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COMPUTER SCIENCE (1148 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 872 Journals sorted alphabetically
3D Printing and Additive Manufacturing     Full-text available via subscription   (Followers: 11)
Abakós     Open Access   (Followers: 3)
Academy of Information and Management Sciences Journal     Full-text available via subscription   (Followers: 67)
ACM Computing Surveys     Hybrid Journal   (Followers: 23)
ACM Journal on Computing and Cultural Heritage     Hybrid Journal   (Followers: 8)
ACM Journal on Emerging Technologies in Computing Systems     Hybrid Journal   (Followers: 13)
ACM Transactions on Accessible Computing (TACCESS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Applied Perception (TAP)     Hybrid Journal   (Followers: 6)
ACM Transactions on Architecture and Code Optimization (TACO)     Hybrid Journal   (Followers: 9)
ACM Transactions on Autonomous and Adaptive Systems (TAAS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Computation Theory (TOCT)     Hybrid Journal   (Followers: 11)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Computer Systems (TOCS)     Hybrid Journal   (Followers: 18)
ACM Transactions on Computer-Human Interaction     Hybrid Journal   (Followers: 12)
ACM Transactions on Computing Education (TOCE)     Hybrid Journal   (Followers: 3)
ACM Transactions on Design Automation of Electronic Systems (TODAES)     Hybrid Journal   (Followers: 1)
ACM Transactions on Economics and Computation     Hybrid Journal  
ACM Transactions on Embedded Computing Systems (TECS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Information Systems (TOIS)     Hybrid Journal   (Followers: 20)
ACM Transactions on Intelligent Systems and Technology (TIST)     Hybrid Journal   (Followers: 9)
ACM Transactions on Interactive Intelligent Systems (TiiS)     Hybrid Journal   (Followers: 4)
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMCCAP)     Hybrid Journal   (Followers: 10)
ACM Transactions on Reconfigurable Technology and Systems (TRETS)     Hybrid Journal   (Followers: 7)
ACM Transactions on Sensor Networks (TOSN)     Hybrid Journal   (Followers: 8)
ACM Transactions on Speech and Language Processing (TSLP)     Hybrid Journal   (Followers: 11)
ACM Transactions on Storage     Hybrid Journal  
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
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: 25)
Advanced Science Letters     Full-text available via subscription   (Followers: 6)
Advances in Adaptive Data Analysis     Hybrid Journal   (Followers: 8)
Advances in Artificial Intelligence     Open Access   (Followers: 15)
Advances in Artificial Neural Systems     Open Access   (Followers: 4)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Computer Science : an International Journal     Open Access   (Followers: 13)
Advances in Computing     Open Access   (Followers: 3)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 54)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
Advances in Human-Computer Interaction     Open Access   (Followers: 19)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Advances in Technology Innovation     Open Access  
AEU - International Journal of Electronics and Communications     Hybrid Journal   (Followers: 8)
African Journal of Information and Communication     Open Access   (Followers: 6)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Air, Soil & Water Research     Open Access   (Followers: 7)
AIS Transactions on Human-Computer Interaction     Open Access   (Followers: 6)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1)
Algorithms     Open Access   (Followers: 9)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 3)
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: 2)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 5)
Analysis in Theory and Applications     Hybrid Journal  
Animation Practice, Process & Production     Hybrid Journal   (Followers: 5)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 8)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Software Engineering     Hybrid Journal   (Followers: 12)
Annual Reviews in Control     Hybrid Journal   (Followers: 6)
Anuario Americanista Europeo     Open Access  
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applied and Computational Harmonic Analysis     Full-text available via subscription   (Followers: 2)
Applied Artificial Intelligence: An International Journal     Hybrid Journal   (Followers: 14)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Clinical Informatics     Hybrid Journal   (Followers: 1)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Computer Systems     Open Access   (Followers: 1)
Applied Informatics     Open Access  
Applied Mathematics and Computation     Hybrid Journal   (Followers: 31)
Applied Medical Informatics     Open Access   (Followers: 9)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Soft Computing     Hybrid Journal   (Followers: 16)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Architectural Theory Review     Hybrid Journal   (Followers: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4)
Archive of Numerical Software     Open Access  
Archives and Museum Informatics     Hybrid Journal   (Followers: 121)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Artifact     Hybrid Journal   (Followers: 2)
Artificial Life     Hybrid Journal   (Followers: 5)
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  
Automatic Control and Computer Sciences     Hybrid Journal   (Followers: 3)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Automatica     Hybrid Journal   (Followers: 9)
Automation in Construction     Hybrid Journal   (Followers: 6)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Basin Research     Hybrid Journal   (Followers: 3)
Behaviour & Information Technology     Hybrid Journal   (Followers: 52)
Bioinformatics     Hybrid Journal   (Followers: 258)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Briefings in Bioinformatics     Hybrid Journal   (Followers: 45)
British Journal of Educational Technology     Hybrid Journal   (Followers: 123)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
c't Magazin fuer Computertechnik     Full-text available via subscription   (Followers: 1)
CALCOLO     Hybrid Journal  
Calphad     Hybrid Journal  
Canadian Journal of Electrical and Computer Engineering     Full-text available via subscription   (Followers: 13)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
Cell Communication and Signaling     Open Access   (Followers: 1)
Central European Journal of Computer Science     Hybrid Journal   (Followers: 5)
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: 7)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
CIN Computers Informatics Nursing     Full-text available via subscription   (Followers: 12)
Circuits and Systems     Open Access   (Followers: 14)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
CLEI Electronic Journal     Open Access  
Clin-Alert     Hybrid Journal   (Followers: 1)
Cluster Computing     Hybrid Journal   (Followers: 1)
Cognitive Computation     Hybrid Journal   (Followers: 4)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Communication Methods and Measures     Hybrid Journal   (Followers: 11)
Communication Theory     Hybrid Journal   (Followers: 19)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Algebra     Hybrid Journal   (Followers: 3)
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: 18)
COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering     Hybrid Journal   (Followers: 3)
Complex & Intelligent Systems     Open Access  
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: 9)
Computación y Sistemas     Open Access  
Computation     Open Access  
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational and Structural Biotechnology Journal     Open Access   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Astrophysics and Cosmology     Open Access   (Followers: 1)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computational Cognitive Science     Open Access   (Followers: 1)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Condensed Matter     Open Access  
Computational Ecology and Software     Open Access   (Followers: 8)
Computational Economics     Hybrid Journal   (Followers: 9)
Computational Geosciences     Hybrid Journal   (Followers: 13)
Computational Linguistics     Open Access   (Followers: 23)
Computational Management Science     Hybrid Journal  
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Molecular Bioscience     Open Access   (Followers: 2)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Particle Mechanics     Hybrid Journal   (Followers: 1)
Computational Research     Open Access   (Followers: 1)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computational Science and Techniques     Open Access  
Computational Statistics     Hybrid Journal   (Followers: 13)
Computational Statistics & Data Analysis     Hybrid Journal   (Followers: 28)
Computer     Full-text available via subscription   (Followers: 81)
Computer Aided Surgery     Hybrid Journal   (Followers: 3)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Communications     Hybrid Journal   (Followers: 10)
Computer Engineering and Applications Journal     Open Access   (Followers: 5)
Computer Journal     Hybrid Journal   (Followers: 7)
Computer Methods in Applied Mechanics and Engineering     Hybrid Journal   (Followers: 22)
Computer Methods in Biomechanics and Biomedical Engineering     Hybrid Journal   (Followers: 10)
Computer Methods in the Geosciences     Full-text available via subscription   (Followers: 1)
Computer Music Journal     Hybrid Journal   (Followers: 13)
Computer Physics Communications     Hybrid Journal   (Followers: 6)
Computer Science - Research and Development     Hybrid Journal   (Followers: 7)
Computer Science and Engineering     Open Access   (Followers: 17)
Computer Science and Information Technology     Open Access   (Followers: 11)
Computer Science Education     Hybrid Journal   (Followers: 12)
Computer Science Journal     Open Access   (Followers: 20)
Computer Science Master Research     Open Access   (Followers: 10)

