip-flops.
  • Neural network-based path loss model for cellular mobile networks at 800
           and 1800 MHz bands
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Sreevardhan Cheerla, D. Venkata Ratnam, Hima Sree BorraAbstractCellular radio communication systems have become essential for data/voice/video/multimedia applications. The performance of cellular communication radio systems is assessed by considering the design specifications of frequency planning, channel assignment and interference mitigation strategies among others. Frequency planning is the most important component to improve capacity or quality of cellular radio systems. Large-scale path loss values between the base station and mobile stations are the key regulating factors that limit the performance of cellular systems, especially in urban/vegetation region. There is a necessity to develop a suitable path loss prediction model for predicting path loss values based on received signal strength measurements. In this paper, an ANN-based path loss model was used for macro cell measurement data obtained in the Vijayawada urban region, India. The Multi-Layer Perceptron (MLP) neural network model was considered. The prediction results indicate that the ANN model outperformed the Auto Regressive Moving Average (ARMA) and COST-231-WImodels. The outcome of this research work will be immensely useful for improving coverage and ensuring better frequency planning of cellular radio systems.
  • Mobility Aware and Dual Phase AODV Protocol with Adaptive Hello Messages
           over Vehicular Adhoc Networks
    • Abstract: Publication date: Available online 19 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Khalid A. Darabkh, Mohammad S.E. Judeh, Haythem Bany Salameh, Saud AlthunibatAbstractEstablishing stable routes over high mobility networks is a challenging field and consequently brought the attention of a lot of current researchers. In this article, a new reactive routing protocol has been proposed which is considered as a major extension of both Ad-hoc On-demand Distance Vector (AODV) and Mobility and Direction Aware AODV (MDA-AODV) prior routing protocols. It is named as Mobility Aware and Dual Phase Ad-hoc On-demand Distance Vector with Adaptive Hello Messages (MA-DP-AODV-AHM). It primarily concentrates on building routes considering vehicles’ speeds and direction of motion with respect to source vehicles, thereby establishing more stable routes and reducing the route breakages. Not only to this extent, but rather, we proposed an adaptive control packet announcement mechanism, which is directly connected to the periodic hello messages approach, with vehicles’ speeds, yielding a significant reduction in the amount of control overhead and congestion over the network. Moreover, the new protocol is proposed to alternate working among two phases, for the reason of guaranteeing the generation of efficient routes on a timely basis, which include MA-DP-AODV-AHM and AODV protocols. Our protocol has been evaluated in terms of control overhead, end-to-end delay, and energy consumption using QualNet simulator version 7.1 in which enormous simulations have been conducted under the base of vehicle density, packet rate, and constant bit rate connections. Simulation results summarize that MA-DP-AODV-AHM contributes efficiently in mitigating the network instability through generating effective stable routes and reducing link failures. Furthermore, it has proved its superiority over AODV and MDA-AODV.
  • Reconfigurable Filter Bank Structures for Low Complexity Digital
           Channelizer using Fractional Interpolation and MFIR Filters with Cosine
    • Abstract: Publication date: Available online 18 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): A. Amir, J. Pragadeeshwaran, T.S. Bindiya, Elizabeth EliasAbstractA low complexity digital reconfigurable filter bank structure which is suitable for digital channelizers in software defined radio is proposed in this paper. In order to get a sharp transition width with low hardware complexity, multiplicative finite impulse response(MFIR) filter is used as the prototype filter in the proposed structure. A masking stage and a channel generation stage constitute the two stages of the proposed structure. In the masking stage, 5 sub-bands are generated by performing cosine modulation technique on the prototype filter. In the channel generation stage, different channels are generated by doing spectral addition/subtraction operations on the interpolated versions of the MFIR filter. Hence, the basic techniques used in the proposed structure are, cosine modulation and fractional interpolation technique. By adjusting a 3-bit control signal, different regions and channels, generated by the two stages, can be obtained. The proposed structure has a hardware complexity, which is much lesser than that of the state-of-the art techniques used for SDR channelizers. The number of channels generated using the proposed structure is also more. The main advantage of the proposed structure is that the hardware complexity of the proposed structure remains the same even if the number of channels is increased.
