Wireless is one of the most rapidly developing technologies in our time, with dazzling new products and services emerging on an almost daily basis. These developments present enormous challenges for communications engineers, as the demand for increased wireless capacity grows explosively. Indeed, the discipline of wireless communications presents many challenges to designers that arise as a result of the demanding nature of the PHYsical medium and the complexities in the dynamics of the underlying network.
标签： Communications Wireless MIMO
上传时间： 2020-05-27
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Multi-carrier modulation‚ Orthogonal Frequency Division Multi- plexing (OFDM) particularly‚ has been successfully applied to a wide variety of digital communications applications over the past several years. Although OFDM has been chosen as the PHYsical layer standard for a diversity of important systems‚ the theory‚ algorithms‚ and implementation techniques remain subjects of current interest. This is clear from the high volume of papers appearing in technical journals and conferences.
标签： COMMUNICATIONS MULTI-CARRIER DIGITAL
上传时间： 2020-05-30
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Many wireless communications channels consist of multiple signal paths from the transmitter to receiver. This multiplicity of paths leads to a phenomenon known as multipath fading. The multiple paths are caused by the presence of objects in the PHYsical environment that, through the mechanisms of propagation, alter the path of radiated energy. These objects are referred to as scatterers. In the past, researchers often looked at ways to mitigate multipath scattering, such as in diversity systems. Multiple-input, multiple-output (MIMO) systems, on the other hand, use multipath diversity to their advantage; a MIMO system has the ability to translate increased spatial diversity into increased channel capacity.
标签： Multiple-Output Multiple-Input Channel Models
上传时间： 2020-05-30
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If you would like to follow along with some of the steps outlined in this book, we recommend that you deploy Live Communications Server 2005 SP1 on a PHYsical or virtual server running Microsoft Windows Server 2003. To run Communicator 2005, you will need a PHYsical or virtual PC running Windows XP or Windows Server 2003. To fully test Microsoft Office integration with Communicator 2005, you need to be running Microsoft Office 2003 with Service Pack 2.
标签： Communications Professional Server Live
上传时间： 2020-05-31
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The investigation of the propagation channel is becoming more and more important in mod- ern wireless communication. The demand for spectral efficiency motivates exploitation of all channels that can possibly be used for communications. Nowadays, a common trend for designing PHYsical layer algorithms is to adapt the transceiving strategy, either by maximizing the diversity gains or by utilizing the coherence of the channels to improve the signal-to-noise power ratio.
标签： Characterization Propagation Channel
上传时间： 2020-05-31
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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.
标签： Communication Propagation Handbook Wireless for
上传时间： 2020-05-31
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I love telecommunications. It is powerful and it empowers, with far-reaching consequences. It has demonstrated the potential to transform society and business, and the revolution has only just begun. With the invention of the telephone, human communications and commerce were forever changed: Time and distance began to melt away as a barrier to doing business, keeping in touch with loved ones, and being able to immediately respond to major world events. Through the use of computers and telecommunications networks, humans have been able to extend their powers of thinking, influence, and productivity, just as those in the Industrial Age were able to extend the power of their muscles, or PHYsical self, through use of heavy machinery.
标签： Telecommunications Essentials
上传时间： 2020-06-01
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Wireless communications has become a field of enormous scientific and economic interest. Recent success stories include 2G and 3G cellular voice and data services (e.g., GSM and UMTS), wireless local area networks (WiFi/IEEE 802.11x), wireless broadband access (WiMAX/IEEE 802.16x), and digital broadcast systems (DVB, DAB, DRM). On the PHYsical layer side, traditional designs typically assume that the radio channel remains constant for the duration of a data block. However, researchers and system designers are increasingly shifting their attention to channels that may vary within a block. In addition to time dispersion caused by multipath propagation, these rapidly time-varying channels feature frequency dispersion resulting from the Doppler effect. They are, thus, often referred to as being “doubly dispersive.”
标签： Time-Varying Channels
上传时间： 2020-06-01
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Driven by the rapid advancement of technology and the growing need of business requirements, cyber communications are embedded in many PHYsical systems. The integration of cyber and PHYsical capabilities leads to the creation of many applica- tions with enormous societal impact and economic benefit. The emerging systems that connect the cyber-world of computing and communications with the PHYsical world are cyber-PHYsical systems (CPS).
标签： Resiliency Analytics Security and
上传时间： 2020-06-07
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Sensors are points ofcontact betweenthe material world ofatoms, mass, andenergy and the seemingly immaterial world of information, computation, and cognition. Linking these two domains more tightly yields all sorts of practical benefits, such as improvedinputdevicesforcomputers,moreeffectivemedicaldevices(implantedor worn), more precise agricultural operations, better monitored buildings or bridges, more secure payment systems, and more reliable sensor–actuator control systems. There are many settings in which tighter coupling between digital and PHYsical planes can enhance safety, security, performance, and reliability.
标签： Computational RFID
上传时间： 2020-06-08
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