This book focuses on the study and development of one of the most advanced topics in broadband wireless communications systems: power efficiency and power consumption in wireless communications systems, especially of mobile devices. Hence, the main focus of this book is on the most recent techniques for the conservation of power and increase in power efficiency.
标签： Communications Efficiency Broadband Power in
上传时间： 2020-05-31
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This edition updates and continues the series of books based on the residential courses on radiowave propagation organised by the IEE/IET. The first course was held in 1974, with lectures by H. Page, P. Matthews, D. Parsons, M.W. Gough, P.A. Watson, E. Hickin, T. Pratt, P. Knight, T.B. Jones, P.A. Bradley, B. Burgess and H. Rishbeth.
标签： Propagation Radiowaves edition 3rd of
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This book provides the essential design techniques for radio systems that operate at frequencies of 3 MHz to 100 GHz and which will be employed in the telecommunication service. We may also call these wireless systems, wireless being synonymous with radio, Telecommunications is a vibrant indus- try, particularly on the ‘‘radio side of the house.’’ The major supporter of this upsurge in radio has been the IEEE and its 802 committees. We now devote Ž . an entire chapter to wireless LANs WLANs detailed in IEEE 802.11. We also now have subsections on IEEE 802.15, 802.16, 802.20 and the wireless Ž . Ž metropolitan area network WMAN . WiFi, WiMax,, and UWB ultra wide- . band are described where these comparatively new radio specialties are demonstrating spectacular growth.
标签： Telecommunication Design System Radio for
上传时间： 2020-06-01
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An understanding of the policies, regulations, standards and techniques of radio spectrum management is useful to those who manage and administrate it, to operators, to equipment providers and to the users of wireless communication (i.e., all of us). For many years the author has been deeply involved in ruling the RF spectrum at the national, regional and global levels. The book is based on the professional experience of the author, his academic courses, presenta- tions and tutorials in five continents. The book reflects this legacy and will be of use to engineers, lawyers and economists, who serve the global industry of the wireless world; in it they may find solutions to the problems they frequently encounter.
标签： Management Spectrum Radio
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The multiple-input multiple-output (MIMO) technique provides higher bit rates and better reliability in wireless systems. The efficient design of RF transceivers has a vital impact on the implementation of this technique. This first book is com- pletely devoted to RF transceiver design for MIMO communications. The book covers the most recent research in practical design and applications and can be an important resource for graduate students, wireless designers, and practical engineers.
标签： Transceiver Design RF
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With the advent of IMT-2000, CDMA has emerged at the focal point of interest in wireless communications. Now it has become impossible to discuss wireless communications without knowing the CDMA technologies. There are a number of books readily published on the CDMA technologies, but they are mostly dealing with the traditional spread-spectrum technologies and the IS-95 based CDMA systems. As a large number of novel and interesting technologies have been newly developed throughout the IMT-2000 standardization process in very recent years, new reference books are now demanding that address the diverse spectrum of the new CDMA technologies.
标签： Communications Scrambling Techniques CDMA for
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Convergence between the two largest networks (Telecom and IP) is taking place very rapidly and at diff erent levels: (1) network level: unifi cation of IP networks with traditional Telecom networks through evolving standards (Session Initiation Protocol (SIP), Realtime Transfer Protocol (RTP), SS7, 3G) to support interopera- bility; (2) service level: traditional Telecom services like voice calls are being provi- sioned on the IP backbone (VoIP), while traditional IP services (most data-driven services such as multimedia, browsing, chatting, gaming, etc.) are accessible over the Telecom network.
标签： Platforms Delivery Service
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Short-range communications is one of the most relevant as well as diversified fields of en- deavour in wireless communications. As such, it has been a subject of intense research and development worldwide, particularly in the last decade. There is no reason to believe that this trend will decline. On the contrary, the rapidly crystallizing vision of a hyper-connected world will certainly strengthen the role of short-range communications in the future. Concepts such as wireless social networks, Internet of things, car communications, home and office network- ing, wireless grids and personal communications heavily rely on short-range communications technology.
标签： Communications Short-Range Wireless
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This paper presents a Hidden Markov Model (HMM)-based speech enhancement method, aiming at reducing non-stationary noise from speech signals. The system is based on the assumption that the speech and the noise are additive and uncorrelated. Cepstral features are used to extract statistical information from both the speech and the noise. A-priori statistical information is collected from long training sequences into ergodic hidden Markov models. Given the ergodic models for the speech and the noise, a compensated speech-noise model is created by means of parallel model combination, using a log-normal approximation. During the compensation, the mean of every mixture in the speech and noise model is stored. The stored means are then used in the enhancement process to create the most likely speech and noise power spectral distributions using the forward algorithm combined with mixture probability. The distributions are used to generate a Wiener filter for every observation. The paper includes a performance evaluation of the speech enhancer for stationary as well as non-stationary noise environment.
标签： Telecommunications Processing Signal for
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Software Radio (SR) is one of the most important emerging technologies for the future of wireless communication services. By moving radio functionality into software, it promises to give flexible radio systems that are multi-service, multi- standard, multi-band, reconfigurable and reprogrammable by software. Today’s radios are matched to a particular class of signals that are well defined bytheircarrierfrequencies,modulationformatsandbandwidths.Aradiotransmitter today can only up convert signals with well-defined bandwidths over defined center frequencies, while, on the other side of the communication chain, a radio receiver can only down convert well-defined signal bandwidths, transmitted over specified carrier frequencies.
上传时间： 2020-06-01
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