There are few technologies that have had a more profound effect on people’s lives than mobile communications. As recently as twenty years ago no one had a mobile phone, while today 1.4 billion men, women and children depend on them. This now exceeds the number of landline users, where it took the preceding one hundred years to reach the 1 billion mark. The ability to make mobile voice calls turns Out to be the answer to a deeply felt need across different cultures who simply want to communicate.
標簽： Communications Wireless Mobile and
上傳時間： 2020-05-30
上傳用戶：shancjb
The last decade proved to be hugely successful for the mobile communications industry, characterised by continued and rapid growth in demand, spurred on by new technological advances and innovative marketing techniques. Of course, when we refer to mobile commu- nications, we tend to implicitly refer to cellular systems, such as GSM. The plight of the mobile-satellite industry over the last decade, although eventful, has, at times, been more akin to an Out of control roller coaster ride.
標簽： Communication Satellite Networks Mobile
上傳時間： 2020-05-30
上傳用戶：shancjb
his research aims at creating broadband tunable, fully integrated filters for the application of cognitive radio and signal classification receivers. The approach under study is the N-path filter technique which is capable of translating a baseband impedance to a reference frequency creating a tunable filter. The traditional N-path filter suffers from fundamental architectural limitations, namely : a trade-off between insertion loss and Out-of-band rejection, reference clock feed- through, and jammer power handling limitations. In the first approach, the fundamental trade- off of the traditional N-path filter between insertion loss and Out-of-band rejection is improved by a transmission line (T-line) N-path filter technique.
上傳時間： 2020-05-31
上傳用戶：shancjb
This book stems from its ancestor Digital Transmission Theory,published by Prentice-Hall in 1987 and now Out of print. Following the suggestion of several colleagues who complained abOut the unavailability of a textbook they liked and adopted in their courses, laying a strong emphasis on wireless communication. We hope that those who liked the previous book will find again its flavor here,while new reader, untouched by nostalgia, will judge it favorably.
標簽： Transmission Principles Digital of
上傳時間： 2020-05-31
上傳用戶：shancjb
The first question most readers of an O’Reilly book might ask is abOut the choice of the cover animal. In this case, “why a duck?” Well, for the record, our first choice was a unicorn decked Out in glitter and a rainbow sash. That response always gets a laugh (we are sure you just giggled a little), but it also brings to the surface a common perception of software-defined networks among many expe‐ rienced network professionals. Although we think there is some truth to this perception, there is certainly more meat than myth to this unicorn.
標簽： Networks Software Defined SDN
上傳時間： 2020-06-01
上傳用戶：shancjb
The radio spectrum is one of the most precious resources which must be managed to ensure efficient access for the wireless communication services which use it. The allocation and management of spectrum are administered by the regulatory authorities. Traditionally, spectrum allocation is carried Out exclusively of its use in large geographic areas and assigning frequency bands to specific users or service providers is proved to be inefficient. Recently, substantial knowledge abOut dynamic spectrum access scheme has been accumulated to enable efficient spectrum sharing.
標簽： Management Spectrum Access and
上傳時間： 2020-06-01
上傳用戶：shancjb
Intensive development of digital technologies coincided in time with the beginning of the new era in telecommunications. It made possible to formalize many proce- dures of data exchange and to atomize some operations which made providing of serviceandmakeworkofmanytelecommunicationworkersmucheasier. Somenew telecommunication technologies were born Out of the necessity for use of specific configurations of network elements and networks, as well as for a possibility of providing maximum characteristics of efficiency combined with high requirements to the stability of operation, the overcoming of different catastrophic situations and deadlockconditions,such as failuresand ”pending”of the networkandthe like. The thresholdbetweeninformationsystems andtelecommunicationsystems has become practically invisible. It resulted in such a new term as ”infocommunication”
上傳時間： 2020-06-01
上傳用戶：shancjb
Public telephone operators and new independent wireless operators through- Out the world are deploying wireless access in an effort to drastically reduce delivery costs in the most expensive part of the network?the local loop. Available radio technology enables both existing and new entrants to access subscribers in a rapid manner and deliver their basic telephony products and broadband-enhanced services.
標簽： Transmission Handbooks Systems Design
上傳時間： 2020-06-01
上傳用戶：shancjb
In this book we focus on the basic signal processing that underlies current and future ultra wideband systems. By looking at signal processing in this way we hope this text will be useful even as UWB applications mature and change or regulations regarding ultra wideband systems are modified. The current UWB field is extremely dynamic, with new techniques and ideas being presented at every communications and signal-processing conference. The basic signal-processing techniques presented in this text though will not change for some time to come. Thus, we have taken a somewhat theoretical approach, which we believe is longer lasting and more useful to the reader in the long term than an up-to-the-minute summary that is Out of date as soon as it is published.
標簽： Wideband Signals Systems Ultra 1st
上傳時間： 2020-06-01
上傳用戶：shancjb
The continuing explosive growth in mobile communication is demanding more spectrally efficient radio access technologies than the prevalent second generation (2G) systems such as GSM to handle just the voice traffic. We are already witnessing high levels of mobile penetration exceeding 70% in some countries. It is anticipated that by 2010 more than half of all communications will be carried Out by mobile cellular networks. On the other hand, the information revolution and changing life habits are bringing the requirement of commu- nicating on a multimedia level to the mobile environment. But the data handling capabilities and flexibility of the 2G cellular systems are limited.
上傳時間： 2020-06-01
上傳用戶：shancjb
