Volume 2, Issue 2, May 2010

Improving GPS/INS Integration through Neural Networks [Full Text]

M.Nguyen-H, Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, USA
C. Zhou, Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, USA

Abstract—
The Global Positioning Systems (GPS) and Inertial Navigation System (INS) technology have attracted a considerable importance recently because of its large number of solutions serving both military as well as civilian applications. This paper aims to develop a more efficient and especially a faster method for processing the GPS signal in case of INS signal loss without losing the accuracy of the data. The conventional or usual method consists of processing data through a neural network and obtaining accurate positioning output data. The new or improved method adds selective filtering at the low-band frequency, the mid-band frequency and the high band frquency, before processing the GPS data through the neural network, so that the processing time is decreased significantly while the accuracy remains the same.

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Time Segmentation Approach Allowing QoS and Energy Saving for Wireless Sensor Networks [Full Text]

Gérard Chalhoub, Clermont University/ LIMOS-CNRS, Complexe scientifique des Cézeaux, 63177 Aubière cedex, France
François Delobel, Clermont University/ LIMOS-CNRS, Complexe scientifique des Cézeaux, 63177 Aubière cedex, France
Michel Misson, Clermont University/ LIMOS-CNRS, Complexe scientifique des Cézeaux, 63177 Aubière cedex, France

Abstract—Wireless sensor networks are conceived to monitor a certain application or physical phenomena and are supposed to function for several years without any human intervention for maintenance. Thus, the main issue in sensor networks is often to extend the lifetime of the network by reducing energy consumption. On the other hand, some applications have high priority traffic that needs to be transferred within a bounded end-to-end delay while maintaining an energy efficient behavior. We propose MaCARI, a time segmentation protocol that saves energy, improves the overall performance of the network and enables quality of service in terms of guaranteed access to the medium and end-to-end delays. This time segmentation is achieved by synchronizing the activity of nodes using a tree-based beacon propagation and allocating activity periods for each cluster of nodes. The tree-based topology is inspired from the cluster-tree proposed by the ZigBee standard. The efficiency of our protocol is proven analytically, by simulation and through real testbed measurements.

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Using AMC and HARQ to Optimize System Capacity and Application Delays in WiMAX Networks
[Full Text]

Iwan Adhicandra, Department of Information Engineering, University of Pisa, Via Caruso 16, 56122 Pisa, Italy

Abstract—
The IEEE 802.16 technology (WiMAX) is a promising technology for providing last-mile connectivity by radio link due to its high speed data rates, low cost of deployment, and large coverage area. However, the maximum number of channels defined in the current system may cause a potential bottleneck and limit the overall system capacity. The aim of this paper is to compare the impact on system performance of different solutions used to mitigate the impairments due to the radio channel. In particular, taking into account the WiMAX system capacity as well as application delays, the paper presents the simulation results obtained when a static QPSK ½ Modulation and Coding Scheme (MCS) is adopted. Then, the study is aimed at evaluating the improvements introduced by the adoption of an adaptive modulation and coding (AMC) and an AMC jointly with Hybrid Automatic Repeat reQuest (HARQ). Results indicate that the best strategy is to use an aggressive AMC table with the HARQ.

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Radio Frequency Identifiers: What are the Possibilities?
[Full Text]

Ahmed Elmorshidy, Gulf University for Science and Technology, Kuwait and Claremont Graduate University, California, USA

Abstract—
This paper defines the components of radio frequency identifiers (RFID). It also explores the different areas and sectors where RFID can be beneficial. The paper discusses the uses and advantages of RFID in deference, consumer packaged goods (CPG), healthcare, logistics, manufacturing, and retail.

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Exploring Selfish Trends of Malicious Mobile Devices in MANET
[Full Text]

P.K.Suri, Department Of Comp. Science & Applications, Kurushetra University, Kurukshetra, Haryana, India
Kavita Taneja, M.M. Inst. of Comp. Tech. & B. Mgmt., Maharishi Markandeshwar University, Mullana, Haryana, India

Abstract—
The research effort on mobile computing has focused mainly on routing and usually assumes that all mobile devices (MDs) are cooperative. These assumptions hold on military or search and rescue operations, where all hosts are from the same authority and their users have common goals. The application of mobile ad hoc networks (MANETs) as open networks has emerged recently but proliferated exponentially. Energy is a valuable commodity in MANETs due to the limited battery of the portable devices. Batteries typically cannot be replaced in MANETs, making their lifetime limited. Diverse users, with unlike goals, share the resources of their devices and ensuring global connectivity comes very low in their priority. This sort of communities can already be found in wired networks, namely on peer-to-peer networks. In this scenario, open MANETs will likely resemble social environments. A group of persons can provide benefits to each of its members as long as everyone provides his contribution. For our particular case, each element of a MANET will be called to forward messages and to participate on routing protocols. A selfish behavior threatens the entire community and also this behavior is infectious as, other MDs may also start to perform in the same way. In the extreme, this can take to the complete sabotage of the network. This paper investigates the prevalent malicious attacks in MANET and analyzes recent selfish trends in MANET. We analyzed the respective strengths and vulnerabilities of the existing selfish behaviour prevention scheme.

