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    Partial Update Least-Square Adaptive Filtering

    Xie, B. ; Bose, T.
    DOI: 10.2200/S00575ED1V01Y201403COM010
    Copyright Year: 2014

    Morgan and Claypool eBooks

    Adaptive filters play an important role in the fields related to digital signal processing and communication, such as system identification, noise cancellation, channel equalization, and beamforming. In practical applications, the computational complexity of an adaptive filter is an important consideration. The Least Mean Square (LMS) algorithm is widely used because of its low computational complexity ($O(N)$) and simplicity in implementation. The least squares algorithms, such as Recursive Least Squares (RLS), Conjugate Gradient (CG), and Euclidean Direction Search (EDS), can converge faster and have lower steady-state mean square error (MSE) than LMS. However, their high computational complexity ($O(N^2)$) makes them unsuitable for many real-time applications. A well-known approach to controlling computational complexity is applying partial update (PU) method to adaptive filters. A partial update method can reduce the adaptive algorithm complexity by updating part of the weight vec or instead of the entire vector or by updating part of the time. In the literature, there are only a few analyses of these partial update adaptive filter algorithms. Most analyses are based on partial update LMS and its variants. Only a few papers have addressed partial update RLS and Affine Projection (AP). Therefore, analyses for PU least-squares adaptive filter algorithms are necessary and meaningful. This monograph mostly focuses on the analyses of the partial update least-squares adaptive filter algorithms. Basic partial update methods are applied to adaptive filter algorithms including Least Squares CMA (LSCMA), EDS, and CG. The PU methods are also applied to CMA1-2 and NCMA to compare with the performance of the LSCMA. Mathematical derivation and performance analysis are provided including convergence condition, steady-state mean and mean-square performance for a time-invariant system. The steady-state mean and mean-square performance are also presented for a time-varying syste . Computational complexity is calculated for each adaptive filter algorithm. Numerical examples are shown to compare the computational complexity of the PU adaptive filters with the full-update filters. Computer simulation examples, including system identification and channel equalization, are used to demonstrate the mathematical analysis and show the performance of PU adaptive filter algorithms. They also show the convergence performance of PU adaptive filters. The performance is compared between the original adaptive filter algorithms and different partial-update methods. The performance is also compared among similar PU least-squares adaptive filter algorithms, such as PU RLS, PU CG, and PU EDS. In addition to the generic applications of system identification and channel equalization, two special applications of using partial update adaptive filters are also presented. One application uses PU adaptive filters to detect Global System for Mobile Communication (GSM) signals in a local GSM system using the Open Base Transceiver Station (OpenBTS) and Asterisk Private Branch Exchange (PBX). The other application uses PU adaptive filters to do image compression in a system combining hyperspectral image compression and classification. View full abstract»

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    Resource-Oriented Architecture Patterns for Webs of Data

    Sletten, B.
    DOI: 10.2200/S00498ED1V01Y201304WBE006
    Copyright Year: 2013

    Morgan and Claypool eBooks

    The surge of interest in the REpresentational State Transfer (REST) architectural style, the Semantic Web, and Linked Data has resulted in the development of innovative, flexible, and powerful systems that embrace one or more of these compatible technologies. However, most developers, architects, Information Technology managers, and platform owners have only been exposed to the basics of resource-oriented architectures. This book is an attempt to catalog and elucidate several reusable solutions that have been seen in the wild in the now increasingly familiar "patterns book" style. These are not turn key implementations, but rather, useful strategies for solving certain problems in the development of modern, resource-oriented systems, both on the public Web and within an organization's firewalls. View full abstract»

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    Shared-Memory Synchronization