  • A Miniaturized Multiband Reconfigurable Fractal Slot Antenna for
           GPS/GNSS/Bluetooth/WiMAX/X-band Applications
    • Abstract: Publication date: Available online 18 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Tanweer Ali, Nikhat Fatima, Rajashekhar C. BiradarAbstractA novel miniaturized multiband reconfigurable fractal slot antenna for switchable GPS/GNSS/Bluetooth/WiMax/X-band is reported. By utilizing a Koch fractal in the radiating part miniaturization of about 78.8% and 86% are achieved in volume and active patch area respectively. Multiband operations at 1.47-1.65 GHz (BW= 11.5%) GPS, 2.2-2.43 GHz (BW= 9.9%) Bluetooth, 3.4-3.89 GHz (BW= 13.4%) middle WiMAX, 5.61-5.84 GHz (BW=4%) upper WiMAX and 9.8-10.73 GHz (BW=9.05%) X-band, are achieved by slotted ground approach in conjunction with Complementary Split Ring Resonator (CSRR). Frequency reconfiguration characteristics in the antenna is accomplished by placing a PIN diode switch in the ground plane; thus making the antenna to exhibit switchable radiations at 1.91-2.34 GHz (BW=20.73%) Bluetooth, 3.72-3.89 GHz (BW=4.46%) middle WiMAX, 4.92-5.33 GHz (BW=8.0%) upper WiMAX and 10.16-10.70 GHz (BW=5.1%) X-band, under “ON” condition. During “OFF” condition, antenna exhibits switchable performances at 1.59-1.84 GHz (BW=14.57%) GPS/GNSS, 3.77-4.12 GHz (BW=8.87%) middle WiMAX, 5.1-5.35 GHz (BW=4.78%) upper WiMAX and 10.27-10.62 GHz (BW=3.35%) X-band. The antenna has a compact area of 35×30mm2, and exhibits acceptable gain, stable radiation patterns and good impedance matching at the targeted frequencies.
  • A Narrow-Frame Antenna for WWAN/LTE/WiMAX/WLAN Mobile Phones
    • Abstract: Publication date: Available online 18 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Zeinab Eskandari, Asghar Keshtkar, Javad Ahmadi-ShokouhAbstractIn this paper, we present a novel narrow-frame antenna with a size of 75×8×5.8 mm3 for 5.7 inch mobile phones. The antenna mainly consists of a monopole with four branches that are coupled to a two-branch grounded strip. Our antenna is able to cover more bands than other narrow-frame antennas by excitation of several resonant modes. The improved range of the antenna covers the following eleven bands: LTE700, GSM850, GSM900, DCS, PCS, UMTS, LTE2300, LTE2500, LTE3400 (3400-3800MHz)/WiMAX3.5 GHz (3400-3650 MHz), WLAN5.2 GHz (5150-5350 MHz) and WLAN5.8 GHz (5725-5875 MHz). Another advantage of the proposed antenna is that it does not need any lumped element to match the antenna. The working principles of the proposed antenna are thoroughly studied. A prototype of the proposed antenna is fabricated and measured, with the results in good agreement with the simulation results.
  • Chirping Techniques for Enhancing the Performance of SOA-based UWB over
           Fiber Systems: An Experimental Demonstration
    • Abstract: Publication date: Available online 17 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Haidar Taki, Stéphane Azou, Ali Hamie, Pascal Morel, Ali Al Housseini, Ali Alaeddine, Ammar SharaihaAbstractA phaser-based processing technique was adopted in an UWB over fiber system employing SOA. The target is to simultaneously reduce the ASE noise impact and nonlinear effects inherent to optical amplification. Experimental results prove the effectiveness of chirping in terms of cross correlation and bit error rate.
