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    Contextual Analysis of Videos

    Thida, M. ; Eng, H. ; Monekosso, D. ; Remagnino, P.
    DOI: 10.2200/S00521ED1V01Y201307IVM014
    Copyright Year: 2013

    Morgan and Claypool eBooks

    Video context analysis is an active and vibrant research area, which provides means for extracting, analyzing and understanding behavior of a single target and multiple targets. Over the last few decades, computer vision researchers have been working to improve the accuracy and robustness of algorithms to analyse the context of a video automatically. In general, the research work in this area can be categorized into three major topics: 1) counting number of people in the scene 2) tracking individuals in a crowd and 3) understanding behavior of a single target or multiple targets in the scene. This book focusses on tracking individual targets and detecting abnormal behavior of a crowd in a complex scene. Firstly, this book surveys the state-of-the-art methods for tracking multiple targets in a complex scene and describes the authors' approach for tracking multiple targets. The proposed approach is to formulate the problem of multi-target tracking as an optimization problem of finding ynamic optima (pedestrians) where these optima interact frequently. A novel particle swarm optimization (PSO) algorithm that uses a set of multiple swarms is presented. Through particles and swarms diversification, motion prediction is introduced into the standard PSO, constraining swarm members to the most likely region in the search space. The social interaction among swarm and the output from pedestrians-detector are also incorporated into the velocity-updating equation. This allows the proposed approach to track multiple targets in a crowded scene with severe occlusion and heavy interactions among targets. The second part of this book discusses the problem of detecting and localising abnormal activities in crowded scenes. We present a spatio-temporal Laplacian Eigenmap method for extracting different crowd activities from videos. This method learns the spatial and temporal variations of local motions in an embedded space and employs representatives of different activities to const uct the model which characterises the regular behavior of a crowd. This model of regular crowd behavior allows for the detection of abnormal crowd activities both in local and global context and the localization of regions which show abnormal behavior. View full abstract»

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    Web Corpus Construction

    Schafer, R. ; Bildhauer, F.
    DOI: 10.2200/S00508ED1V01Y201305HLT022
    Copyright Year: 2013

    Morgan and Claypool eBooks

    The World Wide Web constitutes the largest existing source of texts written in a great variety of languages. A feasible and sound way of exploiting this data for linguistic research is to compile a static corpus for a given language. There are several adavantages of this approach: (i) Working with such corpora obviates the problems encountered when using Internet search engines in quantitative linguistic research (such as non-transparent ranking algorithms). (ii) Creating a corpus from web data is virtually free. (iii) The size of corpora compiled from the WWW may exceed by several orders of magnitudes the size of language resources offered elsewhere. (iv) The data is locally available to the user, and it can be linguistically post-processed and queried with the tools preferred by her/him. This book addresses the main practical tasks in the creation of web corpora up to giga-token size. Among these tasks are the sampling process (i.e., web crawling) and the usual cleanups including bo lerplate removal and removal of duplicated content. Linguistic processing and problems with linguistic processing coming from the different kinds of noise in web corpora are also covered. Finally, the authors show how web corpora can be evaluated and compared to other corpora (such as traditionally compiled corpora). For additional material please visit the companion website: sites.morganclaypool.com/wcc Table of Contents: Preface / Acknowledgments / Web Corpora / Data Collection / Post-Processing / Linguistic Processing / Corpus Evaluation and Comparison / Bibliography / Authors' Biographies View full abstract»

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    Data Cleaning:A Practical Perspective

    Ganti, V. ; Sarma, A.
    DOI: 10.2200/S00523ED1V01Y201307DTM036
    Copyright Year: 2013