        1 2 3 4 5 6 | Last

Journal Cover AEU - International Journal of Electronics and Communications
  [SJR: 0.318]   [H-I: 36]   [8 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1434-8411
   Published by Elsevier Homepage  [3042 journals]
  • Low-complexity scheduling for energy-efficient transmission of packets
           with individual deadlines
    • Authors: Siping Liu; Zhangdui Zhong
      Pages: 1 - 8
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Siping Liu, Zhangdui Zhong
      This paper aims at energy-efficient transmission of packets with individual deadlines. In order to reduce the transmission energy of a packet, a lower data rate should be adopted, while the deadline restraint leads to a rate lower limit. It is derived theoretically that the energy-optimal transmission, i.e., the transmission consuming the minimal energy, follows three theorems: (1) the rate is invariable except for the deadlines of the packets; (2) the rate is non-increasing over the whole transmission time; (3) if the rate decreases at a deadline, only the terminated packets have been transmitted. Then, a scheduling algorithm based on backward unidirectional valve (BUV) is proposed, where the packets are divided into multiple groups and each group corresponds to a fixed rate. Specifically, the packets are handled one by one, and any packet is taken as a new group in the initial. If the transmission rate of the new group is not lower than that of its preceding neighboring group, the two groups are amalgamated into one, and this procedure is implemented constantly before the rate decreases in stairs. The BUV scheduling not only achieves the energy-optimal transmission, but also has a low computational complexity.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.04.036
      Issue No: Vol. 79 (2017)
  • Improved online fountain codes based on shaping for left degree
    • Authors: Taiqi Huang; Benshun Yi
      Pages: 9 - 15
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Taiqi Huang, Benshun Yi
      In this paper, an improved encoding scheme for online fountain codes is proposed with the joint optimization of variable node degree and check node degree is proposed. The coding scheme can be divided into the build-up phase and the completion phase. In the build-up phase, left degree distribution is exploited to guarantee optimal performance phase by modifying the traditional coding scheme of choosing input symbols uniformly at random. A memory-based selecting of the source symbols is employed to decrease the number of connected components, which can thus produce the dimension increasement of the linear subspace of a decoding graph constructed in the build-up phase. The upper bound on coding overhead is also derived from the analysis of random graph theory. Compared with conventional online fountain codes, it can be seen from the simulation results that the proposed scheme can provide significant performance improvement with respect to both coding overhead and feedback cost. Moreover, the lower encoding/decoding complexities may make the proposed scheme more practical in energy-constrained applications such as distributed storage.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.05.035
      Issue No: Vol. 79 (2017)
  • Compact wideband Gysel power dividers with harmonic suppression and
           arbitrary power division ratios
    • Authors: Hamed Shahi; Hossein Shamsi
      Pages: 16 - 25
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Hamed Shahi, Hossein Shamsi
      This paper presents a wideband power divider (PD) with a high level of harmonic suppression, wide stopband bandwidth, arbitrary power division ratios, miniaturized dimensions, and high power-handling capability (PHC). The proposed structure consists of five open stubs to suppress the second- to forth- harmonic frequencies, two grounded resistors for better PHC, one resistor between output ports for enhancing the bandwidth of the circuit, and six branch line sections. Derivation of closed-form equations has been performed for the parameters of the proposed structure. The circuit has the flexibility in choosing the values of two load resistors to determine the bandwidth and the level of PHC. To demonstrate the features of the proposed PD, four different examples of the structure are conducted. Furthermore, for verification purposes, two prototypes of the PD with different power division ratios are fabricated and measured at 1GHz. Meanwhile, the PDs have power division ratio of k2 =1 and k2 =1.5. The simulation and measurement results have good agreement with each other and confirm the theoretical procedure. This new structure is suitable for wideband, miniaturized, arbitrary power division ratios, and high power applications.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.05.024
      Issue No: Vol. 79 (2017)
  • A low-power rail-to-rail input-range linear delay element circuit
    • Authors: Hassan Rivandi; Sudeh Ebrahimi; Mehdi Saberi
      Pages: 26 - 32
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Hassan Rivandi, Sudeh Ebrahimi, Mehdi Saberi
      Delay elements are one of the key components in many time-domain circuits such as time-based analog-to-digital converters. In this paper, a new rail-to-rail current-starved delay element is proposed which not only presents good linearity for the voltage-delay curve over the input range of ground to supply voltage, but also it consumes a dynamic power only during the transition times without consuming any static power. The proposed delay element is designed and simulated in a 0.13-µm CMOS technology with a supply voltage of 1.2V. Post-layout simulation results demonstrate that the proposed circuit has a linear voltage-delay transfer function with a voltage-to-time gain of −1.33ps/mV. Moreover, when samples of a full-scale sin-wave input signal are applied to the proposed circuit with a clock frequency of 100MHz, the power consumption is 30µW, and signal-to-noise-and-distortion ratio (SNDR) of the output delay times is 30.4dB, making it suitable for use in a time-based analog-to-digital converter with up to 5-bit resolution.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.04.037
      Issue No: Vol. 79 (2017)
  • An efficient privacy-preserving scheme for secure network coding based on
           compressed sensing
    • Authors: Dong Xie; Haipeng Peng; Lixiang Li; Yixian Yang
      Pages: 33 - 42
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Dong Xie, Haipeng Peng, Lixiang Li, Yixian Yang
      Network coding (NC) provides an elegant solution for improving capacity and robustness in computer networks. Different to traditional “store-and-forward” transmission paradigm, each intermediate node linearly combines received data packets, and the original files can be decoded at the sink nodes in NC settings. This brand-new paradigm is vulnerable to pollution attack, which means that some malicious nodes inject fake data packets into the network and this will lead to incorrect decoding. There are some information-theoretical solutions and cryptographic solutions for solving this security issue, and most existing schemes can thwart data pollution attacks. However, the privacy of the original files are vital to some application environments (e.g. military network). To the best of our knowledge, there is not a secure scheme which can thwart pollution attack and can protect the privacy of transmitted data simultaneously. In this paper, we present an efficient privacy-preserving scheme for secure network coding based on compressed sensing (CS), which has attracted considerable research interest in the signal processing community. Specifically, we embed CS into the general NC framework, i.e., the source node needs to compress each original data packet using the sensing matrix before creating the augmented vector and the sink nodes require to perform an additional CS reconstruction algorithm for reconstructing the original file. In addition, we construct a simple key distribution protocol and each intermediate node just needs two secret keys for verifying the integrity of received data packets. Such novel hybrid construction enables the privacy-preserving guarantee, and the performance comparison shows the high-efficiency of our scheme in terms of the computational complexity and communication overhead.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.05.028
      Issue No: Vol. 79 (2017)
  • Chaos generation in fractional-order switched systems and its digital
    • Authors: E. Zambrano-Serrano; J.M. Muñoz-Pacheco; E. Campos-Cantón
      Pages: 43 - 52
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): E. Zambrano-Serrano, J.M. Muñoz-Pacheco, E. Campos-Cantón
      A double-scroll chaotic attractor generated by a fractional-order switched system is presented. Based on unstable dissipative systems (UDS) and a switching law, a fractional-order UDS is proposed. Chaos behavior is found with a fractional order as low as 2.568 by satisfying the stability criterion for fractional order chaotic systems. The fractional-order switched system is transformed to an equivalent switched system with augmented states. Then, the equivalent system is straightforward implemented on an ARM system-on-chip board by using Python high level programming language. Numerical simulations are in good agreement with experimental results, which demonstrates the usefulness of proposed method. Additionally, the test 0–1 and a chaos definition for finite state sets are given to demonstrate chaotic behavior. Finally, a random number generator is also proposed as a possible application.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.05.032
      Issue No: Vol. 79 (2017)
  • A modified Otsu’s algorithm for improving the performance of the energy
           detector in cognitive radio
    • Authors: A.J. Onumanyi; E.N. Onwuka; A.M Aibinu; O.C. Ugweje; M.J.E. Salami
      Pages: 53 - 63
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): A.J. Onumanyi, E.N. Onwuka, A.M Aibinu, O.C. Ugweje, M.J.E. Salami
      In this paper, we present a modified Otsu’s algorithm for solving the automatic threshold estimation problem in energy detection based Cognitive Radio (CR) application. The modified algorithm was tested extensively and compared with other known algorithms using both simulated and real datasets. In particular, our findings reveal that the modified algorithm provides an averagely lower false alarm rate than the other techniques compared with in this paper. Furthermore, the results obtained show that the algorithm is independent of the bandwidth’s size, while having a total complexity of O ( V ) , where V is the total sample size. Thus, from the results of this paper, full and effective automatic blind spectrum sensing using an Energy Detector is possible in CR. This can be achieved at a Signal-to-Noise Ratio of 5dB to meet the IEEE 802.22 draft standard of P D > 90 % and P FA < 10 % .