  • A hybrid-mode bulk-driven folded cascode OTA with enhanced unity-gain
           bandwidth and slew rate
    • Abstract: Publication date: Available online 17 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Xiao Zhao, Qisheng Zhang, Liyuan Dong, Yongqing WangAbstractA hybrid-mode bulk-driven folded cascode OTA with the enhanced unity-gain bandwidth and slew rate is presented in this paper. To achieve a faster large-signal transient response, a hybrid-mode output stage composed of a traditional folded cascode and an additional current mirror output stage is proposed. The proposed hybrid-mode output stage activates the additional current mirror output stage to produce a large transient charge/discharge current when slewing happens, overcoming the issue of limitation of folded current source in traditional folded cascode structure. By the combination of super bulk-driven input stage and proposed hybrid-mode output stage, not only does the bulk-driven folded cascode OTA achieve a large unity-gain bandwidth and high dc gain, but also the large-signal transient response is significantly improved. Designed under SMIC 0.18μm process, simulation results demonstrate that the proposed bulk-driven OTA achieves 2 times the unity-gain bandwidth and 12 times the slew rate of conventional counterpart at the same power dissipation.
  • On Topology Modifications for Wideband Antenna Miniaturization
    • Abstract: Publication date: Available online 17 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Muhammad Aziz Ul Haq, Slawomir KozielAbstractIntroducing various topological modifications is a common practice in the design of miniaturized wideband antennas. Some examples of successful alterations include ground plane stubs or slits below the feed line. In general, novel antenna topologies are reported on the case-to-case basis, often in the form of geometry evolution supported by parameter sweeps, supposedly demonstrating the benefits of the particular changes made to the device. The fundamental problem of such approaches is that neither the reference nor the modified structures are properly optimized. Due to complex interactions between geometry parameters and electrical/field properties of the antenna, the actual suitability of specific topology modifications is therefore unclear or even may lead to performance degradation. In order to illustrate this point, three antenna structures selected from the available literature are considered with geometry parameters rigorously optimized in order to find the minimum-size designs, with and without particular topology changes introduced by the authors of the respective papers. The results indicate that the optimization process virtually removes the said modifications and the optimized antenna footprints are smaller without these. The major message of the work is that conclusive assessment of the suitability of any geometry changes requires proper optimization of all relevant antenna parameters. Numerical results presented in the paper are validated experimentally.
  • 45°–45°–90° Triangular dielectric resonator antenna with broadside
           radiation patterns
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Sudipta Maity, Malay Gangopadhyaya, Bhaskar GuptaAbstractTheoretical and experimental investigations on isosceles 45°–45°–90° Triangular Dielectric Resonator Antenna (TDRA) is presented here for TMmnpz modes. Approximate expression is given here to predict the resonant frequency for different TMmnpz modes with an accuracy of 2.3%. It is found that isosceles 45°–45°–90° TDRA radiates in the broadside direction at fundamental TM101z mode. One prototype is also fabricated to validate our theory. It is also found that the fundamental TM101z mode produces slanted polarization. The study of 45°–45°–90° TDRA is important as it just takes approximately half volume compared to square Dielectric Resonator Antenna (DRA) for a given resonant frequency. Our theory can easily be extended to design filter, oscillator etc.
