Download or read book Cooperative Multiplexing in Wireless Relay Networks written by Vinayak Nagpal and published by . This book was released on 2012 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless networks are experiencing an explosive growth in the number of users and the demand for data capacity. One of the methods to improve capacity is to use tighter cooperation between terminals. In order to design a cooperative wireless link, several theoretical as well as practical challenges need to be addressed. In this dissertation we develop tools for the design of practical cooperative links that perform very close to fundamental limits. Using the tools of information theory, we begin by showing that cooperative relaying provides additional degrees-of-freedom for communication. For a simple network with a single-antenna source, single-antenna half-duplex relay and a two antenna destination, we show that cooperation allows the link throughput to increase approximately by a factor of 2. This gain is achievable using the recently introduced quantize-map-and-forward (QMF) cooperation scheme. However, QMF requires joint decoding of multiple information streams at the destination. The computational complexity of joint decoding is prohibitive for practical implementation. We address this problem by developing a low-complexity practical coding and system design framework for QMF relaying. The framework presents several pragmatic design choices to achieve cooperative degree-of-freedom gains in practice. The framework uses a combination of LDPC and LDGM codes decoded jointly over a low complexity factor graph. Signal processing requirements at all terminals are shown to have linear time complexity. Density evolution tools are developed for the design of specialized linear codes and mapping functions. Based on these tools, we demonstrate the design of cooperative links that perform within 0.5-1.0dB of information-theoretic limits.

Download or read book Cooperative Communications and Networking written by Y.-W. Peter Hong and published by Springer Science & Business Media. This book was released on 2010-07-28 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cooperative and relay communications have recently become the most widely explored topics in communications, whereby users cooperate in transmitting their messages to the destination, instead of conventional networks which operate independently and compete among each other for channel resources. As the field has progressed, cooperative communications have become a design concept rather than a specific transmission technology. This concept has revolutionized the design of wireless networks, allowing increased coverage, throughput, and transmission reliability even as conventional transmission techniques gradually reach their limits. Cooperative and relay technologies have also made their way toward next generation wireless standards, such as IEEE802.16 (WiMAX) or LTE, and have been incorporated into many modern wireless applications, such as cognitive radio and secret communications. Cooperative Communications and Networking: Technologies and System Design provides a systematic introduction to the fundamental concepts of cooperative communications and relays technology to enable engineers, researchers or graduate students to conduct advanced research and development in this area. Cooperative Communications and Networking: Technologies and System Design provides researchers, graduate students, and practical engineers with sufficient knowledge of both the background of cooperative communications and networking, and potential research directions.

Download or read book Coherent Cooperative Relaying in Low Mobility Wireless Multiuser Networks written by Stefan Berger and published by Logos Verlag Berlin GmbH. This book was released on 2010 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Cooperative Communications written by Gerhard Kramer and published by Now Publishers Inc. This book was released on 2007 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cooperative Communications reviews progress in cooperative communication networks. It assembles a representative sample of recent results to serve as a roadmap for the area. The emphasis is on wireless networks, but many of the results apply to cooperation in wireline networks and mixed wireless/wireline networks. Cooperative Communications is intended as a tutorial for the reader who is familiar with information theory concepts but has not actively followed the field. For the active researcher, it serves as an invaluable digest of significant results. It is designed to encourage readers to find new ways to apply the fundamental ideas of network cooperation. It is also intended to make the area sufficiently accessible to practicing network designers.

Download or read book Link Adaptation for Relay Based Cellular Networks written by Basak Can and published by CRC Press. This book was released on 2022-09-01 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cover TextLink Adaptation for Relay-Based Cellular Networks focuses on the implementation of various link adaptation methods in OFDM(A) (Orthogonal Frequency Division Multiplexing/Multiple Access)?Time Division Duplex (TDD) based two-hop cellular networks. The analysis and design consider infrastructure based relays. New link adaptive transmission methods which dynamically select the channel coding, modulation, forwarding, relaying mechanisms and the packet size have been designed and evaluated for such networks. The selection among various schemes is based on maximizing the end-to-end throughput.This book provides a channel adaptive scheduler which considers the multiplexing loss caused by the two-phase nature of wireless relaying. The scheduler dynamically schedules the users on the frequency-time radio resources with efficient Modulation and Coding Schemes (MCS)s selected by Adaptive Modulation and Coding (AMC). Relaying is used only if it can provide throughput enhancement. The guidelines for efficient deployment of infrastructure based relay terminals are given. For the two-hop cellular communication systems, the system level performance of various cooperative diversity schemes has been investigated with the scheduler developed and the relays efficiently deployed in the cell. This investigation for low mobility scenarios shows that, a simple cooperative diversity scheme that dynamically chooses the best scheme among direct transmission and two-hop conventional relaying is a promising choice when compared to various more complex cooperative diversity schemes.In this book, a hop adaptive Medium Access Control (MAC)-Protocol Data Unit (PDU) size optimization is proposed for wireless relay networks.

