Download or read book Resource Management for Multiuser Systms with Multiple Antennas in Wireless Networks written by İlhan Baştürk and published by . This book was released on 2014 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we explore radio resource management algorithms for OFDMA based cellular networks. Firstly, we combine the OFDMA technology with multiple antennas technology and handle the resource allocation problem for the MISO-OFDMA systems. We take care of the fairness issue among users to prevent the users, which have good channel conditions, to obtain most of the system resources. Thus, we propose a fairness aware resource allocation algorithm and compare it with the existing schemes. Next, we enhance the conventional cellular network structure with mobile relays and examine relay selection and resource allocation algorithms for the OFDMA-based mobile relay enhanced cellular networks. We propose a novel relaying frame structure with efficient resource management algorithms in order to reveal the opportunities of the mobile relays. Then, we consider the queue-lengths of the users and propose a queue and channel aware joint relay selection and resource allocation algorithm to use the system resources efficiently. Finally, we combine mobile relaying and offloading technologies in order to overcome the capacity and coverage problems of the conventional cellular networks. We focus on the radio resource management problem for the OFDMA-based mobile relay-enhanced heterogenous cellular networks that contains multiple radio access technologies. We propose a network interface selection algorithm that consider the bandwidth availability information of each network in order to prevent sending the users to overloaded networks.

Download or read book Multichannel Multiuser and Multiple Antenna Wireless Communication Systems written by Erdem Bala and published by . This book was released on 2007 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: We also study the design of precoding and decoding matrices for the downlink of a multiuser MIMO system when spatial multiplexing is used. We investigate the block diagonalization approach for multiuser MIMO systems and propose a random precoding technique that schedules users for transmission with only limited feedback from the receivers. We then introduce a new optimization criterion for designing a linear transceiver which tries to minimize the maximum mean-squared error among all users or data substreams; we show that this approach results in fairness among users and improved average BER.

Download or read book Interference Management for Multiuser Mimo Wireless Networks written by Tiangao Gou and published by . This book was released on 2012 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the primary goals of designing communication systems is to achieve high data rates. Due to limited spectrum, users need to share the common resource, which causes interference with each other. Interference in turn creates a bottleneck on the communication rate. Recently two breakthroughs have been made to relieve this bottleneck. One is using multiple antennas known as multiple input multiple output (MIMO) technology and the other is an interference management technique called interference alignment. While much progress has been made on understanding of each individually, relatively little is known about how to use both techniques together to deal with interference. This thesis presents the progress we have made towards determining the capacity benefits of multiple antennas and interference alignment in different network settings and under various assumptions about the channel state information known at the transmitters. The thesis consists of five main results. First, we characterize the optimal degrees of freedom (DoF) of the K user MIMO Gaussian interference channel with M transmit and N receive antennas for each user when the ratio of the maximum to the minimum of M and N is equal to an integer. Second, we study the N+1 user single input multiple output (SIMO) Gaussian interference channel with one transmit and N receive antennas for each user. We characterize the generalized degrees of freedom (GDoF) of the network, which directly leads to a capacity approximation within a bounded gap which is independent of the signal strength. We also derive outer bounds which identify a strong interference regime where the capacity region is established. Third, we characterize the optimal DoF of two classes of finite state compound wireless networks including the multiple-input single-output (MISO) finite state compound broadcast channel (BC) with arbitrary number of users and antennas at the transmitter and the finite state scalar (single antenna nodes) compound X networks with arbitrary number of users. Fourth, we propose a blind interference alignment scheme through staggered antenna switching, i.e., we seek to align interference without any knowledge of the channel coefficient values at the transmitters. This scheme achieves the optimal DoF of the vector broadcast channel where the transmitter is equipped with M antennas and there are K receivers, each equipped with a reconfigurable antenna capable of switching among M preset modes. Fifth, we go beyond the single hop wireless networks to multihop interference networks and characterize the DoF of the 2-source 2-destination 2-hop interference network formed by concatenation of two 2-user interference channels. The key to this result is a new idea, called aligned interference neutralization, that provides a way to align interference terms over each hop in a manner that allows them to be cancelled over the air at the last hop.

Download or read book Radio Resource Management in Multi Tier Cellular Wireless Networks written by Ekram Hossain and published by John Wiley & Sons. This book was released on 2013-12-09 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing an extensive overview of the radio resource management problem in femtocell networks, this invaluable book considers both code division multiple access femtocells and orthogonal frequency-division multiple access femtocells. In addition to incorporating current research on this topic, the book also covers technical challenges in femtocell deployment, provides readers with a variety of approaches to resource allocation and a comparison of their effectiveness, explains how to model various networks using Stochastic geometry and shot noise theory, and much more.

