The genesis for this book was my involvement with the development of the SystemView (now SystemVue) simulation program at Elanix, Inc. Over several years of development, technical support, and seminars, several issues kept recur- ring. One common question was, “How do you simulate (such and such)?” The sec- ond set of issues was based on modern communication systems, and why particular developers did what they did. This book is an attempt to gather these issues into a single comprehensive source.
标签: Communication Introduction Systems to
上传时间: 2020-05-27
上传用户:shancjb
Fixed-mobile.convergence.and.voice-data.networks.have.merged.next-gen- eration,.value-added.applications.and.integrated.multimedia.services,.com- bining. Web. browsing,. instant. messaging,. presence,. voice. over. IP,. video. conferencing,. application. sharing,. telephony,. unified. messaging,. multi- media.content.delivery,.etc..on.top.of.different.network.technologies..The. convergence.of.the.communications.networks.is.motivated.by.the.need.to. support.many.forms.of.digital.traffic.as.well.as.to.amortize.implementation. and.operational.costs.of.the.underlying.networks..Historically,.the.approach. to. build. and. deploy. multimedia. services. has. focused. upon. single-point. solutions..
标签: Multimedia Subsystem Handbook IMS IP
上传时间: 2020-05-27
上传用户: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.
标签: Transmission Microwave Networks
上传时间: 2020-05-28
上传用户:shancjb
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: 2020-05-31
上传用户: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.
上传时间: 2020-05-31
上传用户:shancjb
Since the advent of optical communications, a great technological effort has been devoted to the exploitation of the huge bandwidth of optical fibers. Start- ing from a few Mb/s single channel systems, a fast and constant technological development has led to the actual 10 Gb/s per channel dense wavelength di- vision multiplexing (DWDM) systems, with dozens of channels on a single fiber. Transmitters and receivers are now ready for 40 Gb/s, whereas hundreds of channels can be simultaneously amplified by optical amplifiers.
标签: Communication Techniques Optical Theory and
上传时间: 2020-05-31
上传用户:shancjb
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
上传用户: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.
标签: Communications Satellite Systems
上传时间: 2020-06-01
上传用户:shancjb
The single-carrier frequency division multiple access (SC-FDMA) system is a well-known system that has recently become a preferred choice for mobile uplink channels. This is attributed to its advantages such as the low peak-to-average power ratio (PAPR) and the use of frequency domain equalizers. Low PAPR allows the system to relax the specifications of linearity in the power amplifier of the mobile terminal, which reduces cost and power consumption.
标签: Communications SC-FDMA Mobile for
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