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.
上传时间: 2020-06-01
上传用户:shancjb
In this first part of the book the Vienna Link Level (LL) Simulators are described. The first chapter provides basics of LL simulations, introduces the most common variables and parameters as well as the transceiver structures that are applied in Long-Term Evolution (LTE) and Long-Term Evolution-Advanced (LTEA). We focus here mostly on the Downlink (DL) of LTE as most results reported in later chapters are related to DL transmissions.
标签: LTE-Advanced Simulators Vienna
上传时间: 2020-06-01
上传用户:shancjb
The focus of this book is on developing computational algorithms for transmit wave- form design in active sensing applications, such as radar, sonar, communications and medical imaging. Waveforms are designed to achieve certain desired properties, which are divided into three categories corresponding to the three main parts in the book, namely good aperiodic correlations, good periodic correlations and beampattern match- ing.
上传时间: 2020-06-01
上传用户:shancjb
During the past three decades, the world has seen signifi cant changes in the telecom- munications industry. There has been rapid growth in wireless communications, as seen by large expansion in mobile systems. Wireless communications have moved from fi rst-generation (1G) systems primarily focused on voice communications to third-generation (3G) systems dealing with Internet connectivity and multi-media applications. The fourth-generation (4G) systems will be designed to connect wire- less personal area networks (WPANs), wireless local area networks (WLANs) and wireless wide-area networks (WWANs).
标签: Communications Networking Wireless
上传时间: 2020-06-01
上传用户:shancjb
Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea phone call, or sitting in front of a personal computer to send an e-mail or download a video program, has become an old story. Nowadays it is commonplace for people to talk over a cell phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain. Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications over three generations, with the fourth generation being under way.
标签: Communications Management Wireless Resource
上传时间: 2020-06-01
上传用户:shancjb
Describing the relevant detection and estimation theory, this detailed guide provides the background knowledge needed to tackle the design of practical WLAN positioning systems. It sets out key system-level challenges and design considerations in increasing positioningaccuracyandreducingcomputationalcomplexity,examinesdesigntradeoffs, and presents experimental results.
标签: Positioning Systems WLAN
上传时间: 2020-06-01
上传用户:shancjb
The challenges associated with the design and implementation of Electro- static Discharge (ESD) protection circuits become increasingly complex as technology is scaled well into nano-metric regime. One must understand the behavior of semiconductor devices under very high current densities, high temperature transients in order to surmount the nano-meter ESD challenge. As a consequence, the quest for suitable ESD solution in a given technology must start from the device level. Traditional approaches of ESD design may not be adequate as the ESD damages occur at successively lower voltages in nano-metric dimensions.
标签: Protection Circuit Device Design ESD and
上传时间: 2020-06-05
上传用户:shancjb
The planarization technology of Chemical-Mechanical-Polishing (CMP), used for the manufacturing of multi- level metal interconnects for high-density Integrated Circuits (IC), is also readily adaptable as an enabling technology in MicroElectroMechanical Systems (MEMS) fabrication, particularly polysilicon surface micromachining. CMP not only eases the design and manufacturability of MEMS devices by eliminating several photolithographic and film issues generated by severe topography, but also enables far greater flexibility with process complexity and associated designs. T
标签: mechanical polishing Chemical
上传时间: 2020-06-06
上传用户:shancjb
For more than three decades, Micro Electro Mechanical Systems (MEMS) have steadily transitioned out of research labs and into production forming a more than $10 billion market [1]. MEMS devices such as accelerometers, pressure sensors and microphones, to name a few, have seen immense utilization, particularly in the consumer electronics market, because of their compact sizes and minute power consumptions. In addition, these devices benefit from batch fabrication, which has enabled year-over-year reductions in cost [2]. In recent years,
上传时间: 2020-06-06
上传用户:shancjb
Over many years, RF-MEMS have been a hot topic in research at the technology and device level. In particular, various kinds of mechanical Si-MEMS resonators and piezoelectric BAW (bulk acoustic wave) resonators have been developed. The BAW technology has made its way to commercial products for passive RF filters, in particular for duplexers in RF transceiver front ends for cellular communica- tions. Beyond their use in filters, micromachined resonators can also be used in conjunction with active devices in innovative circuits and architectures.
标签: MEMS-based Circuits Systems and
上传时间: 2020-06-06
上传用户:shancjb