    Morgan and Claypool eBooks

    Data warehouses consolidate various activities of a business and often form the backbone for generating reports that support important business decisions. Errors in data tend to creep in for a variety of reasons. Some of these reasons include errors during input data collection and errors while merging data collected independently across different databases. These errors in data warehouses often result in erroneous upstream reports, and could impact business decisions negatively. Therefore, one of the critical challenges while maintaining large data warehouses is that of ensuring the quality of data in the data warehouse remains high. The process of maintaining high data quality is commonly referred to as data cleaning. In this book, we first discuss the goals of data cleaning. Often, the goals of data cleaning are not well defined and could mean different solutions in different scenarios. Toward clarifying these goals, we abstract out a common set of data cleaning tasks that often ne d to be addressed. This abstraction allows us to develop solutions for these common data cleaning tasks. We then discuss a few popular approaches for developing such solutions. In particular, we focus on an operator-centric approach for developing a data cleaning platform. The operator-centric approach involves the development of customizable operators that could be used as building blocks for developing common solutions. This is similar to the approach of relational algebra for query processing. The basic set of operators can be put together to build complex queries. Finally, we discuss the development of custom scripts which leverage the basic data cleaning operators along with relational operators to implement effective solutions for data cleaning tasks. View full abstract»

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    Basic Simulation Models of Phase Tracking Devices Using MATLAB

    Tranter, W. ; Thamvichai, R. ; Bose, T.
    DOI: 10.2200/S00245ED1V01Y201009COM005
    Copyright Year: 2010

    Morgan and Claypool eBooks

    The Phase-Locked Loop (PLL), and many of the devices used for frequency and phase tracking, carrier and symbol synchronization, demodulation, and frequency synthesis, are fundamental building blocks in today's complex communications systems. It is therefore essential for both students and practicing communications engineers interested in the design and implementation of modern communication systems to understand and have insight into the behavior of these important and ubiquitous devices. Since the PLL behaves as a nonlinear device (at least during acquisition), computer simulation can be used to great advantage in gaining insight into the behavior of the PLL and the devices derived from the PLL. The purpose of this Synthesis Lecture is to provide basic theoretical analyses of the PLL and devices derived from the PLL and simulation models suitable for supplementing undergraduate and graduate courses in communications. The Synthesis Lecture is also suitable for self study by practicin engineers. A significant component of this book is a set of basic MATLAB-based simulations that illustrate the operating characteristics of PLL-based devices and enable the reader to investigate the impact of varying system parameters. Rather than providing a comprehensive treatment of the underlying theory of phase-locked loops, theoretical analyses are provided in sufficient detail in order to explain how simulations are developed. The references point to sources currently available that treat this subject in considerable technical depth and are suitable for additional study. Download MATLAB codes (.zip) Table of Contents: Introduction / Basic PLL Theory / Structures Developed From The Basic PLL / Simulation Models / MATLAB Simulations / Noise Performance Analysis View full abstract»

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    Packets with Deadlines:A Framework for Real-Time Wireless Networks

    Hou, I. ; Kumar, P.
    DOI: 10.2200/S00507ED1V01Y201305CNT014
    Copyright Year: 2013

    Morgan and Claypool eBooks

    With the explosive increase in the number of mobile devices and applications, it is anticipated that wireless traffic will increase exponentially in the coming years. Moreover, future wireless networks all carry a wide variety of flows, such as video streaming, online gaming, and VoIP, which have various quality of service (QoS) requirements. Therefore, a new mechanism that can provide satisfactory performance to the complete variety of all kinds of flows, in a coherent and unified framework, is needed. In this book, we introduce a framework for real-time wireless networks. This consists of a model that jointly addresses several practical concerns for real-time wireless networks, including per-packet delay bounds, throughput requirements, and heterogeneity of wireless channels. We detail how this framework can be employed to address a wide range of problems, including admission control, packet scheduling, and utility maximization. Table of Contents: Preface / Introduction / A Study of the Base Case / Admission Control / Scheduling Policies / Utility Maximization without Rate Adaptation / Utility Maximization with Rate Adaptation / Systems with Both Real-Time Flows and Non-Real-Time Flows / Broadcasting and Network Coding / Bibliography / Authors' Biographies View full abstract»

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    Underwater Communications

    Lanzagorta, M.
    DOI: 10.2200/S00409ED1V01Y201203COM006
    Copyright Year: 2012

