Relaying techniques, in which a source node communicates to a destination node with the help of a relay, have been proposed as a cost-effective solution to address the increasing demand for high data rates and reliable services over the air. As such, it is crucial to design relay systems that are able to not only provide high spectral efficiency, but also fully exploit the diversity of the relay channel.
标签: Amplify-and-Forward Relaying
上传时间: 2020-05-26
上传用户:shancjb
This book is intended for the RF planners, to serve as a practical tool in their daily work designing indoor radio distribution systems. It is not a complete book about all the deep aspects and corners of GSM, DCS, UMTS and HSPA networks, or all the core network systems. It is dedicated to the last 10–70 m of the network, the indoor air interface between the mobile user and the indoor mobile network.
标签: Practical Planning Indoor Guide Radio GSM for
上传时间: 2020-05-27
上传用户:shancjb
During the 400 days and nights before we finalized this book on January 1, 2012, we saw the sunset decorated by the raindrop, and were accompanied by the flowers blooming to withering. All those past memories are engraved on our hearts and will last eternally, cementing the most profound friendship in the world.
标签: LTE-Advanced Technology Interface Air
上传时间: 2020-05-27
上传用户:shancjb
Since the principle of multi-carrier code division multiple access (MC-CDMA) was simultaneously proposed by Khaled Fazel et al. and Nathan Yee et al. at the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) in the year 1993, multi-carrier spread spectrum (MC-SS) has rapidly become one of the most wide spread independent research topics on the field of mobile radio communications. Therefore, the International Workshop on Multi-Carrier Spread Spectrum (MC-SS) was initiated in the year 1997. Multi-carrier and spread spectrum systems with their generic air interface and adaptive technologies are considered as potential candidates to fulfill the requirements of next generation mobile communications systems.
标签: Multi-Carrier Spectrum Spread 2007
上传时间: 2020-05-31
上传用户:shancjb
The first practical examples of mobile communications were used in many countries like the USA, the UK and Germany in military services, and played a significant role in the First World War to transfer important information from the front to headquarters to take further actions. Good and secure wireless communications were an important need for all military services – army, navy and air force. In this respect, the Second World War was a big experimental battlefield for the development and evolution of mobile radio. It was in the interests of governments that after the Second World War the military investment should be paid back by civilian use, and all western European countries started their so-called first generation of mobile communication networks.
标签: Multimedia Business Mobile The
上传时间: 2020-06-01
上传用户:shancjb
Thanks to the advances in micromachining fabrication technologies and significant cost reduction due to mass production, miniature sensors of angular rate, or gyroscopes, found their way into the everyday life of every user of modern gadgets, such as smart phones, tablets or even wristwatches. Often without realising, many of us are carrying in our pockets fully equipped with all necessary sensors complete inertial navigation systems that not so long ago were available only for advanced vehicles in sea, land, air or space. Accelerometers and gyroscopes are found in specifications of any gadget supposed to react to user movements. And one of the most commonly used type of gyroscopes used to developed these systems is Coriolis vibratory gyroscope (CVG).
标签: Gyroscopes Vibratory Coriolis
上传时间: 2020-06-06
上传用户:shancjb
Battery systems for energy storage are among the most relevant technologies of the 21 st century. They – in particular modern lithium-ion batteries (LIB) – are enablers for the market success of electric vehicles (EV) as well as for stationary energy storage solutions for balancing fluctuations in electricity grids resulting from the integrationofrenewableenergysourceswithvolatilesupply 1 .BothEVandstationary storage solutions are important because they foster the transition from the usage of fossil energy carriers towards cleaner renewable energy sources. Furthermore, EV cause less local air pollution and noise emissions compared to conventional combustion engine vehicles resulting in better air quality especially in urban areas. Unfortunately, to this day, various technological and economic challenges impede a broad application of batteries for EV as well as for large scale energy storage and load leveling in electricity grids.
标签: Multiscale Simulation Approach
上传时间: 2020-06-07
上传用户:shancjb
Sound is simply an airborne version of vibration. The air which carries sound is a mixture of gases. In gases, the molecules contain so much energy that they break free from their neighbors and rush around at high speed. As Figure 1.1(a) shows, the innumerable elastic collisions of these high-speed molecules produce pressure on the walls of any gas container. If left undisturbed in a container at a constant temperature, eventually the pressure throughout would be constant and uniform.
标签: Engineering Audio
上传时间: 2020-06-09
上传用户:shancjb
)Armature windings of the electric motor for NO.2 deck cargo winch found low insulation. Windings re-winded,painted and baked dry. (2) NO.1 main air compressor failed to build up pressure.The machine disassembled, cleaned and inspected. The discharge valve plate found broken. The valve palte renewed and running trials tested after being reassembled.
标签: 答案
上传时间: 2020-07-14
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A coupled thermo-hydro-mechanical model for evaluating air leakage from an unlined compressed air energy storage cavern
标签: thermo-hydro-mechanical compressed evaluating air coupled leakage storage unlined cavern energy
上传时间: 2021-08-13
上传用户:hx09130032