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During the past decade, many wireless communication techniques have been developedto achievevariousgoals suchas higherdata rate,morerobustlink quality, and higher number of users in a given bandwidth. For wireless communication systems, depending on the availability of a feedback link, two approaches can be considered: namely open and closed loop. Open loop communication system that does not exploit the channel knowledge at the transmitter is now well understood from both a theoretical and practical point of view.
標簽： Communication Strategies Feedback Wireless for
上傳時間： 2020-05-27
上傳用戶：shancjb
With the rapid expansion of wireless consumer products,there has been a con- siderable increase in the need for radio-frequency (RF) planning, link plan- ning, and propagation modeling.A network designer with no RF background may find himself/herself designing a wireless network. A wide array of RF planning software packages can provide some support, but there is no substi- tute for a fundamental understanding of the propagation process and the lim- itations of the models employed. Blind use of computer-aided design (CAD) programs with no understanding of the physical fundamentals underlying the process can be a recipe for disaster. Having witnessed the results of this approach, I hope to spare others this frustration.
標簽： Introduction Propagation to RF
上傳時間： 2020-05-27
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By definition, the term “mobile-radio communications” describes any radio communication link between two terminals of which one or both are in motion or halted at unspecified locations and of which one may actually be a fixed terminal such as a base station. This definition applies to both mobile-to-mobile and mobile-to-fixed radio communica- tion links. The mobile-to-mobile link could in fact consist of a mobile- to-fixed-to-mobile radio communication link.The term “mobile” applies to land vehicles, ships at sea, aircraft, and communications satellites. In tactical situations, mobile-radio systems may include any or all of these types of mobile terminals.
標簽： Communications Engineering Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
Optical wireless communication is an emerging and dynamic research and development area that has generated a vast number of interesting solutions to very complicated communication challenges. For example, high data rate, high capacity and minimum interference links for short-range communication for inter-building communication, computer-to-computer communication, or sensor networks. At the opposite extreme is a long-range link in the order of millions of kilometers in the new mission to Mars and other solar system planets.
標簽： Communication Wireless Optical Systems
上傳時間： 2020-05-31
上傳用戶：shancjb
Ever since ancient times, people continuously have devised new techniques and technologies for communicating their ideas, needs, and desires to others. Thus, many forms of increasingly complex communication systems have appeared over the years. The basic motivations behind each new one were to improve the transmission fidelity so that fewer errors occur in the received message, to increase the transmission capacity of a communication link so that more infor- mation could be sent, or to increase the transmission distance between relay sta- tions so that messages can be sent farther without the need to restore the signal fidelity periodically along its path.
標簽： Communications Essentials Optical
上傳時間： 2020-05-31
上傳用戶：shancjb
Wireless means different things to different people. For this book, it refers to the radio systems that provide point-to-point, point-to-multipoint, and Earth-space communications over transmission links that propagate outside buildings through the lower atmosphere. Wireless systems are being built that provide data transmission between computers and other devices on one’s own desk. These are part of the wireless world but not the part where, except for interference perhaps, the atmosphere has any influence. The intent of this book is to provide a description of the physical phenomena that can affect propagation through the atmosphere, present sample measurements and statistics, and provide models that system designers can use to calculate their link budgets and estimate the limitations the atmosphere may place on their design.
標簽： Communication Propagation Handbook Wireless for
上傳時間： 2020-05-31
上傳用戶：shancjb
The book is written for those concerned with the design and performance of satellite communications systems employed in fixed point-to-point, broadcasting, mobile, radio- navigation,data-relay,computercommunications,andrelatedsatellite-basedapplications.The recentrapidgrowthinsatellitecommunicationshascreatedaneedforaccurateinformationon both satellite communications systems engineering and the impact of atmospheric effects on satellite link design and system performance. This book addresses that need for the first time in a single comprehensive source.
標簽： Communications Satellite Systems
上傳時間： 2020-06-01
上傳用戶：shancjb
A wireless communication network can be viewed as a collection of nodes, located in some domain, which can in turn be transmitters or receivers (depending on the network considered, nodes may be mobile users, base stations in a cellular network, access points of a WiFi mesh etc.). At a given time, several nodes transmit simultaneously, each toward its own receiver. Each transmitter–receiver pair requires its own wireless link. The signal received from the link transmitter may be jammed by the signals received from the other transmitters. Even in the simplest model where the signal power radiated from a point decays in an isotropic way with Euclidean distance, the geometry of the locations of the nodes plays a key role since it determines the signal to interference and noise ratio (SINR) at each receiver and hence the possibility of establishing simultaneously this collection of links at a given bit rate. The interference seen by a receiver is the sum of the signal powers received from all transmitters, except its own transmitter.
標簽： Stochastic Geometry Networks Wireless Volume and II
上傳時間： 2020-06-01
上傳用戶：shancjb
T his book covers basic communications theory and practical imple- mentation of transmitters and receivers. In so doing, I focus on dig- ital modulation, demodulation methods, probabilities, detection of digital signals, and spread spectrum system design and analysis. This book was written for those who want a good understanding of the basic prin- ciples of digital wireless communication systems, including spread spec- trum techniques. This book also provides a good intuitive and practical approach to digital communications. Therefore it is a valuable resource for anyoneinvolvedinwirelesscommunicationsandtransceiverdesignfordig- ital communications. The reader will gain a broad understanding of basic communication principles for transceiver design, digital communications, and spread spectrum, along with examples of many types of commercial and military data link systems.
標簽： Transceiver System Design
上傳時間： 2020-06-01
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An acronym for Multiple-In, Multiple-Out, MIMO communication sends the same data as several signals simultaneously through multiple antennas, while still utilizing a single radio channel. This is a form of antenna diversity, which uses multiple antennas to improve signal quality and strength of an RF link. The data is split into multiple data streams at the transmission point and recombined on the receive side by another MIMO radio configured with the same number of antennas. The receiver is designed to take into account the slight time difference between receptions of each signal, any additional noise or interference, and even lost signals.
標簽： Understanding_the_Basics_of_MIMO
上傳時間： 2020-06-01
上傳用戶：shancjb