    Morgan and Claypool eBooks

    Underwater vehicles and underwater moorings are increasing in tactical importance. As such, it is critical to have a robust and secure communication system connecting underwater vehicles on a long seaborne mission and a ground station. As a matter of fact, the deployment of efficient communication links with underwater vehicles is one of the greatest technological challenges presently confronted by the world's naval forces. To circumvent most of the limitations involved in the use of RF or acoustic channels for perfectly secure communications with underwater vehicles, it is worth considering the feasibility of an optical channel to facilitate a two-way satellite communication link secured via perfectly secure ciphers enabled by a quantum key distribution protocol. This book offers a concise review of underwater communications systems. Our approach is pedagogical, making a strong emphasis on the physics behind the attenuating properties of the oceanic environment and the propagation o electromagnetic signals in the ELF, VLF, and optical bands. We assume the reader is familiar with the basic principles of classical electrodynamics and optics. The system design, components, and noise analysis of an underwater optical communications device are discussed in detail. Furthermore, we offer simulations of the performance of the communication system for different types of ocean waters. Our final conclusion is that it appears to be feasible to design and build underwater communications using optical classical and quantum channels secured with quantum key distribution protocols. Table of Contents: Introduction / Electrodynamics of Attenuating Media / Underwater Communication Channels / Underwater Optical Communications: Technology / Underwater Optical Communications: Noise Analysis / Underwater Optical Communications: System Performance / Underwater Quantum Communications / Conclusions PDF (1764 KB) PDF Plus (1444 KB) View full abstract»

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    Semantics Empowered Web 3.0:Managing Enterprise, Social, Sensor, and Cloud-based Data and Services for Advanced Applications

    Sheth, A. ; Thirunarayan, K.
    DOI: 10.2200/S00433ED1V01Y201207DTM031
    Copyright Year: 2012

    Morgan and Claypool eBooks

    After the traditional document-centric Web 1.0 and user-generated content focused Web 2.0, Web 3.0 has become a repository of an ever growing variety of Web resources that include data and services associated with enterprises, social networks, sensors, cloud, as well as mobile and other devices that constitute the Internet of Things. These pose unprecedented challenges in terms of heterogeneity (variety), scale (volume), and continuous changes (velocity), as well as present corresponding opportunities if they can be exploited. Just as semantics has played a critical role in dealing with data heterogeneity in the past to provide interoperability and integration, it is playing an even more critical role in dealing with the challenges and helping users and applications exploit all forms of Web 3.0 data. This book presents a unified approach to harness and exploit all forms of contemporary Web resources using the core principles of ability to associate meaning with data through conceptual or domain models and semantic descriptions including annotations, and through advanced semantic techniques for search, integration, and analysis. It discusses the use of Semantic Web standards and techniques when appropriate, but also advocates the use of lighter weight, easier to use, and more scalable options when they are more suitable. The authors' extensive experience spanning research and prototypes to development of operational applications and commercial technologies and products guide the treatment of the material. Table of Contents: Role of Semantics and Metadata / Types and Models of Semantics / Annotation -- Adding Semantics to Data / Semantics for Enterprise Data / Semantics for Services / Semantics for Sensor Data / Semantics for Social Data / Semantics for Cloud Computing / Semantics for Advanced Applications 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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    Children’s Internet Search:Using Roles to Understand Children’s Search Behavior

    Foss, E. ; Druin, A.
    DOI: 10.2200/S00591ED1V01Y201408ICR034
    Copyright Year: 2014

    Morgan and Claypool eBooks

    Searching the Internet and the ability to competently use search engines are increasingly becoming an important part of children’s daily lives. Whether mobile or at home, children use search interfaces to explore personal interests, complete academic assignments, and have social interaction. However, engaging with search also means engaging with an ever-changing and evolving search landscape. There are continual software updates, multiple devices used to search (e.g., phones, tablets), an increasing use of social media, and constantly updated Internet content. For young searchers, this can require infinite adaptability or mean being hopelessly confused. This book offers a perspective centered on children’s search experiences as a whole instead of thinking of search as a process with separate and potentially problematic steps. Reading the prior literature with a child-centered view of search reveals that children have been remarkably consistent over time as searchers, dis laying the same search strategies regardless of the landscape of search. However, no research has synthesized these consistent patterns in children’s search across the literature, and only recently have these patterns been uncovered as distinct search roles, or searcher types. Based on a four-year longitudinal study on children’s search experiences, this book weaves together the disparate evidence in the literature through the use of 9 search roles for children ages 7-15. The search role framework has a distinct advantage because it encourages adult stakeholders to design children’s search tools to support and educate children at their existing levels of search strength and deficit, rather than expecting children to adapt to a transient search landscape. View full abstract»