    Scott, M.
    DOI: 10.2200/S00506ED1V01Y201305AIM021
    Copyright Year: 2013

    Morgan and Claypool eBooks

    From driving, flying, and swimming, to digging for unknown objects in space exploration, autonomous robots take on varied shapes and sizes. In part, autonomous robots are designed to perform tasks that are too dirty, dull, or dangerous for humans. With nontrivial autonomy and volition, they may soon claim their own place in human society. These robots will be our allies as we strive for understanding our natural and man-made environments and build positive synergies around us. Although we may never perfect replication of biological capabilities in robots, we must harness the inevitable emergence of robots that synchronizes with our own capacities to live, learn, and grow. This book is a snapshot of motivations and methodologies for our collective attempts to transform our lives and enable us to cohabit with robots that work with and for us. It reviews and guides the reader to seminal and continual developments that are the foundations for successful paradigms. It attempts to demystify the abilities and limitations of robots. It is a progress report on the continuing work that will fuel future endeavors. Table of Contents: Part I: Preliminaries/Agency, Motion, and Anatomy/Behaviors / Architectures / Affect/Sensors / Manipulators/Part II: Mobility/Potential Fields/Roadmaps / Reactive Navigation / Multi-Robot Mapping: Brick and Mortar Strategy / Part III: State of the Art / Multi-Robotics Phenomena / Human-Robot Interaction / Fuzzy Control / Decision Theory and Game Theory / Part IV: On the Horizon / Applications: Macro and Micro Robots / References / Author Biography / Discussion View full abstract»

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    Energy-Efficient Scheduling under Delay Constraints for Wireless Networks

    Berry, R. ; Modiano, E. ; Zafer, M.
    DOI: 10.2200/S00443ED1V01Y201208CNT011
    Copyright Year: 2012

    Morgan and Claypool eBooks

    Packet delay and energy consumption are important considerations in wireless and sensor networks as these metrics directly affect the quality of service of the application and the resource consumption of the network; especially, for a rapidly growing class of real-time applications that impose strict restrictions on packet delays. Dynamic rate control is a novel technique for adapting the transmission rate of wireless devices, almost in real-time, to opportunistically exploit time-varying channel conditions as well as changing traffic patterns. Since power consumption is not a linear function of the rate and varies significantly with the channel conditions, adapting the rate has significant benefits in minimizing energy consumption. These benefits have prompted significant research in developing algorithms for achieving optimal rate adaptation while satisfying quality of service requirements. In this book, we provide a comprehensive study of dynamic rate control for energy minimizatio under packet delay constraints. We present several formulations and approaches adopted in the literature ranging from discrete-time formulations and dynamic programming based solutions to continuous-time approaches utilizing ideas from network calculus and stochastic optimal control theory. The goal of this book is to expose the reader to the important problem of wireless data transmission with delay constraints and to the rich set of tools developed in recent years to address it. Table of Contents: Introduction / Transmission Rate Adaptation under Deadline Constraints / Average Delay Constraints View full abstract»

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    Practical Phase-Locked Loop Design

    Fischette, Dennis
    Publication Year: 2005

    IEEE eLearning Library Courses

    This tutorial provides a practical introduction to PLL design for clock synthesis. The twin goals of the tutorial are to provide practical advice on solving real-world PLL problems and to help develop an intuitive feel for PLL theory in order to prevent common design mistakes. This tutorial includes basic feedback loop theory and common circuit implementations, with emphasis on typical problem spots. It also focuses on design for test and debug, an important but often overlooked topic. In 1988 I joined Integrated CMOS Systems as a circuit/device engineer, working on device modeling and characterization as well as cell library automation. View full abstract»

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    Advanced Protocols for Wireless Ad-hoc Networks

    Sohrabi, Kathy
    Publication Year: 2006

    IEEE eLearning Library Courses

    This is a 2-part course. The Advanced Protocols for Wireless Ad-hoc Networks will illustrate that in Ad-Hoc networks where there is no underlying fixed infrastructure, tasks such as network self-organization, mobility management, adaptive route detection for unicast and multicast applications, and provisioning of Gateway functionality to interconnect the ad-hoc network to the rest of the Internet space must be handled according to rules that are unique to the ad-hoc nature of the system. Topics related to support of QoS at various network layers will also be discussed, with emphasis on layers 2, 3, and 4 of the network. We will investigate the performance of these protocols in terms of their level of scalability to different sizes, and traffic loads. Topics of security will also be discussed. View full abstract»

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    Electric Drives: Understanding Basics

    Mohan, Ned
    Publication Year: 2006

    IEEE eLearning Library Courses

    This is a 2-part tutorial. The first-half of this course will focus on the basics and analyze induction and permanent-magnet ac machines in a way that clearly explains how these machines operate on a physical basis, and hence how they ought to be controlled for optimum performance. After completing this course you should be able to develop an understanding of how ac machines operate on a physical basis. View full abstract»

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    Advances in Digital RF Architectures and Digitally-Assisted RF

