Description : This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spectrum system is the code synchronization, which is usually broken down into the operations of acquisition and tracking. Means for performing these operations are discussed next. Finally, the performance of spread spectrum systems is of fundamental interest and the effect of jamming is considered, both without and with the use of forward error correction coding. The presentation ends with consideration of spread spectrum systems in the presence of other users.
Description : This textbook provides a concise but lucid explanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles. The choice of specific topics is tempered by the author’s judgment of their practical significance and interest to both researchers and system designers. Throughout the book, learning is facilitated by many new or streamlined derivations of the classical theory. Problems at the end of each chapter are intended to assist readers in consolidating their knowledge and to provide practice in analytical techniques. This third edition includes new coverage of topics such as CDMA networks, Acquisition and Synchronization in DS-CDMA Cellular Networks, Hopsets for FH-CDMA Ad Hoc Networks, and Implications of Information Theory, as well as updated and revised material on Central Limit Theorem, Power Spectral Density of FH/CPM Complex Envelopes, and Anticipative Adaptive-Array Algorithm for Frequency-Hopping Systems.
Description : This book provides a concise but lucid explanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles. Throughout the book, learning is facilitated by many new or streamlined derivations of the classical theory. Problems at the end of each chapter are intended to assist readers in consolidating their knowledge and to provide practice in analytical techniques. The choice of specific topics is tempered by the author’s judgment of their practical significance and interest to both researchers and system designers. The evolution of spread spectrum communication systems and the prominence of new mathematical methods in their design provided the motivation to undertake this new edition of the book. This edition is intended to enable readers to understand the current state-of-the-art in this field. More than 20 percent of the material in this edition is new, including a chapter on systems with iterative channel estimation, and the remainder of the material has been thoroughly revised.
Description : This book will provide the reader with a concise introduction to the use of spread spectrum waveforms in multiple user systems, often termed code division multiple access or CDMA. Code Division Multiple Access (CDMA) is appropriate for courses on spread spectrum, advanced digital communication or multiple access, and also for professional engineers in need of a basic understanding of CDMA.Readers are expected to have a fundamental understanding of digital communications, wireless systems, stochastic processes, detection theory, and communication theory. The book builds on these fundamentals by explaining how spread spectrum systems differ from standard digital communication systems, and more importantly, how spread spectrum waveforms are used as a means of channelization in a multiple user scenario.Key Features:* Demonstrates the difference between CDMA and the more widely understood techniques as time division multiple access (TDMA), frequency division multiple access (FDMA), and carrier sense multiple access (CSMA)* Reviews basic spread spectrum techniques such as direct sequence spread spectrum, frequency-hopped spread spectrum and time hopping approaches* Presents four basic principles of cellular CDMA systems: interference averaging, universal frequency reuse, soft handoff, and statistical multiplexing* Examines CDMA system functions such as power control, mobile-assisted hand-off, load control and admission control* Discusses spread spectrum based packet radio networks (PRNs), emphasizing spreading code assignment techniques* Covers multi-user detection algorithms, including both linear and non-linear techniques
Description : Frequency spectrum is a limited and valuable resource for wireless communications. A good example can be observed among network operators in Europe for the prices to pay for UMTS-frequency bands. Therefore, the first goal when designing future wireless communication systems (e.g. 4G - fourth generation) has to be the increase in spectral efficiency. The development in digital communications in the past years has enabled efficient modulation and coding techniques for robust and spectral efficient data, speech, audio and video transmission. These are the multi-carrier modulation (e.g. OFDM) and the spread spectrum technique (e.g. DS-CDMA), where OFDM was chosen for broadcast applications (DVB, DAB) as well as for broadband wireless indoor standards (ETSI HIPERLAN-II, IEEE-802.11) and the DS-CDMA was selected in mobile communications (IS-95, third generation mobile radio systems world wide, UMTS/IMT 2000). Since 1993 various combinations of multi-carrier (MC) modulation and the spread spectrum (SS) technique have been introduced and the field of MC-SS communications has become an independent and important research topic with increasing activities. New application fields have been proposed such as high rate cellular mobile, high rate wireless indoor and LMDS. It has been shown that MC-SS offers the high spectral efficiency, robustness and flexibility that is required for the next generation systems. Meanwhile, different alternative hybrid schemes such as OFDM/OFDMA, MC-TDMA, etc. have been deeply analysed and adopted in different international standards (ETSI-BRAN, IEEE-802 & MMAC). Multi-Carrier & Spread-Spectrum: Analysis of Hybrid Air Interfaces draws together all of the above mentioned hybrid schemes therefore providing a greatly needed resource for system engineers, telecommunication designers and researchers in order to enable them to develop, build and deploy several schemes based on MC-transmission for the next generation systems (which will be an integration of broadband multimedia services covering both 4G mobile and fixed wireless systems). * Offers a complete treatment of multi-carrier, spread-spectrum (SS) and time division multiplexing (TDM) techniques * Provides an in-depth insight into hybrid multiple access techniques based on multi-carrier (MC) transmission * Presents numerous hybrid multiple access and air interface architectures including OFDM/CDMA, MC-CDMA, MC-DS-CDMA and MT-CDMA * Covers new techniques such as space-time coding and software radio Telecommunications engineers, hardware & software system designers and researchers as well as students, lecturers and technicians will all find this an invaluable addition to their bookshelf.