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    RF Filters in Next Generation Cellular Radio Systems

    Ali-Ahmad, Walid
    Publication Year: 2005

    IEEE eLearning Library Courses

    This tutorial provides an overview of the different requirements for RF filters in next generation multi-band multi-standard radio platforms. It also presents the required RF filter characteristics in relation to 3G radio performance parameters and system requirements. View full abstract»

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    Fundamentals of LTE Standards and Technologies

    Wang, Elva ; Chan, Peter
    Publication Year: 2010

    IEEE eLearning Library Courses

    In this tutorial, you will learn about LTE air-interface standards and technologies. After completing this tutorial, you should have obtained a high level understanding of LTE, knowing its technical features, key advanced technologies, frame structure and resource grid. Both downlink and uplink transmissions will be addressed. For downlink, we will discuss OFDMA modulation, the physical channels and their general processing, the physical signals and MBSFN. We will also highlight the MIMO technologies in downlink, which includes SIMO, transmit diversity, spatial multiplexing and multiuser MIMO.

    In uplink, we will introduce the key feature of LTE, SC-FDMA, which is a technology that strikes a balance between low peak-to-average-power-ratio and the advantages of OFDMA. WE will also cover the physical channels and their processing and physical signals. We will introduce the possible use of uplink multiuser MIMO, which is a a technology transparent to the UEs and achieve significant increase in the system throughput. Finally, cell search and random access are covered. 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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    Implementations of Computational Intelligence Techniques

    Scotti, Fabio ; Piuri, Vincenzo
    Publication Year: 2007

    IEEE eLearning Library Courses

    Computational Intelligence techniques are a powerful and adaptable approach to tackle problems and cases for which the conventional technologies have not been proved sufficiently effective. These results are achieved by mimicking some aspects of the knowledge representation and processing performed by the brain. The computational efforts implied by these approaches are usually quite relevant. View full abstract»

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    Wireless Sensor Networks and Applications

    Borses, Dwight
    Publication Year: 2004

    IEEE eLearning Library Courses

    A Wireless Sensor Network (WSN) is made up of a large number of sensors which are extremely small, low-cost, and low-power devices that collect environmental data (acoustics, light, temperature, humidity, imaging, etc.) that is then communicated through radio or optical means to infrastructure processing nodes. WSNs may consist of up to thousands of nodes, which can be deployed in very high density, in homes, highways, buildings, cities, and infrastructures for monitoring and/or controlling purposes. Applications may range from detecting and monitoring occurrences of natural disasters and homeland security, to military surveillance. This introduction to emerging WSN applications reveals how developments in micro- and nanotechnology have aided advancements in WSNs and highlights implementation of several real systems that hint of tomorrow's potential. View full abstract»

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    Wireless Network Pricing

    Huang, J. ; Gao, L.
    DOI: 10.2200/S00505ED1V01Y201305CNT013
    Copyright Year: 2013

    Morgan and Claypool eBooks

    Today's wireless communications and networking practices are tightly coupled with economic considerations, to the extent that it is almost impossible to make a sound technology choice without understanding the corresponding economic implications. This book aims at providing a foundational introduction on how microeconomics, and pricing theory in particular, can help us to understand and build better wireless networks. The book can be used as lecture notes for a course in the field of network economics, or a reference book for wireless engineers and applied economists to understand how pricing mechanisms influence the fast growing modern wireless industry. This book first covers the basics of wireless communication technologies and microeconomics, before going in-depth about several pricing models and their wireless applications. The pricing models include social optimal pricing, monopoly pricing, price differentiation, oligopoly pricing, and network externalities, supported by introd ctory discussions of convex optimization and game theory. The wireless applications include wireless video streaming, service provider competitions, cellular usage-based pricing, network partial price differentiation, wireless spectrum leasing, distributed power control, and cellular technology upgrade. More information related to the book (including references, slides, and videos) can be found at ncel.ie.cuhk.edu.hk/content/wireless-network-pricing. View full abstract»