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.04.013
      Issue No: Vol. 79 (2017)
  • A systematic realization of third-order quadrature oscillator with
           controllable amplitude
    • Authors: Hua-Pin Chen; Yuh-Shyan Hwang; Yi-Tsen Ku
      Pages: 64 - 73
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Hua-Pin Chen, Yuh-Shyan Hwang, Yi-Tsen Ku
      A systematic realization of third-order quadrature oscillator using a voltage-mode non-inverting lowpass filter and a voltage-mode inverting lossless feedback integrator is presented in this paper. The proposed circuit consists of two multiple-output differential voltage current conveyor transconductance amplifiers (MO-DVCCTAs), two grounded resistors and three grounded capacitors. The new circuit provides three quadrature voltage outputs, two high-impedance quadrature current outputs, and one high-impedance current output with controllable amplitude, simultaneously. When the input bias current of the first MO-DVCCTA is a modulating signal, the circuit can generate amplitude modulation or amplitude shift keying signals. The condition of oscillation and the frequency of oscillation can be controlled independently through grounded resistors. The proposed circuit only uses grounded capacitors and grounded resistors, which can be easily implemented as an integrated circuit. The experimental results and H-Spice simulation results are given to confirm the theoretical analysis.

      PubDate: 2017-06-05T07:03:08Z
      DOI: 10.1016/j.aeue.2017.05.039
      Issue No: Vol. 79 (2017)
  • New differential difference stage and its application to band-pass filter
           at 10.7MHz with high quality factor
    • Authors: Abdullah Yesil; Firat Kacar; Shahram Minaei
      Pages: 74 - 82
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Abdullah Yesil, Firat Kacar, Shahram Minaei
      In this study, we present a new NMOS implementation of differential difference stage containing only eight transistors. The introduced new differential difference stage has high input impedance and low output impedance; accordingly, it can be directly cascaded without loading effect. In addition, a detailed study on the input referred noise voltage density of the proposed differential difference stage is performed and low noise design possibility is investigated. As an example, to show performance of differential difference stage, a modified band-pass filter with high quality factor is presented for intermediate frequency stage of FM receiver. Furthermore, the non-ideal, parasitic and stability analyses of the presented filter having high quality factor are surveyed and its working boundaries are determined.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.022
      Issue No: Vol. 79 (2017)
  • Optimum design of a wideband planar N-way fork power divider with
           arbitrary power division and input-to-output impedance matching
    • Authors: Homayoon Oraizi; Atie Yousefi
      Pages: 83 - 93
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Homayoon Oraizi, Atie Yousefi
      An effective design procedure based on method of least squares is proposed for multi-section and multi-output fork power divider/combiner with arbitrary power division ratios among its outputs in a specified frequency bandwidth together with impedance matching among its arbitrary source/load impedances. Transmission and scattering matrices are obtained for its equivalent circuit. An error function is constructed based on design specifications on its output power division ratios, isolations among output ports, return losses at its input and output ports and source/load impedances in a desired frequency bandwidth. The design procedure is fully developed, which determines the widths and lengths of microstrip line sections and resistor values. A design example is described for unequal power division ratio and unequal input/output impedances. A 3-section and 3-output fork power divider is designed for equal power division and load/source impedances for 2–12GHz band. It is fabricated and measured. Variations of its transmission coefficients are less than 0.5dB, isolations at its outputs are better than −15dB and reflection coefficients at its ports are better than −10dB. Excellent agreement is observed among the results of the proposed design procedure, full wave computer software and measurement data.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.038
      Issue No: Vol. 79 (2017)
  • On the distributed order PID controller
    • Authors: Boris B. Jakovljević; Tomislav B. Šekara; Milan R. Rapaić; Zoran D. Jeličić
      Pages: 94 - 101
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Boris B. Jakovljević, Tomislav B. Šekara, Milan R. Rapaić, Zoran D. Jeličić
      This paper proposes a generalized fractional controller that covers the complete range of differintegrators of order −1 to order 1. This controller is named distributed order PID controller (DOPID) due to the fact that it broadens the structure of the conventional PID controller. Furthermore, a new method for implementation of distributed order PID controller (DOPID), as well as analysis of its properties in both time and frequency domain are proposed. As DOPID controller represents generalized classical PID controller, it is approximated by a compound fractional controller with multiple fractional differintegrators, with multiple gains, connected in parallel. Orders of these differintegrators have been equally spaced, with the first one being the first order classical integrator, and the last one being the first order classical differentiator. Noise cancellation filter is considered explicitly in the controller’s structure.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.036
      Issue No: Vol. 79 (2017)
  • Optical wireless communications omnidirectional receivers for vehicular
    • Authors: Alberto Rui Frutuoso Barroso; Julia Johnson
      Pages: 102 - 109
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Alberto Rui Frutuoso Barroso, Julia Johnson
      Wide aperture omnidirectional free-space optical (FSO) receivers using wavelength shifting (WLS) fibers that enable the use of small active area high-speed photodetectors in optical wireless communications, are presented. In particular, the influence of WLS fiber decay time in the bit rate is evaluated when receiving intensity modulated light generated with commercial off-the-shelf light-emitting diodes. The option of increasing the photon collecting area of a 7 mm 2 active area avalanche photodiode using WLS fiber, gave a 300% improvement in the bit rate, when compared with the option of using a bare 31 mm 2 active area avalanche photodiode. It was also experimentally verified, that a WLS spiral receiver mounted over a reflective base gave more gain than simulated Lambert‘s cosine law, proving that reflective optics can be used to increase the WLS-FSO receiver aperture.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.042
      Issue No: Vol. 79 (2017)
  • Timing synchronizer and its architecture for OFDM-based high-throughput
           millimeter wave systems
    • Authors: Trong Nghia Le; Yi-Ting Hsieh; Wen-Long Chin
      Pages: 110 - 115
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Trong Nghia Le, Yi-Ting Hsieh, Wen-Long Chin
      In this work, a new symbol time synchronization and its architecture design for high-throughput millimeter wave systems based on orthogonal frequency-division multiplexing (OFDM) are introduced. Complementary Golay sequences with good signal properties are popular training sequences used for the preamble design of a multi-gigabit communication system, which is the promising technology for future 5G communications. The basic idea of our contribution is to obtain a time estimate based on the aperiodic autocorrelation function (ACF) of complementary Golay sequences. Besides, achieving low power consumption and less chip area remains the challenge of high-throughput millimeter wave systems. To achieve over 2.64GSamples/s throughput requirement, the proposed algorithm is especially suitable for the parallel design architecture of very high throughput receivers. Moreover, the complexity is further reduced by employing the correlation characteristic of the ACF of complementary Golay sequences and the regularity of the algorithm. Simulations confirm the advantages of the proposed synchronizer.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.043
      Issue No: Vol. 79 (2017)
  • Grounded capacitor based fully cascadable electronically tunable
           current-mode universal filter
    • Authors: Firat Yucel; Erkan Yuce
      Pages: 116 - 123
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Firat Yucel, Erkan Yuce
      A novel current-mode (CM) universal filter configuration composed of five plus-type second-generation current conveyors (CCII+s) as active components besides three resistors and three grounded capacitors as passive elements is proposed in this paper. The proposed filter can simultaneously provide high-pass, band-pass and low-pass responses. Also, it can realize all-pass and notch responses with interconnection of convenient output currents. It can be cascaded with other CM ones easily because it has low input and high output impedances. It offers orthogonal control of angular resonance frequency and quality factor. An electronically tunable universal filter can be easily obtained if plus-type current controlled current conveyors are replaced instead of each of the five CCII+s and all the three resistors are removed. Nevertheless, it needs a single passive element matching constraint for notch and all-pass filter responses. Some simulation and experimental test results are included to confirm the theory.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.041
      Issue No: Vol. 79 (2017)
  • Performance enhancement of patch antenna array for 5.8GHz Wi-MAX
           applications using metamaterial inspired technique
    • Authors: Chirag Arora; Shyam S. Pattnaik; R.N. Baral
      Pages: 124 - 131
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Chirag Arora, Shyam S. Pattnaik, R.N. Baral
      Though a microstrip patch antenna has advantages of low profile and structural planarity, but a single microstrip patch antenna has limitation of low gain and narrow bandwidth. To overcome these problems, multi-layer structures are used. The antenna performance can further be enhanced, if multi-layer structures are designed for array of patch antennas. Moreover, the simultaneous improvement of gain and bandwidth, which are two conflicting parameters, is another challenge. To meet these challenges, this article proposes a microstrip patch antenna array, inspired with a superstrate – comprising of Split Ring Resonators (SRR) and wire strips. Gain and bandwidth of 4.3dBi and 425MHz, respectively, is achieved by an unloaded array at IEEE 802.16a 5.8GHz Wi-MAX band. However, by covering this array with the proposed superstrate, gain and bandwidth of 12.1dBi and 780MHz, respectively, is obtained, thus providing the gain improvement of 7.8dBi and bandwidth enhancement of 355MHz. Fabrication and testing of the proposed antenna is done for comparing simulated and measured results. Equivalent circuit of this newly devised array has been designed and discussed.

