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  Subjects -> COMPUTER SCIENCE (Total: 2092 journals)
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COMPUTER SCIENCE (1215 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 21)
Abakós     Open Access   (Followers: 4)
ACM Computing Surveys     Hybrid Journal   (Followers: 28)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 8)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 15)
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: 9)
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: 6)
ACM Transactions on Economics and Computation     Hybrid Journal   (Followers: 1)
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: 32)
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: 4)
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: 55)
Advances in Engineering Software     Hybrid Journal   (Followers: 28)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 14)
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: 49)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access   (Followers: 6)
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  
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: 6)
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: 13)
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: 8)
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: 13)
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: 145)
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: 5)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 13)
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: 307)
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: 49)
British Journal of Educational Technology     Hybrid Journal   (Followers: 147)
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: 15)
ChemSusChem     Hybrid Journal   (Followers: 7)
China Communications     Full-text available via subscription   (Followers: 8)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Hybrid Journal   (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: 2)
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: 23)
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: 3)
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: 17)
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: 8)
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: 98)
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: 24)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 12)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 2)
Computer Music Journal     Hybrid Journal   (Followers: 20)

        1 2 3 4 5 6 7 | 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  [3162 journals]
  • Dual Stop Band Frequency Selective Surface for C and WLAN Band
           Applications
    • Abstract: Publication date: Available online 15 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Payal Jindal, Ajay Yadav, Sudhir Kumar Sharma A miniaturized unit cell design of Frequency Selective Surface (FSS) to produce stop band characteristics for two bands is presented. The presented unit cell structure is showing the band filtering characteristics for dual frequency band specifically C-band for satellite communication and Wireless Local Area Network (WLAN). The designed FSS structure is comprised of I shaped and modified I shaped metallic strips. The distinct unit cells of suggested are investigated for band filtering characteristics and finally integrated on a single unit cell for dual-band filtering applications. The I shaped and modified I shaped unit cell is producing band filtering properties at center frequencies like 4 GHz and 5.5 GHz respectively. The presented FSS design is modeled on an FR-4 substrate with dielectric constant of 4.4 and the dimension of the unit cell is 10x10x1.6 mm3. The fabricated FSS structure is simulated and measured for its characteristics verification like S11 and S21 and it has been found a satisfactory agreement in simulated and measured results.
       
  • Bayesian Compressive Sensing Using Reweighted Laplace Priors
    • Abstract: Publication date: Available online 13 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Tao Jiang, XiaoWei Zhang, Yingsong Li Bayesian compressive sensing (BCS) plays an important role in signal processing for dealing with sparse representation related problems. BCS utilizes a Bayesian model to solve the compressing sensing (CS) problem, such as signal sampling processing and model parameters using the hierarchical Bayesian framework. The use of Gaussian and Laplace distribution priors on the basic coefficients has already been demonstrated in previous works. However, the two existing priors cannot more effectively encode sparsity representation for unknown signals. In this paper, a reweighted Laplace distribution prior is proposed for hierarchical Bayesian to fully exploit the sparsity of unknown signals. The proposed algorithm can automatically estimate all the coefficients of unknown signal, and the expected model parameters are solely gotten from observation by developing a fast greedy algorithm to solve the Bayesian maximum posterior and type-II maximum likelihood. Theoretical analysis on the sparsity of the proposed model is analyzed and compared with the Laplace priors model. Moreover, numerical experiments are conducted to prove that the proposed algorithm can achieve superior performance for reconstructing unknown sparse signal with low computational burden as well as high accuracy.
       
  • Fractional Order Integrator/Differentiator: FPGA implementation and FOPID
           Controller Application
    • Abstract: Publication date: Available online 13 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohammed F. Tolba, BahaaAlDeen M. AboAlNaga, Lobna A. Said, Ahmed H. Madian, Ahmed G. Radwan This paper introduces two FPGA based design approaches of the fractional order integrator and differentiator using Grünwald Letnikov (GL) definition where fixed window and linear approximation approaches are considered. The main advantage of the linear approximation method is that it reduces the huge memory of the fractional order systems. One of the top applications of fractional calculus is the fractional order Proportional Integral Derivative (FOPID) controller. It has gained a great attention in academic studies and in industrial applications. The proposed approaches have been used as building blocks to implement FOPID controller. Oscilloscope experimental results for several cases are presented for GL and the fractional order PID controller. The proposed designs have been implemented based on Verilog Hardware Description Language (HDL) and realized on Nexys 4 Artix-7 FPGA XC7A100T. Moreover, a comparison between the proposed FPGA Implementation results for the GL operator and previous work has been investigated.
       
  • A New Approach for 1-D and 2-D DWT Architectures using LUT based Lifting
           and Flipping Cell
    • Abstract: Publication date: Available online 12 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ganapathi Hegde, Kotha Srinivasa Reddy, Telugu Kuppu Shetty Ramesh In this paper, area and power efficient lifting and flipping discrete wavelet transform (DWT) architectures are proposed. DWT architectural metrics such as critical path delay, area of utilization, power consumption are mainly dependent on the arithmetic components such as adders and multipliers. They constitute the data-path of the DWT structure. A multiplier of the DWT data-path plays major role in basic lifting, flipping cells and further it demands optimization. In this work, an area and power efficient lifting and flipping cells are implemented using look up table (LUT) based multipliers. The proposed DWT architectures are implemented in gate level Verilog HDL and are synthesized using Cadence RC design compiler. Based on the area, delay, and power results obtained from post synthesis, parameters like area delay product (ADP) and power delay product (PDP) are computed. The ADP and PDP values prove that the proposed LUT based architectures are efficient over recently projected lifting and flipping DWT architectures.
       
  • Novel Algorithm for Designing Reflect-Array Antennas Based on Analytical
           Methods
    • Abstract: Publication date: Available online 12 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): H. Nasrollahi, M. Fallah, Amir.H Nazeri, A. Abdolali this paper presents a comprehensive and accurate algorithm based on circuit model to design reflect-array antennas (RAAs). The proposed algorithm can extract geometry of RAA structure corresponding to radiation parameters without employing any approximation or optimization intervention into the algorithm. Simulation results for some comprehensive examples, verify the validity of the proposed algorithm. This method is simple, fast, accurate, and can be expanded to all species of RAAs with arbitrary geometries. One of the main problems confronted in RAAs is low bandwidth characteristics. To attain wide bandwidth, we exploited the proposed algorithm with combination of multi-layer design of RAAs and subwavelength element. Convergence is observed between simulation and fabrication results, asserting good accuracy in method. In 10–15 GHz band, the maximum gain and -1dB bandwidth of two-layer antenna is 31.4 dB and 18.5%, respectively.
       
  • A Novel Robust Filtering Strategy for Systems with Non-Gaussian Noises
    • Abstract: Publication date: Available online 11 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Hongping Zhou, Lin Xu, Wenliang Chen, Kai Guo, Fei Shen, Zhongyi Guo For estimating the states of moving targets in the nonlinear system with non-Gaussian noise, the combination of Gaussian Sum Filter (GSF) and other nonlinear filters has been chosen as the filtering algorithm conventionally. The Smooth Variable Structure Filter (SVSF) is a new predictor-corrector method used for state and parameter estimation, which has good stability and robustness. In this paper we propose a new strategy called the modified GS-EKF-SVSF, which inherits good robustness of Gaussian Sum and Smooth Variable Structure Filter (GS-SVSF) and high accuracy of Gaussian Sum and Extended Kalman Filter (GS-EKF). A nonlinear system with non-Gaussian noise for target tracking is used to test the proposed new strategy. The simulation results demonstrate that our proposed strategy has higher accuracy and better robustness when there are modelling uncertainties existing in the system.
       
  • A 28 GHz Four-Channel Phased-Array Transceiver in 65-nm CMOS Technology
           for 5G Applications
    • Abstract: Publication date: Available online 11 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Hesham A. Ameen, Kareem Abdelmonem, Mohamed A. Elgamal, Mohamed A. Mousa, Omaira Hamada, Yahia Zakaria, Mohamed A.Y. Abdalla A 28GHz fully integrated 4-channel TX/RX 5G beam-forming transceiver is implemented in 65-nm CMOS technology. Each TX/RX channel can be digitally controlled with 5.625° phase step and 2 dB gain step. The transceiver employs a heterodyne architecture with 6 GHz intermediate frequency (IF). The transciever works in a band of frequencies between 26GHz and 30GHz. The up/down-conversion mixers are integrated on the same chip with a shared LO chain. The phased-array power combining/splitting is done using a Wilkinson power combiner/divider. Each channel features 3.4 to 3.9 dB NF and -5 to -3.5 dBm IIP3 in RX mode, high OP1dB of 14.7 dBm and 18 dB gain in TX mode. The maximum rms amplitude and phase error for each channel is 0.25 dB and 1.5° across gain and phase states, respectively. The RFIC area is 5.29x3.4 mm2 including pads and it consumes 240 mW per channel in TX mode, 120 mW per channel in RX mode and 174 mW for the LO chain with a total power of 1.58 W from a 1.2 V supply.
       