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    Design of Phase Locked Loops

    Dayaratna, Lama
    Publication Year: 2009

    IEEE eLearning Library Courses

    The objective of this course is to provide a state of the art review of phase locked loop circuits and applications from a design and development perspective. Intended for RF and Microwave Engineers, the course details out the design and development of phase locked loop circuits. Topics include PLL basics, VCOs, phase detectors, open and close loop characterization, loop filter design, and phase noise concepts. Examples will be given to a variety of problems relevant to the design of phase locked loops. View full abstract»

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    IEEE 802.11N Physical Layer

    Perahia, Eldad
    Publication Year: 2008

    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 Physical Layer (PHY) technology in the p802.11n draft standard. The course will begin 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. The technical description of the draft standard starts with a detailed discussion of the key throughput enhancing features: multiple-input, multiple-output (MIMO) / space division multiplexing (SDM) in the PHY. Further throughput enhancements in the PHY include 40 MHz channelization, reduced guard interval, tone filling, high rate coding, and efficient (greenfield) preambles. Additional topics include PHY interoperability techniques such as the mixed mode preamble, legacy spoofing, and auto-preamble detection. An overview will be provided of the robustness enhancements in the PHY. The PHY techniques include spatial spreading, receive diversity, transmit beamforming, space-time block code (STBC), and low density parity check (LDPC) codes. View full abstract»

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    MIMO-aided OFDM for LTE, WiMAX, WiFi and other Next-generation Multi-carrier Wireless Systems Part 2

    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 2, we delve into characterizing the attainable performance over both non-dispersive Gaussian and dispersive fading channels. View full abstract»

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    Stochastic Network Optimization with Application to Communication and Queueing Systems

    Neely, M.
    DOI: 10.2200/S00271ED1V01Y201006CNT007
    Copyright Year: 2010

    Morgan and Claypool eBooks

    This text presents a modern theory of analysis, control, and optimization for dynamic networks. Mathematical techniques of Lyapunov drift and Lyapunov optimization are developed and shown to enable constrained optimization of time averages in general stochastic systems. The focus is on communication and queueing systems, including wireless networks with time-varying channels, mobility, and randomly arriving traffic. A simple drift-plus-penalty framework is used to optimize time averages such as throughput, throughput-utility, power, and distortion. Explicit performance-delay tradeoffs are provided to illustrate the cost of approaching optimality. This theory is also applicable to problems in operations research and economics, where energy-efficient and profit-maximizing decisions must be made without knowing the future. Topics in the text include the following: - Queue stability theory - Backpressure, max-weight, and virtual queue methods - Primal-dual methods for non-convex stochasti utility maximization - Universal scheduling theory for arbitrary sample paths - Approximate and randomized scheduling theory - Optimization of renewal systems and Markov decision systems Detailed examples and numerous problem set questions are provided to reinforce the main concepts. Table of Contents: Introduction / Introduction to Queues / Dynamic Scheduling Example / Optimizing Time Averages / Optimizing Functions of Time Averages / Approximate Scheduling / Optimization of Renewal Systems / Conclusions View full abstract»

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    Ultra-Wideband Radio Technology

    Siwiak, Kai
    Publication Year: 2005

    IEEE eLearning Library Courses

    This tutorial traces UWB technology through history, regulations, standards, system implementations and commercial applications. Methods of generating and modulating UWB signals are described and set in the context of UWB proposals for IEEE802 Standards. UWB antenna, radiation, and propagation phenomena, including unique behavior in multipath, are presented in contrast with narrow band radio. Examples of UWB link margins including data throughput versus range and system data capacity (up to 2 Gb/s) are compared with conventional and much higher power 802.11a/b systems. The future of UWB is a mix of wireless communications, precision positioning and radar. UWB can enable an accurate indoor adjunct to GPS with centimeter accuracy. Discussions of applications show that UWB capabilities make possible delivery of location-specific content and information, tracking of high value assets, security systems and various automotive and interesting home based location awareness systems. View full abstract»

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    Social Media and Library Services