      PubDate: 2017-06-10T07:26:01Z
      DOI: 10.1016/j.aeue.2017.05.045
      Issue No: Vol. 79 (2017)
  • General study of jitter mechanisms for metric-based wireless routing
    • Authors: Shahbaz Rezaei; Ali Mohammad Afshin Hemmatyar
      Pages: 132 - 140
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Shahbaz Rezaei, Ali Mohammad Afshin Hemmatyar
      To ameliorate high collision, a nefarious side effect of route discovery stage of reactive routing protocols in wireless networks, jitter mechanisms are proposed which enforce wireless nodes to postpone their transmission for a random amount of time so as to reduce probability of simultaneous transmission. Although it has been shown that jitter mechanisms can dramatically improve reactive routing protocols, it was not until recently that jitter mechanisms have been subjected to study. In this paper, different random distributions are proposed for jittering mechanisms and also shaping function, with the aim of which a simple routing protocol like AODV becomes sensitive to any arbitrary metric, is defined. Comprehensive simulation of routing metrics and jitter mechanisms have revealed that simple modification of a jitter mechanism, which can be even implemented independent of a routing protocol, greatly improves routes discovered by any routing protocol.

      PubDate: 2017-06-14T08:49:35Z
      DOI: 10.1016/j.aeue.2017.05.044
      Issue No: Vol. 79 (2017)
  • Fractional Order Linear Variable Differential Transformer: Design and
    • Authors: Parthasarathi Veeraian; Uma Gandhi; Umapathy Mangalanathan
      Pages: 141 - 150
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Parthasarathi Veeraian, Uma Gandhi, Umapathy Mangalanathan
      Linear Variable Differential Transformer (LVDT) is the most preferred displacement measurement transducer used in industries because of its simple design and proven reliability. The major challenge faced in LVDT is linearity in limited stroke range. In this paper, a fractional order model of LVDT is developed and its characteristics like sensitivity, nonlinearity and stroke range are analysed by considering fractional behaviour only in self-inductance, mutual inductance and both. The results presented in this paper shows that Fractional Order Linear Variable Differential Transformer (FOLVDT) provides high sensitivity with reduced nonlinearity compared to the conventional LVDT. The results also demonstrate that the FOLVDT can be operated for increased stroke range without compromising on sensitivity and linearity.

      PubDate: 2017-06-14T08:49:35Z
      DOI: 10.1016/j.aeue.2017.05.037
      Issue No: Vol. 79 (2017)
  • Analysis of nanometer-scale InGaAs/InAs/InGaAs composite channel MOSFETs
           using high-K dielectrics for high speed applications
    • Authors: J. Ajayan; D. Nirmal; P. Prajoon; J. Charles Pravin
      Pages: 151 - 157
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): J. Ajayan, D. Nirmal, P. Prajoon, J. Charles Pravin
      The outstanding electron transport properties of InGaAs and InAs semiconductor materials, makes them attractive candidates for future nano-scale CMOS. In this paper, the ON state and OFF state performance of 30nm gate length InGaAs/InAs/InGaAs buried composite channel MOSFETs using various high-K dielectric materials is analyzed using Synopsys TCAD tool. The device features a composite channel to enhance the mobility, an InP spacer layer to minimize the defect density and a heavily doped multilayer cap. The simulation results show that MOSFETs with Al2O3/ZrO2 bilayer gate oxide exhibits higher gm/ID ratio and lower sub threshold swing than with the other dielectric materials. The measured values of threshold voltage (VT), on resistance (RON) and DIBL for Lg=30nm In0.53Ga0.47As/InAs/In0.53Ga0.47As composite channel MOSFET having Al2O3/ZrO2 (EOT=1.2nm) bilayer dielectric as gate oxide are 0.17V, 290Ω-µm, and 65mV/V respectively. The device displays a transconductance of 2mS/µm.

      PubDate: 2017-06-14T08:49:35Z
      DOI: 10.1016/j.aeue.2017.06.004
      Issue No: Vol. 79 (2017)
  • A novel 2-DOF fractional-order PIλ-Dμ controller with inherent
           anti-windup capability for a magnetic levitation system
    • Authors: Sandeep Pandey; Prakash Dwivedi; A.S. Junghare
      Pages: 158 - 171
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Sandeep Pandey, Prakash Dwivedi, A.S. Junghare
      The facility of an extra degree-of-freedom (DOF) to reshape the transient response of unstable systems arises to the concept of 2-DOF controller. Integration of fractional calculus strengthens the performance of it. In this paper, a novel methodology for the design of a 2-DOF PI λ - D μ controller for a class of open-loop unstable systems is proposed and is applied in a magnetic levitation system (MLS). The restructuring of PI λ controller dematerializes the requirement of a dedicated anti-wind scheme for removing the actuator saturation problem. A new graphical tuning approach is suggested to tune the fractional order parameters of the controller and the integer order gain parameters are decided by employing the pole-placement technique. Stability of the proposed controller scheme employed to MLS is analyzed on the basis of Riemann sheets concept in w-plane. Experimental demonstration of proposed scheme on MLS confirms the ability of the controller to reject the external random perturbations as well as actuator saturation.

      PubDate: 2017-06-14T08:49:35Z
      DOI: 10.1016/j.aeue.2017.05.031
      Issue No: Vol. 79 (2017)
  • A linear ultra wide band low noise amplifier using pre-distortion
    • Authors: Roya Jafarnejad; Abumoslem Jannesari; Jafar Sobhi
      Pages: 172 - 183
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Roya Jafarnejad, Abumoslem Jannesari, Jafar Sobhi
      This paper presents an Ultra Wide-Band (UWB) high linear low noise amplifier. The linearity of Common Gate (CG) structure is improved based on pre-distortion technique. An auxiliary transistor is used at the input to sink the nonlinear terms of source current, resulting linearity improvement. Furthermore, an inductor is used in the gate of the main amplifying transistor, which efficiently improves gain, input matching and noise performance at higher frequencies. Detailed mathematical analysis show the effectiveness of both linearity improvement and bandwidth extension techniques. Post-layout simulation results of the proposed LNA in TSMC 0.18µm RF-CMOS process show a gain of 13.7dB with −3dB bandwidth of 0.8–10.4GHz and minimum noise figure (NF) of 3dB. Input Third Intercept Point (IIP3) of 10.3–13dBm is achieved which shows 8dB improvement compared to conventional common gate structure. The core circuit occupies an area of 0.19mm2 including bond pads, while consuming 4mA from a 1.8-V supply.