  • Monostatic Multi-Source Direction Finding Based on I/Q Radio Frequency
           Data
    • Abstract: Publication date: Available online 10 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Zhenjia Chen, Yonghui Zhang At present, many researchers study methods for estimating signal sources through direction finding. The use of phase interferometry for directional applications is common. This method measures the phase through the phase-locked loop module, and the detection bandwidth is limited. We propose to extract the phase information of signals from the I/Q data by electromagnetic measurement. In this paper, One-dimensional phase interferometer is expanded to two-dimensional antenna array. Use the equilateral triangle antenna array to increase the spatial dimension of the direction finding antenna array, and to avoid the phase ambiguity. Through the calculation of associated phase difference to achieve all-directional angle detection. The angle incidence of multi-signal estimation method in single station is proposed in this work. The estimated phase difference is converted into the calculated the duty cycle of the phase waveform. The experiment result show that the method based on the I/Q data can quickly achieve multi-signal source direction finding.
       
  • A Compact Meta-atom Loaded Asymmetric Coplanar Strip-Fed Monopole Antenna
           for Multiband operation
    • Abstract: Publication date: Available online 10 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rajeshkumar Venkatesan, Rajkumar Rengasamy, Praveen Vummadisetty. Naidu, Arvind Kumar In this paper, a compact asymmetric coplanar strip (ACS)-fed monopole antenna is presented. The proposed antenna consists of a tapered shaped radiating element and a meta-atom (complementary split ring resonator-CSRR), loaded in the ground plane which helps in obtaining multiband characteristics with proper impedance matching performance. Antenna with dimensions of 25 × 12.2 × 1.6 mm3 has been designed, fabricated and tested. The experimental result that exhibits of -10 dB impedance bandwidth by the proposed antenna at the center frequency of 2.88 GHz (1100 MHz), 5.78 GHz (1940 MHz) and 7.64 GHz (660 MHz). It covers wireless applications namely wireless local area network (WLAN) 2.4/5.2/5.8 GHz, long-term evolution (LTE) 2500 GHz, public safety applications 4.9 GHz, worldwide interoperability for microwave access (WiMAX) 5.5 GHz, wireless access for vehicular environments (WAVE) 5.9 GHz and X-band downlink frequency band 7.5 GHz. The antenna has good radiation characteristics in both E-plane and H-plane for all the operating frequencies. The proposed antenna exhibits a better performance compared to the previously reported designs to the existing antenna designs which are discussed in the literature. Moreover, the antenna possesses compact size, the total size occupied by the design is 0.20λ0 × 0.1λ0.
       
  • On The Outage Probability of Large Scale Decode-And-Forward Relay Wireless
           Networks
    • Abstract: Publication date: Available online 9 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Yamen Alsaba, Sharul Kamal Abdul Rahim, Chee Yen Leow, Mohammed Bahjat Majed This paper considers a wireless network consisting of large number of clusters, wherein each cluster represents a decode-and-forward (DF) relay network. Two main scenarios according to the distances among the nodes in the network are investigated. In the case of deterministic distances, the outage probability is obtained in a closed-form expression. Whereas for the case when these distances are independent random variables, the framework of Stochastic Geometry (SG) is exploited for deriving the closed-form of the outage probability in case of Rayleigh fading channel. Furthermore, a lower and upper bound for the outage probability in case of general fading channel have been also provided. Numerical simulations are carried out to validate the derived analytical expressions, and to illustrate how the obtained results can be utilized in interference management of such networks.
       
  • Design and Analysis of a Super Compact Wide-Band Bandpass Filter Based on
           Metamaterial Resonators
    • Abstract: Publication date: Available online 9 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mahdieh Gholami Mayani, Shahrooz Asadi, Abbas Pirhadi, Sina Mortezazadeh Mahani In this paper, a novel compact wide-band bandpass filter (BPF) with a wide frequency range is presented. This filter consisting of a multi-mode resonator (MMR) and four metamaterial unit-cells benefits from a very compact size. Unit-cells based on a complementary spiral resonator (CSR) including a metallic via, improve both upper and lower stopband rejection and compensate the insertion loss (I.L) within the passband altogether. This wide-band filter presents a 3-dB bandwidth of 7.7 GHz, ranging from 3 GHz to 10.7 GHz and the Insertion loss is less than 0.7 dB over the passband. The measured results are in good agreement with both the full-wave electromagnetic simulation and the proposed circuit model results. The dimension of the fabricated filter is 0.128 λ × 0.1λ (i.e., 5.6 × 4.4 mm2). This filter is considerably compact compared to the other wide-band bandpass filters with the same substrate.
       
  • Fully-Differential Current-Mode Higher Order Filters Using All Grounded
           Passive Elements
    • Abstract: Publication date: Available online 9 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Alok Kumar Singh, Pragati Kumar, Raj Senani In this paper the realization of nth order (n≥3) fully-differential current-mode filters using Current Differencing Current Conveyors (CDCC) has been presented which results in circuits employing all grounded passive elements. In contrast to earlier known realizations of fully-differential filters which invariably require more than one capacitors per pole, the proposed realization employs only one capacitor per pole. The cut-off frequency of the realized filter can be electronically tuned when all the grounded resistors associated with the integrators are implemented by identical CMOS grounded voltage-controlled-resistors (VCR) driven by a common control voltage. The methodology has been illustrated by realizing a fifth order Butterworth filter as a specific example whose workability has been verified using SPICE simulations in 0.18 µm TSMC technology. A reduced-component-version of the designed fifth order Butterworth filter has also been presented which also employs all grounded RC components but does not have electronic-tunability. Some representative simulation results have been included.
       
  • Integrated Circuit Technology Characterization and Evaluation Using
           Automated CAD Tool
    • Abstract: Publication date: Available online 7 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Omar Elgabry, Faisal Hussein, Ahmed N. Mohieldin In this paper an automated CAD tool that can be used in integrated circuit technology characterization is proposed. The proposed methodology fills the gap found in old, as well as, new IC design methodologies. The tool allows the user to perform a rapid and full characterization for different device models available in a process design kit (PDK) . A set of pre-defined suite of test-benches are created to cover different aspects of circuit design. A seamless integration of the tool in typical design environments is achieved using SKILL code and OCEAN script. Moreover, the tool can compare different PDK releases or different technologies in terms of DC/AC performance, high frequency operation, leakage, and layout area efficiency. The paper presents the tool structure, interface, and capabilities. Finally, a characterization example is applied to CMOS 130 nm technology; results are shown for different devices characterization: MOSFET, BJT, Diode, Resistor, and Capacitor.
       
  • A Low-Noise Voltage-Controlled Ring Oscillator in 28-nm FDSOI Technology
           for UWB Applications
    • Abstract: Publication date: Available online 7 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mouhammad Abou Chahine, Hussein Bazzi, Ali Mohsen, Adnan Harb, Abdallah Kassem In millimeter wave systems, performance degradation mainly occurs due to high phase noise of voltage-controlled oscillators (VCOs). This paper proposes a low power, low phase noise ring-VCO developed for ultra-wide band applications identified for possible 5G usage. For this purpose, a novel differential symmetrical load delay cell based 3-stage ring oscillator has been introduced to design the ring-VCO. The 28 nm CMOS Fully Depleted Silicon On Insulator (FDSOI) technology is adopted for designing this VCO circuit with 1 V power supply while a new voltage control through the transistor body bias is implemented. The simulated results show that the proposed oscillator works in the tuning range of 29–49 GHz and dissipates 3.75 mW of power. It exhibits a phase noise of −129.2 dBc/Hz at 1 MHz offset from 49 GHz oscillation frequency, and a remarkable Figure of Merit (FoM) of -217.26 dBc/Hz. With similar power supply, the phase noise rises to -93.16 dBc/Hz for a second oscillator involving more of active components exactly 9 delay cells. Further, the impact of the operation temperature variation on the VCO performance is investigated. Results show a drift in the oscillation frequency for a temperature step from 27˚ C to 40˚ C and a degradation of 3dBc in the phase noise performance.
       
