Coherent Cooperative Relaying in Low Mobility Wireless Multiuser Networks PDF Download
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Author: Stefan Berger
Publisher: Logos Verlag Berlin GmbH
ISBN: 383252536X
Category :
Languages : en
Pages : 337
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Book Description
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.
Author: Stefan Berger
Publisher: Logos Verlag Berlin GmbH
ISBN: 383252536X
Category :
Languages : en
Pages : 337
Get Book Here
Book Description
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.
Author: Henry Ruben Lucas Schulten
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832555862
Category : Technology & Engineering
Languages : en
Pages : 198
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Book Description
Body-centric wireless sensor networks are expected to enable future technologies such as medical in-body micro robots or unobtrusive smart textiles. These technologies may advance personalized healthcare as they allow for tasks such as minimally invasive surgery, in-body diagnosis, and continuous activity recognition. However, the localization of individual sensor nodes within such networks or the determination of the entire network topology still pose challenges that need to be solved. This work provides both theoretic and simulative insights to enable the required sub-millimeter localization accuracy of such sensors using magneto-inductive networks. It identifies inherent localization issues such as the asymmetry of the position estimation in magneto-inductive networks and outlines how such issues may be addressed by using passive relays or cooperation. It further proposes a novel approach to recognize the entire structure of a magneto-inductive network using simple impedance measurements and clusters of passive tags. This approach is evaluated extensively by simulation and experiment to demonstrate the feasibility of low-cost human body posture recognition.
Author: Raphael T. L. Rolny
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832542299
Category : Technology & Engineering
Languages : en
Pages : 353
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Book Description
The increasing demand for ubiquitous data service sets high expectations on future cellular networks. They should not only provide data rates that are higher by orders of magnitude than today's systems, but also have to guarantee high coverage and reliability. Thereby, sophisticated interference management is inevitable. The focus of this work is to develop cooperative transmission schemes that can be applied to cellular networks of the next generation and beyond. For this, conventional network architectures and communication protocols have to be challenged and new concepts need to be developed. Starting from cellular networks with base station cooperation, this thesis investigates how classical network architectures can evolve to future networks in which the mobile stations are no longer served by base stations in their close vicinity, but by a dynamic and flexible heterogeneity of different nodes. With the transition from classical cell-based networks to relay enabled post-cellular networks, we trade off node complexity with density. Aggressive spatial multiplexing can thereby deliver high data rates to large areas in a very efficient way, even when the backhaul capacity is limited or when in certain areas no backhaul access is available at all. The beneficial performance scaling shows that such post-cellular networks can offer a flexible and dynamic solution for mobile communication of future generations.
Author: Celal Eşli
Publisher: Logos Verlag Berlin
ISBN: 9783832524845
Category : Electrical engineering
Languages : en
Pages : 0
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Book Description
Employing multiple antennas at the transmitter and receiver sides has been identified as the key enabler for high spectral efficiency in point-to-point communication, since it facilitates multiplexing of several data streams in space rather than in time/frequency. In this work, we are interested in achieving spatial multiplexing through efficient cooperative relaying schemes, even if both the transmit and receive antennas are distributed. To this end, we focus on wireless multiuser networks and aim at designing novel cooperative communication protocols, developing corresponding transmission and signal processing techniques, and optimizing the network performance.In the first part, we consider coherent multiuser amplify-and-forward (AF) relaying, where a set of source-destination (S-D) terminal pairs communicate concurrently over the same physical channel and a set of AF relay nodes assist the communication in a half-duplex scheme. We study various relay gain allocation schemes and system imperfections such as phase-noise and noisy channel estimates; investigate the necessary amount of channel information at relays and distributed computation of relay gains; and finally propose clustered relays networks.We shift our focus to decode-and-forward (DF) relaying in the second part, and address both multiuser one- and two-way multiple-input multiple-output (MIMO) relaying. First we consider two MIMO terminals exchanging information via a single MIMO relay node, and then, extend this scenario to the case of simultaneous MIMO communication of multiple S-D pairs. Therein, we investigate achievable rate regions, propose various relay transmit covariance optimizations, and consider channel estimation uncertainty.
Author: Gregor Dumphart
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832554831
Category : Technology & Engineering
Languages : en
Pages : 261
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Book Description
Utilizing magnetic induction for wireless communication, wireless powering, passive relaying, and localization could enable massive wireless sensor applications with tiny nodes in challenging media, foremost biomedical in-body sensor networks. This work investigates the performance limits of these unique wireless systems with hardly any assumptions. As a foundation, a general system model and an interface to communication theory are developed. A major part of this work identifies two crucial magneto-inductive fading channels: that between randomly oriented coils and that caused by a nearby swarm of resonant passive relay coils. The analysis yields important technological implications. Based thereon, an investigation of wirelessly-powered in-body sensors is conducted, revealing their active and passive data transmission capabilities. Finally, a treatise of magneto-inductive node localization develops algorithms that perform near identified accuracy limits in theory and practice.
