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Systems and Communications Commons

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2007

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Articles 1 - 19 of 19

Full-Text Articles in Systems and Communications

Reed-Solomon Codes Construction & Decoding, Samuel J. Parsons Dec 2007

Reed-Solomon Codes Construction & Decoding, Samuel J. Parsons

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.


Novel And Efficient Download Test For Two Path Echo Canceller, Mohammad Asif Iqbal, Steven L. Grant Dec 2007

Novel And Efficient Download Test For Two Path Echo Canceller, Mohammad Asif Iqbal, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

The two-path echo cancellation technique is a popular method for handling the double-talk problem in acoustic and line echo cancellation applications. the method uses two filters. a so-called background adaptive filter adapts its coefficients to predict echo all or most of the time regardless of signal activity on the near end. a second foreground filter, that also predicts the echo, receives it coefficients from the background filter, but only when the background is performing better than the foreground. Only the foreground residual echo is sent to the far-end. so any background divergence due to double-talk is not observed by the …


Wireless Positioning Techniques: A Developer's Update, Seamus Rooney, Keith Gardiner, James Carswell Nov 2007

Wireless Positioning Techniques: A Developer's Update, Seamus Rooney, Keith Gardiner, James Carswell

Conference papers

This paper describes the current efforts to develop an open source, privacy sensitive, location determination software component for mobile devices. Currently in mobile computing, the ability of a mobile device to determine its own location is becoming increasingly desirable as the usefulness of such a feature enhances many commercial applications. There have been numerous attempts to achieve this from both the network positioning perspective and also from the wireless beacon angle not to mention the integration of GPS into mobile devices. There are two important aspects to consider when using such a system which are privacy and cost. This paper …


The Effects Of Contention Among Stations On Video Streaming Applications Over Wireless Local Area Networks: An Experimental Approach, Nicola Cranley, Tanmoy Debnath Oct 2007

The Effects Of Contention Among Stations On Video Streaming Applications Over Wireless Local Area Networks: An Experimental Approach, Nicola Cranley, Tanmoy Debnath

Conference papers

Multimedia streaming applications have a large impact on the resource requirements of the WLAN. There are many variables involved in video streaming, such as the video content being streamed, how the video is encoded and how it is sent. This makes the role of radio resource management and the provision of QoS guarantees extremely difficult. For video streaming applications, packet loss and packets dropped due to excessive delay are the primary factors that affect the received video quality. In this paper, we experimentally analyse the effects of contention on the performance of video streaming applications with a given delay constraint …


Distributed Cluster-Based Outlier Detection In Wireless Sensor Networks, Swetha Gali Oct 2007

Distributed Cluster-Based Outlier Detection In Wireless Sensor Networks, Swetha Gali

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks find several potential applications in a variety of fields, such as environmental monitoring and control, battlefields, surveillance, smart buildings, human health monitoring, etc. These sensor networks consist of a large number of very tiny, inexpensive, and low power sensor nodes, which are deployed in a variety of harsh environments that may result in the sensor data getting corrupted. It is thus critical to detect and report these abnormal values in the sensor data, in order to have a better understanding of the monitored environment. Detection of the abnormal values is of special interest for the sensor network …


Examination Of Energy And Group Velocities In Positive And Negative Index Chiral Materials With And Without Dispersion, Monish Ranjan Chatterjee, Partha P. Banerjee Sep 2007

Examination Of Energy And Group Velocities In Positive And Negative Index Chiral Materials With And Without Dispersion, Monish Ranjan Chatterjee, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

Concepts of energy and group velocities, Poynting and propagation vectors are examined for both positive and negative index materials. Known definitions for these entities are explored in terms of the interplay of chirality and dispersion.


Energy-Efficient Querying Of Wireless Sensor Networks, Christopher R. Mann Sep 2007

Energy-Efficient Querying Of Wireless Sensor Networks, Christopher R. Mann

Theses and Dissertations

Due to the distributed nature of information collection in wireless sensor networks and the inherent limitations of the component devices, the ability to store, locate, and retrieve data and services with minimum energy expenditure is a critical network function. Additionally, effective search protocols must scale efficiently and consume a minimum of network energy and memory reserves. A novel search protocol, the Trajectory-based Selective Broadcast Query protocol, is proposed. An analytical model of the protocol is derived, and an optimization model is formulated. Based on the results of analysis and simulation, the protocol is shown to reduce the expected total network …


Experimental Tuning Of Aifsn And Cwmin Parameters To Prioritize Voice Over Data Transmission In 802.11e Wlan Networks, Miroslaw Narbutt, Mark Davis Aug 2007

Experimental Tuning Of Aifsn And Cwmin Parameters To Prioritize Voice Over Data Transmission In 802.11e Wlan Networks, Miroslaw Narbutt, Mark Davis

