Free Space Optical Communication (FSOC) is an effective alternative technology to meet the Next Generation Network (NGN) demands as well as highly secured (mili- tary) communications. FSOC includes various advantages like last mile access, easy installation, free of Electro Magnetic Interference (EMI)/Electro Magnetic Compatibil- ity (EMC) and license free access etc. In FSOC, the optical beam PROPAGATION in the turbulentatmosphereisseverelyaffectedbyvariousfactorssuspendedinthechannel, geographicallocationoftheinstallationsite,terraintypeandmeteorologicalchanges. Therefore a rigorous experimental study over a longer period becomes significant to analyze the quality and reliability of the FSOC channel and the maximum data rate that the system can operate since data transmission is completely season dependent.
标签： Communication Optical System Space Free
上传时间： 2020-05-27
上传用户：shancjb
An optical fiber amplifier is a key component for enabling efficient transmission of wavelength-divisionmultiplexed(WDM)signalsoverlongdistances.Eventhough many alternative technologies were available, erbium-doped fiber amplifiers won theraceduringtheearly1990sandbecameastandardcomponentforlong-haulopti- caltelecommunicationssystems.However,owingtotherecentsuccessinproducing low-cost, high-power, semiconductor lasers operating near 1450 nm, the Raman amplifiertechnologyhasalsogainedprominenceinthedeploymentofmodernlight- wavesystems.Moreover,becauseofthepushforintegratedoptoelectroniccircuits, semiconductor optical amplifiers, rare-earth-doped planar waveguide amplifiers, and silicon optical amplifiers are also gaining much interest these days.
标签： PROPAGATION Light Media Gain in
上传时间： 2020-05-27
上传用户：shancjb
In the nineteenth century, scientists, mathematician, engineers and innovators started investigating electromagnetism. The theory that underpins wireless communications was formed by Maxwell. Early demonstrations took place by Hertz, Tesla and others. Marconi demonstrated the first wireless transmission. Since then, the range of applications has expanded at an immense rate, together with the underpinning technology. The rate of development has been incredible and today the level of technical and commercial maturity is very high. This success would not have been possible without understanding radio- wave PROPAGATION. This knowledge enables us to design successful systems and networks, together with waveforms, antennal and transceiver architectures. The radio channel is the cornerstone to the operation of any wireless system.
标签： LTE-Advanced Generation Next and
上传时间： 2020-05-27
上传用户：shancjb
When we started thinking about writing the first edition of this book a few years ago, we had been working together for more than five years on the borderline between PROPAGATION and signal processing. Therefore, it is not surprising that this book deals with PROPAGATION models and design tools for MIMO wireless communications. Yet, this book should constitute more than a simple combination of these two domains. It hopefully conveys our integrated understanding of MIMO, which results from endless controversial discussions on various multi-antenna related issues, as well as various interactions with numerous colleagues. Obviously, this area of technology is so large that it is beyond our aim to cover all aspects in details. Rather, our goal is to provide researchers, R&D engineers and graduate students with a comprehensive coverage of radio PROPAGATION models and space–time signal processing techniques for multi-antenna, multi-user and multi-cell networks.
上传时间： 2020-05-28
上传用户：shancjb
When we started thinking about writing this book, we had been working together for more than five years on the borderline between PROPAGATION and signal processing.Therefore, it is not surprising that this book deals with PROPAGATION models and design tools for MIMO wirelesscommunications.Yet, thisbookshouldconstitutemorethanasimplecombination of these two domains. It hopefully conveys our integrated understanding of MIMO, which results from endless controversial discussions on various multi-antenna related issues, as well as various interactions with numerous colleagues. Obviously, this area of technology is so large that it was beyond our aim to cover all aspects in details. Rather, our goal has been to provide researchers, R&D engineers and graduate students with a comprehensive coverage of radio PROPAGATION models and space–time coding techniques.
标签： Communications5 Wireless MIMO
上传时间： 2020-05-28
上传用户：shancjb
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： 2020-05-31
上传用户：shancjb
Some tine ago it become apparent the the first edition of this book was rapidly approaching its sell-by date,since many aspects needed revise.There were two obvious courses of action : to forget the whole thing and concentrate my energies on other pursuits such as golf or fishing, or to embark on a new edition.For several reasons Iwas persuaded that a new edition was a worthwhile endeavour;many people had made complimentary remakrs or written complinentary letters about the first edition and I understood that it had become a recommended text for several postgraduate coures.
标签： TMobile Radio PROPAGATION Channel
上传时间： 2020-06-01
上传用户：shancjb
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
上传用户：shancjb
The use of optical free-space emissions to provide indoor wireless commu- nications has been studied extensively since the pioneering work of Gfeller and Bapst in 1979 [1]. These studies have been invariably interdisciplinary in- volving such far flung areas such as optics design‚ indoor PROPAGATION studies‚ electronics design‚ communications systems design among others. The focus of this text is on the design of communications systems for indoor wireless optical channels. Signalling techniques developed for wired fibre optic net- works are seldom efficient since they do not consider the bandwidth restricted nature of the wireless optical channel.
标签： Communication Wireless Optical Systems
上传时间： 2020-06-01
上传用户：shancjb