  • SIW cavity-backed circularly polarized square ring slot antenna with wide
           axial-ratio bandwidth
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Arvind Kumar, Divya Chaturvedi, Singaravelu RaghavanAbstractIn the proposed work, Substrate Integrated Waveguide (SIW) cavity-backed circularly polarized slot antenna for wideband operation is proposed. A square-ring-slot is etched on the top of the SIW cavity, used for radiation To generate the circularly polarized (CP) wave, the slot is placed slightly offset from the centroid of the cavity. By finely optimizing the antenna dimensions, it exhibits a wide axial-ratio (AR) bandwidth of 789 MHz (7.1%) ranging from 10.64 to 11.45 GHz. Moreover, the radiating slot is excited by an SIW based feed by an inductive window, which lead to a wide impedance matching over 1.74 GHz ranging from 9.92 to 11.67 GHz. Due to the SIW cavity-backing structure, the antenna offers unidirectional radiation patterns while maintaining a low-profile and planar compatibility. To validate the proposed design, the antenna is fabricated and experimentally tested in terms of reflection coefficients, AR, gain, and radiation patterns. The simulated and measured results reveal good mutual agreement. Moreover, the proposed antenna is very useful for wideband applications operating in X-band (8–12 GHz)
  • A fully-integrated 16-channel EEG readout front-end for neural recording
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Mahshid Nasserian, Ali Peiravi, Farshad MoradiAbstractIn this paper, a power-efficient, low noise analog front-end (AFE) is presented which employs the chopper-stabilized technique. A new instrumentation amplifier structure leads to a high input impedance beyond 10 GΩ at the frequency of 10 Hz. Furthermore, an adaptive DC servo loop (DSL) is proposed which is conditionally activated to minimize the negative impact of this block on the noise performance of the AFE. The integrated input-referred noise of the amplifier is 1.33 µVrms and 1.19 µVrms over the 0.5 Hz–100 Hz frequency range when the DSL is enabled or disabled, respectively. Also, considering different aspects of the AFE, a new comprehensive figure of merit (FOM) is introduced to compare different state-of-the-art biopotential amplifiers. The power consumption and bandwidth of the designed 16-channel AFE are 15.81 µW and 235 Hz, respectively. The circuit is realized in the 180 nm standard complementary metal–oxide–semiconductor technology using a 1 V power supply.
  • A novel real-time Fourier and inverse Fourier transforming system based on
           non-uniform coupled-line phaser
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Li Ma, Yongle Wu, Zheng Zhuang, Yuanan LiuAbstractA novel real-time Fourier and inverse Fourier transforming (RTFaIFT) system realizing both positive and inverse transformations is designed and verified, using non-uniform coupled-line phaser. Two kinds of Fourier transformations are integrated within one system for the first time. This system can map the spectrum of the input signal into a waveform in time domain whose amplitude mimics the spectrum magnitude, owing to the frequency-varying group delay (GD) response of the phaser. Furthermore, the correspondence between the output waveform and the spectrum of the input signal is given for accurate analysis of the spectrum. This configuration possesses the characteristic of compact structure, simple design procedure, and perfect performance, consisting of a mixer, a phaser with linear group delay, a diode, and a LPF. For experimental demonstration, a RTFaIFT system operating at 6 GHz is designed and fabricated, the bandwidth of which is 4 GHz with −0.5 ns/GHz GD slope. Both single- and double-pulse signals have been chosen as the test signals to verify the performance of the RTFaIFT system, respectively. The experimental results agree well with simulation and theoretical results.
  • Cascadable current mode instrumentation amplifier
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Deepak Agrawal, Sudhanshu MaheshwariAbstractIn this paper, a Current Mode Instrumentation Amplifier (CMIA) is presented. The proposed circuit employs two Extra X Current Controlled Current Conveyors (EX-CCCII) and a single grounded resistor. The circuit offers a wide differential-gain bandwidth, wide CMRR bandwidth, and electronically tunable differential gain. The circuit offers cascadibility feature with input impedance of 2.167 kΩ which is very small in comparison to the output impedance of 2.17 MΩ. Simultaneously, a Transresistance (TR) instrumentation amplifier is also obtained with the features of electronically tunable high differential gain and wide bandwidth. The effect of non-idealities of EX-CCCII on the circuit performance is also analysed. The validity of the proposed circuit is verified through PSPICE simulations using 0.25 µm parameters with a supply voltage of ±1.25 V. Also, the circuit is verified by experimental results.
  • Reduction of the effects of dielectric coating with the extended ground on
           a small slot leaky wave waveguide antenna
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Hadi Faezi, Farokh Hodjat Kashani, Majid TayaraniAbstractThe effects of a Teflon dielectric coating with the extended ground on the radiation characteristics of a small uniform longitudinal slot leaky wave waveguide antenna is investigated. Unwanted ripples, which are generated due to the surface wave excitation inside the dielectric and diffraction from the dielectric edges, are observed in the E-plane pattern. It is shown that the amplitude of the surface wave can be reduced by using conductor posts around the slot before reaching the dielectric edge. These posts help us eliminating the ripples from the E-plane pattern. Simulated and measured results for the antenna are presented and discussed.
