Relay channels have been in use for decades as an effective means to tackle some of the challenges facing wireless transmission. Recent studies considered re-employing the relay channel to serve modern wireless systems. Material offered in this book was originally presented by the author as a thesis for the degree of Ph.D. to University College London. In this book two-hop and multi-hop D&F relay channels with half-duplex constraint on relays are studied. Channel s mutual information and outage probability are investigated for AWGN and Rayleigh fading channels. Optimum routing and optimum time allocation policies are also considered. In addition, a scheme is presented for user cooperation. Material offered in this book is useful to further investigate the visibility of relaying in wireless transmission and to develop user cooperative schemes. This book can be of use to communication and information theoretic researchers investigating relay channels, routing in wireless networks, cross-layer design, ad hoc networks, user cooperative communications and cognitive systems.
This SpringerBrief explores the advantage of relaying techniques in addressing the increasing demand for high data rates and reliable services over the air. It demonstrates how to design cost-effective relay systems that provide high spectral efficiency and fully exploit the diversity of the relay channel. The brief covers advances in achievable rates, power allocation schemes, and error performance for half-duplex (HD) and full-duplex (FD) amplify-and-forward (AF) single-relay systems. The authors discuss the capacity and respective optimal power allocation for a wide range of HD protocols over static and fading channels. Then, optimal amplification coefficients in terms of achievable rate are presented. Chapters also examine performance with finite constellations, including the error and diversity performance. The brief concludes with a capacity and error performance analysis of the FD relay mode of operation, where the residual self-interference due to FD transmission is explicitly taken into account. Amplify-and-Forward Relaying in Wireless Communications reveals the benefits and challenges of relaying techniques. It is designed for researchers and professionals in wireless communication. This material is also appropriate for advanced-level students in electrical engineering and computer science.
In this thesis, several important aspects of cooperative wireless multiuser networks are investigated. The focus lies on coherent two-hop relaying networks where several amplify-and-forward (AF) relays assist the communication between multiple source-destination pairs. First, the impact of local oscillator (LO) imperfections and I/Q imbalance at the relays on two-hop relaying is investigated. A special focus lies on the comparison between frequency division duplexing (FDD) and time division duplexing (TDD) relays. Based on the observation that the direction in which a channel between two wireless nodes is measured has an impact on the estimate, phase synchronization requirements for coherent relaying networks are then found. Several channel estimation protocols that differ in the direction in which the single-hop channels are measured are furthermore identi'ed and their performance is compared. Next, a very simple phase synchronization scheme is presented that provides a set of relays with a common LO phase. Two coherent beamforming schemes, namely multiuser zero-forcing (MUZF) and multiuser minimum mean squared error (MMSE) relaying, are then investigated. Finally, a real-world demonstrator for distributed wireless communication networks (called RACooN Lab) is presented. It was used to implement coherent cooperative communication schemes on a practical two-hop relaying network.
The main goal of this thesis is to develop an opportunistic scheduling strategy in distributed networks with decode-and-forward (DF) relays without direct link. Two cases are considered: 1) the winner source has full CSI (CSI of source-relay link and relay-destination link), 2) the winner source has partial CSI (CSI of source-relay link only). For the first case, a pure threshold scheduling strategy is proposed. Specifically, only when the minimum of the detected signal-to-noise ratio (SNR) of the source-relay link and relay-destination link exceeds a certain threshold, it is optimal for the source to transmit data. For the second case, the scheduling strategy is also threshold-based. In specific, when the detected SNR of the source-relay link exceeds a certain threshold, it is optimal for the winner source to transmit data. After the relay receives the data, the optimal strategy is probing the second hop until the second-hop channel condition is good.
This book advocates the idea of breaking up the cellular communication architecture by introducing cooperative strategies among wireless devices through cognitive wireless networking. It is divided into different parts dealing with cooperative and cognitive aspects for future wireless communication networks. Chapters written by world leading researchers in the field cover, among others, social and biological inspired behavior applied to wireless networks, peer-to-peer networking, cognitive radio or more generally cognitive networks, cooperative networks, game theory, spectrum sensing and management. In addition, tools and methodologies for modeling and analyzing cooperative and cognitive interactions in wireless networks are explained in detail to facilitate access to this advanced research topic.
Green Communications and Networking introduces novel solutions that can bring about significant reductions in energy consumption in the information and communication technology (ICT) industry-as well as other industries, including electric power. Containing the contributions of leading experts in the field, it examines the latest research advances
Reporting the findings of COST 2100, a major European intergovernmental project, this volume offers system designers a good source of guidelines based on channel characterization and measurement-based modeling, as well as worthwhile ideas for future research.
This book is one of the most comprehensive and up-to-date books written on Energy Efficiency. The readers will learn about different technologies for energy efficiency policies and programs to reduce the amount of energy. The book provides some studies and specific sets of policies and programs that are implemented in order to maximize the potential for energy efficiency improvement. It contains unique insights from scientists with academic and industrial expertise in the field of energy efficiency collected in this multi-disciplinary forum.