  • - Circular+DGS+for+Wireless+Applications&rft.title=AEU+-+International+Journal+of+Electronics+and+Communications&rft.issn=1434-8411&rft.date=&rft.volume=">Design and Realization of Low profile Dual-Wideband Monopole Antenna
           Incorporating a Novel Ohm (Ω) shaped DMS and Semi - Circular DGS for
           Wireless Applications
    • Abstract: Publication date: Available online 6 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohammad Ahmad Salamin, Sudipta Das, Asmaa Zugari In this paper, a compact microstrip line fed dual-wideband printed monopole antenna (PMA) for wireless communication applications is presented. The proposed antenna consists of an asymmetric rectangular patch via a microstrip-fed line, an ohm (Ω) shaped DMS loaded at the rectangular patch, and dual semi-circular shaped DGS embedded in the partial rectangular ground plane. The combination of an ohm shaped DMS and two semi-circular DGS is used to broaden the bandwidth of the two bands and improve the return loss for the desired antenna. The measured 10 dB bandwidth for return loss are achieved to be 21.52% (3.40-4.22GHz) and 47.32% (5-8.1GHz) in the lower and upper band, respectively which covers the bandwidth requirements of 5.2/5.8 GHz WLAN and 3.5/5.5 GHz Wi-MAX application bands. Furthermore, the proposed antenna has a very simple planar structure and occupies a small area of only 621 mm2(23 mm × 27 mm). The proposed antenna has a desirable VSWR level, radiation pattern, radiation efficiency and gain characteristics which are suitable for wireless communication applications.
       
  • A Simple Low-Complexity Algorithm for Generalized Spatial Modulation
    • Abstract: Publication date: Available online 4 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Gökhan Altın, Mehmet E. Çelebi Generalized spatial modulation (GSM) is an extension of spatial modulation which is significant for the next generation communication systems. Optimal detection process for the GSM is the maximum-likelihood (ML) detection which jointly detects the antenna combinations and transmitted symbols. However, the receiver is much more complicated than SM due to inter-antenna interference and/or increased number of combinations. Therefore, the computational complexity of the ML detection grows with the number of transmit antennas and the signal constellation size. In this letter, we introduce a novel and simple detection algorithm which uses sub-optimal method based on the least squares solution to detect likely antenna combinations. Once the antenna indices are detected, ML detection is utilized to identify the transmitted symbols. For obtaining near-ML performans while keeping lower complexity than ML detection, sphere decoding is applied. Our proposed algorithm reduces the search complexity while achieving a near optimum solution. Computer simulation results show that the proposed algorithm performs close to the optimal (ML) detection resulting in a significant reduction of computational complexity.
       
  • Pseudo-elliptic Slow wave Line
    • Abstract: Publication date: Available online 4 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ananya Parameswaran, Singaravelu Raghavan Quasi elliptic filters are of great demand in the present day communication systems. Coupling matrix analysis of pseudo-elliptic low pass filter using conventional microstrip line is presented in this paper. The conventional microstrip line has no non-zero cut off frequency. The conventional microstrip line is transformed into a pseudo-elliptic low-pass filter using the concept of slow wave. The slow wave microstrip line exhibits pseudo-elliptic low-pass behavior with transmission zeros at finite frequencies unlike the conventional Butterworth and Chebyshev filters. The coupling matrix of the slow wave microstrip line is arrived at by using the generalized Chebyshev functions. The coupling matrix of the slow wave line is validated using the MATLAB tool box. Finally, the prototype is fabricated and the performance is measured.
       
  • Memristive Retinomorphic Grid Architecture Removing Noise and Preserving
           Edge
    • Abstract: Publication date: Available online 3 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Melih Yildirim, Yunus Babacan, Firat Kacar In this paper, special memristor circuit and memristive retina network structure for analogue image processing have been presented. The new developments on memristor element have opened various possibilities due to its being in nano-scale and having nonlinear behavior. The proposed memristor emulator consists of only one Operational Transconductance Amplifier (OTA) and two MOS transistors which are operated in sub-threshold region. The memristor fuse structure is obtained by connecting two proposed memristor emulators. In the second section of our paper, we proposed a circuit block which is composed of 16x16 pixels retinomorphic memristive grid to maintain a smoothed and edges preserved image. All simulation results for both proposed memristor circuits and retinomorphic grid are obtained as expected.
       
  • An adaptive congestion-aware routing algorithm based on network load for
           wireless routers in wireless network-on-chip
    • Abstract: Publication date: Available online 1 October 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Shokoofeh Mikaeeli Mamaghani, Mohammad Ali Jabraeil Jamali Wireless Network-on-Chip (WiNoC) is regarded as one of the promising alternative approaches for sorting out the issues of latency and power consumption in the conventional Network-on-Chip (NoC). Despite the additional bandwidth of wireless channels on a chip, wireless routers (WRs) are prone to congestion in WiNoC due to the limited number of wireless channels on a chip and the shared use of these channels among all the cores. In this paper, an adaptive congestion-aware routing algorithm consistent with traffic load is proposed for solving the congestion problem of WRs. The proposed algorithm selects source-destination pairs with the longest wired hop distance for using wireless channels. The number of selected packets is determined based on the wireless channel bandwidth and the network traffic load. Simulation results show up to 65% latency improvement, 16% wired/wireless link utilization improvement and a saturation throughput increase of approximately 11%.
       
  • Single active element implementation of fractional-order differentiators
           and integrators
    • Abstract: Publication date: Available online 29 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Stavroula Kapoulea, Costas Psychalinos, Ahmed S. Elwakil A novel topology for implementing fractional-order differentiator and integrator transfer functions is presented in this paper. This topology is based on the employment of second generation Current Conveyor with EXtra inputs (EX-CCII), passive resistors, and fractional-order capacitors. The main benefit offered by this implementation is that both fractional-order differentiator and integrator transfer functions are simultaneously available at different output terminals, and that their frequency characteristics can be orthogonally adjusted without disturbing each other. With only one EX-CCII device needed, the proposed design is attractive from the active component count point of view. As an application example, a fractional-order controller is designed in order to control the velocity of a small scale submersible equipped with one propeller. Evaluation of the performance of the presented topology is performed using Cadence and the Design Kit provided by the Austria Mikro Systeme (AMS) 0.35μm CMOS process.
       
  • Bidirectional Hybrid OFDM based Wireless-over-fiber Transport system using
           Reflective Semiconductor Amplifier and Polarization Multiplexing Technique
           
    • Abstract: Publication date: Available online 29 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Khaleda Mallick, Rahul Mukherjee, Binoy Das, Gour Chandra Mandal, Ardhendu Sekhar Patra In this paper, a bidirectional hybrid OFDM based Wireless-over-fiber architecture has been investigated and demonstrated to transmit 10 Gbps as well as 6.25 Gbps OFDM data for downlink transmission and 5 Gbps as well as 2.5 Gbps OFDM data for uplink transmission over 50-km single mode fiber (SMF) employing polarization multiplexing technique (POLMUX) at optical line terminal (OLT) and optical network unit (ONU). The POLMUX technique is exercised by polarization beam splitters and polarization beam combiners. Mach-zehnder modulator and RSOA have been used for modulation at OLT and ONU respectively. Transmission performances are observed by constellation diagrams, EVM and BER values. For 10 Gbps, 6.25 Gbps down-link signal and 5 Gbps, 2.5 Gbps up-link signal the power penalty of 3 dBm, 2.3 dBm and 4 dBm, 3.2 dBm at a BER of 10-9 between back-to-back and over 50-km SMF plus 10-m and 5-m wireless link, are observed respectively. For 32-QAM
       
  • Closed-formed Distribution for the SINR of MMSE-Detected MIMO Systems and
           Performance Analysis
    • Abstract: Publication date: Available online 28 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Kai Zhai, Zheng Ma, Xianfu Lei In this paper, we investigate the error performance of multiple-input multiple-output (MIMO) wireless communications systems using minimum mean-square error (MMSE) detection. Particularly, a new closed-form statistical distribution for the output signal-to-interference-plus-noise ratio (SINR) of MMSE receiver is derived, for independent Rayleigh fading channels. The expression for the distribution of SINR is shown to be a linear combination of gamma distributions and polynomial of 11+x, where x is the SINR. Base on the derived distribution for the SINR, closed-form and approximated expressions for the symbol error probability (SEP) of quadrature amplitude modulation (QAM) and phase shift keying (PSK) signaling are obtained, respectively. The derived SINR density and SEP are valid for arbitrary number of transmit and receive antennas. Furthermore, a reduced complexity approximation is introduced to obtain the SINR distribution and SEP performance of MMSE-Detected MIMO Systems with a large number of antennas. The provided simulation results confirm the validity of our theoretical analysis for both the SINR and SEP.
       