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Improved Method for Individualization of Head-Related Transfer Functions on Horizontal Plane Using Reduced Number of Anthropometric Measurements
[Full Text]

Hugeng, Department of Electrical Engineering, University of Indonesia, Depok 16424 – Indonesia
W. Wahab
, Department of Electrical Engineering, University of Indonesia, Depok 16424 – Indonesia
D. Gunawan, Department of Electrical Engineering, University of Indonesia, Depok 16424 – Indonesia

Abstract—
An important problem to be solved in modeling head-related impulse responses (HRIRs) is how to individualize HRIRs so that they are suitable for a listener. We modeled the entire magnitude head-related transfer functions (HRTFs), in frequency domain, for sound sources on horizontal plane of 37 subjects using principal components analysis (PCA). The individual magnitude HRTFs could be modeled adequately well by a linear combination of only ten orthonormal basis functions. The goal of this research was to establish multiple linear regression (MLR) between weights of basis functions obtained from
PCA and fewer anthropometric measurements in order to individualize a given listener’s HRTFs with his or her own anthropomety. We proposed here an improved individualization method based on MLR of weights of basis functions by utilizing 8 chosen out of 27 anthropometric measurements. Our objective experiments’ results show a superior performance than that of our previous work on individualizing minimum phase HRIRs and also better than similar research. The proposed individualization method shows that the individualized magnitude HRTFs could approximated well the the original ones with
small error. Moving sound employing the reconstructed HRIRs could be perceived as if it was moving around the horizontal plane.

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Treatment the Effects of Studio Wall Resonance and Coincidence Phenomena for Recording Noisy Speech Via FPGA Digital Filter
[Full Text]

Mahmoud I. A. Abdalla, Department of electronic and communication, Zagaig University, Zagaig, Egypt

Abstract—
This work introduces an economic solution for the problems of sound insulation of recording studios. Sound insulation at wall resonance frequency is weak. Instead of acoustical treatment, a digital filter is used to eliminate the effects of wall resonance and coincidence phenomena on recording of speech. Sound insulation of studio is measured to calculate the wall resonance frequency and the coincidence frequency. Pole /zero placement technique is used to calculate the IIR filter coefficients. The digital filter is designed, simulated and implemented. The proposed system is used to treat these problems and it is shown to be effective in recording the noisy speech. In this work digital signal processing is used instead of the acoustic
treatment to eliminate the effect of noise at the studio wall resonance. This technique is cheap and effective in canceling the noise at the desired frequencies. Field Programmable Gate Array (FPGA) is used for hardware implementation of the proposed filter structure which provides fast and cheap solution for processing real time audio signals. The implementation is carried out using Spartan chip from Xinlinx achieving higher performance than commercially available software solutions.

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Performance of RCPC-Encoded V-BLAST MIMO In Nakagami-m Fading Channel
[Full Text]

L. Sari, Department of Electrical Engineering, University of Indonesia, Depok 16424, Indonesia
G. Wibisono
, Department of Electrical Engineering, University of Indonesia, Depok 16424, Indonesia
D. Gunawan, Department of Electrical Engineering, University of Indonesia, Depok 16424, Indonesia

Abstract—
Multiple Input Multiple Output (MIMO) wireless communication link has been theoretically proven to be reliable and capable of achieving high capacity. However, these two advantageous characteristics tend to be addressed separately in many major researches. Researches on various approaches to attain both characteristics in a single MIMO system are still on-going and an established approach is yet to be concluded. To address this problem, in this paper a Vertical Bell Laboratories Layered Space-Time (V-BLAST) MIMO enhanced with Rate-Compatible Convolutional (RCPC) codes with Zero Forcing (ZF) and Minimum Mean Squared Error (MMSE)-based detection is proposed. The analytical BER of the system is presented and numerically analyzed. The system performance is analyzed in Nakagami-m fading channel, which provides accuracy and flexibility in matching the signals statistics compared to other fading models. The complexity which arises in the calculations of the RCPC codes parameters is significantly reduced by using equivalent convolutional codes. Results show that the use of high-rate code allows for bandwidth efficiency and at the same time does not severely degrades the system performance. It is also shown that the MMSE-based system outperforms the conventional ZF-based system especially in the low Eb/N0 region and in severe fading conditions.