Download or read book Radio Resource Management for Multimedia QoS Support in Wireless Networks written by Huan Chen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the great success and enormous impact of IP networks, In ternet access (such as sending and receiving e-mails) and web brows ing have become the ruling paradigm for next generation wireless systems. On the other hand, great technological and commercial success of services and applications is being witnessed in mobile wire less communications with examples of cellular, pes voice telephony and wireless LANs. The service paradigm has thus shifted from the conventional voice service to seamlessly integrated high quality mul timedia transmission over broadband wireless mobile networks. The multimedia content may include data, voice, audio, image, video and so on. With availability of more powerful portable devices, such as PDA, portable computer and cellular phone, coupled with the easier access to the core network (using a mobile device), the number of mobile users and the demand for multimedia-based applications is increasing rapidly. As a result, there is an urgent need for a sys tem that supports heterogeneous multimedia services and provides seamless access to the desired resources via wireless connections. Therefore, the convergence of multimedia communication and wireless mobile networking technologies into the next generation wireless multimedia (WMM) networks with the vision of "anytime, anywhere, anyform" information system is the certain trend in the foreseeable future. However, successful combination of these two technologies presents many challenges such as available spectral bandwidth, energy efficiency, seamless end-to-end communication, robustness, security, etc.

Download or read book Wireless Communications Resource Management written by Byeong Gi Lee and published by John Wiley & Sons. This book was released on 2009-07-28 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless technologies continue to evolve to address the insatiable demand for faster response times, larger bandwidth, and reliable transmission. Yet as the industry moves toward the development of post 3G systems, engineers have consumed all the affordable physical layer technologies discovered to date. This has necessitated more intelligent and optimized utilization of available wireless resources. Wireless Communications Resource Managem ent, Lee, Park, and Seo cover all aspects of this critical topic, from the preliminary concepts and mathematical tools to detailed descriptions of all the resource management techniques. Readers will be able to more effectively leverage limited spectrum and maximize device battery power, as well as address channel loss, shadowing, and multipath fading phenomena. Presents the latest resource allocation techniques for new and next generation air interface technologies Arms readers with the necessary fundamentals and mathematical tools Illustrates theoretical concepts in a concrete manner Gives detailed coverage on scheduling, power management, and MIMO techniques Written by an author team working in both academia and industry Wireless Communications Resource Managementis geared for engineers in the wireless industry and graduate students specializing in wireless communications. Professionals in wireless service and device manufacturing industries will find the book to be a clear, up-to-date overview of the topic. Readers will benefit from a basic, undergraduate-level understanding of networks and communications. Course instructors can access lecture materials at the companion website:(www.wiley.com/go/bglee)

Download or read book Radio Communications written by Alessandro Bazzi and published by IntechOpen. This book was released on 2010-04-01 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book On the Efficient Utilization of Multiple Antennas for Multiuser Wireless Networks written by Bongyong Song and published by . This book was released on 2006 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Competition Coexistence and Confidentiality in Multiuser Multi antenna Wireless Networks written by Amitav Mukherjee and published by . This book was released on 2012 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Competition for limited bandwidth, power, and time resources is an intrinsic aspect of multi-user wireless networks. There has been a recent move towards optimizing coexistence and confidentiality at the physical layer of multi-user wireless networks, mainly by exploiting the advanced capabilities of multiple-input multiple-out (MIMO) signal processing methods. Coexistence of disparate networks is made possible via interference mitigation and suppression, and is exemplified by the current interest in cognitive radio (CR) systems. On the other hand, MIMO communications that are secure at the physical layer without depending upon network-layer encryption are achieved by redirecting jamming or multi-user interference to unauthorized receivers, while minimizing that to legitimate receivers. In all cases, the accuracy of the channel state information (CSI) available at the transmitters plays a crucial role in determining the degree of interference mitigation and confidentiality that is achieved. This dissertation seeks to examine the development of multi-antenna transmission techniques for interference mitigation and/or secure communication in multi-user wireless networks, with emphasis on robust designs for scenarios with imperfect channel state information. Commencing with coexistence in MIMO CR networks, we design novel precoding algorithms for the novel scenario where the CSI of the primary users is completely unknown to the CR, and for a novel network where the primary users coexist with both underlay and spectrum-sensing CRs. The latter half of the thesis considers the secure communication problem in the socalled MIMO wiretap channel with a passive eavesdropper. We first examine the impact of imperfect knowledge of the legitimate channel on the achievable secrecy rate of the MIMO wiretap channel, and design two robust beamforming schemes that are able to recover a large fraction of the secrecy rate lost due to the channel estimation errors. We then consider a more formidable adversary capable of either eavesdropping or jamming in the MIMO wiretap channel. We formulate the interactions between the multi-antenna transmitter and the dual-mode eavesdropper/jammer as a zerosum game with the MIMO ergodic secrecy rate as the payoff function, and deduce the existence and properties of steady-state Nash Equilibria for a variety of gametheoretic scenarios. The culmination of this dissertation is to bring together the coexistence and confidentiality aspects by considering a MIMO cognitive radio network where the CR transmissions serve a dual purpose of jamming the eavesdropper while communicating meaningful information to the underlay receivers, but the CR interference to the primary receiver (PR) must also be limited to a prescribed threshold. When only imperfect CSI is available to the CRs, the primary link security is severely degraded since the CR interference to the PR cannot be effectively controlled, and the jamming signals cannot accurately target the eavesdropper. Therefore, we devise robust CR transmission schemes that reduce the degradation in primary secrecy rate under imperfect CSI.