  • A Compact Triple-Band Dual-Element MIMO Antenna with High Port-to-Port
           Isolation for Wireless Applications
    • Abstract: Publication date: Available online 28 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Hesam Ekrami, Shahrokh Jam In this literature, a compact planar triple-band multiple input multiple output (MIMO) antenna with two monopole elements is presented. Each element includes a defective complementary open-loop resonator (COLR), two slots on both sides of the feedline, two stepped stubs and a monopole ground plane. This structure operates in the frequency bands of 2.22-2.54 GHz, 3.14-3.9 GHz and 5.3-5.7 GHz for WiFi, WiMAX and WLAN applications, respectively. The antenna is not based on a common ground plane, so antenna is low cost and compact. High measured isolation is achieved which is better than 34 dB in all operating bands without using additional decoupling structure. An equivalent circuit model is proposed to investigate the behaviour of the antenna. The envelope correlation coefficient of antenna is less than 0.001 and diversity gain is about 10. The proposed MIMO antenna is fabricated and there is a good agreement between the experimental measurements with the simulation results.
       
  • Flexible and efficient hardware platform and architectures for waveform
           design and proof-of-concept in the context of 5G
    • Abstract: Publication date: Available online 28 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Jeremy Nadal, Charbel Abdel Nour, Amer Baghdadi Several technical contributions are emerging nowadays to fulfill the new requirements foreseen in the 5th generation (5G) of mobile communication systems. Among these contributions, different variants of waveform design are proposed for the new radio air interface as alternative to orthogonal frequency-division multiplexing (OFDM) adopted in 4G. However, in order to prove the feasibility and the benefits of the proposed waveforms, practical hardware implementations are necessary. This paper presents one of the first flexible and efficient hardware platforms for waveform design and proof-of-concept. The proposed platform constitutes a complete hardware/software development environment, with digital processing, radio frequency boards, and all associated interfaces for control, communication, and display. Furthermore, the proposed platform allows the support of several communication scenarios as foreseen in 5G. Promising waveform candidates are implemented, in addition to OFDM, with careful architectural choices to allow fair comparisons. Particularly, this paper presents novel hardware architectures for the UF-OFDM transmitter and receiver.
       
  • Design of Dual-band and High Gain Waveguide Slot Antenna
    • Abstract: Publication date: Available online 28 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Dong-Ya Cheng, Jun Wang, Ya-Dong Wei, Chun-Yang Jin, Kai-Feng Cui, Min-Quan Li A new kind of dual-band and high gain waveguide slot antenna is designed in this paper. By combining a folded plate and a double-layer metal structure with four apertures on its top floor, the proposed antenna has a dual-band characteristic and its gain reaches up to 11.9dB with only 35 degrees (HPBW) of E-plane at 12.7GHz and 12.1dB with 39degrees at 15.0GHz. Compared to the conventional single-aperture flat antenna, the simulated and measured results show that the proposed antenna with resonant cavity achieves better impedance matching and low profile, meanwhile, the gain improved almost 5.2dB at 12.7GHz and 6dB at 15.0GHz, the HPBW of E-plane is reduced by 100 degrees and 108 degrees respectively.
       
  • An Ultra Low-Power DAC with Fixed Output Common Mode Voltage
    • Abstract: Publication date: Available online 28 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ata Khorami, Roghayeh Saeidi, Mohammad Sharifkhani A novel structure of Capacitive Digital to Analog Converters (CDAC) for Successive Approximation Register Analog to Digital Converters (SAR ADC) is presented. In this CDAC, a number of pre-charged capacitors are placed in different series configurations to produce a desired voltage level. Therefore, given an input code, a series configuration of the capacitors is created to produce a voltage. Current is drawn from the supply voltage only in one step of the ADC conversion to reduce the power consumption. Therefore, the proposed CDAC consumes a fixed and small amount of power regardless of the input code. The output common mode voltage (Vcm) of the DAC remains fixed for all the digital codes. This feature helps a lot to improve the linearity of a typical SAR ADC and reduce the power consumption of comparator. The layout of the proposed DAC is very simple and easy to extend in contrast to the binary weighted CDACs where the layout needs lots of care and time. Several Monte-Carlo and Post-Layout simulations using CMOS 0.18μm technology prove the benefits of the proposed CDAC. The proposed CDAC reduces the power consumption by 99.8% while enhances the speed and linearity of the comparator in a SAR ADC.
       
  • Passive memristor synaptic circuits with multiple timing dependent
           plasticity mechanisms
    • Abstract: Publication date: Available online 27 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): O. Šuch, M. Klimo, N.T. Kemp, O. Škvarek Adaptation of synaptic strength is central to memory and learning in biological systems, enabling important high-level processes such as the ability of animals to respond to a changing environment. Memristor devices are a promising new, nanoscale technology that emulates the function of synapses and can therefore be used to represent synaptic elements in analog artificial neural networks. The main mechanism to carry out unsupervised adaptation of weights in memristive synapses currently involves artificial spiking neural network designs relying on spike-timing dependent plasticity (STDP). We present and analyze a new memristive circuit that in addition to STDP learning rules also implements competitive adjustment based on relative timing of presynaptic inputs. The cooperative effect of multiple learning rules in the new circuit may ameliorate the problem of erasure of synaptic weights
       
  • Common Source Power Amplifier Design for 5G Application in 28-nm UTBB
           FD-SOI Technology
    • Abstract: Publication date: Available online 27 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ali Mohsen, Mohammad Jaafar Ayoub, Mostafa Alloush, Adnan Harb, Nathalie Deltimple, Abraham Serhane The telecommunication market examines a highly growing demand for RF mobile devices where low latency and high performance are ongoing improvement. The power amplifier (PA) is a major element of the radio frequency front-end; especially if power consumption and bandwidth are considered. This paper presents the design of 5G mm-wave PA using both Common Source Class-AB and Class-J topologies utilizing 28-nm UTBB FD-SOI technology and its body bias technique. Upon taking into consideration the parasitic extraction of the transistor, RF pads, and interconnection to ground, a comparison is made and the theoretical effectiveness of Class-J topology for single stage large signal amplification is simulated. Moreover, two distinct transistors - widths of 250 µm and 350 µm - are simulated where each has its own topology in order to study the impact of increasing the width on the performance of the PA. The stability of the designed Power Amplifiers is taken into consideration and the unconditional stability conditions are approved. While 5G spectral band is not yet specified and determined, recent studies proved that the 28 GHz band is particularly effective for 5G mobile standardization.
       
  • Reduction of Mutual Coupling and Cross-Polarization of a MIMO/Diversity
           Antenna using a String of H-Shaped DGS
    • Abstract: Publication date: Available online 27 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Juin Acharjee, Kaushik Mandal, Sujit Kumar Mandal In this article, a simple string of H-shaped defected ground structure (DGS) is used to reduce the mutual coupling and cross-polarization of a MIMO antenna. A MIMO antenna has been designed using two identical square patches to operate at the frequency of 2.4 GHz. The proposed DGS decreases the direct coupling path among the closely spaced (edge to edge gap 0.038 λ0) patches and thereby reduces the mutual coupling and cross-polarization by 46dB and 11 dB respectively. To study the amount of mutual coupling is decoupled; a new term namely, coupling to decoupling ratio (CDR) has been defined. A mathematical model is developed using multiple polynomial regression analysis techniques to observe the dependency of CDR as a function of frequency and inter-element spacing. Also, an equivalent circuit of the DGS is constructed and validated. Diversity performance of this MIMO antenna is presented through Envelope Correlation Coefficient (ECC) and Mean Effective Gain (MEG) ratio and well acceptable values of 0.0002 and 0.03dB are obtained respectively. A prototype is fabricated and measured. The experimental results show good agreement with that of the simulated results. Maximum peak gain of 2dBi and radiation efficiency of 74% also proves the practicality of this design.
       
  • Ultra-Low Power LNA Design Technique for UWB Applications
    • Abstract: Publication date: Available online 26 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ahmed M. Saied, Mostafa M. Abutaleb, Mohamed I. Eladawy, Hani Ragai In this paper, a design technique to improve low noise amplifier (LNA) performance is proposed. This technique is based on a new operating parameter (OP) of MOSFETs for radio frequency (RF) applications. This technique is used to optimize low noise Amplifier (LNA) parameters for Ultra-Wideband (UWB) applications. The presented methodology predicts the optimum biasing point to maximize LNA performance. Simulation results show that the proposed methodology can increase the figure of merit (FoM) by 70 % compared to traditional methodologies, without having a significant effect on either noise figure (NF) or linearity characteristics.
       