Download or read book Cooperative Wireless Communications written by Yan Zhang and published by CRC Press. This book was released on 2009-03-10 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 wit

Download or read book Cooperation in Wireless Networks Principles and Applications written by Frank H. P. Fitzek and published by Springer Science & Business Media. This book was released on 2006-07-25 with total page 679 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cooperation in Wireless Networks: Principles and Applications covers the underlying principles of cooperative techniques as well as several applications demonstrating the use of such techniques in practical systems. The book is written in a collaborative manner by several authors from Asia, America, and Europe. This book puts into one volume a comprehensive and technically rich appraisal of the wireless communications scene from a cooperation point of view.

Download or read book Cooperative Strategies for Wireless Relay Networks written by Ivana Marić and published by . This book was released on 2006 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is to understand the mechanisms and potential benefits of relaying and node cooperation in wireless networks. We analyze specific cooperative schemes, present practical cooperative protocols for large networks, and derive capacity results for systems with limited transmitter cooperation.

Download or read book Design and Analysis of New Wireless Transmission Strategies for Cooperative Relay Networks written by Gayan Lasintha Amarasuriya Aruma Baduge and published by . This book was released on 2013 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cooperative relay technologies are currently being researched to address the ever-increasing demand for higher data rates, extended coverage, greater mobility, and enhanced reliability. This thesis thus focuses on (1) developing new physical-layer wireless technologies for cooperative relay networks and (2) ascertaining their viability through performance analysis. Specifically, (i) new system and channel models, (ii) signaling and relay-processing algorithms, (iii) joint relay-antenna selection strategies, (iv) joint transmit-receive beamforming techniques, and (v) comprehensive performance analysis frameworks are developed for one-way, two-way, and multi-way cooperative relay networks. Our first research focuses on developing a comprehensive analytical framework for deriving closed-form performance bounds of multi-hop amplify-and-forward (AF) relay networks. Specifically, mathematically-tractable, asymptotically-exact end-to-end signal-to-noise ratio bounds are first formulated, and thereby, the outage probability and average bit error rate bounds are derived. In our second work, adaptive multiple-relay selection strategies are designed and analyzed for multi-relay AF networks to optimize the tradeoffs among the system performance, complexity, and wireless resource usage. Our third research investigates joint antenna and relay selection strategies, which are optimal in the sense of the achievable diversity gains, for multiple-input multiple-output (MIMO) one-way relay networks and MIMO two-way relay networks. Finally, joint transmit/receive zero forcing transmission strategies are developed for MIMO multi-way relay networks for optimizing the achievable diversity-multiplexing trade-off. The key design criterion of the aforementioned transmission designs is to leverage spatial diversity and/or spatial multiplexing gains available among distributed single-antenna and/or multiple-antenna wireless terminals through distributed transmission and efficient signal processing. Moreover, the fundamental relationships among the data rate, coverage, and reliability metrics are characterized, and thereby, the detrimental impact of practical wireless transmission impairments on the performance of the aforementioned transmission strategies are quantified. The insights obtained through these analyses are then used to refine our physical-layer designs to achieve desirable trade-offs between the system performance, resource usage and implementation complexity.

Download or read book Performance Analysis of Cooperative Networking with Multi Channels written by Praveen Kumar Devulapalli and published by CRC Press. This book was released on 2024-07-18 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers wireless cooperative communication and advanced communication techniques for research scholars and post-graduate students. Features: • This book will be the reference book for cooperative communication. • It addresses the problems in small-scale cooperative communication. • It presents cooperative routing algorithms for large-scale cooperative networks with the constraint of throughput and transmission time. • It presents energy- efficient transmission approach by making use of multiple radio terminals. • It presents adaptive routing algorithm for large-scale cooperative network under mobility environment.

Download or read book Cooperative Communications for Improved Wireless Network Transmission Framework for Virtual Antenna Array Applications written by Uysal, Murat and published by IGI Global. This book was released on 2009-07-31 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers practitioners, researchers, and academicians with fundamental principles of cooperative communication. This book provides readers diverse findings and exposes underlying issues in the analysis, design, and optimization of wireless systems.