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Rectangular and Circular Antenna Design on Thick Substrate
[Full Text]

Harsh kumar, Department of ECE, Birla Institute of Technology, Mesra, Ranchi, India
Shweta Srivastava
, Department of ECE, Birla Institute of Technology, Mesra, Ranchi, India

Abstract— Millimeter wave technology being an emerging area is still very undeveloped. A substantial research needs to be done in this area as its applications are numerous. In the present endeavor, a rectangular patch antenna is designed on thick substrate and simulated using SONNET software, also a novel analysis technique is developed for circular patch antenna for millimeter wave frequency. The antenna is designed at 39 GHz on thick substrate and has been analyzed and simulated.The results of the theoretical analysis are in good agreement with the simulated results.

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Mutual Coupling Reduction in Two-Dimensional Array of Microstrip Antennas Using Concave Rectangular Patches
[Full Text]

S. Mohanna, Faculty of Electrical and Computer Engineering, The University of Sistan and Baluchestan, Zahedan, Iran
A. Farahbakhsh
, Faculty of Electrical and Computer Engineering, The University of Sistan and Baluchestan, Zahedan, Iran
S. Tavakoli, Faculty of Electrical and Computer Engineering, The University of Sistan and Baluchestan, Zahedan, Iran

Abstract—
Using concave rectangular patches, a new solution to reduce mutual coupling and return loss in two-dimensional array of microstrip antennas is proposed. The effect of width and length concavity on mutual coupling and return loss is studied. Also, the patch parameters as well as the amounts of width and length concavity are optimized using an enhanced genetic algorithm. Simulation results show that the resulting array antenna has low amounts of mutual coupling and return loss.

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Image transmission over OFDM channel with rate allocation scheme and minimum peak-toaverage power ratio
[Full Text]

Usama S. Mohammed,
Department of Electrical Engineering Department, Assiut University, Assiut 71516, Egypt
H. A. Hamada Author,
Department of Electrical Engineering, South Valley University, Aswan 81542, Egypt

Abstract—
This paper proposes new scheme for efficient rate allocation in conjunction with reducing peak-to-average power ratio (PAPR) in orthogonal frequency-division multiplexing (OFDM) systems. Modification of the set partitioning in hierarchical trees (SPIHT) image coder is proposed to generate four different groups of bit-stream relative to its significances. The significant bits, the sign bits, the set bits and the refinement bits are transmitted in four different groups. The proposed method for reducing the PAPR utilizes twice the unequal error protection (UEP), using the Read-Solomon codes (RS), in conjunction with bit-rate allocation and selective interleaving to provide minimum PAPR. The output bit-stream from the source code (SPIHT) will be started by the most significant types of bits (first group of bits). The optimal unequal error protection (UEP) of the four groups is proposed based on the channel destortion. The proposed structure provides significant improvement in bit error rate (BER) performance. Performed computer simulations have shown that the proposed scheme outperform the performance of most of the recent PAPR reduction techniques in most cases. Moreover, the simulation results indicate that the proposed scheme provides significantly better PSNR performance in comparison to well-known robust coding schemes.

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Performance Evaluation of Two-Stage Shared FDL Optical Packet Switch using Contention Resolution Scheme with Packet Releasing Priority
[Full Text]

A.Galib Reza, Faculty of Information Technology, Multimedia University, Malaysia
S.C. Tan, Faculty of Information Technology,  Multimedia University,
Malaysia
F.M. Abbou,  Al-Madinah International University, Malaysia

A
bstract—This paper proposes a two-stage optical packet switch with second stage of recirculate switch of FDL to reduce the number of the FDL used in the switch for contention resolution. The contention resolution scheme with priority in packet releasing from FDL is tested in the two-stage switch for performance evaluation. Simulation result shows that zero packet loss rate achievable with ı< 0.8 for 32x 32 two-stage switch.