  • Dual Band Rectangular Patch Antenna Array With Defected Ground Structure
           For ITS Application
    • Abstract: Publication date: Available online 26 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Nand Kishore, Gaurav Upadhyay, Vijay Shanker Tripathi, Arun Prakash A dual band inset fed rectangular patch antenna array has been proposed for intelligent transportation system (ITS) application. This paper proposes 8–element patch array antenna with defected ground structure (DGS). The simulated results of 2, 4 and 8 element patch with and without DGS are also compared. Proposed antenna gets dual band of 5.02 GHz and 5.92 GHz centre frequency with DGS. The 8–element patch array antenna with DGS is fabricated and its result is compared with simulation result. 26.5 dBi and 24.9 dBi is measured gain of the proposed antenna structure for 5.02 GHz and 5.92 GHz centre frequency respectively.
       
  • A simplified radix-4 successive cancellation decoder with partial sum
           lookahead
    • Abstract: Publication date: Available online 26 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Hussein G.H. Hassan, Amr M.A. Hussien, Hossam A.H. Fahmy Polar codes recently received high attention by researchers as proven to approach channel capacity at higher codeword length. However, the decoding latency grows significantly with codeword length, rendering implementation for latency constrained applications impossible. To tackle this problem, this paper proposes a polar decoder architecture based on radix-4 processing units with a special last stage processing unit to decode up to 16 bits in the same clock. In addition, it proposes decoding extended special subcodes to reduce latency. Moreover, it uses partial sum look-ahead technique, resulting in a high throughput low latency decoding architecture.
       
  • A New Design Methodology for Time-Based Capacitance-to-Digital Converters
           (T-CDCs)
    • Abstract: Publication date: Available online 26 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Ali H. Hassan, Ahmed Fouad, Hassan Mostafa, Khaled N. Salama, Ahmed M. Soliman This paper introduces a 9-bit time-based capacitance-to-digital converter (T-CDC). This T-CDC adopts a new design methodology for parasitic cancellation with a simple calibration technique. In T-CDCs, the input sensor capacitance is first converted into a delay pulse using a capacitance-to-time converter (CTC) circuit; then this delay signal is converted into a digital code through a time-to-digital converter (TDC) circuit. A prototype of the proposed T-CDC is implemented in UMC 0.13 μm CMOS technology. This T-CDC consumes 8.42 μW and achieves a maximum SNR of 45.14 dB with a conversion time of 1 μs that corresponds to a figure of merit (FoM) of 16.4 fJ/Conv.
       
  • A Hybrid NMOS/PMOS Capacitor-Less Low-Dropout Regulator with Fast
           Transient Response for SoC Applications
    • Abstract: Publication date: Available online 26 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mahmoud H.Kamel, Ahmed N. Mohieldin, El-Sayed Hasaneen, Hesham F.A. Hamed In this paper, a new architecture of a fully integrated low-dropout voltage regulator (LDO) is presented. It is composed of hybrid architecture of NMOS/PMOS power transistors to relax stability requirements and enhance the transient response of the system. The LDO is capable of producing a stable output voltage of 1.1V from 1.3V single supply with recovery settling time about 680nsec. It can supply current from 10µA to 100mA consuming quiescent current of 20.5µA and 95µA, respectively. It supports load capacitance from 0-50 pF with phase margin that increases from 43° at low load (10µA) to 74° at high load (100mA) and power supply rejection ratio (PSRR) less than -20dB up to 100kHz. The proposed LDO is designed in 130nm CMOS technology and occupies an area of 0.11mm2. Post layout simulations show better performance compared with other reported techniques.
       
  • Microwave Sintered Mg-Cd Ferrite Substrates for Microstrip Patch Antennas
           in X-band
    • Abstract: Publication date: Available online 26 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Sanjay R. Bhongale, Hanmant R. Ingavale, Tukaram J. Shinde, Pramod N. Vasambekar The ferrites with chemical formulae MgFe2O4, Mg0.6Cd0.4Fe2O4 and Mg0.2Cd0.8Fe2O4 specified with Ferrite S1, S2 and S3 were prepared by the oxalate co-precipitation method using AR grade sulphates under microwave sintering technique. The single phase cubic spinel structure formation of all the ferrites was confirmed by XRD and FTIR techniques. The dielectric parameters such as permittivity (εr), dielectric loss tangent (tanδe), permeability (µr) and magnetic loss tangent (tanδm) were determined from parameters S11 and S21 by using material measurement software with VNA. The synthesized ferrites S1, S2 and S3 with determined dielectric parameters were used as substrate to design rectangular microstrip patch antenna by simulation using Ansoft Designer SV 2.2. The designed antennas were fabricated by using screen printing technique. The return loss (RL), 10dB % bandwidth and VSWR of these fabricated antennas were measured on vector network analyzer. The simulated and measured values of resonating frequency, return loss (RL), 10dB % bandwidth and VSWR were nearly matched with each other. Mg0.2Cd0.8Fe2O4 (Ferrite S3) can be used as substrate of antenna for better results.
       
  • Design of an FPGA Based DPLL with Fuzzy Logic Controllable Loop Filters
           with Application Customization Capability
    • Abstract: Publication date: Available online 25 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohieddin Moradi, Mehdi Ehsanian The carrier recovery loops are important in carrier tracking approaches particularly in the presence of high dynamic stress on user receivers and noisy environment applications. The precise carrier tracking techniques are proposed in systems that are sensitive to carrier mismatches, such as terrestrial or satellite tracking systems. The fading phenomenon, phase and frequency step changes and high user dynamics are currently most important challenges in the development of robust carrier tracking systems. In this work, a novel Digital Phase Locked Loop (DPLL) is proposed using type-2 fuzzy logic controller to improve noise immunity and handling user dynamic in digital receivers with application customization capability. Due to fast and accurate decision-making by proposed fuzzy logic controller, optimal loop filter coefficients are generated for DPLL. The proposed DPLL is simulated with Xilinx System Generator Software and can be implemented on FPGA. In comparison to traditional approaches, proposed new DPLL shows better performance in response to phase step, frequency step and frequency ramp signals with acceptable settling time alongside minimum complexity in implementation and customization.
       
  • Wideband GNSS Antenna Covered by a Double-Sided Metasurface
    • Abstract: Publication date: Available online 25 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Xue-Shi Li, Liang-Lun Cheng, Xiong-Ying Liu, Qing Huo Liu A novel global navigation satellite system (GNSS) antenna that employs a double-sided metasurface (MS) to cover a circularly slotted patch antenna is presented. With this MS, the antenna has a wide -10-dB reflection coefficient bandwidth from 1.160 GHz to 1.640 GHz (34.3%) and 3-dB axial ratio (AR) bandwidth from 1.170 GHz to 1.720 GHz (38.1%), covering all frequency bands of the GNSSs within a single band. Meanwhile, the right-handed circular polarization (RHCP) gain of the antenna is enhanced by the MS, with a peak value of 6.44 dBic at 1.600 GHz. An electrically small footprint of 0.364 λ0 × 0.364 λ0 is also achieved by the antenna at the operating frequency of 1.170 GHz.
       
  • Polarization-independent Frequency-Selective Rasorber with a Broadened
           Absorption Band
    • Abstract: Publication date: Available online 25 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Qiang Chen, Min Guo, Zhanshan Sun, Di Sang, Yunqi Fu A polarization-independent frequency selective rasorber (FSR) with a transmission band at high frequency and a broadened absorption band at low frequency is designed and analyzed in this paper. The FSR consists of a resistive sheet and a bandpass frequency selective surface (FSS). A strip-type micro resonator (MR) is developed and applied in the resistive element. The MR is equivalent to a parallel LC circuit and resonates at the transmission band. The induced surface current distributions on the resistive element at different frequencies can be controlled as expected using the MRs, so that a high in-band transmission at high frequency and an absorption band at low frequency can be obtained, which are almost independent to each other. The absorption bandwidth can be broadened by cascading more MRs with several resistor-loaded metallic strips. Besides, due to the tiny dimensions of the MRs, polarization-independent absorptive/ transmissive performances can be achieved by printing two orthogonal arrays of resistive elements on different surfaces of a dielectric substrate. The performance of the FSR is verified by both numerical simulation and experimental measurement.
       
  • Analytical and Experimental Study of LINC Amplifier Using Unmatched
           Wilkinson Combiners
    • Abstract: Publication date: Available online 24 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mohamad El-Asmar, Ahmed Birafane, Ahmad El-Rafhi This work presents an analytical and experimental study of LINC power amplifier where an unmatched Wilkinson combiner is used at the output of two class-B amplifiers. This combiner is called unmatched because of the elimination of the one hundred ohms resistor from its input. This resistor is used to guaranty a good impedance matching between the combiner and the amplifier outputs. An amount of reflection coefficient can be presented at the input of the combiner depending on the signals phase different of the two LINC branches which that may damage the linearity of the amplified signals. Our Analytical study in this paper presents equations for the power efficiency and the signal linearity showing that despite of reflection between the combiner and the amplifiers, very good efficiency and linearity will be obtained. An ADS simulation and experimental work of the LINC system is performed shows an excellent agreement with the analytical study.
       