Download or read book Protocol Design and Analysis for Cooperative Wireless Networks written by Wei Song and published by Springer. This book was released on 2016-11-03 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the design and analysis of protocols for cooperative wireless networks, especially at the medium access control (MAC) layer and for crosslayer design between the MAC layer and the physical layer. It highlights two main points that are often neglected in other books: energy-efficiency and spatial random distribution of wireless devices. Effective methods in stochastic geometry for the design and analysis of wireless networks are also explored. After providing a comprehensive review of existing studies in the literature, the authors point out the challenges that are worth further investigation. Then, they introduce several novel solutions for cooperative wireless network protocols that reduce energy consumption and address spatial random distribution of wireless nodes. For each solution, the book offers a clear system model and problem formulation, details of the proposed cooperative schemes, comprehensive performance analysis, and extensive numerical and simulation results that validate the analysis and examine the performance under various conditions. The last section of this book reveals several potential directions for the research on cooperative wireless networks that deserve future exploration. Researchers, professionals, engineers, and consultants in wireless communication and mobile networks will find this book valuable. It is also helpful for technical staff in mobile network operations, wireless equipment manufacturers, wireless communication standardization bodies, and governmental regulation agencies.

Download or read book Non Orthogonal Multiple Access in Cooperative Relay Networks Based on Statistical Channel State Information written by Sharief N. Abdel-Razeq and published by . This book was released on 2018 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-orthogonal multiple access (NOMA) has been considered as an essential enabling technology for fifth generation (5G) and beyond 5G (B5G) cellular networks to meet the increasing demands on low latency, high reliability, massive connectivity, improved fairness, and high throughput. Cooperative relay networks, on the other hand, have been shown to significantly improve the throughput, coverage, and achievable rates of wireless networks, in which, the relay nodes assist the communication between the source node and the destination node when the direct channel is poor. There has been extensive research on the subject of NOMA and cooperative relay networks. However, most of the existing research relies on two main assumptions: flat fading channels and perfect channel state information (CSI) at the transmitting nodes. Instead of those idealistic assumptions, we study NOMA in cooperative relay networks under practical assumptions: frequency selective multipath fading channels and statistical CSI at the transmitting nodes. This dissertation begins with an overview of the basic concept of NOMA. Then, it focuses on downlink NOMA transmissions in a cooperative relay network. Specifically, a base station communicates with two paired mobile users simultaneously via superposition coded orthogonal frequency division multiplexing (OFDM) transmissions with the help of a half-duplex relay under either the decode-and-forward (DF) or amplify-and-forward (AF) scheme, where the power splitting between two mobile users depends on the statistical CSI. We derive the ergodic rates under Rayleigh fading channels and present an ad-hoc approach to determine the power splitting parameters when the target data rates are given. After that, this dissertation presents uplink NOMA transmissions in a cooperative relay network. Specifically, two users, a near user and a far user, communicate with a base station at the same time with existence of a half-duplex relay employing the DF scheme to assist the far user. At the transmitting nodes, the power allocation factors are decided based on the statistical CSI while, at the receiving nodes, the effect of imperfect successive interference cancellation (SIC) implementation is taken into account. Under Rayleigh fading channels, we derive the exact ergodic rate for the near user and the upper bound of the ergodic rate for the far user, then present an ad-hoc approach to determine the power allocation factors when the target data rates are given, and we study the outage probability of the two users at the base station. The last part of this dissertation extends the study into an energy harvesting cooperative wireless sensor network. We consider a two-hop network consisting of a source, two parallel half-duplex relay nodes, and two destinations. While the destinations have adequate power supply, the source and relay nodes rely on harvested energy for data transmission. Different from all existing works, the two relay nodes can also transfer their harvested energy to each other via energy conferencing channels. For such a system, an optimization problem is formulated with the objective of maximizing the total data rate and conserving the source and relay transmission energy.

Download or read book Cooperative Communications written by Mischa Dohler and published by John Wiley & Sons. This book was released on 2010-01-29 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Facilitating Cooperation for Wireless Systems Cooperative Communications: Hardware, Channel & PHY focuses on issues pertaining to the PHY layer of wireless communication networks, offering a rigorous taxonomy of this dispersed field, along with a range of application scenarios for cooperative and distributed schemes, demonstrating how these techniques can be employed. The authors discuss hardware, complexity and power consumption issues, which are vital for understanding what can be realized at the PHY layer, showing how wireless channel models differ from more traditional models, and highlighting the reliance of PHY algorithm performance on the underlying channel models. Numerous transparent and regenerative relaying protocols are described in detail for a variety of transparent and regenerative cooperative schemes. Key Features: Introduces background, concepts, applications, milestones and thorough taxonomy Identifies the potential in this emerging technology applied to e.g. LTE/WiMAX, WSN Discusses latest wireless channel models for transparent and regenerative protocols Addresses the fundamentals as well as latest emerging PHY protocols Introduces transparent distributed STBC, STTC, multiplexing and beamforming protocols Quantifies regenerative distributed space-time, channel and network coding protocols Explores system optimization, such as distributed power allocation and relay selection Introduces and compares analog and digital hardware architectures Quantifies complexity, memory and power consumption of 3G UMTS & 4G LTE/WiMAX relay Highlights future research challenges within the cooperative communications field This book is an invaluable guide for professionals and researchers in communications fields. It will also be of interest to graduates of communications and electronic engineering courses. It forms part of an entire series dedicated to cooperative wireless systems.