Download or read book Radio Communications written by Alessandro Bazzi and published by IntechOpen. This book was released on 2010-04-01 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Resource Allocation in Multiuser Multicarrier Wireless Systems written by Ian C. Wong and published by Springer Science & Business Media. This book was released on 2007-11-15 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book proposes a unified algorithmic framework based on dual optimization techniques that have complexities that are linear in the number of subcarriers and users, and that achieve negligible optimality gaps in standards-based numerical simulations. Adaptive algorithms based on stochastic approximation techniques are also proposed, which are shown to achieve similar performance with even much lower complexity. All the algorithms proposed are clearly presented in concise block diagrams allowing the reader to implement these algorithms in the software of their choice. This book is an accessible reference for researchers and industry practitioners alike.

Download or read book Design and Optimization of Distributed Multiuser Cooperative Wireless Networks written by Celal Eşli and published by Logos Verlag Berlin. This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Utility Maximization in Nonconvex Wireless Systems written by Johannes Brehmer and published by Springer Science & Business Media. This book was released on 2012-03-15 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph develops a framework for modeling and solving utility maximization problems in nonconvex wireless systems. The first part develops a model for utility optimization in wireless systems. The model is general enough to encompass a wide array of system configurations and performance objectives. Based on the general model, a set of methods for solving utility maximization problems is developed in the second part of the book. The development is based on a careful examination of the properties that are required for the application of each method. This part focuses on problems whose initial formulation does not allow for a solution by standard methods and discusses alternative approaches. The last part presents two case studies to demonstrate the application of the proposed framework. In both cases, utility maximization in multi-antenna broadcast channels is investigated.

Download or read book Resource Management in Wireless Networking written by Mihaela Cardei and published by Springer Science & Business Media. This book was released on 2006-07-06 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following the pattern of the Internet growth in popularity, started in the early 1990s, the current unprecedented expansion of wireless technology promises to have an even greater effect on how people communicate and interact, with considerable socio-economic impact all over the world. The driving force behind this growth is the remarkable progress in component miniaturization, integration, and also devel- ments in waveforms, coding, and communication protocols. Besides established infrastructurebased wireless networks (cellular, WLAN, sat- lite) ad-hoc wireless networks emerge as a new platform for distributed applications and for personal communication in scenarios where deploying infrastructure is not feasible. In ad-hoc wireless networks, each node is capable of forwarding packets on behalf of other nodes, so that multi-hop paths provide end-to-end connectivity. The increased flexibility and mobility of ad-hoc wireless networks are favored for appli- tions in law enforcement, homeland defense and military. In a world where wireless networks become increasingly interoperable with each other and with the high-speed wired Internet, personal communication systems will transform into universal terminals with instant access to variate content and able of handle demanding tasks, such as multimedia and real-time video. With users roaming between networks, and with wide variation in wireless link quality even in a single domain, the communications terminal must continue to provide a level of Quality of Service that is acceptable to the user and conforms to a contracted Service Level Agreement.

Download or read book Smart Antennas written by Thomas Kaiser and published by Hindawi Publishing Corporation. This book was released on 2005 with total page 891 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart Antennas—State of the Art brings together the broad expertise of 41 European experts in smart antennas. They provide a comprehensive review and an extensive analysis of the recent progress and new results generated during the last years in almost all fields of smart antennas and MIMO (multiple-input multiple-output) transmission. The following represents a summarized table of content.Receiver: space-time processing, antenna combining, reduced rank processing, robust beamforming, subspace methods, synchronization, equalization, multiuser detection, iterative methods Channel: propagation, measurements and sounding, modelling, channel estimation, direction-of-arrival estimation, subscriber location estimation Transmitter: space-time block coding, channel side information, unified design of linear transceivers, ill-conditioned channels, MIMO-MAC strategies Network Theory: channel capacity, network capacity, multihop networks Technology: antenna design, transceivers, demonstrators and testbeds, future air interfaces Applications and Systems: 3G system and link level aspects, MIMO HSDPA, MIMO-WLAN/UMTS implementation issues This book serves as a reference for scientists and engineers who need to be aware of the leading edge research in multiple-antenna communications, an essential technology for emerging broadband wireless systems.