  • Design and Development of Multi-Port Switchable Power Dividers
    • Abstract: Publication date: Available online 24 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Debajit De, Prasanna Kumar Sahu Microstrip line based two switchable power dividers are presented in this paper and these models are capable of power division control at four output ports. Here, power switching is implemented with terminating some open-ended stub-lines using varactor diodes and corresponding mathematical equations are derived. Proper DC voltages are applied for biasing the activator diodes and consequently to have appropriate stub-line terminations. For designing these power dividers, CST Microwave Studio is used here as the EM tool. The characteristics such as return loss, insertion loss and isolation have been explored from the simulation results followed by it’s fabrication and measurement. Quite good agreement is achieved between the simulation and the experimental results. Much better performance characteristics make this proposed power divider a good candidate for various microwave systems where switchable power dividers are required.
       
  • Binary Constant Modulus Blind Equalization for Multi-Level QAM Signals
           under Gaussian and Non-Gaussian Noise
    • Abstract: Publication date: Available online 22 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Xiang Li, Bingbing Li, Jin Li, Mingwu Yao, Weike Nie A binary constant modulus algorithm (BCMA) is proposed in this work for the blind equalization of multi-level quadrature amplitude modulation (QAM) systems. A novel cost function and its corresponding iteration formula are developed, which removes both the excess error and the steady state error introduced in the design of the most popular constant modulus algorithm (CMA). Theoretical analysis indicates the proposed algorithm can solve the performance degradation of CMA applying to the non-constant QAM signals. Moreover, it can combat the impulsiveness of alpha stable noise. Simulation results illustrate the effectiveness and robustness of the new algorithm under both Gaussian and non-Gaussian environments.
       
  • System Utility based Resource Allocation for D2D Multicast Communication
           in Software-Defined Cellular Networks
    • Abstract: Publication date: Available online 21 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Wenrong Gong, Guomin Li, Baiping Li Device-to-device (D2D) multicast communication is a useful way to improve the communication efficiency of local services. This study considers a scenario of D2D multicast communication in software defined cellular network and investigates the frequency resource allocation problem. Firstly, we build the system model and formulate the optimization problem. Secondly, a hierarchical scheme to achieve a suboptimal solution is proposed. To select appropriate user equipments (UEs) as potential D2D transmitters (PDTs), a social aware PDT selection method is proposed. Then, a resource allocation algorithm considering users’ priorities is proposed. Furthermore, to study the resource allocation for general system that UEs without priorities, a non-priority considered allocation algorithm is proposed also. Numerical simulation results show that the proposed schemes are effective in improving the system utility and reducing the resource consuming for D2D communications.
       
  • High-Selectivity Single-Ended and Balanced Bandpass Filters Using Ring
           Resonators and Coupled Lines Loaded with Multiple Stubs
    • Abstract: Publication date: Available online 20 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Kai Da Xu, Zekai Luo, Yanhui Liu, Qing Huo Liu High-selectivity single-ended and balanced bandpass filters (BPFs) using dual-mode ring resonators and coupled lines loaded with multiple stubs are proposed in this paper. With the help of the loaded short-circuited and open-circuited stubs, six deep transmission zeros (TZs) from 0 to 2f0 (f0: center frequency of the passband) can be realized in both of single-ended and balanced BPFs to improve the stopband suppressions. The functions of the loaded short/open stubs and calculated analysis of TZs’ positions have been presented. For further demonstration, two examples of single-ended BPF and balanced BPF with high common-mode suppression are designed and fabricated, whose center frequencies are both at 2.1 GHz. Their measured 3-dB fractional bandwidths are 23.7% and 24.7% (differential-mode), respectively. The simulated results and measurements of these two filters are in good agreement.
       
  • Tunable Characteristics of Ferrite Composite Right/left Handed Coplanar
           Waveguide Coupled Line Coupler – Measurement and Experimental
           Verification
    • Abstract: Publication date: Available online 20 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Mahmoud A. Abdalla, Zhirun Hu This paper presents the experimental verification of the tunable characteristics of a ferrite composite right/left handed coupled line coupler. The coupler is designed using two coupled CRLH-CRLH transmission lines. The coupler is designed to demonstrate equal through and backward coupling. The novel coupler has been designed and realized in coplanar waveguide configuration on a ferrite substrate. The tunable characteristics are achieved by changing the applied DC magnetic bias to the ferrite substrate. The measurement results reveal that the coupler’s fractional bandwidth can be tuned from 29% to 69% by varying the applied DC magnetic bias from 1000 Oe to 1750 Oe. Within the tunable bandwidth, the maximum backward coupling is -5 dB. The coupler has high forward coupling isolation, close to -30 dB at its centre operating frequency. In addition to its tuning capability, the coupler has the advantages of its compact size; it has the length of 11.5 mm and not-so-tight line separations of 2.5 mm. Furthermore the coupler only requires low DC magnetic bias.
       
  • Impact of Leakage Current in Germanium Channel based DMDG TFET using
           Drain-Gate Underlap Technique
    • Abstract: Publication date: Available online 20 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): D. Gracia, D. Nirmal, D. Jackuline Moni In this work, a dual metal (DM) double-gate (DG) Tunnel Field Effect Transistor (DMDG-TFET) with drain-gate underlap is proposed to overcome the challenges in conventional TFET. The ON-current (Ion), OFF-current (Ioff), Ion/Ioff ratio, subthreshold swing (SS) and ambipolar current (Iambi) of the proposed device with drain underlap are investigated as gate length is scaled (LGATE) down. The proposed device gives a better suppression in leakage current and low ambipolar current. The suppressed leakage current (Ioff) and ambipolar current (Iambi) are 9.49x10-14 A/µm and 1.95x10-12 A/µm respectively for a gate length(LGATE) of 36 nm and a channel length (LCh) of 50 nm for a supply voltage of 0.5 V.Excellent switching behavior is achieved when gate length (LGATE) is 72 % of the channel length (LCh). The proposed architecture is suitable for low power applications.
       
  • Spectral efficiency and Energy efficiency of distributed antenna systems
           with virtual cells
    • Abstract: Publication date: Available online 20 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Xingquan Li, Chunlong He, Jihong Zhang In this paper, we consider user centric virtual cells model in distributed antenna systems (DAS). We investigate different power allocation optimization problems with interferences in DAS with and without user centric virtual cells model, respectively. The first objective problem is maximizing spectral efficiency (SE) of the DAS with user centric virtual cells model under the constraints of the minimum SE requirements of each user equipment (UE), maximum transmit power of each remote access unit (RAU). We firstly transform this non-convex objective function into a difference of convex functions (D.C.) problem, and then we obtain the optimal solutions by using the concave-convex procedure (CCCP) algorithm. The second objective problem is maximizing energy efficiency (EE) of the DAS with user centric virtual cells model under the same constraints as the first objective problem. Firstly, we exploit fractional programming theory to obtain the equivalent objective function of the second problem with subtract form, and then transform it into a D.C. problem and use CCCP algorithm to obtain the optimal power allocation. In each part, we propose the corresponding optimal power allocation algorithm and also use similar method to obtain optimal solutions of the same optimization problems in DAS without using user centric virtual cells model. Simulation results are provided to demonstrate the effectiveness of the DAS with user centric virtual cells model, which can significantly improve the SE and the EE of the communication systems.
       