    Staszewski, Robert
    Publication Year: 2010

    IEEE eLearning Library Courses

    In the last few years, a series of breakthrough innovations have been made to transform analog-intensive RF circuitry into digitally-intensive implementations. In Texas Instruments, this disruptive technology falls under the umbrella of a Digital RF Processor (DRP^TM) platform and enables to integrate almost all of cellular phone modem electronics into a single IC chip fabricated using nanoscale digital CMOS process. The first such single-chip mobile phone was sampled in December 2004 and is now in a mass- volume production targeting ultra low cost handsets for the Emerging Markets. The ultra low cost handsets typically support a single standard, GSM, and are mostly dual-band with occasional quad-band for world travel compatibility. As the Emerging Markets consumers get more sophisticated, there will be an increase in demand for more sophisticated phones with Third Generation (3G) modem interface, as well as wireless connectivity, such as Bluetooth, Wireless LAN, in addition to mobile digital TV and Global Positioning System (GPS). This presentation will also overview recent advances in digital RF architectures in more sophisticated wireless standards beyond GSM and EDGE. View full abstract»

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    Scheduling and Congestion Control for Wireless and Processing Networks

    Jiang, L. ; Walrand, J.
    DOI: 10.2200/S00270ED1V01Y201008CNT006
    Copyright Year: 2010

    Morgan and Claypool eBooks

    In this book, we consider the problem of achieving the maximum throughput and utility in a class of networks with resource-sharing constraints. This is a classical problem of great importance. In the context of wireless networks, we first propose a fully distributed scheduling algorithm that achieves the maximum throughput. Inspired by CSMA (Carrier Sense Multiple Access), which is widely deployed in today's wireless networks, our algorithm is simple, asynchronous, and easy to implement. Second, using a novel maximal-entropy technique, we combine the CSMA scheduling algorithm with congestion control to approach the maximum utility. Also, we further show that CSMA scheduling is a modular MAC-layer algorithm that can work with other protocols in the transport layer and network layer. Third, for wireless networks where packet collisions are unavoidable, we establish a general analytical model and extend the above algorithms to that case. Stochastic Processing Networks (SPNs) model manuf cturing, communication, and service systems. In manufacturing networks, for example, tasks require parts and resources to produce other parts. SPNs are more general than queueing networks and pose novel challenges to throughput-optimum scheduling. We proposes a "deficit maximum weight" (DMW) algorithm to achieve throughput optimality and maximize the net utility of the production in SPNs. Table of Contents: Introduction / Overview / Scheduling in Wireless Networks / Utility Maximization in Wireless Networks / Distributed CSMA Scheduling with Collisions / Stochastic Processing networks View full abstract»

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    Joint Source Channel Coding Using Arithmetic Codes

    Dongsheng, B. ; Sayood, K. ; Hoffman, M.
    DOI: 10.2200/S00222ED1V01Y200911COM004
    Copyright Year: 2009

    Morgan and Claypool eBooks

    Based on the encoding process, arithmetic codes can be viewed as tree codes and current proposals for decoding arithmetic codes with forbidden symbols belong to sequential decoding algorithms and their variants. In this monograph, we propose a new way of looking at arithmetic codes with forbidden symbols. If a limit is imposed on the maximum value of a key parameter in the encoder, this modified arithmetic encoder can also be modeled as a finite state machine and the code generated can be treated as a variable-length trellis code. The number of states used can be reduced and techniques used for decoding convolutional codes, such as the list Viterbi decoding algorithm, can be applied directly on the trellis. The finite state machine interpretation can be easily migrated to Markov source case. We can encode Markov sources without considering the conditional probabilities, while using the list Viterbi decoding algorithm which utilizes the conditional probabilities. We can also use contex -based arithmetic coding to exploit the conditional probabilities of the Markov source and apply a finite state machine interpretation to this problem. The finite state machine interpretation also allows us to more systematically understand arithmetic codes with forbidden symbols. It allows us to find the partial distance spectrum of arithmetic codes with forbidden symbols. We also propose arithmetic codes with memories which use high memory but low implementation precision arithmetic codes. The low implementation precision results in a state machine with less complexity. The introduced input memories allow us to switch the probability functions used for arithmetic coding. Combining these two methods give us a huge parameter space of the arithmetic codes with forbidden symbols. Hence we can choose codes with better distance properties while maintaining the encoding efficiency and decoding complexity. A construction and search method is proposed and simulation results show that we can chieve a similar performance as turbo codes when we apply this approach to rate 2/3 arithmetic codes. Table of Contents: Introduction / Arithmetic Codes / Arithmetic Codes with Forbidden Symbols / Distance Property and Code Construction / Conclusion View full abstract»