This practically-oriented, all-inclusive guide covers all the major enabling techniques for current and next-generation cellular communications and wireless networking systems. Technologies covered include CDMA, OFDM, UWB, turbo and LDPC coding, smart antennas, wireless ad hoc and sensor networks, MIMO, and cognitive radios, providing readers with everything they need to master wireless systems design in a single volume. Uniquely, a detailed introduction to the properties, design, and selection of RF subsystems and antennas is provided, giving readers a clear overview of the whole wireless system. It is also the first textbook to include a complete introduction to speech coders and video coders used in wireless systems. Richly illustrated with over 400 figures, and with a unique emphasis on practical and state-of-the-art techniques in system design, rather than on the mathematical foundations, this book is ideal for graduate students and researchers in wireless communications, as well as for wireless and telecom engineers.
Cooperative devices and mechanisms are increasingly important to enhance the performance of wireless communications and networks, with their ability to decrease power consumption and packet loss rate and increase system capacity, computation, and network resilience. Considering the wide range of applications, strategies, and benefits associated with cooperative wireless communications, researchers and product developers need a succinct understanding of relevant theory, fundamentals, and techniques to navigate this challenging field. Cooperative Wireless Communications provides just that. Assesses Applications, Benefits, and Methods of Cooperative Strategies This comprehensive reference handbook contains useful background to develop and implement cooperative mechanisms for infrastructure-based wireless systems and self-organizing multi-hop wireless networks (e.g., ad hoc, mesh, peer-to-peer, and sensor networks). It introduces key cooperative strategies and details recent improvements to a variety of cooperative mechanisms and frameworks applicable in diverse scenarios. Addressing fundamentals and techniques, this invaluable reference: Offers comprehensive guidance on technical, practical, and deployment aspects of cooperative strategies and the latest IEEE standard specifications Explores key challenges and solutions in 3G, B3G, 4G WiMAX, and ad hoc, mesh, and sensor networks Covers cooperative diversity, virtual MIMO, cognitive radio networks, and resource and mobility management Discusses energy efficiency, relaying strategy, routing, MAC, topology control, and security Provides Guidance to Resolve Key Challenges A distinct introduction to different cooperative mechanisms, cooperation frameworks in diverse scenarios, and recent improvements to wireless network performance, this one-stop reference consolidates the essential information and guidance that readers will need to resolve key challenges in various protocol issues from a cooperation perspective.
In this dissertation we consider cooperative communication systems with relay conferencing, where the relays own the capabilities to talk to their counterparts via either wired or wireless out-of-band links. In particular, we focus on the design of conferencing protocols incorporating the half-duplex relaying operations, and study the corresponding capacity upper and lower bounds for some typical channels and networks models, including the diamond relay channels (one source-destination pairs and two relays), large relay networks (one source-destination pairs and N relays), and interference relay channels (two source-destination pairs and two relays). First, for the diamond relay channels, we consider two different relaying schemes, i.e., simultaneous relaying (for which the two relays transmit and receive in the same time slot) and alternative relaying (for which the two relays exchange their transmit and receive modes alternatively over time), for which we obtain the respective achievable rates by using the decode-and-forward (DF), compress-and-forward (CF), and amplify-and-forward (AF) relaying schemes with DF and AF adopted the conferencing schemes. Moreover, we prove some capacity results under some special conditions. Second, we consider the large relay networks, and propose a "p-portion" conferencing scheme, where each relay can talk to the other "p-portion" of the relays. We obtain the DF and AF achievable rates by using the AF conferencing scheme. It is proved that relay conferencing increases the throughput scaling order of the DF relaying scheme from O(log(log(N))) for the case without conferencing to O(log(N)); for the AF relaying scheme, it achieves the capacity upper bound under some conditions. Finally, we consider the two-hop interference relay channels, and obtain the AF achievable rates by adopting the AF conferencing scheme and two different decoding schemes at the destination, i.e., single-user decoding and joint decoding. For the derived joint source power allocation and relay combining problem, we develop some efficient iterative algorithms to compute the AF achievable rate regions. Moreover, we compare the achievable degree-of-freedom (DoF) performance of these two decoding schemes, and show that single-user decoding with interference cancellation at the relays is optimal.
Transmission over the wireless medium is a challenge compared to its wired counterpart. Scarcity of spectrum, rapid degradation of signal power over distance, interference from neighboring nodes and random behavior of the channel are some of the difficulties with which a wireless system designer has to deal. Moreover, emerging wireless networks assume mobile users with limited or no infrastructure. Since its early application, relaying offered a practical solution to some of these challenges. Recently, interest on the relay channel is revived by the work on user-cooperative communications. Latest studies aim to re-employ the channel to serve modern wireless networks. In this work, the decode-and-forward (D&F) relay channel with half-duplex constraint on the relay is studied. Focus is on producing analytical results for the half-duplex D&F relay channel with more attention given to time allocation. First, an expression for the mutual information for the channel with arbitrary time allocation is developed. Introduction of the concept of conversion point explains some of the channel behavior and help in classifying the channel into suppressed and unsuppressed types. In the case of Rayleigh fading, cumulative distribution function (cdf) and probability density function (pdf) are evaluated for the mutual information. Consequently, expressions for average mutual information and outage probability are obtained. Optimal operation of the channel is investigated. Optimal time allocation for maximum mutual information and optimal time allocation for minimum total transmission time are worked out for the case of channel state information at transmitter (CSIT). Results revealed important duality between optimization problems. Results obtained are extended from a two-hop channel to any number of hops. Only sequential transmission is considered. A cooperative scheme is also developed based on the three-node relay channel. A two-user network is used as a prototype for a multi-user cooperative system. Based on the model assumed, an algorithm for partner selection is developed. Simulation results showed advantages of cooperation for individual users as well as the overall performance of the network.
