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.
标签: Wireless Systems Mobile Beyond and 3G
上传时间: 2020-05-30
上传用户:shancjb
Mobile wireless communications are in constant evolution due to the continu- ously increasing requirements and expectations of both users and operators. Mass multimedia* services have been for a long time expected to generate a large amount of data traffic in future wireless networks [1]. Mass multimedia services are, by definition, purposed for many people. In general, it can be distinguished between the distribution of any popular content over a wide area and the distribu- tion of location-dependent information in highly populated areas. Representative examples include the delivery of live video streaming content (like sports compe- titions, concerts, or news) and file download (multimedia clips, digital newspa- pers, or software updates).
标签: Broadcasting Generation Mobile Next
上传时间: 2020-05-31
上传用户:shancjb
The telecommunications industry has seen a rapid boost within the last decade. New realities and visions of functionalities in various telecommunications networks have brought forward the concept of next-generation networks (NGNs). The competitions among operators for support- ing various services, lowering of the cost of having mobile and cellular phones and smartphones, increasing demand for general mobility, explosion of digital traffic, and advent of convergence network technologies added more dynamism in the idea of NGNs. In fact, facilitating con- vergence of networks and convergence of various types of services is a significant objective of NGNs.
标签: Next-Generation Converged Networks
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
Transmit power in wireless cellular networks is a key degree of freedom in the management of interference, energy, and connectivity. Power control in both uplink and downlink of a cellular network has been extensively studied, especially over the last 15 years, and some of the results have enabled the continuous evolution and significant impact of the digital cellular technology.
标签: Cellular Networks Wireless Control Power in
上传时间: 2020-05-31
上传用户:shancjb
Wireless communications is rapidly becoming one of the ubiquitous technological underpinnings of modern society (such as electric power, fossil fuels, automobiles, etc.).Fewpeoplethinkaboutthetechnologywithintheirmobilephones,remotecontrols, garage door openers, GPS navigation devices, and so on. They are always at hand and reliably work for the user.
标签: Practical wireless digital signals
上传时间: 2020-05-31
上传用户:shancjb
Without doubt, the age of information communications is upon 11s. The rapid pace of technological advancement in digital data communications can be wit- nessed in a multitude of applications in our day-to-day existence. In recent years, the widespread proliferation of wireless digital cornmunications hass been readily accepted by the general population worldwide; this is nearly unpa~rallcled in few other human scientific achievements in terms of scope and speed of devel- opment.
标签: Practical Wireless Design Modem Data
上传时间: 2020-05-31
上传用户:shancjb
The goal of this book is to provide a concise but lucid explanation and deriva- tion of the fundamentals of spread-spectrum communication systems. Although spread-spectrum communication is a staple topic in textbooks on digital com- munication, its treatment is usually cursory, and the subject warrants a more intensive exposition. Originally adopted in military networks as a means of ensuring secure communication when confronted with the threats of jamming and interception, spread-spectrum systems are now the core of commercial ap- plications such as mobile cellular and satellite communication.
标签: Principles Spectrum Spread of
上传时间: 2020-05-31
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Communication has been one of the deepest needs of the human race throughout recorded history. It is essential to forming social unions, to educating the young, and to expressing a myriad of emotions and needs. Good communication is central to a civilized society. The various communication disciplines in engineering have the purpose of providing technological aids to human communication. One could view the smoke signals and drum rolls of primitive societies as being technological aids to communication, but communication technology as we view it today became important with telegraphy, then telephony, then video, then computer communication, and today the amazing mixture of all of these in inexpensive, small portable devices.
标签: communication Principles digital of
上传时间: 2020-05-31
上传用户:shancjb
Digital mobile wireless communication and the Internet have undergone a fantastic growth in the last few years and, despite originating from two different worlds, they are converging. This convergence corresponds to the evolution of mobile systems towards the highest broadband data transmissions (GSM, EDGE/GPRS, UMTS then HSDPA), while the computing world gets equipped with wireless technologies such as Wi-Fi or Wi-Max.
标签: Reconfigurable Systems Mobile Radio
上传时间: 2020-06-01
上传用户:shancjb