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Capacity Optimized For Multicarrier OFDM-MIMO Antenna Systems
[Full Text]

Nirmalendu Bikas Sinha, Department of ECE and EIE , College of Engineering & Management, Kolaghat, K.T.P.P Township, India
Prosenjit kumar, Department of ECE, College of Engineering & Management, Kolaghat, K.T.P.P Township, India
Dr. M.Mitra, Bengal Engineering and science University, Shibpur, Howrah, India


Abstract— Motivated by MIMO broad-band fading channel model, in this section we deals with the capacity behaviour of wireless MIMO and OFDM based spatial multiplexing systems in broad-band fading environments for the case where the channel is unknown at the transmitter and perfectly known at the
receiver. This influence the propagation and system parameters on ergodic capacity, we furthermore demonstrate that, unlike the single-input single-output (SISO) case, delay spread channels may provide advantage over flat-fading channels not only in terms of outage capacity but also in terms of ergodic
capacity. Therefore, MIMO delay spread channels will in general provide both higher diversity gain and higher multiplexing gain than MIMO flat-fading channels.

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Improving GPS Precision and Processing Time using Parallel and Reduced-Length Wiener Filters
[Full Text]

J. Garcia, D
epartment Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, USA
C. Zhou, Department Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, USA

Abstract—
Increasing GPS precision at low cost has always been a challenge for the manufacturers of the GPS receivers. This paper proposes the use of a Wiener filter for increasing precision in substitution of traditional GPS/INS fusion systems, which require expensive inertial systems. In this paper, we first implement and compare three GPS signal processing schemes: a Kalman filter, a neural network and a Wiener filter and compare them in terms of precision and the processing time. To further reduce the processing time of Wiener filter, we propose parallel and reduced-length implementations. Finally, we calculate the sampling frequency that would be required in every Wiener scheme in order to obtain the same total processing time as the Kalman filter and the neural network.

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Imprvoing QoS of all-IP Generation of Pre-WiMax Networks Using Delay-Jitter Model
[Full Text]

H. Dahmouni, INPT, Telecommunications Department, Rabat, Morocco
H. El Ghazi
, INPT, Telecommunications Department, Rabat, Morocco
D. Bonacci, TéSA Laboratory, Toulouse, France
B. Sansò, Ecole Polytechnique de Montréal, Electrical Engineering Department, CP 6079 succ Centre-Ville Montreal, Qc, Canada
A. Girard,  INRS-EMT and GERAD, 800, de la Gauchetire O Suite 6900, Montreal, Qc, Montreal, Qc, Canada

Abstract—The topic of this paper is the evaluation of QoS parameters in live Pre-Wimax environments. The main contribution is the validation of an analytical delay-jitter behavior model. These models can be used in optimization algorithms in order to provide opportunistic and reliable all-IP networks. It allows understanding the impact of the jitter constraints on the throughput and packet loss in wireless systems. However, we show that the real-time QoS requirements of real-time and interactive services can be avoided to a large degree by controlling only the packet delay-jitter in a fixed and mobile environment. The QoS metrics have been computed from live measurements in a Pre-Wimax realistic environment (Toulouse/Blagnac Airport).

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Holographic Projection Technology: TheWorld is Changing
[Full Text]

Ahmed Elmorshidy, Gulf University for Science and Technology, Kuwait and Claremont Graduate University, California, USA

Abstract—This research papers examines the new technology of Holographic Projections. It highlights the importance and need of this technology and how it represents the new wave in the future of technology and communications, the different application of the technology, the fields of life it will dramatically affect including business, education, telecommunication and healthcare. The paper also discusses the future of holographic technology and how it will prevail in the coming years highlighting how it will also affect and reshape many other fields of life, technologies and businesses.

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Analysis of Beaulieu Pulse Shaping Family Based FIR Filter for WCDMA
[Full Text]

A S Kang, Department of Electronics and Communication Engg, University Institute of Engg and Technology, Panjab
University,Chandigarh-160014
Vishal Sharma, Department of Electronics and Communication Engg, University Institute of Engg and Technology, Panjab University,Chandigarh-160014


Abstract—The analysis and simulation of transmit and receive pulse shaping filter is an important aspect of digital wireless communication since it has a direct effect on error probabilities. Pulse shaping for wireless communication over time as well as frequency selective channels is the need of hour for 3G and 4G systems. The pulse shaping filter is a useful means to shape the signal spectrum and avoid interferences. Basically digital filters are used to modify the characteristics of signal in time and frequency domain and have been recognized as primary digital signal processing operations.