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    Collaborative Web Search:Who, What, Where, When, and Why

    Morris, M. ; Teevan, J.
    DOI: 10.2200/S00230ED1V01Y200912ICR014
    Copyright Year: 2009

    Morgan and Claypool eBooks

    Today, Web search is treated as a solitary experience. Web browsers and search engines are typically designed to support a single user, working alone. However, collaboration on information-seeking tasks is actually commonplace. Students work together to complete homework assignments, friends seek information about joint entertainment opportunities, family members jointly plan vacation travel, and colleagues jointly conduct research for their projects. As improved networking technologies and the rise of social media simplify the process of remote collaboration, and large, novel display form-factors simplify the process of co-located group work, researchers have begun to explore ways to facilitate collaboration on search tasks. This lecture investigates the who, what, where, when and why of collaborative search, and gives insight in how emerging solutions can address collaborators' needs. Table of Contents: Introduction / Who? / What? / Where? / When? / Why? / Conclusion: How? View full abstract»

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    IEEE 802.11N MAC Layer

    Stacey, Robert
    Publication Year: 2009

    IEEE eLearning Library Courses

    The IEEE802.11n standard will enable a new class of consumer and enterprise products utilizing wireless LAN connectivity that is ten times faster than is feasible with the current IEEE802.11a/b/g standards. This tutorial will provide a comprehensive overview of the Media Access Control (MAC) Layer defined in the p802.11n draft standard. The 802.11n MAC tutorial is a companion to the 802.11n PHY tutorial although familiarity with the PHY tutorial is not required for this tutorial.

    The tutorial begins with an overview of the applications, environments, channel models, use cases, and usage models developed by the study group and task group which provided the framework for proposal development. We continue with a history of the various coalitions that ultimately led to the final joint proposal adopted as the draft standard. This part of the tutorial contains similar information to the PHY tutorial and is repeated in a truncated form for the benefit of participants who may not view the PHY tutorial.

    The technical portion of the tutorial begins with an overview of why changes are needed in the MAC to achieve high throughput. The tutorial then covers the major features that improve MAC efficiency, including aggregation and the various modifications made to the block acknowledgement protocol.

    The 802.11n amendment introduces 40MHz operation, new frame formats and reduced interframe spacing among other things. The tutorial goes on to describe the features that support coexistance and interoperability with legacy devices as well as among the various capability classes of 802.11n devices.>>Finally the tutorial covers some of the more advanced features added to the standard, including the reverse direction protocol, fast link adaptation and transmit beamforming. View full abstract»

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    Usable Security:History, Themes, and Challenges

    Garfinkel, S. ; Lipford, H.
    DOI: 10.2200/S00594ED1V01Y201408SPT011
    Copyright Year: 2014

    Morgan and Claypool eBooks

    There has been roughly 15 years of research into approaches for aligning research in Human Computer Interaction with computer Security, more colloquially known as ``usable security.'' Although usability and security were once thought to be inherently antagonistic, today there is wide consensus that systems that are not usable will inevitably suffer security failures when they are deployed into the real world. Only by simultaneously addressing both usability and security concerns will we be able to build systems that are truly secure. This book presents the historical context of the work to date on usable security and privacy, creates a taxonomy for organizing that work, outlines current research objectives, presents lessons learned, and makes suggestions for future research. View full abstract»

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    Block Transceivers:OFDM and Beyond

    Diniz, P. ; Martins, W. ; Lima, M.
    DOI: 10.2200/S00424ED1V01Y201206COM007
    Copyright Year: 2012