  • Compact, high selectivity and wideband bandpass filter with multiple
           transmission zeros
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Kanaparthi V. Phani Kumar, S.S. KarthikeyanAbstractThis paper presents the design of a compact, high selectivity and wideband bandpass filter based on signal interference technique. The proposed filter consists of open coupled line and stepped impedance modified Π-type (SMΠ) transmission line with short circuited stubs in transmission path 1 and path 2, respectively. Due to the superposition of signals of the two transmission paths, a fourth-order wideband bandpass filter with six transmission zeros can be obtained from 0 to 2f0 (f0 is the operating frequency). A bandpass filter prototype centring at 0.9 GHz, with 3 dB fractional bandwidth of 50% is designed, fabricated and tested. Good agreement is found between the simulated and experimental results.
  • Quadrature oscillator and universal filter based on translinear current
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Montree Kumngern, Eakluck Wareechol, Pattarapong PhasukkitAbstractThis paper presents quadrature oscillator and universal filter based on translinear current conveyors. The proposed circuit can realize as a quadrature oscillator or a universal filter without changing the circuit topology. When it works as a quadrature oscillator, four quadrature current outputs and two quadrature voltage outputs can be obtained. The condition and frequency of oscillation of oscillator can be controlled orthogonally and electronically. When it works as a universal filter, low-pass, band-pass, high-stop, band-stop, and all-pass filtering functions can be obtained simultaneously. The natural frequency and quality factor of filters can be controlled orthogonally and electronically. The proposed topology is simulated using PSPICE simulators and experimental results are also used to confirm workability of new circuit.
  • A hyperchaotic memristor oscillator with fuzzy based chaos control and LQR
           based chaos synchronization
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Karthikeyan Rajagopal, Hadi Jahanshahi, Metin Varan, Ihsan Bayır, Viet-Thanh Pham, Sajad Jafari, Anitha KarthikeyanAbstractChaotic and hyperchaotic systems with interesting behaviors have been of interest in the recent years. In this paper we introduce a hyperchaotic memristor oscillator which shows both stable and unstable fixed points. Such systems have been less investigated in the literatures. It should also to be noted that the proposed hyperchaotic system has only one nonlinearity which is a flux controlled memristor. Depending on the control parameter, the system displays different behaviors and coexisting attractors. A linear quadratic regulator based synchronization of the proposed hyperchaotic system is designed and numerically analyzed. We also design such a fuzzy based PID controller for chaos control in such a memristor oscillator.
  • Hexagonal ring fractal antenna with dumb bell shaped defected ground
           structure for multiband wireless applications
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Robert Mark, Nipun Mishra, Kaushik Mandal, Partha Pratim Sarkar, Soma DasAbstractA compact hexagonal nested loop antenna with hexagon dumb bell shaped defected ground structure is proposed for quad band wireless application. Effects of fractal iterations and position of dumbbell defect on ground plane are optimized for wideband characteristics and better performance of the antenna. An equivalent circuit of the proposed antenna and defected ground structure (DGS) is modelled and the same is verified using ADS. Reflection coefficient and radiation properties further confirm the performance of the proposed design for wireless applications. The proposed design is fabricated on FR4 substrate with an overall dimension of 40 × 32 × 1.6 mm3. Simulated results are validated by proper measurement and are in good agreement with experimental results.
