Download or read book Joint Optimal Power Control and Beamforming in Wireless Networks Using Antenna Arrays written by and published by . This book was released on 1996 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interference reduction capability of antenna arrays and power control algorithms have been considered separately as means to increase the capacity in wireless communications networks. The MVDR (Minimum Variance Distortionless Response) beamformer maximizes the Carrier to Interference Ratio (CIR) when it is employed in the receiver of a wireless link. In a system with omnidirectional antennas, power control algorithms are used to maximize CIR as well. In this paper, the authors consider a system with beamforming capabilities in the receiver and power control. An iterative algorithm is proposed to jointly update the transmission powers and the beamformer weights so that they converge to the jointly optimal beamforming and transmission power vector. The algorithm is distributed and uses only local interference measurements. In an uplink transmission scenario, it is shown how base assignment can be incorporated in addition to beamforming and power control such that a globally optimum solution is obtained. The network capacity increase and the savings in mobile power achieved by beamforming are evaluated through numerical study.

Download or read book Power Control in Wireless Cellular Networks written by Mung Chiang and published by Now Publishers Inc. This book was released on 2008 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transmit power in wireless cellular networks is a key degree of freedom in the management of interference, energy, and connectivity. Power control in both the uplink and downlink of a cellular network has been extensively studied, especially over the last 15 years, and some of the results have enabled the continuous evolution and significant impact of the digital cellular technology. This survey provides a comprehensive discussion of the models, algorithms, analysis, and methodologies in this vast and growing literature. It starts with a taxonomy of the wide range of power control problem formulations, and progresses from the basic formulation to more sophisticated ones. When transmit power is the only set of optimization variables, algorithms for fixed SIR are presented first, before turning to their robust versions and joint SIR and power optimization. This is followed by opportunistic and non-cooperative power control. Then joint control of power together with beamforming pattern, base station assignment, spectrum allocation, and transmit schedule is surveyed one-by-one. Throughout the survey, we highlight the use of mathematical language and tools in the study of power control, including optimization theory, control theory, game theory, and linear algebra. Practical implementations of some of the algorithms in operational networks are discussed in the concluding section. As illustrated by the open problems presented at the end of most chapters, in the area of power control in cellular networks, there are still many under-explored directions and unresolved issues that remain theoretically challenging and practically important.

Download or read book Academic Press Library in Signal Processing written by Fulvio Gini and published by Academic Press. This book was released on 2013-09-10 with total page 1389 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second volume, edited and authored by world leading experts, gives a review of the principles, methods and techniques of important and emerging research topics and technologies in communications and radar engineering. With this reference source you will: Quickly grasp a new area of research Understand the underlying principles of a topic and its application Ascertain how a topic relates to other areas and learn of the research issues yet to be resolved Quick tutorial reviews of important and emerging topics of research in array and statistical signal processing Presents core principles and shows their application Reference content on core principles, technologies, algorithms and applications Comprehensive references to journal articles and other literature on which to build further, more specific and detailed knowledge Edited by leading people in the field who, through their reputation, have been able to commission experts to write on a particular topic

Download or read book Handbook of Antennas in Wireless Communications written by Lal Chand Godara and published by CRC Press. This book was released on 2018-10-03 with total page 1043 pages. Available in PDF, EPUB and Kindle. Book excerpt: The move toward worldwide wireless communications continues at a remarkable pace, and the antenna element of the technology is crucial to its success. With contributions from more than 30 international experts, the Handbook of Antennas in Wireless Communications brings together all of the latest research and results to provide engineering professionals and students with a one-stop reference on the theory, technologies, and applications for indoor, hand-held, mobile, and satellite systems. Beginning with an introduction to wireless communications systems, it offers an in-depth treatment of propagation prediction and fading channels. It then explores antenna technology with discussion of antenna design methods and the various antennas in current use or development for base stations, hand held devices, satellite communications, and shaping beams. The discussions then move to smart antennas and phased array technology, including details on array theory and beamforming techniques. Space diversity, direction-of-arrival estimation, source tracking, and blind source separation methods are addressed, as are the implementation of smart antennas and the results of field trials of systems using smart antennas implemented. Finally, the hot media topic of the safety of mobile phones receives due attention, including details of how the human body interacts with the electromagnetic fields of these devices. Its logical development and extensive range of diagrams, figures, and photographs make this handbook easy to follow and provide a clear understanding of design techniques and the performance of finished products. Its unique, comprehensive coverage written by top experts in their fields promises to make the Handbook of Antennas in Wireless Communications the standard reference for the field.

