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.
標簽： LTE-Advanced Generation Next and
上傳時間： 2020-05-27
上傳用戶：shancjb
Nature is seldom kind. One of the most appealing uses for RADIO- telephone systems—communication with people on the move—must over- come RADIO transmission problems so difficult they challenge the imagina- tion. A microwave RADIO signal transmitted between a fixed base station and a moving vehicle in a typical urban environment exhibits extreme variations in both amplitude and apparent frequency.
標簽： Communications Microwave Mobile
上傳時間： 2020-05-28
上傳用戶：shancjb
Microwave RADIO network design is a subset of activities that constitute the overall transmission network design. Transmission networks are sometimes called transport networks, access networks, or connectivity networks. For many wireless carriers, microwave is becoming a popu- lar preference over wireline (leased lines) transport for many reasons, especially as microwave RADIO equipment costs decrease and installation becomes simpler. Low monthly operating costs can undercut those of typical single (and especially multiple) T1/E1 expenses, proving it to be more economical over the long term—usually two to four years. Network operators also like the fact that they can own and control microwave RADIO networks instead of relying on other service providers for network components.
標簽： Transmission Microwave Networks
上傳時間： 2020-05-28
上傳用戶：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.
上傳時間： 2020-05-28
上傳用戶：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.
標簽： Communications5 Wireless MIMO
上傳時間： 2020-05-28
上傳用戶：shancjb
At the macroscopic level of system layout, the most important issue is path loss. In the older mobile RADIO systems that are limited by receiver noise, path loss determines SNR and the maximum coverage area. In cellular systems, where the limiting factor is cochannel interference, path loss determines the degree to which transmitters in different cells interfere with each other, and therefore the minimum separation before channels can be reused.
標簽： Characteristics Channel Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
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
Since the principle of multi-carrier code division multiple access (MC-CDMA) was simultaneously proposed by Khaled Fazel et al. and Nathan Yee et al. at the IEEE International Symposium on Personal, Indoor and Mobile RADIO Communications (PIMRC) in the year 1993, multi-carrier spread spectrum (MC-SS) has rapidly become one of the most wide spread independent research topics on the field of mobile RADIO communications. Therefore, the International Workshop on Multi-Carrier Spread Spectrum (MC-SS) was initiated in the year 1997. Multi-carrier and spread spectrum systems with their generic air interface and adaptive technologies are considered as potential candidates to fulfill the requirements of next generation mobile communications systems.
標簽： Multi-Carrier Spectrum Spread 2007
上傳時間： 2020-05-31
上傳用戶：shancjb
Notwithstanding its infancy, wireless mesh networking (WMN) is a hot and growing field. Wireless mesh networks began in the military, but have since become of great interest for commercial use in the last decade, both in local area networks and metropolitan area networks. The attractiveness of mesh networks comes from their ability to interconnect either mobile or fixed devices with RADIO interfaces, to share information dynamically, or simply to extend range through multi-hopping.
上傳時間： 2020-05-31
上傳用戶：shancjb
Advances in communication and networking technologies are rapidly making ubiq- uitous network connectivity a reality. Wireless networks are indispensable for supporting such access anywhere and at any time. Among various types of wire- less networks, multihop wireless networks (MWNs) have been attracting increasing attention for decades due to its broad civilian and military applications. Basically, a MWN is a network of nodes connected by wireless communication links. Due to the limited transmission range of the RADIO, many pairs of nodes in MWNs may not be able to communicate directly, hence they need other intermediate nodes to forward packets for them. Routing in such networks is an important issue and it poses great challenges.
標簽： Multihop Wireless Networks
上傳時間： 2020-05-31
上傳用戶：shancjb