  • A compact quasi-self-complementary dual band notched UWB MIMO antenna with
           enhanced isolation using Hilbert fractal slot
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Abhik Gorai, Anwesha Dasgupta, Rowdra GhatakAbstractA compact ultrawideband multiple input multiple output antenna with dual band notch characteristics is proposed. The design utilizes the property of quasi-self-complementary monopoles to achieve a bandwidth that ranges from 2.2 GHz to 11 GHz. The design has a compact size of 30 mm × 41 mm × 1.59 mm. Two quasi-self complementary half circular monopoles are symmetrically arranged to obtain MIMO antenna. Bandnotch characteristics are obtained by adding parasitic strips of Levy's Fractal shape near the feed line. A Hilbert Fractal shaped slot is etched in the ground plane to enhance the isolation ( S21  
  • Third-order RLCM-four-elements-based chaotic circuit and its coexisting
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Bocheng Bao, Li Xu, Ning Wang, Han Bao, Quan Xu, Mo ChenAbstractThis paper presents a new third-order RLCM-four-elements-based chaotic circuit, in which the memristor element is equivalently implemented by a diode-bridge cascaded with an inductor. Mathematical model is established and its equilibrium stability is analyzed. The dynamical properties of the memristive chaotic circuit are disposed by MATLAB numerical simulations and confirmed by breadboard experimental measurements. In particular, the antimonotonicity phenomena of coexisting periodic and chaotic bubbles are observed under some specified control system parameters and the evolutions of coexisting bubbles are exhibited with the variations of two control system parameters. The presented memristive chaotic circuit is very simple and only third-order but can emerge complex dynamics with chaos, period, coexisting bifurcation modes, and coexisting bubbles.
  • Analytical modeling of InSb/AlInSb heterostructure dual gate high electron
           mobility transistors
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): T. Venish Kumar, N.B. BalamuruganAbstractThis paper presents an approximate solution of a 2D Poisson’s equation within the channel region for Double-Gate AlInSb/InSb High Electron Mobility Transistors (DGHEMTs), using variable separation technique. The proposed model is used to obtain the surface potential, electric field, threshold voltage and drain current of both tied and separated gate bias conditions for Double-Gate AlInSb/InSb HEMTs. The surface potential and electric field are derived for both effective conduction paths of front and back heterointerface by a simple analytical expression and an analytical solution is verified with sentarus TCAD device simulator.
  • Microstrip antenna with aperture reflector and C-shaped dipoles for LTE
           and wireless communications
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): MirHamed Rezvani, Pejman MohammadiAbstractA dual-band microstrip patch antenna with copper reflector plate, and high gain for LTE and wireless communications applications is presented. The proposed antenna consists of an FR4 substrate which is kept by Teflon spacers at a specified distance from the reflector plate. The bottom layer of substrate includes two identical C-shaped dipoles, and the top layer contains irregular microstrip lines which are excited using a coaxial cable. This antenna operates in two frequency bands of 1.5–2.8 GHz and 5–5.9 GHz with gains of ∼5.5 dBi and ∼5.7 dBi, respectively. Also, it has a unidirectional radiation pattern, wide HPBW, and F/B ratio of over 12.5 dB in both frequency bands.
  • GCRP: Grid-cycle routing protocol for wireless sensor network with mobile
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Ayush Agrawal, Vinay Singh, Shubhra Jain, Rajeev Kumar GuptaAbstractEnergy conservation is a critical issue in resource constraint wireless sensor networks. Employing mobile sink to deliver the sensed data becomes pervasive approach to conserve sensors’ limited energy. However, mobile sink makes data delivery a hard nut to crack since nodes need to know its latest location. Providing sink’s latest location by traditional flooding, erode the energy conservation goal. In this paper, we propose a Grid-Cycle Routing Protocol (GCRP) with the aim of minimizing the overhead of updating the mobile sink’s latest location. In GCRP, sensor field is partitioned into grid of cells and for each cell a grid cell head (GCH) is elected. Cycles of four GCHs is formed. Cycle(s) involving border GCHs is called exterior cycle and said to belong to a region. Another cycle involving non-boundary GCHs is called interior cycle, connecting GCHs of different regions. When sink stays at one location, it updates the nearest GCH, which in turn updates the other GCHs through exterior and interior cycle. Moreover, we propose a set of sharing rules that govern GCHs when and with who share sink’s latest location information. The performance of GCRP is evaluated at different number of nodes and compared with existing work using NS-2.31.