    Morgan and Claypool eBooks

    The demand for data traffic over mobile communication networks has substantially increased during the last decade. As a result, these mobile broadband devices spend the available spectrum fiercely, requiring the search for new technologies. In transmissions where the channel presents a frequency-selective behavior, multicarrier modulation (MCM) schemes have proven to be more efficient, in terms of spectral usage, than conventional modulations and spread spectrum techniques. The orthogonal frequency-division multiplexing (OFDM) is the most popular MCM method, since it not only increases spectral efficiency but also yields simple transceivers. All OFDM-based systems, including the single-carrier with frequency-division equalization (SC-FD), transmit redundancy in order to cope with the problem of interference among symbols. This book presents OFDM-inspired systems that are able to, at most, halve the amount of redundancy used by OFDM systems while keeping the computational complexity co parable. Such systems, herein called memoryless linear time-invariant (LTI) transceivers with reduced redundancy, require low-complexity arithmetical operations and fast algorithms. In addition, whenever the block transmitter and receiver have memory and/or are linear time-varying (LTV), it is possible to reduce the redundancy in the transmission even further, as also discussed in this book. For the transceivers with memory it is possible to eliminate the redundancy at the cost of making the channel equalization more difficult. Moreover, when time-varying block transceivers are also employed, then the amount of redundancy can be as low as a single symbol per block, regardless of the size of the channel memory. With the techniques presented in the book it is possible to address what lies beyond the use of OFDM-related solutions in broadband transmissions. Table of Contents: The Big Picture / Transmultiplexers / OFDM / Memoryless LTI Transceivers with Reduced Redundancy / FIR LTV Transc ivers with Reduced Redundancy View full abstract»

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    3G Wireless Systems

    Dahlman, Eric
    Publication Year: 2010

    IEEE eLearning Library Courses

    The aim of this tutorial is to give some insight into the technical details of the different technologies that exists for 3G wireless communication.

    The tutorial begins with a short overview of the different technologies that exist for 3G wireless communication. This also includes an overview of the related specification and standardization activities technologies.

    In the second, main part, of the tutorial, a more detailed description of the different 3G wireless technologies, Wideband CDMA (WCDMA), cdma2000, and UTRA TDD, is given. The main focus is on the physical layer but some higher-layer aspects are also being discussed. Furthermore, the differences between the different 3G technologies are high-lighted.

    The third part of the tutorial covers the evolution of the 3G wireless technologies. I this part, WCDMA HSDPA, WCDMA Enhanced uplink, and cdma2000 1xEV is covered. View full abstract»

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    Network Simulation

    Fujimoto, R. ; Perumalla, K. ; Riley, G.
    DOI: 10.2200/S00046ED1V01Y200609CNT001
    Copyright Year: 2006

    Morgan and Claypool eBooks

    A detailed introduction to the design, implementation, and use of network simulation tools is presented. The requirements and issues faced in the design of simulators for wired and wireless networks are discussed. Abstractions such as packet- and fluid-level network models are covered. Several existing simulations are given as examples, with details and rationales regarding design decisions presented. Issues regarding performance and scalability are discussed in detail, describing how one can utilize distributed simulation methods to increase the scale and performance of a simulation environment. Finally, a case study of two simulation tools is presented that have been developed using distributed simulation techniques. This text is essential to any student, researcher, or network architect desiring a detailed understanding of how network simulation tools are designed, implemented, and used. View full abstract»

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    MIMO-aided OFDM for LTE, WiMAX, WiFi and other Next-generation Multi-carrier Wireless Systems Part 4

    Hanzo, Lajos
    Publication Year: 2010

    IEEE eLearning Library Courses

    Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies.

    CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimising the use of available bandwidth. Multiplexing is sending multiple signals or streams of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end.

    Multi-Carrier (MC) CDMA is a combined technique of Direct Sequence (DS) CDMA (Code Division Multiple Access) and OFDM techniques. It applies spreading sequences in the frequency domain.

    Wireless communications has witnessed a tremendous growth during the past decade and further spectacular enabling technology advances are expected in an effort to render ubiquitous wireless connectivity a reality.

    This series of courses will provide exposure to OFDM, MIMO-OFDM and MC-CDMA. Some working experience on signal processing, OFDM, CDMA, radio-frequency electronics, is assumed. In Part 4 of this series, we will focus on MIMO-aided OFDM systems, which will be classified as beamforming, SDMA, SDM and STTC/STBC systems. Various space-time block- and trellis-coded OFDM systems will be compared in terms of their performance and complexity. View full abstract»

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    Wireless-LAN Radio Design Course and IEEE Standards Bundle

    Behzad, Arya
    Publication Year: 2012

    IEEE eLearning Library Courses

    As one of the few rising stars of the semiconductor industry; WLAN design is engaging more and more engineers and companies. Essential to the overall system design is the radio design. This tutorial will introduce the various flavors of the 802.11 WLAN PHY standards (A/B/G) and describe their specifications and impact on the radio design. The possible choices for the radio architecture (direct-conversion, low-IF, super-heterodyne) are examined and their impact on the transistor-level design will be studied. The emphasis of this tutorial is on practical aspects of design for wireless LAN radios.

