Volume 3, Issue 1, June 2010

Performances of FH/MFSK Lump Likelihood Ratio Decision Methods and their Applications for Power Line Communications  [Full Text]

Shin’ichi Tachikawa, Nagaoka National College of Technology, Nagaoka, Niigata, 940-2188, Japan
Takuma Maeda
, Nagaoka National College of Technology, Nagaoka, Niigata, 940-2188, Japan

Abstract—This paper presents performances of novel detection methods of frequency hopping/ multilevel FSK (FH/MFSK) pattern by lump likelihood ratio calculation decision and their applications for power line communications (PLCs). In the method, the whole likelihood ratio value from both time-axis and frequency-axis together is calculated for coherent detection or non-coherent detection, and the desirable value can be obtained against a fluctuated transmission line. Applying for high frequency PLC including CW jamming and burst noise, it is shown bit error rate (BER) of the system by the proposed method can be much improved to compare with that by the conventional decision methods for coherent detection or non-coherent detection.

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Vectorized Broadcast Routing in Mobile Ad Hoc Networks
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Mohammad Al-Shurman, Department of Network Engineering and Secu-rity, Jordan University of Science and Technology, Ramtha, Jordan
Seong-Moo Yoo, Electrical & Computer Engineering Department, The University of Alabama in Huntsville, Huntsville, AL 35899, USA
Seungjin Park
, Department of Management, MIS, & CS, University of Southern Indiana, Evansville, IN 47712, USA

Abstract—Mobile ad hoc networks routing protocols rely on traditional broadcast (flooding) to establish a route to the destination. Every node which receives this broadcast packet will rebroadcast it to all neighbors. This broadcast consumes valuable network resources (e.g., battery power, bandwidth, processing time, etc.). Many schemes were proposed to restrict traditional flooding by means of probability or mathematical methods. Some of these protocols utilize the location information on the nodes to restrict the broadcast zone like Location Aided Routing (LAR). In this paper, we will propose Vectorized Broadcast Routing (VBR) as an enhancement for LAR scheme 1 to reduce the broadcast by enlarging the broadcast region around the destination. In case of discovery phase failure, VBR will enlarge the broadcast region again around the destination, unlike LAR where the network will be flooded with this request again. Simulation results show that VBR can decrease the number of routing packets by about one-third compared to LAR.

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A comparative study on Indium Phosphide and
a-Gallium Nitride based Impatt Oscillators for Terahertz Communication [Full Text]

Jayanta Mukhopadhyay, Department of Physics, Rabindra Ma-havidyalaya, Hooghly, WB, India
Soumen Banerjee, Department of Electronics & Communication Engg., Hooghly Engineering & Technology College, Hooghly, WB, India
Moumita Mukherjee, Centre of Millimeter wave Semiconductor Devices & Systems, Kolkata, India
J. P. Banerjee,  Institute of Radio Physics & Electronics, Univer-sity of Calcutta, Kolkata, India


Abstract — The properties and performance of p+pnn+  III-V semiconductor, viz., Indium Phosphide (InP) and Wurtzite phase of  Gallium Nitride (Wz-GaN or a-GaN) based DDR Impatt diodes at Terahertz (THz) frequency has been investigated for optimum bias current density through modeling and simulation technique. A double iterative computer method based on drift-diffusion model has been used to study their performance. The bias current density is optimized with respect to maximum conversion efficiency and device negative resistance. The simulation studies reveal that these devices are potential sources for generating high RF power. The DC-to-RF conversion efficiency for InP DDR Impatt diode is found to be 18.38% at 0.3 THz and 13.18% at 0.5 THz at an optimum bias current density of 8.0 x 108 A/m2 and 1.6 x 109 A/m2 respectively. The same for a-GaN DDR Impatt diode is found to be 15.47% at 0.3 THz and 15.14% at 0.5 THz at an optimum bias current density of 0.5 x 107 A/m2 and 1.1 x 108 A/m2 respectively. The RF output power in case of DDR Impatt diode based on InP is found to be 2.81 W at 0.3 THz and 1.77 W at 0.5 THz while that in case of a-GaN DDR Impatt is 6.23 W at 0.3 THz and 9.34 W at 0.5 THz.  The extensive simulation results reveal that Impatt diode based on a-GaN gives better performance in terms of efficiency and output power. The design results and the proposed experimental methodologies presented in this paper will be helpful to realize InP and a-GaN IMPATT oscillators for Terahertz communication.  