  • A MC-CDMA system based on orthogonal filter banks of wavelet transforms
           and partial combining
    • Abstract: Publication date: September 2018Source: AEU - International Journal of Electronics and Communications, Volume 94Author(s): Damoon Shahbaztabar, Shahpour Alirezaee, Majid Ahmadi, Ramiyar HeydariAbstractMulti Carrier Code Division Multiple Access (MC-CDMA) is an appropriate modulation technique for high data rates. In this modulation scheme, employing of combining techniques are unavoidable for restoring orthogonality between different user signals. In this paper, the combining techniques of a MC-CDMA based on wavelet transform are studied. The partial combining of the wavelet based MC-CDMA system is suggested and its performance is compared with the maximum ratio combining (MRC), equal gain combining (EGC), orthogonality restoring combining (ORC) and the minimum mean square error (MMSE) techniques. Orthogonal filter banks of the wavelet transforms provide orthogonality between the wavelets and scaling functions, subcarriers and spreading sequences. Therefore, they provide new dimensions in combatting multipath fading, inter carrier interference (ICI) and narrowband interference in MC-CDMA systems. Furthermore, analysis of partial combining shows that coefficients of this technique can be computed in a simple manner. Simulations results indicate that the bit error rate (BER) performance of the proposed scheme is almost comparable with the MMSE combining scheme and the proposed system has a proper performance in terms of BER versus the signal to noise ratio (SNR) in frequency selective fading channels.
  • Performance analysis of Wi-Fi shaped SIW Antennas
    • Abstract: Publication date: Available online 10 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rajat Arora, Shashi B. Rana, Sandeep AryaAbstractIn this paper, two different Wi-Fi shaped Substrate Integrated Waveguide (SIW) antennas are designed and fabricated. Both antennas were designed to operate at 7 GHz frequency or in centimeter-wavelength range. The essential parameters and dimensions of the proposed designs were estimated theoretically via mathematical calculations. Both the antennas were then simulated by using CST Studio suite finite element method based simulation software and have been optimized to operate within the Wi-Fi, Bluetooth and Wi-Max frequency bands respectively. In fabrication process, Wi-Fi shaped antennas were designed by taking dimensions of patch as 35 (L) mm × 26 (W) mm × 0.035 (h) mm on Roger RT Duroid 5880 substrate. The copper metal of thickness 8270 μm with loss tangent is 0.0009 is deposited with dielectric constant 2.20 on the substrate. Then microdrill is used to obtained vias or holes on the substrate. Experimental results related to antenna parameters highlighted in the paper further shows that fabricated SIW antennas are in good agreement with the predicted values calculated by the simulated model. Based on the experimental prototypes modeling, a thorough comparative analysis between the two different Wi-Fi shaped SIW antennas is investigated for different parameters like gain, bandwidth, reflection coefficient (S11) and radiation pattern & hence highlighted in the paper. The results of double Wi-Fi shaped antenna reveal better performance than the single Wi-Fi shaped antenna.
  • Chaos Synchronization Using Higher-order Adaptive PID Controller with
           Application to Secure Communication
    • Abstract: Publication date: Available online 10 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Majid Moradi Zirkohi, Saeed khorashadizadehAbstractThis paper is devoted to designing higher-order adaptive PID controllers as a new generation of PID controllers for chaos synchronization, in which second order integration and second-order derivative terms to the PID controller (PII2DD2) are employed. The five PII2DD2 control gains are updated online with a stable adaptation law driven by Lyapunov’s stability theory. This is the unique advantage of the proposed approach. Furthermore, it is equipped with a novel robust control term to improve controller robustness against system uncertainties and unknown disturbances. An important feature of the proposed approach is that it is a model-free controller. In addition, to determine the control design parameters and avoid trial and error, the Teaching–learning-based optimization algorithm (TLBO) is employed to regulate these parameters and enhance the performance of the proposed controller. Based on the Lyapunov stability theory, it is proven that the proposed control scheme can guarantee the synchronization and the stability of closed-loop control system. The case study is the Duffing–Holmes oscillator. Comparative simulation results are presented which confirm the superiority of the proposed approach.