      PubDate: 2017-06-14T08:49:35Z
      DOI: 10.1016/j.aeue.2017.05.046
      Issue No: Vol. 79 (2017)
  • A 5Gbps serial link pre-emphasis transmitter with a novel-designed
           register based multiplexer
    • Authors: Xiaoran Li; Shunan Zhong; Fei Shi; Weijiang Wang
      Pages: 184 - 191
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Xiaoran Li, Shunan Zhong, Fei Shi, Weijiang Wang
      A serial link transmitter with 4-tap pre-emphasis is presented in this manuscript. The system consists of two 5:1 multiplexers, a 2:1CML multiplexer, and a driver with 4-tap pre-emphasis. A new 5:1 multiplexer structure is proposed to prevent sampling on the data edge, which shows a lower power consumption and chip size. Implement in standard 180nm CMOS 1P6M process with 1.8V power supply, the newly designed transmitter can be able to work with bit error rate (BER) as 10−14. The transmitter output jitter is 0.09UI while the amplitude can reach from 540mV to 750mV.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.05.033
      Issue No: Vol. 79 (2017)
  • SRR and S-shape slot loaded triple band notched UWB antenna
    • Authors: Ajay Yadav; Sweta Agrawal; R.P. Yadav
      Pages: 192 - 198
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Ajay Yadav, Sweta Agrawal, R.P. Yadav
      This paper demonstrates the design of a triple band notched ultrawideband circular microstrip patch antenna loaded with Complementary Split RingResonator (CSRR) and S-shaped slot in microstrip feed line. Complementary Split Ring Resonator slot and S-shaped slot are used to produce band notched characteristics for WiMAX band (3.30–3.60GHz) and WLAN band (5.10–5.80GHz) respectively. The downlink frequency band (7.25–7.75GHz) of X-band for satellite communication is notched using Symmetrical Split Ring Resonator Pair (SSRRP) as electromagnetic coupling element near microstrip feed line which produces band stop characteristics. Measured results of fabricated antenna prototype are compared with simulated results and found in correspondence. The VSWR and vector current plots show evidence of the significant suppression in the desired frequency bands.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.06.003
      Issue No: Vol. 79 (2017)
  • Resonant characteristics of aperture type FSS and its application in
           directivity improvement of microstrip antenna
    • Authors: Samineni Peddakrishna; Taimoor Khan; Binod Kumar Kanaujia
      Pages: 199 - 206
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Samineni Peddakrishna, Taimoor Khan, Binod Kumar Kanaujia
      In this paper, we propose an aperture type frequency selective surface (FSS) by employing an array of 12×12 unit cell elements and its resonant characteristics is analyzed. A resonant cavity antenna is then formed by the ground plane substrate and the FSS superstrate. The high reflective behavior of the proposed FSS at an offset of the resonance is then utilized for improving the performance of this cavity antenna. The impedance bandwidth and directivity are improved up to 0.66GHz and 8.95dBi, simultaneously at an optimum gap of 17.6mm between the antenna substrate and FSS superstrate. For validation purpose, prototypes of both patch antenna and FSS, are fabricated and characterized. A fairly good agreement is achieved between the measured and simulated results.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.06.007
      Issue No: Vol. 79 (2017)
  • Real-time image tamper localization based on fragile watermarking and
           Faber-Schauder wavelet
    • Authors: Assma Azeroual; Karim Afdel
      Pages: 207 - 218
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Assma Azeroual, Karim Afdel
      This paper presents a real-time image tamper detection and localization based on fragile watermarking and Faber-Schauder discrete wavelet transform (FSDWT). The maximum coefficients of FSDWT are used with a logo to generate the watermark which is embedded in the least significant bit (LSB) of specified pixels of the original image. Experimental results prove the effectiveness of the proposed method through a series of attacks and affirm that the requirements of imperceptibility, fidelity, effectiveness and real-time processing are satisfied. The proposed method contains simple operations and has low complexity, hence, it is suitable for applications working on real-time.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.06.001
      Issue No: Vol. 79 (2017)
  • Hybridized ABC-GA optimized fractional order fuzzy pre-compensated FOPID
           control design for 2-DOF robot manipulator
    • Authors: Anupam Kumar; Vijay Kumar
      Pages: 219 - 233
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Anupam Kumar, Vijay Kumar
      The robotic manipulator is an extremely nonlinear, multi-input multi-output (MIMO), highly coupled, and complex system wherein the parameter uncertainties and external disturbances adversely affect the performance of this system. From this, it necessitates that the controllers designed for such system must overcome these complexities. In this paper, we develop a novel fractional order fuzzy pre-compensated fractional order PID (FOFP-FOPID) controller for 2-degree of freedom (2-DOF) manipulator dealing with trajectory tracking problem. In order to optimize the controller’s parameters while minimizing integral of time absolute error (ITAE), a metaheuristic optimization technique, viz., artificial bee colony-genetic algorithm (ABC-GA) is presented. The efficacy of our proposed controller is demonstrated by comparing it with some existing controllers, such as integer order fuzzy pre-compensated PID (IOFP-PID), fuzzy PID (FPID), and conventional PID controllers. Furthermore, the robustness analysis for proposed controllers is also investigated for parameter variations and external disturbances. The simulation results indicate that FOFP-FOPID controller can not only guarantee the best trajectory tracking but also ameliorate the system robustness for parameter variations as well as external disturbances.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.06.008
      Issue No: Vol. 79 (2017)
  • Log-domain high-order low-pass and band-pass filters
    • Authors: Pipat Prommee; Preecha Thongdit; Krit Angkeaw
      Pages: 234 - 242
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Pipat Prommee, Preecha Thongdit, Krit Angkeaw
      Continuous time current-mode high-order low-pass and band-pass filters based on the log-domain concept are presented in this paper. The passive RLC ladder networks are used as the prototype to achieve the proposed filter by simulating the RLC network synthesis method. The achieved filters have inherited the good sensitivity performance from the RLC passive prototype. Fifth-order RLC ladder low-pass filter and sixth-order RLC ladder band-pass filter are used as prototypes and the signal flow graph (SFG) technique is used for the synthesis. The SFG can identify group of integrators and several signal paths. Log-domain lossy and lossless integrators based on BJT technology are deployed to achieve the integrators for realization of proposed filters. The simulations were carried out and the results exhibited several features which are in agreement with the RLC prototype. The frequency response of filters along 100kHz to 10MHz can be electronically tuned through 5–500µA of bias currents. The THD lower than 1% of LP and BP filters were measured at 10MHz input. The multi-tone tested was included in the paper for verifying the performance of proposed LP and BP filters. The intermodulation distortions around −50dB and −60dB were also investigated for the proposed LP and BP filters.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.06.014
      Issue No: Vol. 79 (2017)
  • Grounded capacitance multipliers based on active elements
    • Authors: Abdullah Yesil; Erkan Yuce; Shahram Minaei
      Pages: 243 - 249
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Abdullah Yesil, Erkan Yuce, Shahram Minaei
      In this study, we present two new grounded capacitance multiplier circuits based on a negative-type second-generation current conveyor (CCII-) and an inverting second-generation current conveyor (ICCII). The first proposed circuit consists of one CCII- and a voltage follower (VF) employing two NMOS transistors while the second proposed circuit is composed of an ICCII and an inverting voltage follower (IVF) including two NMOS transistors. Each circuit contains two resistors, and single grounded capacitor, which is attractive for integrated circuit realization. No active and passive component matching conditions are required for the realization of the proposed capacitance multiplier circuits. The simulation results are included to confirm the theory.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.06.006
      Issue No: Vol. 79 (2017)
  • Online task interleaving scheduling for the digital array radar
    • Authors: Haowei Zhang; Junwei Xie; Zhaojian Zhang; Binfeng Zong; Tangjun Chen
      Pages: 250 - 256
      Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Haowei Zhang, Junwei Xie, Zhaojian Zhang, Binfeng Zong, Tangjun Chen
      Aiming at the task scheduling problem in the DAR (digital array radar), an online task interleaving scheduling algorithm is proposed. The full structure of the DAR task is explicitly considered in a way that the waiting duration can be utilized to transmit or receive subtasks, which is called the task interleaving, as well as the receiving durations of different tasks can be overlapped. The algorithm decomposes the task interleaving analysis into the time resource constraint analysis and the energy resource constraint analysis, and online schedules all kinds of tasks that can be interleaved. Thereby the waiting durations and receiving durations can be fully utilized. The simulation results demonstrate that the proposed algorithm improves the successfully scheduling ratio by 73%, the high value ratio by 86% and the time utilization ratio by 55% compared with the HPEDF (highest priority and earliest deadline first) algorithm.