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Simulink based VoIP Analysis
[Full Text]

Hardeep Singh is Research Scholar Department of Physics, Guru Nanak Dev University, Amritsar
Jasvir Singh is Professor in Dept of Electronics Technology, Guru Nanak Dev University, Amritsar
M. Mian is Professor in Dept of Physics, Guru Nanak Dev University, Amritsar


Abstract— Voice communication over internet not be possible without a reliable data network, this was first available when distributed network topologies were used in conjunction with data packets. Early network used single centre node network in which a single workstation (Server) is responsible for the communication. This posed problems as if there was a fault with the centre node, (workstation) nothing would work. This problem was solved by the distributed system in which reliability increases by spreading the load between many nodes. The idea of packet switching & distributed network were combined, this combination were increased reliability, speed & responsible for voice communication over internet, Voice-over-IP (VoIP)These data packets travel through a packet-switched network such as the Internet and arrive at their destination where they are decompressed using a compatible Codec (audio coder/decoder) and converted back to analogue audio. This paper deals with the Simulink architecture for VoIP network.

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Novel method for planar microstrip antenna matching impedance
[Full Text]

Mahdi Ali, Laboratoire d’Electronique et des Technologies de l’Information (LETI), Ecole Nationale d’Ingénieurs de Sfax
Abdennacer Kachouri, Laboratoire d’Electronique et des Technologies de l’Information (LETI), Ecole Nationale d’Ingénieurs de Sfax
Mounir Samet, Laboratoire d’Electronique et des Technologies de l’Information (LETI), Ecole Nationale d’Ingénieurs de Sfax


Abstract— Because all microstrip antennas have to be matched to the standard generator impedance or load, the input impedance matching method for antenna is particularly important. In this paper a new methodology in achieving matching impedance of a planar microstrip antenna for wireless application is described. The method is based on embedding an Interdigital capacitor. The fine results obtained by using a microstrip Interdigital capacitor for matching antenna impedance led to an efficient method to improve array antenna performance. In fact, a substantial saving on the whole surfaces as well as enhancement of the gain, the directivity and the power radiated was achieved.

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To Optimally Design Microstrip Nonuniform Transmission Lines as Lowpass Filters
[Full Text]

M. Khalaj-Amirhosseini, Iran University of Science and Technology, Tehran, Iran
S. A. Akbarzadeh-Jahromi, Iran University of Science and Technology
Tehran, Iran

Abstract— A method is proposed to optimally design the Microstrip Nonuniform Transmission Line (MNTLs) as lowpass filters.
Some electrical and physical restrictions are used to design MNTLs. To optimally design the MNTLs, their strip width is
expanded as truncated Fourier series, firstly. Then, the optimum values of the coefficients of the series are obtained through an
optimization approach. The performance of the proposed structure is studied by design and fabrication of two lowpass filters of
cutoff frequency 2.0 GHz.

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Implementation of Handoff through wireless access point Techniques
[Full Text]

N.S.V.Shet, NITK, Surathkal, India
K.Chandrasekaran, NITK, Surathkal, India
K.C.Shet, NITK, Surathkal, India


Abstract— Handoff has become an inevitable part of wireless cellular communication, Soon users will carry small portable handheld devices which will incorporate the computer, phone, camera, GPS, personal control module etc. This paper proposes a new scheme to deal with seam less roaming and reduce failed handoffs. The simulation is done using software called Qualnet meant for wireless communication. The results clearly indicate the advantages of this new scheme.

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Mechanism for Learning Object retrieval supporting adaptivity
[Full Text]

Sonal Chawla, Dept of computer Science & Appl, Panjab University, Chandigarh, India
R.K. Singla, Dept of computer Science & Appl, Panjab University, Chandigarh, India


Abstract— In today’s world designing adaptable course material requires new technical knowledge which involves a need for a uniform protocol that allows organizing resources with emphasis on quality and Learning. This can be achieved by bundling the resources in a known and prescribed fashion called Learning objects. Learning Objects are composed of two aspects namely “Learning “ and “Object”. The Learning aspect of Learning objects refers to Education. Since Education is a process so the primary aim of learning objects tends to be facilitating acquisition, assessment and conversion of content into Learning objects while fostering the assimilation of these Learning objects into learning modules and instruction. The Object part of Learning objects relates to the Digital Electronic format of the resources i.e. to say that it deals with the physical resource that forms the Learning objects. The objects in LOs are analogous to objects used in object-oriented modeling (OOM). The analogy helps visualize how LOs will be packaged, processed and transported across the digital library as well as utilized in course building. OOM concepts such as encapsulation, classification, polymorphism, inheritance and reuse can be borrowed to describe the operations on LOs in the digital library. Thus, the aim of this paper is threefolds. Firstly, to discuss the background of this research and the concept of Learning Objects. Secondly, to provide a framework for adaptive mechanism for the retrieval of Learning Objects and thirdly to highlight the benefits that this new proposed framework shall bring.