Download or read book Adaptive Antenna Arrays written by Sathish Chandran and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: This compilation of the works and insights of various key scientists and engineers in this area addresses the current and future trends of scenarios for employing adaptive antenna arrays in communication systems. Ideal as a quick reference for engineers, researchers, advanced undergraduate and postgraduate students.

Download or read book Antenna and Array Technologies for Future Wireless Ecosystems written by Yingjie Jay Guo and published by John Wiley & Sons. This book was released on 2022-07-20 with total page 795 pages. Available in PDF, EPUB and Kindle. Book excerpt: ANTENNA AND ARRAY TECHNOLOGIES FOR FUTURE WIRELESS ECOSYSTEMS Discover a timely and accessible resource on the latest antenna research driving new developments in the field In Antenna and Array Technologies for Future Wireless Ecosystems, distinguished academics and authors Drs. Y. Jay Guo and Richard W. Ziolkowski deliver a cutting-edge resource for researchers, academics, students, and engineers who need the latest research findings on the newest challenges facing antenna designers who will be creating the technology that drives future 6G and beyond wireless systems and networks. This timely and impactful book offers the fundamental knowledge that will facilitate new research activities in the antennas and applied electromagnetics communities, and conveys innovative and practical solutions to many wireless industry problems. Its international cohort of leading authors delivers their findings on a variety of advanced topics in antenna and array research, including metasurface antennas; electrically small directive antennas; RF, millimeter-wave and THz antennas and arrays; atom-based sensors, and arrays of quantum emitters. The book also includes resources that cover the important topics: A thorough introduction to various intelligent and low-cost beam scanning, beamforming and beam-reconfigurable array technologies to support dynamic networking of future systems An exploration of advanced techniques for analyzing large arrays, as well as an examination of advanced antenna-in-package technologies for future mm-wave systems Discussions of the latest research on electrically small and extremely large hybrid antenna arrays, and photonic beamforming networks to address spectrum scarcity in future systems Low form-factor, low energy-consumption, and wireless power transfer antennas for the Internet of Things (IoT) This book is the companion of the Wiley book by the same authors, Advanced Antenna Array Engineering for 6G and Beyond Wireless Communications. Perfect for antenna engineers in academia and industry, Antenna and Array Technologies for Future Wireless Ecosystems will also be an essential resource in the libraries of senior undergraduate and graduate students studying antenna engineering applied electromagnetics and seeking a one-stop reference for state-of-the-art global antenna and antenna array research activities.

Download or read book Towards Power efficient and Intelligent Wireless Communication Systems written by Yunseong Cho and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the growing demand for higher date rates and more reliable service capabilities, wireless communication systems continue to grow in popularity and importance. In order to enable higher data rate via broader bandwidth, millimeter wave (mmWave) systems are deployed for modern and future communication systems. Due to the high transmission loss of the mmWave frequency bands, a massive number of antennas are employed to focus transmitted power in narrow radio frequency (RF) beams. However, associating one RF chain with two high-resolution data converters for each antenna element would consume a prohibitively large amount of power. Furthermore, challenging service requirements can be handled by machine learning techniques in a variety of application spaces. The goal of this dissertation is to propose communication systems that are not only reliable and high-performing, but also power-efficient as well as intelligent. Two possible ways to alleviate the huge power consumption problem are 1) low-resolution data converters, and 2) hybrid analog-digital beamforming architectures since the former tries to reduce the power consumption of each individual RF chain and the latter directly scales down the number of RF chains. Additionally, intelligent communication systems that can adapt to changing network conditions and user requirements are crucial for ensuring reliable and efficient communication. In either case, these solutions introduce severe non-convexity and non-linearity to the entire system. In this regard, I propose new solutions that can respond to future communication systems requiring a fundamental re-design of current communication systems based on a power-efficient and intelligent framework. First, I investigate a coordinated multipoint (CoMP) beamforming and power control problem for base stations (BSs) with a massive number of antenna arrays under coarse quantization by low-resolution analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). I first formulate total power minimization problems of both uplink (UL) and downlink (DL) systems subject to signal-to-quantization-plue-interference-and-noise ratio (SQINR) constraints. I then show strong duality for the UL and DL problems under the coarse quantization condition when channel reciprocity holds with time-division duplexing (TDD) assumption. Leveraging the duality, I propose a framework that is directed toward a twofold aim: to discover the optimal transmit powers in UL by developing iterative algorithm in a distributed manner and to obtain the optimal precoder in DL as a scaled instance of UL combiner. Under homogeneous transmit power and SQINR constraints per cell, I further derive a deterministic solution for the UL CoMP problem by analyzing the lower bound of the SQINR. Lastly, I extend the derived result to wideband orthogonal frequency-division multiplexing (OFDM) systems to optimize transmit power and beamformer for all subcarriers. Simulation results validate the theoretical results and proposed algorithms in terms of total transmit power, duality gap, and convergence. Second, I aim to find the DL beamformer that minimizes the maximum power on transmit antenna array of each BS under received SQINR constraints while minimizing per-antenna transmit power for a more realistic deployment. I first formulate formulating the quantized DL OFDM antenna power minimax problem and deriving its associated dual problem. With proving strong duality, I use the associated UL dual solution to compute the DL beamformer. Subsequently, the DL beamformer is used in updating the covariance matrix of the uplink noise signals. The series of processes builds an efficient algorithm to find a numerical solution. Simulations validate the proposed algorithm in terms of the maximum antenna transmit power and peak-to-average-power ratio. Third, I propose a learning-based maximum likelihood detection framework with an acceptable learning length for uplink massive multiple-input-multiple-output (MIMO) systems with one-bit ADCs. The learning-based detection only requires counting the occurrences of the quantized outputs at each antenna. The learning in the high signal-to-noise ratio (SNR) regime, however, needs excessive training to estimate the extremely small likelihood probabilities. To address this drawback, I utilize a dithering signal to artificially decrease the SNR and then remove the impact of the dithering noise via post processing. I evolve the technique by developing an adaptive dither-and-learning method that updates the dithering power according the patterns observed in the quantized dithered signals. Lastly, the computed likelihood probabilities are utilized in deriving log-likelihood ratio to enable state-of-the-art channel coding schemes. I compare the uncoded and coded detection performance of the proposed algorithm with other learning-based frameworks and show that the proposed algorithm shows the performance closest to optimal performance. Fourth, I propose a deep reinforcement learning (DRL)-based solution for joint hybrid beamforming (HB) and power control problems when multiple massive MIMO BSs are communicating with multiple users in the uplink mmWave band. The HB method requires both digital and analog beamformers, with the latter using discrete phase shifters to project high-dimensional antenna ports to low-dimensional logical ports and scale down the number of RF chains. However, this results in non-convexity, making the problem difficult to solve using existing algorithms. In multicell uplink communication systems, I aim to jointly design the HB at each BS and transmit power control of the associated users while ensuring that the received signal-to-interference-and-noise ratio (SINR) constraints are satisfied. Considering the use of the DRL-based approach and the primal problem, I formulate the RL basics. To handle the combination of discrete and continuous inputs, I use the DDPG RL algorithm, which outputs a valid action that maps to the design factors. In particular, I aim to control each phase shifter individually by introducing an intermediate vector and applying a differentiable argmax function to estimate the phase angle index. The proposed method is evaluated through simulation results based on the achieved SINR. The four contributions could make a worthwhile enhancement to the development of power-efficient and intelligent wireless communication systems by meeting the communication needs of modern society while minimizing energy consumption and maximizing the use of available resources

Download or read book Advanced Wireless Communications written by Savo G. Glisic and published by John Wiley & Sons. This book was released on 2005-12-13 with total page 878 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wireless community is on the verge of the standardization of fourth generation (4G) systems. Research has generated a number of solutions for significant improvement of system performance. The development of enabling technologies such as adaptive coding and modulation, iterative (turbo) decoding algorithms and space-time coding, means that industry can now implement these solutions. Advanced Wireless Communications: 4G Technologies focuses on the system elements that provide adaptability and reconfigurability and discusses how these features can improve 4G system performance. There are several different systems comprising 4G, including adaptive WCDMA (Wideband Code Division Multiple Access), ATDMA (Adaptive Time Division Multiple Access), Multicarrier (OFDMA) and Ultra Wide Band (UWB) receiver elements. This book provides a comparative study of these technologies and focuses on their future co-existence. Topics covered include: Space Time Coding, including discussions on diversity gain, the encoding and transmission sequence, the combining s cheme and ML decision rule for two-branch transmit diversity scheme with one and M receivers. Ultra Wide Band Radio, UWB multiple access in Gaussian channels, the UWB channel, UWB system with M-ary modulation, M-ary PPM UWB multiple access, coded UWB schemes, multi-user detection in UWB radio, UWB with space time processing and beam forming for UWB radio. Antenna array signal processing with focus on Space-Time receivers for CDMA communications, MUSIC and ESPRIT DOA estimation, joint array combining and MLSE receivers, joint combiner and channel response estimation and complexity reduction in the wide-band beam forming Channel modeling and measurement, adaptive MAC, adaptive routing and TCP layer are also addressed. This book will supply the reader with a comprehensive understanding of the relationship between the systems performance, its complexity/reliability and cost-effectiveness. It gives an insight into the impact of existing and new technologies on the receiver structure and provides an understanding of current approaches and evolving directions for personal and indoor communication.

Download or read book Wireless Coordinated Multicell Systems written by Duy H. N. Nguyen and published by Springer. This book was released on 2014-05-15 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This SpringerBrief discusses the current research on coordinated multipoint transmission/reception (CoMP) in wireless multi-cell systems. This book analyzes the structure of the CoMP precoders and the message exchange mechanism in the CoMP system in order to reveal the advantage of CoMP. Topics include interference management in wireless cellular networks, joint signal processing, interference coordination, uplink and downlink precoding and system models. After an exploration of the motivations and concepts of CoMP, the authors present the architectures of a CoMP system. Practical implementation and operational challenges of CoMP are discussed in detail. Also included is a review of CoMP architectures and deployment scenarios in the LTE-Advanced standard. Readers are exposed to the latest multiuser precoding designs for the CoMP system under two operating modes, interference aware and interference coordination. Wireless Coordinated Multi cell Systems: Architectures and Precoding Designs is a concise and approachable tool for researchers, professionals and advanced-level students interested in wireless communications and networks.

Download or read book Interference Calculus written by Martin Schubert and published by Springer Science & Business Media. This book was released on 2011-11-20 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book develops a mathematical framework for modeling and optimizing interference-coupled multiuser systems. At the core of this framework is the concept of general interference functions, which provides a simple means of characterizing interdependencies between users. The entire analysis builds on the two core axioms scale-invariance and monotonicity. The proposed network calculus has its roots in power control theory and wireless communications. It adds theoretical tools for analyzing the typical behavior of interference-coupled networks. In this way it complements existing game-theoretic approaches. The framework should also be viewed in conjunction with optimization theory. There is a fruitful interplay between the theory of interference functions and convex optimization theory. By jointly exploiting the properties of interference functions, it is possible to design algorithms that outperform general-purpose techniques that only exploit convexity. The title “network calculus” refers to the fact that the theory of interference functions constitutes a generic theoretical framework for the analysis of interference coupled systems. Certain operations within the framework are “closed”, that is, combinations of interference functions are interference functions again. Also, certain properties are preserved under such operations. This, provides a methodology for analyzing different multiuser performance measures that can be expressed as interference functions or combinations of interference functions.

Download or read book Handbook of Green Information and Communication Systems written by Alagan Anpalagan and published by Academic Press. This book was released on 2012-11-20 with total page 815 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a comprehensive guide on the fundamental concepts, applications, algorithms, protocols, new trends and challenges, and research results in the area of Green Information and Communications Systems. It is an invaluable resource giving knowledge on the core and specialized issues in the field, making it highly suitable for both the new and experienced researcher in this area. Key Features: Core research topics of green information and communication systems are covered from a network design perspective, giving both theoretical and practical perspectives Provides a unified covering of otherwise disperse selected topics on green computing, information, communication and networking Includes a set of downloadable PowerPoint slides and glossary of terms for each chapter A ‘whose-who’ of international contributors Extensive bibliography for enhancing further knowledge Coverage includes: Smart grid technologies and communications Spectrum management Cognitive and autonomous radio systems Computing and communication architectures Data centres Distributed networking Cloud computing Next generation wireless communication systems 4G access networking Optical core networks Cooperation transmission Security and privacy Core research topics of green information and communication systems are covered from a network design perspective, giving both a theoretical and practical perspective A ‘whose-who’ of international contributors Extensive bibliography for enhancing further knowledge

Download or read book Personal Wireless Communications Pwc 05 Proceedings Of The 10th Ifip Conference written by Pascal Lorenz and published by World Scientific. This book was released on 2005-07-07 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 10th IFIP International Conference on Personal Wireless Communications covers a wide spectrum: wireless sensors, signalization, traffic and QoA in wireless networks, Ad-Hoc, IEEE 802.11, cellular and mobile networks. This volume offers a large range of solutions to key problems in wireless networking and explores challenging avenues for industrial research and development. It is accessible to engineers, practitioners, and scientists as well as industry professionals from manufacturers to service providers.

Download or read book Design and Performance of 3G Wireless Networks and Wireless LANs written by Mooi Choo Chuah and published by Springer Science & Business Media. This book was released on 2005-12-12 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presentation of background material of wireless communications, traffic modeling and traffic engineering techniques. Provides descriptions of upcoming features such as IP multimedia subsystems, multimedia broadcast/multicast services and Push-to-Talk over Cellular (PoC) for 3G networks Including problems at the end of each chapter Written for lecturers, graduate students and system designers

Download or read book Algorithms for Next Generation Networks written by Graham Cormode and published by Springer Science & Business Media. This book was released on 2010-02-06 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data networking now plays a major role in everyday life and new applications continue to appear at a blinding pace. Yet we still do not have a sound foundation for designing, evaluating and managing these networks. This book covers topics at the intersection of algorithms and networking. It builds a complete picture of the current state of research on Next Generation Networks and the challenges for the years ahead. Particular focus is given to evolving research initiatives and the architecture they propose and implications for networking. Topics: Network design and provisioning, hardware issues, layer-3 algorithms and MPLS, BGP and Inter AS routing, packet processing for routing, security and network management, load balancing, oblivious routing and stochastic algorithms, network coding for multicast, overlay routing for P2P networking and content delivery. This timely volume will be of interest to a broad readership from graduate students to researchers looking to survey recent research its open questions.

Download or read book Improving Efficiency of Wireless Networks Using Network Optimized Beamforming Virtual Terrain Leveling and High performance Computing written by Vinay Bharadwaj Ramakrishnaiah and published by . This book was released on 2018 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communication is sensitive to ambient noise as well as interference due to the use of a shared medium, unlike wired communication. The range of frequencies used for wireless communication is limited, which prompts the reuse of frequencies causing increased interference. Wireless devices are often portable or mobile units with limited battery capacity, which makes effective low-power communication in harsh noise environments a high priority. In addition, wireless communication is significantly affected by the surrounding terrain like buildings, hills, foliage, etc. Many of these problems can be addressed through careful antenna design. Typically, omni-directional antennas are used in wireless communication due to their relative simplicity. These antennas radiate signal equally in all directions resulting in a waste of transmitter power and a source of interference to other nodes. More sophisticated techniques are available, but these can be challenging as they require complex software, which in turn demands powerful and expensive hardware. Use of adaptive directional antenna arrays can minimize interference while also being more energy efficient. Such “smart antennas” use digital beamforming based on signal processing algorithms to compute the appropriate weights to form effective antenna patterns. Smart antennas require the knowledge of the signal received at each antenna in the antenna array, thereby increasing the complexity of hardware and cost. Analog beamforming is a low hardware complexity alternative to smart antennas, which relies on a single transceiver and power splitter/combiner. Computer controlled analog amplifiers and phase shifters are used to form the desired beam patterns. The disadvantage of analog beamforming is that the computer only has access to the combined signals in the antenna array. We use analog beamforming in our implementation along with Noise-to-Signal ratio of nearby communicating nodes to mitigate this disadvantage. Conventional smart antennas optimize results for each individual node, while it is preferable to have a global optimal solution. It is also possible to compute the antenna array weights to adapt to the radio propagation characteristics of the surrounding terrain. This requires the knowledge of path loss at various distances and directions from the transmitter calculated using one of several available path loss models to compute a radio propagation map. This research has the following objectives: The first objective is to develop a new analog beamforming technique using Noise-to-Signal ratio as the performance measure. An iterative algorithm is developed that uses distributed node information along with analog beamforming, instead of individual antenna information. The antenna weights are sequentially adjusted across all nodes in the route to achieve optimization across the network. This provides a network optimized, low cost and hardware complexity solution for adaptive beamforming. The second objective is to explore another novel method called Virtual Terrain Leveling (VTL) where the effects of the terrain are virtually nullified using antenna arrays up to a specified distance from the transmitter. This work investigates whether VTL can mitigate the difficulties that the terrain features pose for implementation of wireless networks by attempting to provide uniform propagation in the presence of terrain with the use of directional antennas. The final objective is to use high performance computing (HPC) to develop more efficient storage and processing of radio propagation maps. Processing and storage of radio propagation maps can be computationally intensive based on the area and the resolution of the map. The technique of adaptive region construction is developed to efficiently store radio propagation maps while preserving the shape of the external contour for a given set of points. A GPU implementation of the algorithm with optimizations tailored to the hardware shows possible near - real time performance.

Download or read book Dynamic Spectrum Management written by Ying-Chang Liang and published by Springer Nature. This book was released on 2019-11-02 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book, authored by a world-leading researcher in this field, describes fundamentals of dynamic spectrum management, provides a systematic overview on the enabling technologies covering cognitive radio, blockchain, and artificial intelligence, and offers valuable guidance for designing advanced wireless communications systems. This book is intended for a broad range of readers, including students and professionals in this field, as well as radio spectrum policy makers.

Download or read book Wireless Network Performance Enhancement via Directional Antennas Models Protocols and Systems written by John D. Matyjas and published by CRC Press. This book was released on 2015-11-18 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Directional antenna technologies have made significant advancements in the last decade. These advances have opened the door to many exciting new design opportunities for wireless networks to enhance quality of service (QoS), performance, and network capacity. In this book, experts from around the world present the latest research and development in