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
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
This book presents millimeter wave communication system design and analysis at the level to produce an understanding of the interaction between a wireless system and its front end so that the overall performance can be predicted. Gigabit wireless commu- nications require a considerable amount of bandwidth, which can be supported by millimeter waves. Millimeter wave technology has come of age, and at the time of writing the standards of IEEE 802.15.3c, WiGig, Wireless HD TM , and the European Computer Manufacturers Association have recently been finalized.
標簽: Communication Millimeter Systems Wave
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
With the rapid growth of the wireless mobile applications, wireless voice has begun to challenge wireline voice, whereas the desire to access e-mail, surf the Web or download music (e.g., MP3) wirelessly is increasing for wireless data. While second generation (2G) cellular wireless systems, such as cdmaOne1, GSM2 and TDMA3, introduced digital technology to wireless cellular systems to deal with the increasing demand for wireless applications, there is still the need for more spectrally efficient technologies for two reasons. First, wireless voice capacity is expected to continue to grow. Second, the introduction of high-speed wireless data will require more bandwidth.
標簽: Wireless Systems Mobile Beyond and 3G
上傳時間: 2020-05-30
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
This is believed to be the first book that takes a view of nanotechnology from a telecommunications and networking perspective. Nanotechnology refers to the manip- ulation of materials at the atomic or molecular level. Nanotechnology is getting a lot of attention of late not only in academic settings and in laboratories around the world, but also in government and venture capitalists’ initiatives. There now is a major drive to commercialize the technology by all sorts of firms, ranging from start- ups to Fortune 100 companies.
標簽: Nanotechnology Applications
上傳時間: 2020-05-31
上傳用戶:shancjb
Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant background material must be presented first. The purpose of this chapter is to provide the necessary building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled with the necessary mathematical foundation, we proceed with an overview of digital communication systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus OFDM.
上傳時間: 2020-05-31
上傳用戶:shancjb