  • A comprehensive Auxiliary Functions of Generalized Scattering Matrix
           (AFGSM) method to determine bandgap characteristics of periodic structures
    • Abstract: Publication date: Available online 10 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Agah Oktay Ertay, Serkan ŞimşekAbstractA comprehensive Auxiliary Functions of Generalized Scattering Matrix (AFGSM) method is presented on the bandgap analysis of periodic structures encountered in many engineering applications. Proposed method accurately determines the bandgaps of periodic structures with symmetric and asymmetric unit cells. In order to test the feasibility of the proposed method, numerical results are compared with Eigenvalue method (EIV) and HFSS/CST frequency domain simulations. The validity and applicability of the presented method are demonstrated by analysing the bandgap characteristics of periodically dielectric loaded rectangular waveguides, photonic crystals, helix Slow Wave Structures (SWSs) of Traveling Wave Tubes (TWTs) and excellent agreements on the simulation results are obtained. Bandgap analysis and design of different periodic structure problems can be effectively achieved using the proposed AFGSM method.
  • Blind Time-Domain Equalizer for Doubly-Selective Channel with Reduced Time
           Averaging and Computational Complexity
    • Abstract: Publication date: Available online 6 July 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Vanita Pawar, R. Pawar, Krishna NaikAbstractThis study presents a blind time-domain equalizer for a CP-free multiuser /MIMO-OFDM system over a doubly selective fast-fading channel, which enables a pertinent trade-off in error performance and complexity. A high-velocity outdoor system is considered, such as a vehicular user in which the channel varies too rapidly to be tracked. The proposed method applies the computationally efficient modified recursive Cholesky (RChol) algorithm incorporating a linear predictor and the LMMSE criteria, which scales down the correlation matrix time averaging and hence results in a significantly computationally efficient algorithm for the multiuser/MIMO-OFDM time-domain equalizer. The method reduces the effect of any perturbation introduced by the linear prediction, noise, and multipath. The performance of the proposed method is analyzed and compared with those of the existing pilot-based, semi-blind, and blind methods. The results show that the proposed RChol algorithm is computationally efficient compared with the existing subspace-based and linear prediction-based methods.
  • Electromechanical Beamsteering Reflectarray Antenna for X-band
    • Abstract: Publication date: Available online 21 June 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Aghil Derakhshan, Javad Nourinia, Changiz GhobadiAbstractAn electromechanical beamsteering reflectarray antenna for x-band applications was designed, fabricated, and tested. Circular aperture of antenna consists of 316 elements and each element of the array is comprised of two stacked PCBs. The upper PCB consists of a rectangular patch coupled to a pair of rectangular slots in the bottom layer and the lower PCB has a jagged slot on the top and perfect GND at the bottom. The phase shift coverage required for scanning the beam of the antenna was provided by moving and sliding the lower PCB under the fixed top one. The antenna was designed to scan the main beam about ±40° from boresight in E-plane of the antenna. This concept was demonstrated by fabricating and testing a prototype of the proposed antenna. The maximum measured gain of 23 dB with an aperture efficiency of 23.2% was obtained at center frequency of 10 GHz. The measured radiation patterns of the antenna were well matched to simulation results.
  • An Improved Channel Estimation Method Based on the Correlation of
           Preambles in FBMC/OQAM Systems
    • Abstract: Publication date: Available online 18 June 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Yi Yang, Zhinian Luo, Zhu Xiao, Jinding GaoAbstractFilter bank multicarrier transmission with offset QAM (FBMC/OQAM) is recognized as one of candidates for the next generation of multi-carrier modulation scheme due to its high spectral efficiency and extremely low out-of-band attenuation. However, channel estimation (CE) performance may be seriously deteriorated by the intrinsic interference in practice. Because the correlations of preambles at the receiver may not be taken into account for traditional methods, which are recognized as inter-symbol interference. This paper proposes an improved preamble-based CE method, which has lower preamble power and higher time efficiency, and a CE algorithm using correlation between adjacent subcarriers is introduced to improve performances further. Finally, the CE algorithm with correlations between adjacent K subcarriers is deduced. Simulation results show that the proposed scheme has lower BER and preamble power, compared to the traditional methods.
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