      PubDate: 2017-06-20T09:06:37Z
      DOI: 10.1016/j.aeue.2017.05.040
      Issue No: Vol. 79 (2017)
  • Excitation of piezoelectric device through resonant helical coil
           antenna-like structure
    • Authors: Praveen P Nayak; Durga P Kar; Satish kumar Samal; Ayesha Mohanty; Satyanarayan Bhuyan
      Pages: 1 - 6
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Praveen P Nayak, Durga P Kar, Satish kumar Samal, Ayesha Mohanty, Satyanarayan Bhuyan
      A resonant helical coil antenna-like structure has been explored for wireless excitation of piezoelectric devices. The basic idea behind this wireless excitation of piezoelectric device is electromagnetic resonance along with piezoelectric resonance. The analytical studies reveal that the maximum excitation occurs in the piezoelectric device when the operating frequency of the system coincides with its mechanical resonant frequency. It has been seen that the intensity of piezoelectric stimulation depends on the frequency of operation, air gap, relative position, electric load, and the generated electric field strength by the helical coil antenna-like structure. The analytical results are verified with the measured experimental results, and are found to be in well agreement. By adopting this proposed wireless excitation system the free actuation of the piezoelectric devices can be enabled as opposed to the confined motion for various potential applications.

      PubDate: 2017-05-21T08:41:40Z
      DOI: 10.1016/j.aeue.2017.05.006
      Issue No: Vol. 78 (2017)
  • A quad-polarization and frequency reconfigurable square ring slot loaded
           microstrip patch antenna for WLAN applications
    • Authors: Anantha Bharathi; Merugu Lakshminarayana; P.V.D. Somasekhar Rao
      Pages: 15 - 23
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Anantha Bharathi, Merugu Lakshminarayana, P.V.D. Somasekhar Rao
      In this paper, a novel polarization and frequency reconfigurable microstrip patch antenna which can switch between vertical and horizontal linear polarizations, left hand and right hand circular polarizations at two WLAN frequencies is presented. The orthogonal linear polarizations are achieved by a square microstrip patch antenna fed by two ports on adjacent sides. By introducing corner truncated perturbation on opposite corners of right diagonal of a square patch, orthogonal circular polarizations are achieved. By controlling the bias voltage of two PIN diodes loaded at perturbed corners, a single structure can achieve quad polarization states. Furthermore, by superimposing a square ring slot into the corner truncated square patch and incorporating four PIN diodes into the square ring slot, quad polarization are achieved at dual frequencies. Simulated and measured results indicate that the antenna can achieve quad polarization at two WLAN bands (5.15–5.35GHz) and (5.75–5.85GHz). The proposed antenna is simple, has low profile and can be scaled easily for other frequencies.

      PubDate: 2017-05-21T08:41:40Z
      DOI: 10.1016/j.aeue.2017.05.015
      Issue No: Vol. 78 (2017)
  • A wideband high gain dielectric resonator antenna for RF energy harvesting
    • Authors: Sachin Agrawal; Ravi Dutt Gupta; Manoj Singh Parihar; Praveen Neminath Kondekar
      Pages: 24 - 31
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Sachin Agrawal, Ravi Dutt Gupta, Manoj Singh Parihar, Praveen Neminath Kondekar
      A novel high gain and broadband hybrid dielectric resonator antenna (DRA) is designed and experimentally validated. To obtain the wide impedance bandwidth, the proposed antenna geometry combines the dielectric resonator antenna and an underlying slot with a narrow rectangular notch, which effectively broadens the impedance bandwidth by merging the resonances of the slot and DRA. An inverted T-shaped feed line is used to excite both antennas, simultaneously. It supports amalgamation of different resonant modes of the both, DRA and slot antenna. The measured results show that the proposed antenna offers an impedance bandwidth of 120% from 1.67 to 6.7GHz. The antenna gain is next enhanced by a reflector placed below the antenna at an optimum distance. On engineering the height and dimension of this reflector the antenna gain is improved from 2.2dBi to 8.7dBi at 1.7GHz. Finally, antenna operation is attested experimentally with a rectifier circuit in the frequency range of 1.8–3.6GHz, where various strong radio signals are freely available for RF energy harvesting. The measured maximum efficiency of the rectifier and rectenna circuit were found to be 74.4% and 61.4%, respectively.

      PubDate: 2017-05-21T08:41:40Z
      DOI: 10.1016/j.aeue.2017.05.018
      Issue No: Vol. 78 (2017)
  • Inductively coupled small self resonant coil (SSRC) reader antennas for HF
           RFID applications
    • Authors: Soheyl Soodmand; Tim W.C. Brown
      Pages: 32 - 40
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Soheyl Soodmand, Tim W.C. Brown
      A new model of inductively coupled high frequency radio frequency identification (HF RFID) reader antennas is presented in this paper based on the idea of using the self resonance frequency (SRF) of a small multi turn coil. The introduced multi turn small self resonant coil (MT SSRC) antenna is mathematically analyzed in terms of SRF, number of turns, dimensions and dielectric characteristics of the insulation, where present. Based on the analysis, a compact planar version of MT SSRC antennas having two turns, the two turn planar SSRC (TTP SSRC), is investigated and the dependency of the SRF to the antenna dimension is observed. A TTP SSRC antenna operating at 13.56MHz is fabricated and is compared with an old model of HF RFID antennas; an optimized Q factor and a more uniform near field pattern is obtained for the new antenna. The benefits of the obtained optimized Q factor and uniform near pattern is explained for smart shelf application. Also, a number of TTP SSRC antennas operating at a distinct frequency, 13.56MHz here, are fabricated on different substrates and it is shown that the Q factor and dimension of the TTP SSRC antenna could be controlled and adjusted based on the dielectric characteristics of the substrate. The new antenna prototype has a beneficial application to smart shelf applications in HF RFID.

      PubDate: 2017-05-21T08:41:40Z
      DOI: 10.1016/j.aeue.2017.05.019
      Issue No: Vol. 78 (2017)
  • Double stub microstrip fed two element Rectangular Dielectric Resonator
           Antenna for multiband operation
    • Authors: E. Vinodha; S. Raghavan
      Pages: 46 - 53
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): E. Vinodha, S. Raghavan
      This article presents a design of multiband Rectangular Dielectric Resonator Antenna (RDRA) using two elements with different aspect ratio. The proposed DRA is excited by means of micro-strip feedline with double stubs which not only improves the bandwidth of each band but also achieves good impedance matching. The proposed DRA operates at “C” band, “WLAN” and “X” band frequencies and yields wide bandwidth of about 6.5%, 13.5% and 17.4% respectively. Two Rectangular DRs of completely different aspect ratio and double stub microstrip feeding achieve this multiband operation. The designed antenna is very compact and has a volume of 1737mm3 only. It provides stable radiation patterns in all the three bands and has a maximum gain of 6.35dBi with radiation efficiency of more than 82% over the operating band of frequencies. The proposed antenna has been studied, analyzed and optimized using Ansoft HFSS simulation software. The designed antenna is fabricated, tested and compared with other multiband designs. Good agreement is achieved between simulated and measured ones.

      PubDate: 2017-05-26T09:46:01Z
      DOI: 10.1016/j.aeue.2017.05.020
      Issue No: Vol. 78 (2017)
  • Smith-fuzzy fractional control of systems with time delay
    • Authors: Isabel S. Jesus; Ramiro S. Barbosa
      Pages: 54 - 63
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Isabel S. Jesus, Ramiro S. Barbosa
      The fractional calculation is over 300years old, but only in the last decades its application arisen in many areas of science and engineering. The explanation for this expansion in the scientific and tecnologic worlds is due to the good results obtained in solving different problems, which have overcome the classics. On the other hand, in the control area there was an increasing interest in the development of new strategies, which resulted in new algorithms where the use of the fractional calculus revealed an helpfull tool. In this paper we apply the fractional order concepts into two systems with time delay. Several algorithms are investigated and compared, when integrated within a Smith predictor structure and with an optimal fuzzy fractional PD β +I controller in which the parameters are tuned by a genetic algorithm. Simulations are presented assessing the performance of the proposed fractional schemes.