Conference papers

In this paper we experimentally study the impact of two EDCA parameters, namely AIFSN and CWmin, on a mixed voice/data wireless transmission. In particular we investigate how the tuning of these parameters affects both the voice transmission quality and background data throughput. We predict end-to-end voice transmission quality from time varying transmission impairments using the latest Appendix to the ITU-T E-model. Our experimental results show that the tuning of the EDCA parameters can be used to successfully prioritize voice transmission over data in real 802.11e networks. We also demonstrate that the AIFSN parameter more effectively protects voice calls against background …


Experimental Tuning Of The Aifsn Parameter To Prioritize Voice Over Data Transmission In 802.11e Wlan Networks, Miroslaw Narbutt, Mark Davis Aug 2007

Experimental Tuning Of The Aifsn Parameter To Prioritize Voice Over Data Transmission In 802.11e Wlan Networks, Miroslaw Narbutt, Mark Davis

Conference papers

In this paper we experimentally study the impact of one EDCA parameter, namely AIFSN on a mixed voice/data wireless transmission. In particular we investigate how the tuning of this parameter affects both the voice transmission quality and background data throughput. We predict end-to-end voice transmission quality from time varying transmission impairements using the latest Appendix to the ITU-T E-model. Our experiemental results show that the tuning of the AIFSN parameter can successfully prioritize voice transmission over data in a real 802.11e network. To the best of our knowledge this is the first experimental investigation on tuning of MAC layer parameters …


Analysis Of Beam Propagation In 90-Degree Holographic Recording And Readout Using Transfer Functions And Numerical 2-D-Laplace Inversion, Monish Ranjan Chatterjee, Partha P. Banerjee, George Nehmetallah Jun 2007

Analysis Of Beam Propagation In 90-Degree Holographic Recording And Readout Using Transfer Functions And Numerical 2-D-Laplace Inversion, Monish Ranjan Chatterjee, Partha P. Banerjee, George Nehmetallah

Electrical and Computer Engineering Faculty Publications

Recently, 2-D-Laplace analysis of recording and readout of edge-holograms was reported. Numerical Laplace inversion was examined for simple test cases. Inversion algorithms are applied to examine beam shaping and distortion in photovoltaic and photorefractive materials.


An Experimental Investigation Of Parallel Multimedia Streams Over Ieee 802.11e Wlan Networks Using Txop, Nicola Cranley, Tanmoy Debnath, Mark Davis Jun 2007

An Experimental Investigation Of Parallel Multimedia Streams Over Ieee 802.11e Wlan Networks Using Txop, Nicola Cranley, Tanmoy Debnath, Mark Davis

Conference papers

In this paper we perform an experimental investigation of the IEEE 802.11 TXOP facility to enhance the transmission of parallel multimedia streaming sessions through efficient bandwidth reservation and explicitly consider both the audio and video streams. The delay constraints associated with the audio and video streams that comprise a multimedia session pose the greatest challenge since real-time multimedia is particularly sensitive to delay as the packets require a strict bounded end-to-end delay. We show how the TXOPlimit parameter can be efficiently dimensioned to reduce the tranmission delay for the video frames. Due to tis frame-based nature, video applications are considered …


User Quality Of Experience-Aware Multimedia Streaming Over Wireless Home Area Network, Gabriel-Miro Muntean, Nicola Cranley Apr 2007

User Quality Of Experience-Aware Multimedia Streaming Over Wireless Home Area Network, Gabriel-Miro Muntean, Nicola Cranley

Conference papers

For multimedia streaming over wireless networks, there is a trade-off between the capacity of the wireless links and the end-user perceived-quality, which can be affected by the compression scheme used, content characteristics and adaptation algorithm (if any). In this paper, this trade-off is investigated for streaming various motion content multimedia over an IEEE 802.11b-based Wireless-Home Area Network using the Quality-Oriented Adaptation Scheme (QOAS). QOAS performance is compared to that of a non-adaptive scheme when using MPEG-2 and MPEG-4 encoding in terms of average end-user perceived quality, number of streaming sessions concurrently supported, loss rate, delay, jitter and total throughput. Simulation …


Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet Apr 2007

Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet

Electrical & Computer Engineering Theses & Dissertations

Wireless Local Area networks (WLAN) and Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. The 802.11b WLAN operates in the 2.4 GHz band and uses a Direct Sequence Spread Spectrum technique. It is designed to cover large areas ranging up to 100 meters in diameter, which may connect hundreds of computers. Bluetooth (BT) WPAN also operates in the same frequency band as the IEEE 802.lib and it uses a Frequency Hopping Spread Spectrum technique. BT is primarily used for communications between notebooks, palm units and other personal computing devices within relatively …


Study Of Soliton Stabilization In D+1 Dimensions Using Novel Analytical And Numerical Techniques, George Nehmetallah, Partha P. Banerjee Jan 2007

Study Of Soliton Stabilization In D+1 Dimensions Using Novel Analytical And Numerical Techniques, George Nehmetallah, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

