搜索结果

According to the statistics of the Federal Communications Commission (FCC), temporal and geographical variations in the utilization of the as- signed spectrum range from 15% to 85%. The limited available radio spec- trum and the inefficiency in spectrum usage necessitate a new commu- nication paradi ...

Cognitive radio has emerged as a promising technology for maximizing the utiliza- tion of the limited radio bandwidth while accommodating the increasing amount of services and applications in wireless networks. A cognitive radio (CR) transceiver is able to adapt to the dynamic radio environment and ...

This book examines the technologies underlying the compression and trans- mission of digital video sequences over networking platforms. The incorporated study covers a large spectrum of topics related to compressed video communica- tions. It presents to readers a comprehensive and structured analysi ...

This thesis is about wireless communication in shared radio spectrum. Its origin and motivation is ideally represented by the two quotations from above. In this thesis, the support of Quality-of-Service (QoS) in cognitive radio networks is analyzed. New approaches to distributed coordination of cogn ...

The first Third Generation Partnership Project (3GPP) Wideband Code Division Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005 there were 100 open WCDMA networks and a total of over 150 operators having frequency licenses for WCDMA operation. Currently, the WCDMA network ...

Mobile operators must continuously pursue cost‐ effective and efficient solutions to meet the high data demand requirements of their subscribers. Limited spectrum allocations and non‐contiguous spectrum blocks continue to pose challenges for mobile operators supporting large data uploads and downl ...

Radio propagation measurements and channel modelling continue to be of fundamental importance to radio system design. As new technology enables dynamic spectrum access and higher data rates, radio propagation effects such as shadowing, the presence of multipath and frequency dispersion are the limit ...

One of the prerequisites for the development of telecommunication services is the understanding of the propagation of the waves, either acoustic, electromagnetic, radio or light waves, which are used for the transmission of information. In this work, we shall limit ourselves to the study of radio wa ...

Cognitive radios have become a vital solution that allows sharing of the scarce frequency spectrum available for wireless systems. It has been demonstrated that it can be used for future wireless systems as well as integrated into 4G/5G wireless systems. Although there is a great amount of literatur ...

Ultra-wideband (UWB) technology enables high data-rate short-range communica- tion, in excess of hundredmegabit-per-secondsand up to multi-gigabit-per-seconds, over a wide spectrum of frequencies, while keeping power consumption at low lev- els. This low power operation results in a less-interfering ...