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Modelling and Design of Microwave Structures Using Neural Networks and Particle Swarm Optimization
  [Full Text]

Mahdieh Zeinadini, Faculty of Electrical and Computer Eng, The University of Sistan and Baluchestan, Iran
Saeed Tavakoli
, Faculty of Electrical and Computer Eng, The University of Sistan and Baluchestan, Iran
Amir Banookh, Faculty of Electrical and Computer Eng, The University of Sistan and Baluchestan, Iran

Abstract— Optimization of design parameters based on electromagnetic simulation of microwave circuits is a time-consuming and iterative procedure. To provide a fast and fairly accurate frequency response for a given case-study, this paper employs a neural network modelling approach. First, the real and imaginary parts of case-study's output, S are predicted using two neural network models. Then, particle swarm optimization is employed to optimize the case-study's design parameters so that a design objective is optimized.

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Solar Energy Based Medium Access Control for Out Door Applications of WSN
  [Full Text]

Swati V. Sankpal, Department of Electronics D.Y. Patil college of engineering Kolhapur, India
Vishram Bapat
, College of Engineering, Miraj Shivaji University, Kolhapur, India

Abstract— The wireless sensor network (WSN) is an autonomous long-term environment monitoring network. For outdoor applications sensor networks needs battery supply for their operations. Limitation of energy supply is holding up the progress of WSNs towards large scales and true autonomous operations. In many applications it is very difficult or rather impossible to recharge battery. Research is going on to minimize battery consumption and improve the life of networks. Much of the research is based on minimizing duty cycle of Radio which is most power consuming part in WSN. In this paper we are implementing a technique of MAC Protocol based on Solar Energy. The capacitor charges to maximum energy depending on solar intensity. This energy is used for data transmission by sensor node. We have evaluated performance in terms of throughput by analytical and simulation method and energy required for transmission and reception of variable data packet size.

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Biometric Security: The Next Authentic Step to Secure our Future
  [Full Text]

Ahmed Elmorshidy, Gulf University for Science and Technology, Kuwait
Issam El-Moughrabi,
Gulf University for Science and Technology, Kuwait

Abstract -This paper discusses the current types of technologies that are used in biometric security. The paper also discusses biometric security as the future wave in authentic security affecting many critical aspects of life such as justice and law enforcement biometrics, time and attendance biometrics, healthcare biometrics, financial and transactions biometrics, mobile, PDAs and laptop fingerprints biometrics, consumer and residential biometrics and other types of biometrics that directly affects the convenience of consumers.

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Design and analysis of Inhomogeneous Dielectric Reflect-Array Antennas
  [Full Text]

M. Moeini-Fard,
Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran
M. Khalaj-Amirhosseini, Department of Electrical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran

Abstract—
A new reflect-array antenna structure is proposed. This structure utilizes an Inhomogeneous Dielectric layer as a reflecting surface with the electric permittivity (x , y ) r  . The variable electric permittivity provides the required phase shift at each point on the reflect-array surface to produce a reflected radiation beam in a specific direction. In addition, a simple method based on an equivalent circuit model is introduced for analyzing and designing this kind of antennas. Using this method, the suitable value of the electric permittivity at each point on the reflecting surface is obtained. Some proposed antennas are designed in x-band and simulated by fullwave analyzer HFSS software to verify theoretical results. An excellent agreement between the simulation and both designing and analyzing results are obtained.

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Use of Tree-based Interleaver in RS Turbo Code for PAPR
  [Full Text]

V. K. Dwivedi, Department of Electronics and Communications,MNNIT, Allahabad, India
S. Tripathi,
Department of Electronics and Communications,MNNIT, Allahabad, India
V. S. Tripathi, Department of Electronics and Communications,MNNIT, Allahabad, India
R. Tripathi, Department of Electronics and Communications,MNNIT, Allahabad, India
S. Tiwari, Department of Electronics and Communications,MNNIT, Allahabad, India

Abstract— High peak-to-average power ratio (PAPR) of the transmit signal is a major drawback of orthogonal frequency division multiplexing (OFDM) system. This paper presents a novel scheme for reduction of PAPR. It is based on use of Reed-Solomon (RS) Turbo code. RS turbo code has maximal Hamming distance and therefore has maximum Euclidean distance. PAPR is related to Euclidean distance and the reduction of PAPR is obtained through redistribution of power of each modulated symbol over the OFDM block using RS Turbo code. In this paper, the performance of the proposed scheme is evaluated. The obtained results show that RS turbo coding scheme is an attractive solution to PAPR problem of OFDM signals.