In this Chapter, we provide a brief review of the underlying nonlinear Schrödinger and associated equations that model spatio-temporal propagation in one and higher dimensions in a nonlinear dispersive environment. Particular attention is given to fast adaptive numerical techniques to solve such equations, and in the presence of dispersion and nonlinearity management, saturating nonlinearity and nonparaxiality. A unique variational approach is also outlined which helps in determining the ranges of nonlinearity and dispersion parameters to ensure stable solutions of the nonlinear equations. The propagation of 3+1 dimensional spatio-temporal pulses, or optical bullets is also modeled using a fast adaptive split-step …


Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow Jan 2007

Improvement To The Data Logging Capability Of A Cough Monitoring System, Matthew Barlow

Inquiry: The University of Arkansas Undergraduate Research Journal

Data logging capability of a previously developed self contained cough recorder using an accelerometer as the sensing element is improved by using a secure digital memory card for later retrieval on a computer. Firmware is developed to enhance the functionality of the cough recorder. Existing libraries are modified for increased write rates. Increased writing speed allows 8-bit sampling at rates exceeding 8kHz, allowing for detailed time and frequency domain analysis. Additional features have also been developed to enable easy management of recordings, such as a file system compatibility with Microsoft Windows., and unique file names for each recording.


Atmospheric Turbulence Compensation Of Point Source Images Using Asynchronous Stochastic Parallel Gradient Descent Technique On Amos 3.6 M Telescope, Mikhail Vorontsov, Jim F. Riker, Gary W. Carhart, Venkata S. Rao Gudimetla, Leonid A. Beresnev, Thomas Weyrauch Jan 2007

Atmospheric Turbulence Compensation Of Point Source Images Using Asynchronous Stochastic Parallel Gradient Descent Technique On Amos 3.6 M Telescope, Mikhail Vorontsov, Jim F. Riker, Gary W. Carhart, Venkata S. Rao Gudimetla, Leonid A. Beresnev, Thomas Weyrauch

Electrical and Computer Engineering Faculty Publications

The Stochastic Parallel Gradient Descent Technique-based Adaptive Optics (SPGD-AO) system described in this presentation does not use a conventional wavefront sensor. It uses a metric signal collected by a single pixel detector placed behind a pinhole in the image plane to drive three deformable mirrors (DMs). The system is designed to compensate the image for turbulence effects. The theory behind this method is described in detail in [1]. However this technique, while widely simulated and tested in the laboratory, was not yet verified in astronomical field site experiments. During the month of May 2007, a series of experiments with SPGD-AO …


Adaptive Optics Performance Over Long Horizontal Paths: Aperture Effects In Multi-Conjugate Adaptive Optical Systems, Miao Yu, Mikhail Vorontsov, Svetlana Lachinova, Jim F. Riker, Venkata S. Rao Gudimetla Jan 2007

Adaptive Optics Performance Over Long Horizontal Paths: Aperture Effects In Multi-Conjugate Adaptive Optical Systems, Miao Yu, Mikhail Vorontsov, Svetlana Lachinova, Jim F. Riker, Venkata S. Rao Gudimetla

Electrical and Computer Engineering Faculty Publications

We analyze various scenarios of the aperture effects in adaptive optical receiver-type systems when inhomogeneities of the wave propagation medium are distributed over long horizontal propagation path, or localized in a few thin layers remotely located from the receiver telescope pupil. Phase aberration compensation is performed using closed-loop control architectures based on phase conjugation and decoupled stochastic parallel gradient descent (DSPGD) control algorithms. Both receiver system aperture diffraction effects and the impact of wave-front corrector position on phase aberration compensation efficiency are analyzed for adaptive systems with single or multiple wave-front correctors.


Krylov Subspaces From Bilinear Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov Jan 2007

Krylov Subspaces From Bilinear Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

For efficient simulation of state-of-the-art dynamical systems as arise in all aspects of engineering, the development of reduced-order models is of paramount importance. While linear reduction techniques have received considerable study, increasingly nonlinear model reduction is becoming a significant field of interest. From a circuits and systems viewpoint, systems involving micromachined devices or systems involving mixed technologies necessitate the development of reduced-order nonlinear models. From a control systems viewpoint, the design of controllers for nonlinear systems is greatly facilitated by nonlinear model reduction strategies. To this end, the paper proposes two novel model-reduction strategies for nonlinear systems. The first involves …


A Service Provisioning Platform For Beyond 3g - The Telecommunication Service Exchange, Donna Griffin Jan 2007

A Service Provisioning Platform For Beyond 3g - The Telecommunication Service Exchange, Donna Griffin

Theses

From the inception of mobile communications one of the most important factors contributing to its success has been a good understanding of user requirements. In the first generation, mobile networks offered subscribers the freedom to communicate regardless of their locations and the joy of instant access to voice telephony services. This provided a competitive edge over wire line communication networks and resulted in large revenue streams. However over the past decade, mobile network operators have been faced with a number of factors that have incurred significant costs and resulting reduced revenue. These factors include deregulation, increased competition and technological progress …