Multiuser Communications with Relaying and User Cooperation

Multiuser Communications with Relaying and User Cooperation PDF Author: Yingbin Liang
Publisher:
ISBN:
Category :
Languages : en
Pages : 394

Get Book Here

Book Description

Multiuser Communications with Relaying and User Cooperation

Multiuser Communications with Relaying and User Cooperation PDF Author: Yingbin Liang
Publisher:
ISBN:
Category :
Languages : en
Pages : 394

Get Book Here

Book Description


Wideband Multi-User Cooperative Networks

Wideband Multi-User Cooperative Networks PDF Author: Etienne Auger
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832532099
Category : Computers
Languages : en
Pages : 262

Get Book Here

Book Description
This book details promising communication schemes and channel modeling for a pervasive wireless access network (PWAN). Such a network is formed by nodes equipped with heterogeneous antenna arrangements and placed up to 10 m apart from each other. Nodes can be static when they belong to the infrastructure or have limited mobility when they are carried by a person. This scenario is extremely interesting for relay-based applications and fills the gap between the body area network that has a coverage up to 1 m and the wireless local area network that has a coverage up to 100 m. When a PWAN is jointly considered with high node density, it allows for node cooperations, and idle or infrastructure nodes can support the communication of source-destination pairs. With an adequate signaling scheme, the PWAN can operate as a virtual antenna array and ultimately achieve multiple-input multiple-output (MIMO) gains in a distributed way. Until now these networks have been studied using oversimplified channel models that were frequency flat and designed for cellular low node density networks. The novelty of this book is the study of a PWAN under realistic channel conditions and hardware constraints.

Coherent Cooperative Relaying in Low Mobility Wireless Multiuser Networks

Coherent Cooperative Relaying in Low Mobility Wireless Multiuser Networks PDF 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.

Efficient Multiuser Cooperative Relay Communications Employing Layered Modulations

Efficient Multiuser Cooperative Relay Communications Employing Layered Modulations PDF Author: Roderick Jaehoon Whang
Publisher:
ISBN:
Category : Cell phone systems
Languages : en
Pages : 102

Get Book Here

Book Description
Relay-assisted cooperative communications are promising solutions for error-performance improvement and cell coverage extension. In this thesis, we propose several efficient cooperative relay communication schemes. First, an efficient space-time coded cooperative relay communications scheme that employs linear precoding and transmission-pattern selection is proposed. This is built upon an existing block linear precoding technique for conventional multiple-input multiple-output systems in order to improve the diversity performance of a multihop relay network. Second, we consider several multiuser cooperative relay communication schemes employing layered modulations, such as hierarchical modulation and superposition coding. Conventional cooperative relay communication is effective in mitigating fading effects. However, additional resources, such as time slots or frequency bands are required for the relay, which reduce the overall throughput. Reduction of throughput will become more severe as the number of users increases. In order to overcome this limitation, multiuser cooperative relaying schemes that employ hierarchical modulation and superposition coding are proposed. These schemes exploit the superimposed message for users in the network and allow the system to transmit two or more independent data streams simultaneously. The proposed schemes do not require additional resources than the conventional schemes, while improving the error performance by flexibly controlling the power division coefficient of superposition coding or the distance parameter of hierarchical modulation.

New Concepts in Multi-User Communication

New Concepts in Multi-User Communication PDF Author: J.K. Skwirzynski
Publisher: Springer Science & Business Media
ISBN: 9789028627710
Category : Language Arts & Disciplines
Languages : en
Pages : 730

Get Book Here

Book Description


Cooperative Communications and Networking

Cooperative Communications and Networking PDF Author: Y.-W. Peter Hong
Publisher: Springer Science & Business Media
ISBN: 1441971947
Category : Technology & Engineering
Languages : en
Pages : 411

Get Book Here

Book Description
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.

Efficiency and Security Analysis in Multi-user Wireless Communication Systems

Efficiency and Security Analysis in Multi-user Wireless Communication Systems PDF Author: Jie Gao
Publisher:
ISBN:
Category : Wireless communication systems
Languages : en
Pages : 153

Get Book Here

Book Description
Efficiency and security are major concerns with increasingly higher importance in modern wireless communications. These two concerns are especially significant for multi-user wireless communications where different users share or compete for resources. Among different users, there are possibilities of cooperation, competition, and/or malicious behavior. Due to the possibility of cooperation among the users, the spectral and energy efficiency in multi-user wireless communications could be boosted. Due to the possibility of competition, the resource allocation in multi-user wireless systems may reach certain equilibrium. Due to the possibility of malicious behavior, the security and reliability of wireless communications can be undermined. In this thesis, a comprehensive analysis on the issues of efficiency and security in multi-user wireless communications is developed for three systems in four scenarios. The first multi-user system of multiple-input multiple-output two-way relaying has the feature of cooperation including a limited coordination scenario and a full coordination scenario. It is shown that high spectral efficiency can be achieved with efficient energy consumption in this system due to the cooperation among the users. Moreover, full coordination yields better results in both spectral and energy efficiency than limited coordination at the cost of higher overhead. The second multi-user system of legitimate transceiver(s) with a jammer features the existence of malicious behavior. To measure the jamming threat, the worst-case jamming is studied for different cases according to the jammer's knowledge of the legitimate communication. The optimal/sub-optimal jamming strategy in each case is analyzed and derived. The third multi-user system of two-user interference channel features the competition of the users. The situation is modeled using noncooperative games with continuous mixed strategies. The outcomes of the games are analyzed through the establishment of the conditions for the existence and uniqueness of mixed strategy Nash equilibrium.

Cooperative Communications for Improved Wireless Network Transmission: Framework for Virtual Antenna Array Applications

Cooperative Communications for Improved Wireless Network Transmission: Framework for Virtual Antenna Array Applications PDF Author: Uysal, Murat
Publisher: IGI Global
ISBN: 1605666661
Category : Computers
Languages : en
Pages : 632

Get Book Here

Book Description
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.

Game Theoretical Power Allocation in Multi-user Wireless Cooperative Systems

Game Theoretical Power Allocation in Multi-user Wireless Cooperative Systems PDF Author: Qian Cao
Publisher:
ISBN:
Category : Game theory
Languages : en
Pages : 140

Get Book Here

Book Description
Cooperative system is a promising concept to improve the performance of the communication in wireless networks. This new paradigm of wireless communication imposes new challenges to traditional problems such as resource allocation. To model the behaviors of selfish and autonomous nodes in a cooperative system, game theory is an appropriate tool. This thesis focuses on power allocation in wireless cooperative systems based on game theory, with three research components. First, we study the power allocation in multi-user relay networks with altruistic relays. We propose an asymmetric Nash bargaining solution-based relay power allocation scheme, which can achieve a balance between global network performance and user fairness. We also give a distributed implementation of the proposed scheme. Second, we consider the power allocation and relay cooperation stimulation problem in multi-user relay networks. We use Stackelberg game to analyze the interaction between the relays and the users. Based on the proposed fair relay power allocation rule, the optimal relay power price is derived analytically. Third, we study the power allocation and user cooperation stimulation problem in multi-user cooperative networks. We propose an iterative double auction-based power allocation algorithm. We show that this algorithm achieves global optimality in the sense of weighted sum-signal-to-noise ratio.

Opportunities, Benefits, and Constraints of Relaying in Mobile Communication Systems

Opportunities, Benefits, and Constraints of Relaying in Mobile Communication Systems PDF Author: Peter Matthias R. Rost
Publisher: Jörg Vogt Verlag
ISBN: 3938860235
Category :
Languages : en
Pages : 226

Get Book Here

Book Description