Download or read book Distributed Space time Block Coding in Cooperative Relay Networks with Application in Cognitive Radio written by Faisal T. Alotaibi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Spatial diversity is an effective technique to combat the effects of severe fading in wireless environments. Recently, cooperative communications has emerged as an attractive communications paradigm that can introduce a new form of spatial diversity which is known as cooperative diversity, that can enhance system reliability without sacrificing the scarce bandwidth resource or consuming more transmit power. It enables single-antenna terminals in a wireless relay network to share their antennas to form a virtual antenna array on the basis of their distributed locations. As such, the same diversity gains as in multi-input multi-output systems can be achieved without requiring multiple-antenna terminals. In this thesis, a new approach to cooperative communications via distributed extended orthogonal space-time block coding (D-EO-STBC) based on limited partial feedback is proposed for cooperative relay networks with three and four relay nodes and then generalized for an arbitrary number of relay nodes. This scheme can achieve full cooperative diversity and full transmission rate in addition to array gain, and it has certain properties that make it alluring for practical systems such as orthogonality, flexibility, low computational complexity and decoding delay, and high robustness to node failure. Versions of the closed-loop D-EO-STBC scheme based on cooperative orthogonal frequency division multiplexing type transmission are also proposed for both flat and frequency-selective fading channels which can overcome imperfect synchronization in the network. As such, this proposed technique can effectively cope with the effects of fading and timing errors. Moreover, to increase the end-to-end data rate, this scheme is extended for two-way relay networks through a three-time slot framework. On the other hand, to substantially reduce the feedback channel overhead, limited feedback approaches based on parameter quantization are proposed. In particular, an optimal one-bit partial feedback approach is proposed for the generalized D-O-STBC scheme to maximize the array gain. To further enhance the end-to-end bit error rate performance of the cooperative relay system, a relay selection scheme based on D-EO-STBC is then proposed. Finally, to highlight the utility of the proposed D-EO-STBC scheme, an application to cognitive radio is studied.

Download or read book Diversity Multiplexing Tradeoff and Capacity Results in Relayed Wireless Networks written by Shahab Oveis Gharan and published by . This book was released on 2010 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation studies the diversity multiplexing tradeoff and the capacity of wireless multiple-relay network. In part 1, we study the setup of the parallel Multi-Input Multi-Output (MIMO) relay network. An amplify-and-forward relaying scheme, Incremental Cooperative Beamforming, is introduced and shown to achieve the capacity of the network in the asymptotic case of either the number of relays or the power of each relay goes to infinity. In part 2, we study the general setup of multi-antenna multi-hop multiple- relay network. We propose a new scheme, which we call random sequential (RS), based on the amplify-and-forward relaying. Furthermore, we derive diversity- multiplexing tradeoff (DMT) of the proposed RS scheme for general single-antenna multiple-relay networks. It is shown that for single-antenna two-hop multiple- access multiple-relay (K> 1) networks (without direct link between the source(s) and the destination), the proposed RS scheme achieves the optimum DMT. In part 3, we characterize the maximum achievable diversity gain of the multi- antenna multi-hop relay network and we show that the proposed RS scheme achieves the maximum diversity gain. In part 4, RS scheme is utilized to investigate DMT of the general multi-antenna multiple-relay networks. First, we study the case of a multi-antenna full-duplex single-relay two-hop network, for which we show that the RS achieves the optimum DMT. Applying this result, we derive a new achievable DMT for the case of multi-antenna half-duplex parallel relay network. Interestingly, it turns out that the DMT of the RS scheme is optimum for the case of multi-antenna two parallel non-interfering half-duplex relays. Furthermore, we show that random unitary matrix multiplication also improves the DMT of the Non-Orthogonal AF relaying scheme in the case of a multi-antenna single relay channel. Finally, we study the general case of multi-antenna full-duplex relay networks and derive a new lower-bound on its DMT using the RS scheme. Finally, in part 5, we study the multiplexing gain of the general multi-antenna multiple-relay networks. We prove that the traditional amplify-forward relaying achieves the maximum multiplexing gain of the network. Furthermore, we show that the maximum multiplexing gain of the network is equal to the minimum vertex cut-set of the underlying graph of the network, which can be computed in polynomial time in terms of the number of network nodes. Finally, the argument is extended to the multicast and multi-access scenarios.

Download or read book Cooperative Strategies in Multi terminal Wireless Relay Networks written by and published by . This book was released on 2012 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: