Описание: This book focuses on the issue of optimizing radio resource allocation (RRA) and user admission control (AC) for multiple multicasting sessions on a single high altitude platform (HAP) with multiple antennas on-board. HAPs are quasi-stationary aerial platforms that carry a wireless communications payload to provide wireless communications and broadband services. They are meant to be located in the stratosphere layer of the atmosphere at altitudes in the range 17-22 km and have the ability to fly on demand to temporarily or permanently serve regions with unavailable telecommunications infrastructure. An important requirement that the book focusses on is the development of an efficient and effective method for resource allocation and user admissions for HAPs, especially when it comes to multicasting. Power, frequency, space (antennas selection) and time (scheduling) are the resources considered in the problem over an orthogonal frequency division multiple access (OFDMA) HAP system. Due to the strong dependence of the total number of users that could join different multicast groups, on the possible ways we may allocate resources to these groups, it is of significant importance to consider a joint user to session assignments and RRA across the groups. From the service provider's point of view, it would be in its best interest to be able to admit as many higher priority users as possible, while satisfying their quality of service requirements. High priority users could be users subscribed in and paying higher for a service plan that gives them preference of admittance to receive more multicast transmissions, compared to those paying for a lower service plan. Also, the user who tries to join multiple multicast groups (i.e. receive more than one multicast transmission), would have preferences for which one he would favor to receive if resources are not enough to satisfy the QoS requirements. Technical topics discussed in the book include: Overview on High Altitude Platforms, their different types and the recent works in this area Radio Resource Allocation and User Admission Control in HAPs Multicasting in a Single HAP System: System Model and Mathematical Formulation Optimization schemes that are designed to enhance the performance of a branch and bound technique by taking into account special mathematical structure in the problem formulation
Описание: In recent years, a considerable amount of effort has been devoted, both in industry and academia, toward the efficient utilization of the available spectrum under the various propagation models which lead toward the design and dimensioning of the future network Internet of Things (IoT).
This book focuses on Television White Space (TVWS) opportunities and regulatory aspects for cognitive radio applications. It includes case studies for the exploitation of TVWS depending on user's mobility and the geo-location between user and the Base Station. The book presents recent advances in spectrum sensing, reflecting state-of-the-art technology and research achievements in this area, as well as new insights in spectrum sensing of performance modeling, analysis, and worldwide applications.
Technical topics discussed include: - Novel Application of TV White Space - Spectrum Sensing in Cognitive Radio - Cooperative Spectrum Sensing - DoA Estimation Algorithms
Описание: A unified treatment of the latest game theoretic approaches for designing, modeling, and optimizing emerging wireless communication networks. Covering theory, analytical tools, and applications, it is ideal for researchers and graduate students in academia and industry designing efficient, scalable and robust protocols for future wireless networks.
Автор: Cripps, Steve C. Название: Rf power amplifiers for wireless communications ISBN: 1596930187 ISBN-13(EAN): 9781596930186 Издательство: Artech House Рейтинг: Цена: 25872.00 р. Наличие на складе: Есть у поставщика Поставка под заказ.
Описание: Offers practitioners a comprehensive, practical understanding of how to tackle a PA (power amplifier) design with confidence and quickly determine the cause of malfunctioning hardware. Supported with nearly 200 illustrations, this book contains the survey of RF PA efficiency enhancement and linearization techniques.
Автор: Petrovski Название: GPS, GLONASS, Galileo, and BeiDou for Mobile Devices ISBN: 1107035848 ISBN-13(EAN): 9781107035843 Издательство: Cambridge Academ Рейтинг: Цена: 15523.00 р. Наличие на складе: Поставка под заказ.
Описание: Get up to speed on all types of GNSS for mobile applications. With step-by-step algorithms and practical methods you will understand the capabilities of current systems and be able to apply your new knowledge to unlocking the potential of future mobile positioning.
The bestselling CWNA study guide, updated for the latest exam
The CWNA: Certified Wireless Network Administrator Study Guide is the ultimate preparation resource for the CWNA exam.
Автор: Grebennikov Название: Broadband RF and Microwave Amplifiers ISBN: 1138800201 ISBN-13(EAN): 9781138800205 Издательство: Taylor&Francis Рейтинг: Цена: 12554.00 р. Наличие на складе: Поставка под заказ.
Описание:
Broadband RF and Microwave Amplifiers provides extensive coverage of broadband radio frequency (RF) and microwave power amplifier design, including well-known historical and recent novel schematic configurations, theoretical approaches, circuit simulation results, and practical implementation strategies. The text begins by introducing two-port networks to illustrate the behavior of linear and nonlinear circuits, explaining the basic principles of power amplifier design, and discussing impedance matching and broadband power amplifier design using lumped and distributed parameters. The book then:
Shows how dissipative or lossy gain-compensation-matching circuits can offer an important trade-off between power gain, reflection coefficient, and operating frequency bandwidth
Describes the design of broadband RF and microwave amplifiers using real frequency techniques (RFTs), supplying numerous examples based on the MATLAB(R) programming process
Examines Class-E power amplifiers, Doherty amplifiers, low-noise amplifiers, microwave gallium arsenide field-effect transistor (GaAs FET)-distributed amplifiers, and complementary metal-oxide semiconductor (CMOS) amplifiers for ultra-wideband (UWB) applications
Broadband RF and Microwave Amplifiers combines theoretical analysis with practical design to create a solid foundation for innovative ideas and circuit design techniques.
Описание: Design of Digital Phase Shifters for Multipurpose Communication Systems covers a new emerging need in designing digital phase shifters for modern communication systems. With the advancement of new generation mobile communication systems, directed beams save a substantial amount of RF-power, and improve the noise immunity. In this regard, beam-forming circuits, namely, digital phase shifters constitute essential parts of the antenna arrays. Therefore, this book is devoted to design of digital phase shifters for various communications systems. In the good old days, phase shifter design requirements used to demand narrow bandwidth with no physical size constraints. Nowadays, they must be compact and suitable for Very Large Scale Integrated Circuits (VLSI) or Microwave Monolithic Integrated Circuit (MMIC) implementation with Wide Phase Range (WPR) and Wide Frequency Band (WFB). Since the 1980s, the author has been designing digital phase shifters for various applications. He started to work with loaded lines phase shifters, and then employed branch line couplers to achieve wider frequency bands. In order to reduce the physical size, he used a 3 element Symmetric LC ladder based T or PI configurations. In order to achieve broad frequency band with large phase range, usage of LC lattice structures is inevitable. Lately, the author designed phase shifters using both lowpass and highpass LC ladder and lattice based switched-structures, which are suitable for monolithic implementation. In the course of design, MOS transistors were employed as switching elements. This book includes several novel digital phase shifter topologies, which provides wide phase range and wideband operation. Technical topics discussed in the book include:
Basic Concept of Antenna Arrays
Concept of Digital Phase Bit
Scattering Parameters to analyze the electric performance of phase shifters
Transmission Lines as circuit elements to construct practical phase shifters
Loaded Line Digital Phase Shifters (DPS)
Lowpass Based T/PI Section DPS
Highpass Based T/PI Section DPS
3-Element LC T/PI Section DPS
Wide Phase Range, Wide Frequency Band Symmetric Lattice Based DPS
For each topology presented, explicit design equations are provided and programs to assess the electric performance of each topology is developed in a MatLab environment. It is expected that the reader will be self-sufficient to design and implement the digital phase shifters topologies presented in this book.
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