      PubDate: 2017-05-26T09:46:01Z
      DOI: 10.1016/j.aeue.2017.05.014
      Issue No: Vol. 78 (2017)
  • Offset-fed complementary split ring resonators loaded monopole antenna for
           multiband operations
    • Authors: R. Samson Daniel; R. Pandeeswari; S. Raghavan
      Pages: 72 - 78
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): R. Samson Daniel, R. Pandeeswari, S. Raghavan
      A miniaturized multiband monopole antenna based on rectangular-shaped Complementary Split Ring Resonators (CSRRs) with offset-fed microstrip line is proposed for Global System for Mobile Communication (GSM) and Wireless Local Area Network (WLAN) applications. The proposed antenna is fabricated on a FR-4 substrate having a dielectric constant (ɛ r) of 4.4 within a small size of 19.18×22.64×1.6mm3. CSRRs in the monopole antenna create a multiband characteristics and bandwidth improvement, which is analyzed by use of the precise quasi-static design equations and electromagnetic simulation software (HFSS version 13). By selecting a proper offset-fed microstrip line, it is capable to achieve 50Ω characteristic impedance and good impedance matching. The parameter extraction procedure of the metamaterial property of the CSRRs is enlightened in detail, by which the negative permittivity existence and the new resonance frequencies are verified. Simulated and measured result coincides with each other. The measured H-Plane (azimuthal plane) exhibits omnidirectional radiation pattern and E-plane (elevation plane) shows a dipole like bidirectional radiation pattern. The proposed antenna has adequate advantages, including simple design, small size, lower return loss and capable of multiband operations.

      PubDate: 2017-05-31T06:25:22Z
      DOI: 10.1016/j.aeue.2017.05.016
      Issue No: Vol. 78 (2017)
  • Biological inspired optimization algorithms for cole-impedance parameters
    • Authors: D.A. Yousri; Amr M. AbdelAty; Lobna A. Said; Ahmed AboBakr; Ahmed G. Radwan
      Pages: 79 - 89
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): D.A. Yousri, Amr M. AbdelAty, Lobna A. Said, Ahmed AboBakr, Ahmed G. Radwan
      This paper introduces new meta-heuristic optimization algorithms for extracting the parameters of the Cole-impedance model. It is one of the most important models providing best fitting with the measured data. The proposed algorithms inspired by nature are known as Flower Pollination Algorithm (FPA) and Moth-Flame Optimizer (MFO). The algorithms are tested over sets of both simulated and experimental data. The results are compared with other fitting algorithms such as the Non-linear least square (NLS) and Bacterial Foraging Optimization (BFO). The comparison showed a better fit in the sum of absolute error sense (SAE) which consolidate the effectiveness of these new algorithms in the extraction process.

      PubDate: 2017-05-31T06:25:22Z
      DOI: 10.1016/j.aeue.2017.05.010
      Issue No: Vol. 78 (2017)
  • Performance analysis of cooperative spectrum sensing over large and small
           scale fading channels
    • Authors: Junfang Li; Bingbing Li; Mingqian Liu
      Pages: 90 - 97
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Junfang Li, Bingbing Li, Mingqian Liu
      As the spectrum sensing performance is effected by large and small scale wireless fading channels, a novel cooperative spectrum sensing (CSS) method is proposed and the performance analysis is conducted. The proposed method completes the spectrum sensing by utilizing different clusters to sense different narrow band spectrum separately over small scale fading channels, makes fusion and decision for sensing information of all secondary users (SUs) with OR rule. Then, each cluster head transmits decision results to fusion center (FC) over large or small scale fading channels, and FC converges all cluster head information of each narrow band spectrum to realize the wideband spectrum sensing. We analyzed the effect of the sensing channel, reporting channel and the number of SUs on sensing performance over fading channels. Simulation results show that the sensing performance of the proposed method is obviously better than the single secondary user spectrum sensing. When the number of SUs in each cluster is greater than 6, the proposed method can not only reduce the sensing process and communication load, but also save energy and extend the life cycle of the rest of SUs.

      PubDate: 2017-05-31T06:25:22Z
      DOI: 10.1016/j.aeue.2017.05.026
      Issue No: Vol. 78 (2017)
  • Synthesis and design of constant phase elements based on the
           multiplication of electronically controllable bilinear immittances in
    • Authors: Roman Sotner; Jan Jerabek; Jiri Petrzela; Ondrej Domansky; Georgia Tsirimokou; Costas Psychalinos
      Pages: 98 - 113
      Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78
      Author(s): Roman Sotner, Jan Jerabek, Jiri Petrzela, Ondrej Domansky, Georgia Tsirimokou, Costas Psychalinos
      The main aim of this paper is the investigation of practical aspects of synthesis of so-called active constant phase elements (CPE). The proposed synthesis is based on the multiplication of partial bilinear immittance segments with electronically adjustable locations of zero and pole. An overview of already known methods for the synthesis of active types of CPE is given and explained as the initial motivation of this work. This work introduces a solution of new simplified two-active-elements-based bilinear immittance and investigates its implementation in loop of operational-transconductance-amplifiers-based impedance converter operating as a general immittance multiplier of a theoretically infinite number of partial immittance segments. The presented results show practical consequences of applying these bilinear immittance segments in CPE synthesis. The most important advantages of the presented proposal are: simplified circuitry of a partial bilinear segment and mutually independent electronic and linear control of zero and pole frequencies allowing electronic reconfiguration of the order of CPE. The design is accompanied by a detailed analysis of real behavior and practical recommendations for design. Real non-ideal features of active elements have significant impact on CPE operation. Therefore, a detailed study of practical aspects has been prepared and supported by Matlab calculations. Conclusions resulting from analyses are supported by PSpice simulations and real experiments.

      PubDate: 2017-05-31T06:25:22Z
      DOI: 10.1016/j.aeue.2017.05.013
      Issue No: Vol. 78 (2017)
  • Optimum Distance and Power allocation Strategies for Quantum-limited
           Inter-Relayed FSO Communication System
    • Abstract: Publication date: October 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 80
      Author(s): Himanshu Khanna, Mona Aggarwal, Swaran Ahuja
      In this work, we analyze the performance of a uni-directional quantum-limited inter-relay assisted free space optical link. We assume that there is no direct line of sight path between source and destination. The influence of path loss, atmospheric turbulence and pointing error impairments is considered for the analysis. The turbulence induced fading is modeled by independent but not necessarily identically distributed Gamma-Gamma fading statistics. The proposed system employs decode and forward relaying protocol assisted with channel state information. The approximate analytical expression for the probability of error is derived and illustrated by numerical plots. The asymptotic analysis for minimizing error probability in order to find optimum distance between the nodes for uniform power transmission, and for optimizing power allocated to different links, has been performed. It is shown that either distance between the nodes can be optimized for minimizing error probability when uniform power allocation is done, or optimum power allocation can be done for minimizing probability of error. Further, it helps to increase the distance for transmission between source and destination, and can make transmission possible in situations where direct link between source and destination can’t be established due to high rise buildings and other obstacles, while keeping the total transmitted power within permissible levels.

      PubDate: 2017-06-27T09:44:02Z
  • Performance analysis of MC-CDMA cellular systems employing MMSE multiuser
           detector in presence of own-cell and co-cell interference
    • Abstract: Publication date: October 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 80
      Author(s): Henry Carvajal Mora, Nathaly Orozco Garzón, Celso de Almeida
      In this work, it is analyzed the uplink performance of MC-CDMA cellular systems in order to show that a MMSE multiuser detector can mitigate not only the own-cell interference, but also the co-cell interference. For the analysis, it is also considered a linear antenna array at the base station. The channel includes additive white Gaussian noise, exponential path-loss and slow frequency-selective Rayleigh fading. First, the interference in the cellular system is analyzed. Then, approximate expressions to evaluate the signal-to-interference ratio (SIR) are derived. Also, expressions to evaluate the bit error rate (BER) both for BPSK and M-QAM modulations are obtained. Monte Carlo simulations verify the tightness of the expressions. The results show that when we include the co-cell interference statistics in the MMSE detector design, the effects of this interference can be mitigated. Also, it is observed that the system can be overloaded when the number of antennas in the array is increased while the mean BER maintains reasonable values. Finally, with an asymptotic analysis of the BER expressions, the BER reduction with the MMSE multiuser detector when compared with the zero-forcing multiuser detector is obtained. This BER reduction has not been previously obtained in the literature.