  • Design of UWB Monopole Antenna with Dual Notched Band Characteristics by
           Using π-Shaped Slot and EBG Resonator
    • Abstract: Publication date: Available online 19 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Samineni Peddakrishna, Taimoor Khan In this paper, we propose the design of coplanar waveguide (CPW) ultra-wideband (UWB) dual notched band monopole antenna with a π-shaped slot and EBG is proposed. The designed antenna produces an impedance bandwidth of 2.7-11.7 GHz (VSWR
       
  • A Fractal Metamaterial based Printed Dipoles on a Nickel Oxide Polymer
           Palm Fiber Substrate for Wi-Fi Applications
    • Abstract: Publication date: Available online 18 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Taha A. Elwi, B.A. Ahmad In this paper, a novel antenna circuit based metamaterial (MTM) structures is proposed for Wi-Fi applications. The antenna consists of two dipoles with 3×5 Hilbert -shaped MTM array printed with Sliver Nanoparticles Conductive Ink (SNPCI). The antenna substrate is mainly created from INP composite of: Iraqi Palm Tree Remnants (IPTR) and Nickel Oxide Nanoparticles (NONP) with Polyethylene (PE) mixture. The relative permittivity (εr) and permeability (μr) are measured using an open-stub microstrip resonator to find εr=3.106-j0.0314 and μr=1.548-j0.0907 at the frequency band of interest. Numerically, Finite Integral Technique (FIT) and Finite Element Method (FEM) of CSTMWS and HFSS formulations, respectively, are invoked to investigate the antenna performance. Experimentally, the antenna exhibits two resonances, S11
       
  • Study on frequency and impulse response of novel triple band notched UWB
           antenna in indoor environments
    • Abstract: Publication date: Available online 18 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Seyed Ramin Emadian, Javad Ahmadi-Shokouh, Changiz Ghobadi, Javad Nourinia In this paper, a novel fork shaped structure backed plane is added to a simple UWB (ultra wideband) slot antenna to enhance the impedance bandwidth as well as create triple band notched characteristics for Impulse Radio (IR) UWB applications. This fork-shaped structure is connected to a rectangular radiating patch at four different points through the cylindrical pins. The proposed antenna with this fork-shaped structure shows a very wide impedance bandwidth which spans from 2.5 up to more than 20 GHz and offers triple band-notched properties in WiMAX, WLAN and X-band downlink satellite communication spectrums. Moreover, the proposed antenna shows good radiation features such as gain, radiation efficiency and radiation patterns. A comprehensive investigation on the antenna time domain performance is also performed throughout the paper, and the effect of the proposed antenna on the two popular excitation pulses including modulated Gaussian (MG) and square root raised cosine (SRRC) pulses is fully investigated. A frequency-domain measurement setup is applied to measure time domain characteristics of the proposed antenna. Also, the realistic indoor multipath propagation channel characteristics when the proposed antennas are applied as the transmitter and receiver antennas are studied. Sub-band divided ray tracing method is used to simulate channel characteristics.
       
  • Analysis and Synthesis of Multiband Dual Polarized Parallel Metallic
           Strips FSS with a Ring Using WCIP Method
    • Abstract: Publication date: Available online 18 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Raouia Saidi, Mohammed Titaouine, Awatef Djouimaa, Ibtissem Adoui, Karima Bencherif, Thayuan Rolim De Sousa, Alfrêdo Gomes Neto, Henry Baudrand In this paper parallel metallic strips FSSs with a ring are introduced and analyzed by the WCIP method for their simple modeling characterized by independent resonant frequencies due to its non-coupled metallic elements. Two FSS structures are manufactured and measured. A FSSs synthesis approach is presented and the curves relating the desired resonant frequencies to the FSS metallic elements lengths responsible of theses frequencies are plotted. To test the synthesis, approach the two manufactured FSSs frequency responses are taken as the desired ones and the proposed synthesis approach is used to determine the metallic strips and the ring lengths for the FSSs unit cell. WCIP results are compared to measurements and a good agreement is observed. For complex pattern FSS the resonant frequencies sources are not always easy to be determined. Thus an equivalent FSS based on metallic strips and a ring can be used maintaining the same frequency response in the limit of the proposed approach. The synthesis approach is used to determine its equivalent FSS structure of a published complex FSS pattern. WCIP method and HFSS software results of the equivalent FSS are compared to published measurements and a good agreement is recorded.
       
  • Multifunctional sandwich structure designed for broadband reflection
           reduction
    • Abstract: Publication date: Available online 17 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Lihao Shen, Yongqiang Pang, Leilei Yan, Quan Li, Shaobo Qu A light-weight sandwich structure is designed in this paper to achieve the broadband reflection reduction based on scattering cancellation. The multifunctional sandwich structure is composed of checkerboard metasurface (MS), foam core and carbon fabric/epoxy composite reflector. The checkerboard MS can redirect the incident waves away from the specular direction to achieve the reflection reduction. In addition, the carbon fabric/epoxy composite has the dual role as the reflection layer of incident waves and load bearing face material of whole structure. A series of simulation and optimization results indicate that the whole structure obtains reflection reduction with the reflectivity less than -10 dB in the frequency of 6.7-19.8 GHz under normal incidence, and the reflectivity less than -15 dB in 9.8-14.0 GHz. The proposed structure is lightweight and the density is 0.58 g/cm3. By fabricating the sample, electromagnetic property has been well demonstrated experimentally.
       
  • Two-neuron-based non-autonomous memristive Hopfield neural network:
           Numerical analyses and hardware experiments
    • Abstract: Publication date: Available online 15 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Quan Xu, Zhe Song, Han Bao, Mo Chen, Bocheng Bao This paper explores a two-neuron-based non-autonomous memristive Hopfield neural network (mHNN) through numerical analyses and hardware experiments. It is interested that the locus and stability of the AC equilibrium point for the mHNN change with the time evolution. Dynamical behaviors associated with the self-coupling strength of the memristive synapse are numerically investigated by bifurcation diagrams, Lyapunov exponents and phase portraits. Particularly, bursting behaviors are revealed when the order gap exists between the natural frequency and external stimulus frequency. The interesting phenomena are illustrated through phase portraits, transmitted phase portraits, and time-domain waveforms of two cases. Moreover, breadboard experimental investigations are carried out, which effectively verify the numerical simulations.
       
  • A Low Power High-Performance Area Efficient RF Front-end exploiting Body
           Effect for 2.4GHz IEEE 802.15.4 Applications
    • Abstract: Publication date: Available online 11 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): S. Chrisben Gladson, M. Bhaskar The rising internet-of-things applications in home automation, smart wearables, healthcare monitoring demand small, area efficient, high-performance and low power radio frequency (RF) blocks for effective short-range communication. This growing market demand is addressed in this paper by proposing a fully CMOS radio frequency front-end (RFE) exploiting bulk effect. Apart from the primary function of frequency translation, proper circuit performance concerning the linearity, conversion gain, and noise figure is required for low-cost densely integrated transceivers operating in the 2.4GHz ISM band. The proposed RFE at 2.4GHz is designed and implemented in UMC 180nm CMOS process technology with two modes of operation. In high gain mode (Mode-I), the post-layout simulation with SpectreRF shows a peak gain of 30.06dB, IIP2 at 64.52dBm, IIP3 at -2.74dBm and a DSB-NF of 7.68dB while consuming only 9.24mW from the 1.8V supply. In the high linear mode (Mode-II), the RFE achieves a higher IIP3 of 10.78dBm, IIP2 of 91.56dBm, the conversion gain of 23.5dB, DSB-NF of 9.46dB while consuming a low power of 3.6mW. The fully CMOS circuit occupies a core area of only 0.0021mm2. The proposed front-end exhibits a spurious free dynamic range (SFDR) of 81.18dB ensuring the high dynamic operation of the wireless system.
       
  • Noise suppression in a common-gate UWB LNA with an inductor resonating at
           the source node
    • Abstract: Publication date: Available online 11 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Hossein Sahoolizadeh, Abumoslem Jannesari, Massoud Dousti In this paper, a noise suppression circuit is proposed and investigated by using resonance technique at the source. Resonance in the source node of the common-gate structure blocks the noise path while transferring the signal from input to output. Through proper analysis, a common gate structure with an active load is improved. As a result, a complementary common gate structure is introduced. A complementary common-gate structure with resonance in the source node can overcome the trade-off between noise and gain in the first stage. Hence, this structure is optimum in terms of the trade-off between gain and noise as well as power dissipation and linearity. Finally, a very-low-noise amplifier is implemented by this method and the post-layout simulation results are obtained: average power gain: 15.8 dB, minimum noise figure: 1.7 dB, bandwidth: 3.1-4.8 GHz, power dissipation of two stage: 11.28 mW, 1-dB compression point at input power: −4.67 dBm, and IP3 at input power: 8.32 dBm.
       