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Rule-based HCH Scheduling and Resource Management in Computational Grid
  [Full Text]

L.Mohammad Khanli, Department of Computer Science, university of Tabriz
F.Davardoost
, Computer Engineering Department, University of Islamic Azad of Shabester

Abstract- Grid system aggregates the heterogeneous resources from every part of the world to form a complicated computing. Resource Management and Scheduling have an important role in enhancing the performance of system. Moreover, well-allocated mechanism could satisfy user’s demand. In this paper we use an Active Grid Information Server (AGIS) for optimal resource selection which supports Even-Condition-Action (ECA) rules. ECA rule-based system can support ad-hoc, adaptive, flexible and dynamic scheduler which allows the system designer to modify scheduler policy. Since there are many resources and users expects to get appropriate Quality of Service (QOS) according to the tasks requirements and cost in the minimum time, therefore in this paper, we propose new rules for classifying tasks and resources and also trading-rule for calculating the cost of resources according to the reliability and credibility during the time. Furthermore for minimizing the task execution time we propose new scheduling called HCH (Hierarchical model based on Classification by Hybrid strategy). The result shows that the new proposed approach has a shorter Makespan in comparison of other approaches.

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Coverage and Capacity Enhancement of WCDMA Network through Utility based CAC Scheme
  [Full Text]

K.Ayyappan, ECE Department of Rajiv Gandhi College of Engineering and Technology, Pondicherry, India
R.Surender, Electronics and Communication Engi-neering Department of Sri Manakula vinayagar college of engineering and technology, Pondicherry, India
R.Kumar, Department of Electronics and Communication Engineering, SRM University, Chennai, India

Abstract—
The wide-band code division multiple access (WCDMA) based 3G and beyond cellular mobile wireless networks are expected to provide a diverse range of multimedia services to mobile users with guaranteed quality of service (QoS). To serve diverse quality of service requirements new and effective radio resource management strategies are absolutely essential. Call admission control (CAC) is a significant component in wireless networks to guarantee quality of service requirements and also to enhance the network resilience. In this paper a utility based CAC is proposed to achieve a better balance between resource utilization and quality of service provisioning. The performance of CAC scheme of this network is compared for macro cell and micro cell site. Simulation results demonstrate the coverage and capacity enhancement of WCDMA network effectiveness of the proposed utility based call admission control scheme.

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Novel Sliding Window Technique of OFDM Modem for the Physical Layer of IEEE 802.11a Standard
  [Full Text]

Salih Mohammed Salih, College of Engineering, University of Anbar, Iraq

Abstract—
This paper presents a reasonable program that uses Orthogonal Frequency Division Multiplexing (OFDM) technology to reduce the Doppler frequency effect and to improve the performance of standard OFDM model under flat fading and the Additive White Gaussian noise (AWGN) channels. A sliding window (SW) technique is proposed to enhance the system performance of OFDM technology based on IEEE 802.11a wireless standards. The simulation results show that the combination of SW and OFDM technology is superior to the OFDM standard technology.

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Improving the control performance in Wireless Network Controlled Systems, using the beacon mode
  [Full Text]

Faiza CHARFI, Electronic and Information Technology Laboratory L.E.T.I, Sfax National Engineering School, Tunisia
Oumsaad SLAMA
Jean-Marc THIRIET, GIPSA-lab (Grenoble Images Parole Signal Automatique, UMR 5216), BP 46, 38 402 Saint Martin d'Hères ce-dex, France
Suzanne LESECQ, CEA-LETI INATEC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France

Abstract—
The current work focuses on analyzing the capabilities of Wireless Sensor Networks based on IEEE 802.15.4 and ZigBee standards to the Wireless Networked Systems Control. Therefore, to achieve the timing constraints and guarantee the performance, the Network Controlled System NCS design are required to maximize the overall quality of control QoC. the QoC is performed through optimally allocating network resources to ensure the quality of service QoS and optimally designed controller to compensate for the time of delays. Unfortunately, few wireless technologies can propose a communication system which respects some constraints like high reliability, low latency and guarantees on messages delivery. In this paper we present the implementation of an extended model of the IEEE 802.15.4 standard for wireless network within TrueTime. Some improvements of the MAC-layer are performed to enable accesses by the use of GTS. Both the sampling period and the controller parameters are assessed to obtain the optimal performance, which are subject to the stability of the control loop and the bandwidth on available network resource.

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Arbitrary Incidence Angle Polarizers using Dielectric and Magnetic Layers
  [Full Text]

Mohammad Khalaj-Amirhosseini, Iran University of Science and Technology, Tehran, Iran

Abstract—
A new structure is proposed to operate as reflection wave polarizer at arbitrary incidence angles even near and less than 45 degrees, in this article. In this structure a magnetic layer is located between two dielectric layers or vice versa. First, the analysis of the structure is presented. Then the required permittivity and permeability of dielectric and magnetic layers are obtained for desired incidence angle. The performance of the proposed structure is investigated using some examples.