    The following IEEE standards are included in this bundle:



    802.11-2007 IEEE Standard for Information Technology - Telecommunications and Information Exchange Between Systems - Local and Metropolitan Area Networks - Specific Requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications

    802.11a-1999 IEEE Standard for Telecommunications and Information Exchange Between Systems - LAN/MAN Specific Requirements - Part 11: Wireless Medium Access Control (MAC) and physical layer (PHY) specifications: High Speed Physical Layer in the 5 GHz band Superceded by ISO/IEC 8802-11: 2005 Information Technology -- Telecommunications and information exchange between systems -- Local and metropolitan area networks -- Specific requirements -- Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications

    802.11b-1999 IEEE Standard for Information Technology - Telecommunications and information exchange between systems - Local and Metropolitan networks - Specific requirements - Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Higher Speed Physical Layer (PHY) Extension in the 2.4 GHz band Superceded by ISO/IEC 8802-11: 2005 Information Technology -- Telecommunications and information exchange between systems -- Local and metropolitan area networks -- Specific requirements -- Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications

    802.11g-2003 IEEE Standard for Information technology-- Local and metropolitan area networks-- Specific requirements-- Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Further Higher Data Rate Extension in the 2.4 View full abstract»

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    Security of Information and Communication Networks Part 2

    Kartalopoulos, Stamatios
    Publication Year: 2010

    IEEE eLearning Library Courses

    The delivery of private or secret messages has been an issue of concern regardless of method of transport. Since antiquity, it was risky to send a message with a messenger without compromise. As a result, certain methods were developed to assure unintelligibility of a message if in enemy hands or to indicate to the rightful recipient that the message has been compromised or not. In our modern era, most messages and private data are transported over the communications network, which unfortunately is not immune to eavesdroppers, malicious attackers, impersonators and in general to bad actors who, with sophisticated methods access the network and harvest or destroy electronic data. In recent years, government and private industry worldwide are witnessing with concern an alarming increase in such malicious acts that aim to harvest information, destroy or alter files, or impersonate a source.

    In this tutorial we provide a simplified description of Quantum Cryptography (QC), the qubit, the superposition of states, and the polarization of photons, the quantum key distribution (QKD), the BB84 and B92 protocols, the K05 enhanced protocol, the generation of entangled photons and the teleportation phenomenon, and the vulnerabilities of realistic quantum networks. We continue with Chaotic processes and Chaos Cryptography, and we introduce Chaotic Quantum Cryptography. We describe biometrics in communications as part of security and privacy, and we finish up with security of the next generation optical network in which we introduce and describe methods for intrusion detection, countermeasure strategies and also autonomous network counterattack scenarios. View full abstract»

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    Optoelectronic Devices for Fiber Optics

    Campbell, Joe C.
    Publication Year: 2005

    IEEE eLearning Library Courses

    This course provides an introductory, tutorial-type overview of key optoelectronic devices for optical communication systems, specifically, semiconductor lasers, photodetectors, optical modulators, and some WDM components. The course covers a broad range of devices with an emphasis on fundamental device physics and operating principles. Important performance parameters including design tradeoffs will also be discussed. The laser section will discuss applications and the types of lasers that are utilized for specific systems. Topics include multiple quantum well lasers, distributed feedback lasers, wavelength tunable lasers and vertical cavity surface emitting lasers. Photodetector topics will cover wide-bandwidth PINs and avalanche photodiodes as well as receivers with optical preamplification. State-of-the-art integrated receiver circuits will also be discussed. In the modulator section Mach-Zehnder interferometers, and quantum-confined-Stark-effect devices will be covered. There will be a brief description of recent developments in optical switching using MEMs technology. View full abstract»

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    Applications of Neural Networks for RF Design

    Gupta, K.C. ; Zhang, Q.J.
    Publication Year: 2007

    IEEE eLearning Library Courses

    Neural Networks are information processing systems inspired by the ability of human brain to learn from observations and to generalize by abstraction. It has been used in diverse fields such as pattern recognition, speech processing, control, medical applications and more. In recent years, it has emerged as an attractive vehicle in the RF/microwave CAD community to address the challenges in high-frequency electronic modeling and design. Neural networks can learn and generalize from data allowing model development even when component formulas are unavailable. Neural network models are universal approximators allowing re-use of the same modeling technology for both linear and nonlinear problems and at both device and circuit levels. View full abstract»