Description : A broad introduction to the fundamentals of wirelesscommunication engineering technologies Covering both theory and practical topics, Fundamentals ofWireless Communication Engineering Technologies offers a soundsurvey of the major industry-relevant aspects of wirelesscommunication engineering technologies. Divided into four mainsections, the book examines RF, antennas, and propagation; wirelessaccess technologies; network and service architectures; and othertopics, such as network management and security, policies andregulations, and facilities infrastructure. Helpfulcross-references are placed throughout the text, offeringadditional information where needed. The book provides: Coverage that is closely aligned to the IEEE's WirelessCommunication Engineering Technologies (WCET) certification programsyllabus, reflecting the author's direct involvement in the development of theprogram A special emphasis on wireless cellular and wireless LANsystems An excellent foundation for expanding existing knowledge in thewireless field by covering industry-relevant aspects of wirelesscommunication Information on how common theories are applied in real-worldwireless systems With a holistic and well-organized overview of wirelesscommunications, Fundamentals of Wireless CommunicationEngineering Technologies is an invaluable resource for anyoneinterested in taking the WCET exam, as well as practicingengineers, professors, and students seeking to increase theirknowledge of wireless communication engineering technologies.
Description : Spread spectrum multiple access communication, known commercially as CDMA (Code Division Multiple Access), is a driving technology behind the rapidly advancing personal communications industry. Its greater bandwidth efficiency and multiple access capabilities make it the leading technology for relieving spectrum congestion caused by the explosion in popularity of cellular mobile and fixed wireless telephones and wireless data terminals. Written by a leader in the creation of CDMA and an internationally recognized authority on wireless digital communication, this book gives you the technical information you need. It presents the fundamentals of digital communications and covers all aspects of commercial direct-sequence spread spectrum technology, incorporating both physical-level principles and network concepts. You will find detailed information on signal generation, synchronization, modulation, and coding of direct-sequence spread spectrum signals. In addition, the book shows how these physical layer functions relate to link and network properties involving cellular coverage, Erlang capacity, and network control. With this book, you will attain a deeper understanding of personal communications system concepts and will be better equipped to develop systems and products at the forefront of the personal wireless communications market.
Description : Learn the fundamentals of efficient design and management of state-of-the-art mobile data networks with this unique and comprehensive text.
Description : Spread spectrum and CDMA are cutting-edge technologies widely used in operational radar, navigation and telecommunication systems and play a pivotal role in the development of the forthcoming generations of systems and networks. This comprehensive resource presents the spread spectrum concept as a product of the advancements in wireless IT, shows how and when the classical problems of signal transmission/processing stimulate the application of spread spectrum, and clarifies the advantages of spread spectrum philosophy. Detailed coverage is provided of the tools and instruments for designing spread spectrum and CDMA signals answering why a designer will prefer one solution over another. The approach adopted is wide-ranging, covering issues that apply to both data transmission and data collection systems such as telecommunications, radar, and navigation. Presents a theory-based analysis complemented by practical examples and real world case studies resulting in a self-sufficient treatment of the subject Contains detailed discussions of new trends in spread spectrum technology such as multi-user reception, multicarrier modulation, OFDM, MIMO and space-time coding Provides advice on designing discrete spread spectrum signals and signal sets for time-frequency measuring, synchronization and multi-user communications Features numerous Matlab-based problems and other exercises to encourage the reader to initiate independent investigations and simulations This valuable text provides timely guidance on the current status and future potential of spread spectrum and CDMA and is an invaluable resource for senior undergraduates and postgraduate students, lecturers and practising engineers and researchers involved in the deployment and development of spread spectrum and CDMA technology. Supported by a Companion website on which instructors and lecturers can find a solutions manual for the problems and Matlab programming, electronic versions of some of the figures and other useful resources such as a list of abbreviations.
Description : Underwater vehicles and underwater moorings are increasing in tactical importance. As such, it is critical to have a robust and secure communication system connecting underwater vehicles on a long seaborne mission and a ground station. As a matter of fact, the deployment of efficient communication links with underwater vehicles is one of the greatest technological challenges presently confronted by the world's naval forces. To circumvent most of the limitations involved in the use of RF or acoustic channels for perfectly secure communications with underwater vehicles, it is worth considering the feasibility of an optical channel to facilitate a two-way satellite communication link secured via perfectly secure ciphers enabled by a quantum key distribution protocol. This book offers a concise review of underwater communications systems. Our approach is pedagogical, making a strong emphasis on the physics behind the attenuating properties of the oceanic environment and the propagation of electromagnetic signals in the ELF, VLF, and optical bands. We assume the reader is familiar with the basic principles of classical electrodynamics and optics. The system design, components, and noise analysis of an underwater optical communications device are discussed in detail. Furthermore, we offer simulations of the performance of the communication system for different types of ocean waters. Our final conclusion is that it appears to be feasible to design and build underwater communications using optical classical and quantum channels secured with quantum key distribution protocols.