Download or read book Interference Management in Multiple antenna Wireless Networks written by Ioannis Spyropoulos and published by . This book was released on 2009 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focuses on the topic of interference management in wireless networks with multiple-antenna nodes. Two network paradigms are considered, namely, time-division duplexing (TDD)/code-division multiple-access (CDMA) cellular and ad hoc. In TDD/CDMA cellular networks with asymmetric data traffic, dynamic channel allocation (DCA) enhances resource utilization compared to fixed channel allocation (FCA); however, it induces base-to-base and mobile-to-mobile crossed-slot intercell interference that can severely degrade network performance. To deal with this problem, a decentralized scheme is proposed, which combines an interference-aware DCA algorithm with space-time linear minimum-mean-square-error (LMMSE) joint detection at the base and mobile stations. The former assigns active links to timeslots in a way that crossed-slot interference is mitigated, while the latter suppresses the remaining intercell interference (along with intersymbol and intracell interference) by exploiting its spatio-temporal autocorrelation statistics. The performance of this scheme is evaluated in terms of SINR outage and average throughput via analytical approximations and Monte Carlo simulations, and it is compared with that of benchmark random DCA (RDCA) and FCA schemes. The cases of single- and dual-antenna reception with perfect and imperfect channel state information are examined. It is shown that the proposed scheme achieves higher average throughput than FCA (particularly for dual-antenna reception) as well as RDCA (for heavy traffic loads). These throughput gains are more significant in uplink than in downlink. In ad hoc networks, interference management via collision-avoidance medium access schemes results in poor spatial reuse and, thus, restricts network throughput. To address this shortcoming, two physical-medium-access-control cross-layer protocols are proposed. The first increases spatial reuse by integrating medium access, power control, and optimum receive beamforming in a distributed manner, and it is named progressive back-off algorithm with optimum receive beamforming (PBOA-ORB). The second additionally incorporates transmit beamforming, on the premise of centralized control, and it is named progressive back-off algorithm with transmit and optimum receive beamforming (PBOA-TORB). The performance of both protocols is evaluated in terms of aggregate throughput and energy efficiency via simulations over a single-hop network. It is shown that the throughput of PBOA-ORB increases linearly with the number of antennas per node thanks to interference suppression provided by optimum receive beamforming. PBOA-TORB achieves only an incremental throughput gain over PBOA-ORB despite its centralized nature. However, it is significantly more energy efficient than PBOA-ORB thanks to extra array gain provided by transmit beamforming. The research for this dissertation was conducted at the UCSD Center for Wireless Communication, under the "MIMO Wireless Communication Systems" project (CoRe research grant com04-10176) and the ``Multiuser MIMO Systems'' project (CoRe research grant com07-10241).

Download or read book MIMO Wireless Networks written by Bruno Clerckx and published by Academic Press. This book was released on 2013-01-23 with total page 773 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is unique in presenting channels, techniques and standards for the next generation of MIMO wireless networks. Through a unified framework, it emphasizes how propagation mechanisms impact the system performance under realistic power constraints. Combining a solid mathematical analysis with a physical and intuitive approach to space-time signal processing, the book progressively derives innovative designs for space-time coding and precoding as well as multi-user and multi-cell techniques, taking into consideration that MIMO channels are often far from ideal.Reflecting developments since the first edition was published, this book has been thoroughly revised, and now includes new sections and five new chapters, respectively dealing with receiver design, multi-user MIMO, multi-cell MIMO, MIMO implementation in standards, and MIMO system-level evaluation. Extended introduction to multi-dimensional propagation, including polarization aspects Detailed and comparative description of physical models and analytical representations of single- and multi-link MIMO channels, covering the latest standardized models Thorough overview of space-time coding techniques, covering both classical and more recent schemes under information theory and error probability perspectives Intuitive illustration of how real-world propagation affects the capacity and the error performance of MIMO transmission schemes Detailed information theoretic analysis of multiple access, broadcast and interference channels In-depth presentation of multi-user diversity, resource allocation and (non-)linear MU-MIMO precoding techniques with perfect and imperfect channel knowledge Extensive coverage of cooperative multi-cell MIMO-OFDMA networks, including network resource allocation optimization, coordinated scheduling, beamforming and power control, interference alignment, joint processing, massive and network MIMO Applications of MIMO and Coordinated Multi-Point (CoMP) in LTE, LTE-A and WiMAX Theoretical derivations and results contrasted with practical system level evaluations highlighting the performance of single- and multi-cell MIMO techniques in realistic deployments