    Mon, L.
    DOI: 10.2200/S00634ED1V01Y201503ICR040
    Copyright Year: 2015

    Morgan and Claypool eBooks

    The rise of social media technologies has created new ways to seek and share information for millions of users worldwide, but also has presented new challenges for libraries in meeting users where they are within social spaces. From social networking sites such as Facebook and Google+, and microblogging platforms such as Twitter and Tumblr to the image and video sites of YouTube, Flickr, Instagram, and to geotagging sites such as Foursquare, libraries have responded by establishing footholds within a variety of social media platforms and seeking new ways of engaging with online users in social spaces. Libraries are also responding to new social review sites such as Yelp and Tripadvisor, awareness sites including StumbleUpon, Pinterest, Goodreads, and Reddit, and social question-and-answer (Q&A) sites such as Yahoo! Answers—sites which engage social media users in functions similar to traditional library content curation, readers' advisory, information and referral, and re erence services. Establishing a social media presence extends the library's physical manifestation into virtual space and increases the library's visibility, reach, and impact. However, beyond simply establishing a social presence for the library, a greater challenge is building effective and engaging social media sites that successfully adapt a library's visibility, voice, and presence to the unique contexts, audiences, and cultures within diverse social media sites. This lecture examines the research and theory on social media and libraries, providing an overview of what is known and what is not yet known about libraries and social media. Chapter 1 focuses on the social media environments within which libraries are establishing a presence, including how social media sites differ from each other, yet work together within a social ecosphere. Chapter 2 examines how libraries are engaging with users across a variety of social media platforms and the extent to which libraries are invo ved in using these different social media platforms, as well as the activities of libraries in presenting a social "self," sharing information, and interacting with users via social media. Chapter 3 explores metrics and measures for assessing the impact of the library's activity in social media sites. The book concludes with Chapter 4 on evolving directions for libraries and social media, including potential implications of new and emerging technologies for libraries in social spaces. 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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    Information Theoretic Learning

    Principe, Jose
    Publication Year: 2006

    IEEE eLearning Library Courses

    This course examines Information Theory and our efforts to develop an information-theoretic criterion which can be utilized in adaptive filtering and neurocomputing. The main aim of our research is to develop new signal processing techniques by going beyond the basic assumptions of Linearity, Gaussianity and Stationarity. By capturing higher order statistics of data using Information Theory, we solve a variety of problems in Biomedical Signal Processing, Communications and Machine Learning. View full abstract»

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    Performance Modeling, Stochastic Networks, and Statistical Multiplexing:second edition

    Mazumdar, R.
    DOI: 10.2200/S00504ED1V01Y201305CNT012
    Copyright Year: 2013

    Morgan and Claypool eBooks

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of introducing an appropriate mathematical framework for modeling and analysis as well as understanding the phenomenon of statistical multiplexing. The models, techniques, and results presented form the core of traffic engineering methods used to design, control and allocate resources in communication networks.The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in computing performance measures. The monograph also covers stochastic network theory including Markovian networks. Recent results on network utility optimization and connections to stochastic insensitivity are discussed. Also presented are ideas of large buffer, and many sources asymptotics that play an important role i understanding statistical multiplexing. In particular, the important concept of effective bandwidths as mappings from queueing level phenomena to loss network models is clearly presented along with a detailed discussion of accurate approximations for large networks. Table of Contents: Introduction to Traffic Models and Analysis / Queues and Performance Analysis / Loss Models for Networks / Stochastic Networks and Insensitivity / Statistical Multiplexing View full abstract»

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    Security of Information and Communication Networks Part 1

    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 an Introduction and a quick Historical Perspective on Information security. Next we describe key definitions that are useful in cryptography and information integrity, as well as in Network security. We provide a quick and over simplified mathematical background which is useful to understand the complexity of cryptographic algorithms. For example, what Prime Numbers are, what Modulus arithmetic is and how it works, and what the Greatest Common Devisor is and how it is calculated. The tutorial concludes with the description of popular Symmetric and Asymmetric Ciphers, such as the RSC, DES, AES, RC4, ECC, RSA, D-H, Merkle, and Shamir. View full abstract»

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