      PubDate: 2017-06-27T09:44:02Z
  • Adaptive Bregmanized total variation model for mixed noise removal
    • Abstract: Publication date: October 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 80
      Author(s): Gen Li, Xiang Huang, Shuang-Gao Li
      To solve the problem of the staircase effect and removing mixed noise, including Gaussian and salt and pepper noise, which can occur during image formation and transmission, a total variation-based denoising model using an edge detection function is proposed. Moreover, an improved split Bregman iteration method is used to solve the nonlinear problem. The results of comparative experiments demonstrate that the proposed model removes Gaussian and salt and pepper noise while maintaining detailed features.

      PubDate: 2017-06-27T09:44:02Z
  • Clipping noise estimation in OFDM systems: A greedy-based approach
    • Abstract: Publication date: October 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 80
      Author(s): Mohammad Javad Azizipour, Kamal Mohamed-pour
      A major drawback of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) which drives transmitter’s power amplifier into saturation. One of the simplest methods for mitigating PAPR is to clip signal prior to the amplifier. However, this technique suffers from noise caused by clipping operation and limits its practical application. To investigate this issue, we have proposed a greedy algorithm based on orthogonal matching pursuit (OMP) utilizing a distance metric and a threshold parameter in order to define a backward condition to achieve better results in clipping noise estimation. The defined distance metric and threshold parameter are jointly used to determine whether the recovered noise indices are valid or not. Besides, a closed form equation for threshold parameter has been obtained in terms of channel statistics and has been validated by extensive numerical simulations. According to such appropriate choice of threshold values, simulations demonstrate that the proposed algorithm outperforms state-of-the-art methods such as OMP, ℓ 1 -minimization and classic methods, especially when SNR grows higher. Also, in terms of computational complexity, proposed algorithm due to its structure imposes a slightly further complexity to the receiver in comparison with conventional OMP algorithm.

      PubDate: 2017-06-27T09:44:02Z
  • Dual-mode OTA based biquadratic filter suitable for current-mode
    • Abstract: Publication date: October 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 80
      Author(s): Ugur Cini, Mustafa Aktan
      In this paper, a dual mode single-input multiple-output (SIMO) biquadratic filter structure is presented using multi-output Operational Transconductance Amplifiers (OTAs). Using a simple switch, the filter operates alternatively in trans-admittance mode or current mode. Selection of working mode using a switch provides flexibility for current-mode design. The filter natural angular frequency (ω0) and quality factor (Q) can be orthogonally adjusted both in current mode and trans-admittance mode operation. The proposed structure has simple structure, requiring only four OTAs and two grounded capacitors. The proposed structure is the only SIMO structure where the working mode is selected using a switch. The proposed biquadratic structure is realized using 0.35µm CMOS technology, and, circuit functionality is verified by SPICE simulations.

      PubDate: 2017-06-27T09:44:02Z
  • Wheel shaped modified fractal antenna realization for wireless
    • Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Manisha Gupta, Vinita Mathur
      A compact, low profile circular fractal patch antenna with low latency, low cost, high speed and multiband is presented. With the help of CST Microwave Studio Suite TM the proposed structure has been designed and analyzed. The simulated results are fixed experimentally. The suggested antenna has dimension of 32×36mm2 (W×L) and operating from 2.93GHz–9.53GHz with VSWR≤2. The aerial is assembled on FR-4 (εr =4.4) substrate with a thickness of substrate 1.25mm. Detailed parametric studies of the antennas have been carried out. This microstrip fed antenna is suitable for ultra wideband (UWB), S, C and part of the X band applications.

      PubDate: 2017-06-27T09:44:02Z
  • The nonparametric Bayesian dictionary learning based interpolation method
           for WSNs missing data
    • Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Lu Zhu, Zhiqun Huang, Yuanyuan Liu, Chaozheng Yue, Baishan Ci
      The conventional data interpolation methods based on sparse representation usually assume that the signal is sparse under the overcomplete dictionary. Specially, they must confirm the dimensions of dictionary and the signal sparse level in advance. However, it is hard to know them if the signal is complicated or dynamically changing. In this paper, we proposed a nonparametric Bayesian dictionary learning based interpolation method for WSNs missing data, which is the combination of sparse representation and data interpolation. This method need not preset sparse degrees and dictionary dimensions, and our dictionary atoms are drawn from a multivariate normal distribution. In this case, the dictionary size will be learned adaptively by the nonparametric Bayesian method. In addition, we implement the Dirichlet process to exploit the spatial similarity of the sensing data in WSNs, thus to improve the interpolation accuracy. The interpolation model parameters, the optimal dictionary and sparse coefficients, can be inferred by the means of Gibbs sampling. The missing data will be estimated commendably through the derived parameters. The experimental results show that the data interpolation method we proposed outperforms the conventional methods in terms of interpolation accuracy and robustness.

      PubDate: 2017-06-27T09:44:02Z
  • Beam pattern design of circular antenna array via efficient
           biogeography-based optimization
    • Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): Geng Sun, Yanheng Liu, Shuang Liang, Aimin Wang, Ying Zhang
      In this paper, an efficient biogeography-based optimization (EBBO) method is proposed to synthesize the circular antenna arrays (CAA) for specific radiation beam pattern properties and null controls. The proposed method achieves the desired beam patterns by jointly optimizing the excitation currents as well as the spaces between the array elements. Three improved components, including chaotic search theory, model learning method and a new random perturbation operator, are introduced into the standard biogeography-based optimization (BBO) to improve the performance of the algorithm. Simulation results show that the maximum sidelobe level obtained by EBBO can be suppressed effectively compared with other algorithms. Moreover, the null controlling performance of EBBO is the best among the algorithms.

      PubDate: 2017-06-27T09:44:02Z
  • Evaluation of a single-input multiple-output antenna array for ultra-wide
           band applications
    • Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): M.A. Ashraf, Khalid Jamil, A.R. Sebak, Saleh Alshebeili, Mobien Shoaib, Majeed Alkanhal, Zeyad Alhekail
      Emerging applications for ultra-wide band (UWB) systems require high performance UWB array systems with excellent characteristics duly verified in time and frequency domains. Thus, we propose an UWB antipodal tapered slot antenna (ATSA) linear array operating over a 2–12GHz band, and present an experimental setup to validate the performance of the single-input, four-element output UWB antenna array system using time- and frequency-domain analysis based on vector network analyzer (VNA) measurements. The time-domain analysis of UWB antenna array is indispensable since each array element uses a wideband instead of a narrowband signal. We characterize the proposed array using an ultra-short pulse of 50ps. All measurements are done in an anechoic chamber to avoid multipath reflections. Our experimental work on time-domain analysis is a step towards realizing a practical timed array-based UWB test-bed for validating system performances in real conditions with practical impairments.

      PubDate: 2017-06-27T09:44:02Z
  • The AB-CCII, a novel adaptive biasing LV-LP current conveyor architecture
    • Abstract: Publication date: September 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 79
      Author(s): V. Stornelli, L. Pantoli, G. Ferri, L. Liberati, F. Centurelli, P. Monsurrò, A. Trifiletti
      We present a low voltage low power architecture for an integrated current conveyor (CCII) topology, designed to decrease the stand-by power dissipation without affecting the CCII transient performance. In the proposed circuit, implemented in a standard AMS 0.35um CMOS technology, an extra current flows into the circuit only when an input voltage variation occurs (through the adaptive biasing technique), so improving the transient response speed without a substantial increase of the average power consumption. Simulation results confirm the expected theoretical considerations.

      PubDate: 2017-06-27T09:44:02Z
  • Editorial board members
    • Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78

      PubDate: 2017-06-10T07:26:01Z
  • Editorial board members
    • Abstract: Publication date: August 2017
      Source:AEU - International Journal of Electronics and Communications, Volume 78

      PubDate: 2017-06-10T07:26:01Z
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
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