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(biāo)簽： Characteristics Channel Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
Do you have a mobile phone? We think you probably do, one way or another. We would also guess that you might use it for many diff erent things in the course of your everyday life—as a telephone certainly, but also as an address book, as a clock or watch, as a camera, or now as a connection to your computer, email and the internet. Th ere will be a range of people you use it to contact (or not), and various strategies you use to take calls—or send texts, or take photos, or receive emails, or search online (or not, in diff erent situations). Th ere are also likely to be a range of social relation- ships in your life that your mobile phone helps to maintain—or disrupts, or inter- venes in, or makes possible, or complicates, or just plain helps to handle.
標(biāo)簽： Communications Introduction Mobile Media New An to
上傳時間： 2020-05-30
上傳用戶：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).
標(biāo)簽： Broadcasting Generation Mobile Next
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
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.
標(biāo)簽： Principles Spectrum Spread of
上傳時間： 2020-05-31
上傳用戶：shancjb
The continuing vitality of spread-spectrum communication systems and the devel- opment of new mathematical methods for their analysis provided the motivation to undertake this new edition of the book. This edition is intended to enable readers to understand the current state-of-the-art in this field. Almost twenty percent of the materialinthiseditionisnew, includingseveralnewsections, anewchapteronadap- tive arrays and filters, and a new chapter on code-division multiple-access networks.
標(biāo)簽： Spread-Spectrum Communication Principles of
上傳時間： 2020-05-31
上傳用戶：shancjb
Communication protocols – for short protocols – form the basis for the opera- tion of computer networks and telecommunication systems. They are behavior conventions which describe how communication systems interact with each other in computer networks. Protocols define the temporal order of the interactions and the formats of the data units exchanged. Communication protocols comprise a wide range of different functions and mechanisms, such as the sending and receiv- ing of data units, their coding/decoding, error control mechanisms, timer control, flow control, and many others.
標(biāo)簽： Engineering Protocol
上傳時間： 2020-05-31
上傳用戶：shancjb
This book provides the essential design techniques for radio systems that operate at frequencies of 3 MHz to 100 GHz and which will be employed in the telecommunication service. We may also call these wireless systems, wireless being synonymous with radio, Telecommunications is a vibrant indus- try, particularly on the ‘‘radio side of the house.’’ The major supporter of this upsurge in radio has been the IEEE and its 802 committees. We now devote ? . an entire chapter to wireless LANs WLANs detailed in IEEE 802.11. We also now have subsections on IEEE 802.15, 802.16, 802.20 and the wireless ? . ? metropolitan area network WMAN . WiFi, WiMax,, and UWB ultra wide- . band are described where these comparatively new radio specialties are demonstrating spectacular growth.
標(biāo)簽： Telecommunication Design System Radio for
上傳時間： 2020-06-01
上傳用戶：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.
標(biāo)簽： Reconfigurable Systems Mobile Radio
上傳時間： 2020-06-01
上傳用戶：shancjb
The market for cellular phones and wireless data transmission equipment has changed dramatically since the late 1970s when cellular phones were first introduced and the late 1980s when wireless data equipment became available. As would be expected, duringthistime RF test requirements and RF test equipment has changed dramatically.
標(biāo)簽： Measurements Cellular Phones for RF
上傳時間： 2020-06-01
上傳用戶：shancjb
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