This book focuses on soft computing and its applications to solve real-life problems occurring in different domains ranging from medical and health care, supply chain management and image processing to cryptanalysis. It presents the proceedings of International Conference on Soft Computing: Theories and Applications (SoCTA 2016), offering significant insights into soft computing for teachers and researchers and inspiring more and more researchers to work in the field of soft computing. The term soft computing represents an umbrella term for computational techniques like fuzzy logic, neural networks, and nature inspired algorithms. In the past few decades, there has been an exponential rise in the application of soft computing techniques for solving complex and intricate problems arising in different spheres of life. The versatility of these techniques has made them a favorite among scientists and researchers working in diverse areas. SoCTA is the first international conference being organized at Amity University Rajasthan (AUR), Jaipur. The objective of SoCTA 2016 is to provide a common platform to researchers, academicians, scientists, and industrialists working in the area of soft computing to share and exchange their views and ideas on the theory and application of soft computing techniques in multi-disciplinary areas. The aim of the conference is to bring together young and experienced researchers, academicians, scientists, and industrialists for the exchange of knowledge. SoCTA especially encourages the young researchers at the beginning of their career to participate in this conference and present their work on this platform.
This book constitutes the proceedings of the First International Conference on 5G for Future Wireless Networks, 5GWN 2017, held in Beijing, China, in April 2017. The 64 full papers were selected from 135 submissions and present the state of the art and practical applications of 5G technologies. The exponentially growing data traffic caused by the development of mobile Internet and smart phones requires powerful networks. The fifth generation (5G) techniques are promising to meet the requirements of this explosive data traffic in future mobile communications.
Based on cutting-edge research projects in the field, this book (part of a comprehensive 4-volume series) provides the latest details and covers the most impactful aspects of mobile, wireless, and broadband communications development. These books present key systems and enabling technologies in a clear and accessible manner, offering you a detailed roadmap the future evolution of next generation communications. Other volumes cover Networks, Services and Applications; Reconfigurability; and Ad Hoc Networks.
This book provides an analysis of transmission power and network performance in different wireless communication networks. It presents the latest research and techniques for power and interference control and performance modeling in wireless communication networks with different network topologies, air interfaces, and transmission techniques. While studying the power distributions and resource management, the reader will also learn basic methodology and skills for problem formulations, can ascertain the complexity for designing radio resource management strategies in modern wireless communication networks, thus keeping pace with state-of-the-art research progress in radio transmission technologies.
In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks.
Multiple-input multiple-output (MIMO) technology constitutes a breakthrough in the design of wireless communications systems, and is already at the core of several wireless standards. Exploiting multipath scattering, MIMO techniques deliver significant performance enhancements in terms of data transmission rate and interference reduction. This 2007 book is a detailed introduction to the analysis and design of MIMO wireless systems. Beginning with an overview of MIMO technology, the authors then examine the fundamental capacity limits of MIMO systems. Transmitter design, including precoding and space-time coding, is then treated in depth, and the book closes with two chapters devoted to receiver design. Written by a team of leading experts, the book blends theoretical analysis with physical insights, and highlights a range of key design challenges. It can be used as a textbook for advanced courses on wireless communications, and will also appeal to researchers and practitioners working on MIMO wireless systems.
This book constitutes the refereed proceedings of the 5th European Workshop on Wireless Sensor Networks, EWSN 2008, held in Bologna, Italy, in January/February 2008. The 23 revised full papers presented were carefully reviewed and selected from 110 submissions. The papers are organized in topical sections on localization, detection of space/time correlated events, network coding, ZigBee, topology, software, as well as deployment and application development.
Cooperative Cognitive Radio Networks: The Complete Spectrum Cycle provides a solid understanding of the foundations of cognitive radio technology, from spectrum sensing, access, and handoff to routing, trading, and security. Written in a tutorial style with several illustrative examples, this comprehensive book: Gives an overview of cognitive radio systems and explains the different components of the spectrum cycle Features step-by-step analyses of the different algorithms and systems, supported by extensive computer simulations, figures, tables, and references Fulfills the need for a single source of information on all aspects of the spectrum cycle, including the physical, link, medium access, network, and application layers Offering a unifying view of the various approaches and methodologies, Cooperative Cognitive Radio Networks: The Complete Spectrum Cycle presents the state of the art of cognitive radio technology, addressing all phases of the spectrum access cycle.