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Implementation of an Extension of the CHAP Protocol based on Quantum Key Distribution
  [Full Text]

Mohamed Elboukhari, Dept. of Mathematics & Computer Science, University Mohamed First, Oujda, Morocco
Mostafa Azizi, Dept. Applied Engineering, ESTO, University Mohamed First, Oujda, Morocco
Abdelmalek Azizi, Academy Hassan II of Sciences & Technology, Rabat, Morocco

Abstract—
Quantum key distribution (QKD) is a technique that permits the secure distribution of a bit string, used as key in cryptographic protocols. Extensive studies have been undertaken on QKD since it was noted that quantum computers could break public key cryptosystems based on number theory. QKD offers unconditionally secure communication based on quantum mechanics. Now there is a strong need of research to exploit this technology in the existing communication networks. In this paper, we explore the possibility of using QKD for authentication for Local Area Networks (LANs). Precisely, we have elaborated a scheme to integrate the new technique of QKD in the CHAP protocol (Challenge Handshake Authentication Protocol) to enhance the security of the authentication service. Also, we describe in detail an example demonstrating the practical use of our scheme’s implementation.

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A Multi-Platform Mobile Banking Framework for Bangladesh
  [Full Text]

Sheikh Shanawaz Mostafa, Electronics and Communication Engineering Discipline in Khulna University, Khulna-9208, Bangladesh
Khondker Jahid Reza, Electronics and Communication Engineering Discipline in Khulna University, Khulna-9208, Bangladesh
Asif Ahmed Tanvir, Department of Computer Science and Engineering, Dhaka City College, National University, Dhaka-1217, Bangladesh

Abstract—
The use of information and communication technology has been playing a vital role in the 21st century due to globalization. The democratic government of Bangladesh has declared the “Vision 2021” which targets establishment of a resourceful and modern country by 2021 through effective use of information and communication technology-a "Digital Bangladesh". “Digital Bangladesh” does not only mean the broad use of computers, perhaps it means the modern philosophy of effective and useful use of technology in terms of implementing the promises in commerce, banking, education, health, job placement, poverty reduction etc. But the government has no technical platform to make this vision come true. Mobile phones have already opened up a new horizon for commerce, business and communication. In this paper, we proposed mobile banking system for Bangladesh, which can be effective to increase the economic growth.

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A hybrid model combining decision tree and Bayesian network for data replication In Grid environment
  [Full Text]

L.Mohammad Khanli, Department of Computer Science, University of Tabriz
F.Veghari Baheri,  Department of Computer, Shabestar Branch, Islamic Azad University, Shabestar, Iran
M.Yazdani Nia,
Department of Computer, Sardrood Branch, Islamic Azad University, Sardrood, Iran

Abstract -
Data Grids composed of the huge distributed and shared data resources. Access of huge data is needed many distributed scientific. Then such huge data must access in least time. Thus we must store data in several physical locations. A key technique is data replication which is managing data to achieve better performance of accessing a distributed and huge amount of data. In this paper, we improve the performance of data access and reduce the access latency. In this research, a hybrid model is developed by integrating a Bayesian method and a decision tree for data classification. We suppose hierarchical architecture which has some clusters. This method decides which data should be replicate. Initially, a greedy algorithm calculates Entropy for dataset then calculated gain for every attribute. Then we can draw decision tree. Finally the probability of result calculated with Bayesian expression and we produce rule. We simulate this method to evaluate the performance of proposed hybrid method. The simulation results show that algorithm can decided data replication credibility.

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Analog Waveform Design for Energy-Efficient UWB Pulse Generators
  [Full Text]

A. Ghanaatian-Jahromi, Depatment of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran
A. Abrishamifar, Depatment of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran
A.Medi, Department of Electrical Engineering, Sharif Universi-ty of Technology, Tehran, Iran
A. Akbarzadeh, Depatment of Electrical Engineering, Iran University of Science and Technology, Tehran, Iran

Abstract—
In this paper, a new optimal waveform for Ultra-wideband (UWB) radios is proposed. This new waveform is extracted through mathematical analysis for achieving high spectral utilization under the restrictions imposed by the U.S. Federal Communications Commission (FCC) spectral masks. Exploiting Inverse Fourier Transform (IFT) of FCC mask, the required analog signals are extracted through robust calculation. Normalized effective signal power (NESP) of the proposed method is 95.27% which shows better efficiency compared to the other methods in the literature. In addition, the method is employed to achieve an optimal pulse for the main UWB band (3.1 GHz to 10.6 GHz) and a block diagram for analog realization is proposed. Simulations verified that the presented technique is very promising and has better performance compared to other pulses in literature.