  • Distributed Trajectory Design for Data Gathering Using Mobile Sink in
           Wireless Sensor Networks
    • Abstract: Publication date: Available online 8 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Areej Alsaafin, Ahmed M. Khedr, Zaher Al Aghbari Several studies have demonstrated the benefits of using a mobile sink (MS) to reduce energy consumption resulting from multi-hop data collection using a static sink in wireless sensor networks (WSNs). However, using MS may increase data delivery latency as it needs to visit each sensor node in the network to collect data. This is a critical issue in delay-sensitive applications where all sensed data must be gathered within a given time constraint. In this paper, we propose a distributed data gathering protocol utilizing MS for WSNs. The proposed protocol designs a trajectory for the MS, which minimizes energy consumption and delay. Our protocol operates in four main phases: data sensing, rendezvous point (RP) selection, trajectory design, and data gathering. In data sensing, a number of deployed sensor nodes keep sensing the target field for a specific period of time to capture events. Then, using a cluster-based RP selection algorithm, some sensor nodes are selected to become RPs based on local information. The selected RPs are then used to determine a trajectory for the MS. To do so, we propose three trajectory design algorithms that support different types of applications, namely reduced energy path (REP), reduced delay path (RDP), and delay bound path (DBP). The MS moves through the constructed path to accomplish its data gathering according to an effective scheduling technique that is introduced in this work. We validate the proposed protocol via extensive simulations over several metrics such as energy, delay, and time complexity.
       
  • Effects of Directional Antennas on Outband D2D mmWave Communications in
           Heterogeneous Networks
    • Abstract: Publication date: Available online 8 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Romain Chevillon, Guillaume Andrieux, Romain Négrier, Jean-François Diouris Device-to-Device (D2D) communications are considered as a keystone of the fifth generation wireless technology (5G). This new approach is very promising in terms of energy and spectrum efficiency. However, the integration of such communications in a typical cellular network increases inevitably the amount of interference. Several researches propose to lower the interference thanks to either sharing the cellular spectrum intelligently, or using non-cellular bands for D2D links. In this paper, we focus on the latter opportunity, and consider that the D2D communications are used with millimeter waves (mmWaves).For what comes to modeling a D2D-enabled (D2D-e) network, many works propose to use stochastic geometry so as to evaluate the impact of interference and noise on the various links. In this work, we aim to analyze the SINR and the average data rate of Outband D2D links for user equipments (UEs) with conventional omnidirectional antennas and with various directional mmWave antennas: patch antennas, horn antennas and uniform linear array antennas. Analytical and empirical evaluations of the Signal-to-Interference-plus Noise Ratio (SINR) are made with stochastic geometry. We propose to discuss the advantages and drawbacks of directional mmWave antennas in Outband D2D for various antenna designs, and their interest in various environments.
       
  • Design of single- and dual-band BPFs using folded 0° feed structures
           and embedded resonators
    • Abstract: Publication date: Available online 5 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): MohammadReza Zobeyri, AhmadReza Eskandari In this paper, a novel symmetric primary structure including two coupled stepped-impedance main-resonators is presented. The primary structure is divided into three different bandpass filters (BPFs) of equal size such as two derived single-band BPFs operating at 0.9 and 1.8 GHz frequencies, respectively, and the third one is a dual-band BPF operating at 0.9/1.8 GHz passbands concurrently. To validate the proposed design methodology, three prototype BPFs have been designed, fabricated and measured successfully using folded main-resonators with 0° feed structures to create the 0.9 GHz passband. Then by embedding two pairs of double-spiral open-loop sub-resonators into the main-resonators with the cross-coupled arrangement, the tuneable 1.8 GHz passband is created. Also, by inserting extra pairs of sub-resonators, the 1.8 GHz BPF can be cascaded to achieve the selective higher-order modes. The dual-band BPF has been optimized not only to reduce the band-ripples and remove the spurious frequencies but also to miniaturize in overall size. The advantages of measured insertion losses, less than 0.9 dB in the single-band BPFs, 0.7 dB in the dual-band BPF with a good return loss and improved band selectivity are achieved with a high flexibility for changing the primary structure into some exclusive BPFs.
       
  • Analysis of Alamouti Scheme using Feedback-Rate Efficient Transmit Antenna
           Selection with Robust Error Performance in the Presence of Feedback Errors
           
    • Abstract: Publication date: Available online 5 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Rajiv Kumar, Sudakar Singh Chauhan This paper proposes a new feedback rate efficient transmit antenna selection (TAS) with Alamouti scheme (AS) with robust error performance which improves physical layer security (PLS) in multiple-input-multiple-output (MIMO) wiretap channel. The proposed scheme is accomplished in two steps 1) The transmitter fixes one antenna and then transmitter select the strongest antenna out of remaining NT-1ones, depending on the feedback from receiver 2) The AS is applied at the fixed antennas for data transmission. Two different scenarios based on availability of channel state information of eavesdropper at the transmitter are examined. The proposed scheme achieves higher average secrecy capacity (ASC) and lower secrecy outage probability (SOP) by selecting two antennas. The result shows that ASC is higher for lower value of signal to noise (SNR) at eavesdropper.
       
  • A Novel White Noise Generator as the Tracking Generator for Filter
           Measurements
    • Abstract: Publication date: Available online 5 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Serdar Arslan, Bahadır S. Yildirim A novel and low-cost white noise generator using an ordinary Zener diode as the source of noise is presented. The Zener diode is driven by a stable dc current source such that the noise signal power generated by the Zener diode increases with increasing frequency under right dc current biasing. A 6-stage MMIC amplifier block was designed to increase the noise power further. Since the gain-frequency response of the amplifier block has a negative slope as the frequency increases, the positive slope of the noise power produced by the Zener diode is balanced with the negative slope of the amplifier gain. The resulting amplified noise signal appears to have almost constant power at the output of the amplifier. As a result, the designed noise generator exhibits white noise characteristics, and is used as a tracking generator to measure insertion loss of a RF/microwave filter.
       
  • Sequential Likelihood Ascent Search Detector for Massive MIMO Systems
    • Abstract: Publication date: Available online 4 September 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Giovanni Maciel Ferreira Silva, José Carlos Marinello Filho, Taufik Abrão In this paper, we have analyzed the performance-complexity tradeoff of a selective likelihood ascent search (LAS) algorithm initialized by a linear detector, such as matched filtering (MF), zero forcing (ZF) and minimum mean square error (MMSE), and considering an optimization factor ρ from the bit flipping rule. The scenario is the uplink of a massive MIMO (M-MIMO) system, and the analyses have been developed by means of computer simulations. With the increasing number of base station (BS) antennas, the classical detectors become inefficient. Therefore, the LAS is employed for performance-complexity tradeoff improvement. Using an adjustable optimized threshold on the bit flip rule of LAS, much better solutions have been achieved in terms of BER with no further complexity increment, indicating that there is an optimal threshold for each scenario. Considering a 32×32 antennas scenario, the factor ρ = 0.8 needs 5 dB less than the proposed in literature (ρ = 1.0) to achieve the same bit error rate of 10-3.
       
  • Pilot Design for Sparse MIMO-OFDM Channel Estimation with Generalized
           Shift Invariance Property
    • Abstract: Publication date: Available online 25 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): Shenyang Xiao, Zhigang Jin, Yishan Su Compressed sensing (CS) based channel estimation is greatly bound by the measurement matrix according to CS theory. We design pilot patterns by minimizing the mutual coherence of the measurement matrix with the generalized shift invariance property (GSIP). GSIP and a corollary are firstly proposed. Then two pilot pattern design schemes termed pilot design with GSIP (PDGSIP) and tradeoff pilot design with GSIP (TPDGSIP) are put forward to design orthogonal pilot patterns based on GSIP for a multiple-input multiple-output orthogonal frequency division multiplexing system. In PDGSIP, a collection of pilot patterns are firstly obtained and then pilot patterns having large mutual coherence are replaced with new ones generated with optimal pilot patterns. TPDGSIP directly produces new pilot patterns based on GSIP to fully exploit the pilot distance of the obtained pilot pattern as soon as one pilot pattern is obtained. Simulation results have shown that, the proposed pilot pattern design schemes are able to obtain the best pilot patterns in comparison to existing methods from the perspective of mutual coherence. Channel estimation performance using pilot patterns designed by proposed schemes precedes that using pilot patterns designed by existing schemes in terms of normalized mean square error and bit error rate.
       
  • Virtual Quadrature Phase Shift Keying with Low-Complexity Equalization for
           Performance Enhancement of OFDM Systems
    • Abstract: Publication date: Available online 25 August 2018Source: AEU - International Journal of Electronics and CommunicationsAuthor(s): K. Ramadan, M.I. Dessouky, F.E. Abd El-Samie, S. Elagooz The Zero-Forcing (ZF) equalizer suffers from two main problems; the noise enhancement and the high complexity due to direct matrix inversion, especially with a large number of sub-carriers. On the other hand, the Minimum Mean Square Error (MMSE) equalizer has a high complexity and requires estimation of the Signal-to-Noise Ratio (SNR). In this paper, we modify the structure of the traditional Orthogonal Frequency Division Multiplexing (OFDM) system by adding a Virtual Quadrature Phase Shift Keying (VQPSK) block that reduces the computational complexity of the equalization process, and duplicates the transmitted symbols.
       
 
 
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