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    Performance Requirements and Verification of the IEEE 802 Wireless Technologies

    Mlinarsky, Fanny
    Publication Year: 2010

    IEEE eLearning Library Courses

    The 802.11 market has seen spectacular growth over the past few years, and this growth is continuing at unprecedented rates. 802.11 technology has had a profound impact on the way consumers work, and on their leisure activities. Growing from cottage industry to a mainstream market across multiple segments, 802.11 products have become increasingly sophisticated; moving beyond traditional internet connectivity to include phones, cameras, gaming systems and even televisions.

    As 802.11 technology has advanced and the industry has matured, the testing methodologies continue to advance as well. Early testing methodologies primarily focused on whether or not two products could exchange data and seamlessly interoperate. In response to both the wireless industry?s need to perform advanced product testing and consumer demand for high quality 802.11 devices, a new testing specification, IEEE 802.11.2, is being developed by the 802.11 Task Group T. 802.11.2 incorporates test methods and metrics for roaming, voice and video quality, power consumption, throughput performance and other important parameters.

    These advances in test methodology are required to improve the quality of 802.11 solutions and enable reduction in design cycles. Voice applications, for example, have pushed the 802.11 industry to specify several new protocols including 802.11r fast roaming, 802.11e quality of Service (QoS) and power-save. New applications that carry both voice and video over 802.11 have stringent performance requirements that can only be guaranteed by thorough and methodical testing.

    This presentation will provide an in-depth look at the performance requirements of the demanding voice and video applications. We will examine how these applications perform today and will look at the improvements offered by the emerging 802.11n standard. We will discuss performance, security and power conservation issues in the context of mesh network architecture being introduced by the emerging 802.11s specification.

    Finally, we will examine the test methods and metrics currently in the 802.11.2 recommended practices document and will discuss performance verification methodology appropriate for a variety of networks and applications. View full abstract»

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    SRAM Design - Sensing and Write Control

    Sheppard, Douglas
    Publication Year: 2010

    IEEE eLearning Library Courses

    This tutorial completes the design of the control circuits and focuses on controlling the Sense Amp and enabling the write data. An additional requirement for decoding which columns are written to and read from will be achieved through column decode circuitry that determines which SACL(3:0) and WCRWT(3:0) will be selected. One of the key features of the design will focus on Bit Line Ref (BLRF) which indicates when acceptable differential has been created at the input to the Sense Amp. This indicator is designed to tract the actual memory cell?s driving of the bit lines in a way that can adjust the timing of SACL based on variations in process, conditions and changes in the drive strength of the accessed memory cell. View full abstract»

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    Fundamentals of Spread Spectrum Modulation

    Ziemer, R.
    DOI: 10.2200/S00096ED1V01Y200708COM003
    Copyright Year: 2007

    Morgan and Claypool eBooks

    This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spectrum system is the code synchronization, which is usually broken down into the operations of acquisition and tracking. Means for performing these operations are discussed next. Finally, the performance of spread spectrum systems is of fundamental interest and the effect of jamming is considered, both without and with the use of forward error correction coding. The presentation ends with considerat on of spread spectrum systems in the presence of other users. For more complete treatments of spread spectrum, the reader is referred to [1, 2, 3]. View full abstract»

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    IP Multimedia Subsystem (IMS): Merging the Mobile and the Internet World

    Varma, Vijay
    Publication Year: 2007

    IEEE eLearning Library Courses

    The IP Multimedia Subsystem (IMS) is considered as the platform of choice for providing a unified session control on top of various access network technologies for realizing flexible multimedia applications. IMS, with its access-agnostic session layer, is also driving the concept of merging the fixed and mobile telecommunication networks with the Internet and the adoption of IP technologies within the telecom domain. IMS represents conceptually a combination of the traditional fixed and mobile networks from the telecom domain with emerging VoIP and Internet applications in order to implement a seamless multimedia service environment. This tutorial will address IMS vision, IMS concepts, procedures, protocols and services, fixed-mobile convergence, standardization activities, and early deployments of IMS networks. View full abstract»

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