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Fast JSPA -CAQA Scheduling Based on Average Channel Information in Multiuser OFDM
  [Full Text]

Abhinav Kumar Arela, Department of Electronics & Communication, MNNIT, Allahabad
V.S Tripathi, Department of Electronics & Communication, MNNIT, Allahabad

Abstract—
In Orthogonal Frequency Division Multiplexing (OFDM) downlink scenario fast joint subcarrier and power allocation technique for average channel information is proposed in this paper .Our objective is to reduce computation time for subcarrier allocation resulting in more throughput and less bit outrage .The Simulation results shows that fast joint subcarrier and power allocation yields a significant performance improvement compared to conventional JSPA scheme .The discussion has been extended to both homogeneous rate user with different channel condition and heterogeneous rate user with similar channel condition .

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Capacity enhancement of 4G- MIMO using Hybrid Blast STBC Systems
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Nirmalendu Bikas Sinha, Department of ECE and EIE , College of Engineering & Management, Kolaghat, K.T.P.P Township, Purba- Medinipur, 721171, W.B., India
Sourav Chakraborty, Department of ECE, College of Engineering & Management, Kolaghat, K.T.P.P Township, Purba- Medinipur, 721171, W.B., India
R.Bera, S.M.I.T, SikkimManipal University, Majitar, Rangpo, East Sikkim, 73713, India

Abstract—
In this paper, we examine a novel signal scheme called “Hybrid BLAST STBC approach” this combines MIMO and STBC to generate a system functionally superior to MIMO and STBC systems. We examine the capacity of high data rate open loop MIMO architectures and their performances. The first part of the study shows how the multi-layered space time block code (MLSTBC) compares to other MIMO systems, such as V-BLAST and STBC. We focus on the information capacity comparison in order to evaluate the optimal performance of the systems. We show the tradeoffs of these systems and what the advantages of MLSTBC are. The results show that when the number of transmit and receive antennas are equal, MLSTBC is more power efficient than VBLAST, since it provides more diversity. Furthermore, at low SNR and low outage probabilities, MLSTBC is more spectrally efficient. Thus, it is more suitable for low power wireless data applications.Finally we evaluates and investigates the capacity of high data rate wireless local area network systems using MIMO techniques. The focus of the study is to compare the information capacity of hybrid systems with V-BLAST and STBCs. Hybrid BLAST STBC can balance transmit diversity gain and spatial multiplexing gain. All three techniques are compared using both theoretical Shannon capacity analysis and by simulation results for the capacity performance of the three methods. The result of this study shows that hybrid method attains superior diversity gain performance to V-BLAST and can out form V-blast at spectral efficiencies of practical interest. The capacity expression and evaluation for “Hybrid BLAST STBC approach” are a unique contribution of this work. This study gives useful insight into the optimal performance of these algorithms and into the spatial multiplexing-diversity tradeoffs of these systems.

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Spectrum Frequency Alternatively for Public Safety Communications in Indonesia
  [Full Text]

Gerson Damanik, Department of Electrical Engineerinf, Univer-sity of Indonesia, Depok 16424 – Indonesia
Djamhari Sirat, Department of Electrical Engineerinf, Univer-sity of Indonesia, Depok 16424 – Indonesia
Dadang Gunawawan, Department of Electrical Engineerinf, Univer-sity of Indonesia, Depok 16424 – Indonesia

Abstract –
Since most of the spectrum used for commercial purposes such as cellular communications, radio and television broadcasting, broad band wireless access communications, looks like there is a gap for Public Safety Communications purposes. Public Safety comunications today is left behind if we compare to cellular communications for example. Cellular communications grow according to the need of people for mobility and broad band. Evolu-tion of the network from narrow band to broadband is faster in the commercial communications purposes than in the Public Safety Communications field. Legacy of lack of planning and lack of strategy by the Government on Public Safety Communications is a problem we should face today. They build their own network, used spectrum with their own network as shown in the Table 1 and Fig.3. The fragmented approach should be studied. Government should quaranted among the agencies could communicate easily and could give services to people. This paper analyze interoperability problem with Public Safe-ty Communications network and give one solution with using 700 MHz band as a common frequency band. The common frequency band is one of stage as shown in Fig.2 as a solution for interoperability gap. Fig. 4 is Indonesia’s Band Plan of Digital Dividend. The portion of 700 MHz frequency band for Public Safety is shown in Fig. 5. 700 MHz is one of future frequency band for Public Safety Communications in some countries.