Author: Zhengguo Sheng
Publisher: CRC Press
ISBN: 1482238217
Category : Computers
Languages : en
Pages : 223
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Book Description
Compared with conventional communications, cooperative communication allows multiple users in a wireless network to coordinate their packet transmissions and share each other's resources, thus achieving high-performance gain and better service coverage and reliability. Energy Efficient Cooperative Wireless Communication and Networks provides a comprehensive look at energy efficiency and system design of cooperative wireless communication. Introducing effective cooperative wireless communication schemes, the book supplies the understanding and methods required to improve energy efficiency, reliability, and end-to-end protocol designs for wireless communication systems. It explains the practical benefits and limitations of cooperative transmissions along with the associated designs of upper-layer protocols, including MAC, routing, and transport protocol. The book considers power efficiency as a main objective in cooperative communication to ensure quality-of-service (QoS) requirements. It explains how to bring the performance gain at the physical layer up to the network layer and how to allocate network resources dynamically through MAC/scheduling and routing to trade off the performance benefits of given transmissions against network costs. Because the techniques detailed in each chapter can help readers achieve energy efficiency and reliability in wireless networks, they have the potential to impact a range of industry areas, including wireless communication, wireless sensor networks, and ad hoc networks. The book includes numerous examples, best practices, and models that capture key issues in real-world applications. Along with algorithms and tips for effective design, the book supplies the understanding you will need to achieve high-performing and energy efficient wireless networks with improved service coverage and reliability.
Author: Robert Heyn
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832556214
Category :
Languages : en
Pages : 166
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Book Description
In our increasingly interconnected world, personalized and technology-assisted healthcare has become a rising trend. In an ageing society, technology enables new ways to care for and assist the elderly. Falls pose a major risk and cause of injuries for senior citizens. Technology-backed fall prevention thus has the potential to avoid severe injuries and further loss of independence, but requires continuous monitoring of the body posture in order to identify imminent falls. This work presents a system concept for a wearable wireless body area network (WBAN) for posture monitoring. It shows the principal feasibility of posture recognition from ultra-wideband (UWB) signals based on a large and diverse set of measurements. For a promising classifier-feature-combination, this work demonstrates how reliable posture recognition can be achieved with a limited number of body-mounted nodes, and analyzes its robustness towards potential pitfalls. It concludes with a proposal for a system implementation, and outlines its integration with existing and future aspects of personalized healthcare.
Author: Ekram Hossain
Publisher: Cambridge University Press
ISBN: 113950049X
Category : Technology & Engineering
Languages : en
Pages : 545
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Book Description
A self-contained guide to the state-of-the-art in cooperative communications and networking techniques for next generation cellular wireless systems, this comprehensive book provides a succinct understanding of the theory, fundamentals and techniques involved in achieving efficient cooperative wireless communications in cellular wireless networks. It consolidates the essential information, addressing both theoretical and practical aspects of cooperative communications and networking in the context of cellular design. This one-stop resource covers the basics of cooperative communications techniques for cellular systems, advanced transceiver design, relay-based cellular networks, and game-theoretic and micro-economic models for protocol design in cooperative cellular wireless networks. Details of ongoing standardization activities are also included. With contributions from experts in the field divided into five distinct sections, this easy-to-follow book delivers the background needed to develop and implement cooperative mechanisms for cellular wireless networks.
Author: Robert Caiming Qiu
Publisher: John Wiley & Sons
ISBN: 1118376293
Category : Technology & Engineering
Languages : en
Pages : 496
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Book Description
The author presents a unified treatment of this highly interdisciplinary topic to help define the notion of cognitive radio. The book begins with addressing issues such as the fundamental system concept and basic mathematical tools such as spectrum sensing and machine learning, before moving on to more advanced concepts and discussions about the future of cognitive radio. From the fundamentals in spectrum sensing to the applications of cognitive algorithms to radio communications, and discussion of radio platforms and testbeds to show the applicability of the theory to practice, the author aims to provide an introduction to a fast moving topic for students and researchers seeking to develop a thorough understanding of cognitive radio networks. Examines basic mathematical tools before moving on to more advanced concepts and discussions about the future of cognitive radio Describe the fundamentals of cognitive radio, providing a step by step treatment of the topics to enable progressive learning Includes questions, exercises and suggestions for extra reading at the end of each chapter Topics covered in the book include: Spectrum Sensing: Basic Techniques; Cooperative Spectrum Sensing Wideband Spectrum Sensing; Agile Transmission Techniques: Orthogonal Frequency Division Multiplexing Multiple Input Multiple Output for Cognitive Radio; Convex Optimization for Cognitive Radio; Cognitive Core (I): Algorithms for Reasoning and Learning; Cognitive Core (II): Game Theory; Cognitive Radio Network IEEE 802.22: The First Cognitive Radio Wireless Regional Area Network Standard, and Radio Platforms and Testbeds.
Author: Ming Ding
Publisher: Springer Science & Business Media
ISBN: 3642349498
Category : Technology & Engineering
Languages : en
Pages : 300
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Book Description
Multi-point Cooperative Communication Systems: Theory and Applications mainly discusses multi-point cooperative communication technologies which are used to overcome the long-standing problem of limited transmission rate caused by the inter-point interference. Instead of combating the interference, recent progress in both academia and industrial standardizations has evolved to adopt the philosophy of “exploiting” the interference to improve the transmission rate by cooperating among multiple points. This book addresses the multi-point cooperative communication system systematically giving the readers a clear picture of the technology map and where the discussed schemes may fit. This book includes not only the theories of the paradigm-shifting multi-point cooperative communication, but also the designs of sub-optimal cooperative communication schemes for practical systems. Ming Ding is a senior researcher at Sharp Laboratories of China; Hanwen Luo is a professor at Shanghai Jiao Tong University.
