Rapid growth of wireless communication services in recent decades has created a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency limit the development of wireless networks. Cognitive radio is a promising tech- nology that allows secondary users to reuse the underutilized licensed spectrum of primary users. The major challenge for spectrum sharing is to achieve high spectrum efficiency while making non-intrusive access to the licensed bands. This requires in- formation of availability and quality of channel resources at secondary transmitters, however, is difficult to be obtained perfectly in practice.
標簽: Opportunistic Spectrum Sharing
上傳時間: 2020-05-31
上傳用戶:shancjb
Since the advent of optical communications, a great technological effort has been devoted to the exploitation of the huge bandwidth of optical fibers. Start- ing from a few Mb/s single channel systems, a fast and constant technological development has led to the actual 10 Gb/s per channel dense wavelength di- vision multiplexing (DWDM) systems, with dozens of channels on a single fiber. Transmitters and receivers are now ready for 40 Gb/s, whereas hundreds of channels can be simultaneously amplified by optical amplifiers.
標簽: Communication Techniques Optical Theory and
上傳時間: 2020-05-31
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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 co-existence with other existed communication technologies (e.g., UNII bands). In addition to carrying a huge amount of data over a distance of up to 230 feet at very low power (less than 0.5mW), the UWB signal has the ability to penetrate through the doors and other obstacles that tend to reflect signals at more limited bandwidths and higher power densities.
標簽: Silicon-Based Front-Ends RF
上傳時間: 2020-06-01
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Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data in the Marconi age, they have transformed, thanks to substantial advances in electronic technology, into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia communications. This, however, would not have been possible unless significant progress had been made in recent decades in the field of signal processing algorithms for baseband and passband signals. In fact, the core of any modern digital radio consists of a set of algorithms running over programmable electronic hardware. This book stems from the research and teaching activities of its co-authors in the field of algorithmic techniques for wireless communications. A huge body of technical literature has accumulated in the last four decades in this area, and an extensive coverage of all its important aspects in a single textbook is impossible. For this reason, we have selected a few important topics and, for ease of reading, organized them into two parts.
標簽: Communications Algorithmic Techniques Wireless
上傳時間: 2020-06-01
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With the proliferation of cloud computing and Internet online services, more and more data and computation are migrated to geographical distributed Internet data centers (IDCs), which can provide reliability, management, and cost benefits. However, IDC operators encounter several major problems in IDC operations, such as huge energy consumption and energy cost, and high carbon emission. To deal with the above problems, IDC operators have to efficiently manage the way of energy consumption and energy supply. Considering the potential of smart grid, we focus on the energy management of IDCs in smart grid from several perspectives, i.e., power outage, carbon emission, heterogeneous service delay guarantees, and operation risk.
上傳時間: 2020-06-07
上傳用戶:shancjb
Modern power systems involve large amount of investment. An electric power system comprises of generation, transmission, and distribution of electric energy. Growth of power systems has led to very complex networks extended across large areas. In such situations, the proper functioning of a modern power system is heavily dependent upon the healthy operation of the transmission lines within it. Transmission lines are used to transmit a huge amount of power over a long distance. But as these lines are located in the open atmosphere, they are highly affected by different types of abnormal conditions or faults.
標簽: Transmission Protection Line
上傳時間: 2020-06-07
上傳用戶:shancjb
Radio frequency identification (RFID) is a type of automatic identification systems which has gained popularity in recent years for being fast and reliable in keeping track of the individual objects. In RFID systems, contactless object identification is achieved using radio signals without the need for physical contact as the case with other existing identification technologies such as barcodes. Therefore, a huge number of items can be identified in a short amount of time with high reliability and low cost which makes the RFID technology very attractive for a wide range of applications such as supply chain management, e-health, monitoring humans, pets, animals, and many other objects, toll control, and electrical tagging. Furthermore, RFID technology eliminates the human error and reduces the total cost of the products.
上傳時間: 2020-06-08
上傳用戶:shancjb
Control systems are becoming more important every day. At the beginning, the in- dustry used sequential controls for solving a lot of industrial applications in control systems, and then the linear systems gave us a huge increase in applying automatic linear control on industrial application. One of the most recent methods for control- ling industrial applications is intelligent control, which is based on human behavior or concerning natural process.
標簽: Intelligent Control Systems LabVIEW with
上傳時間: 2020-06-10
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Although state of the art in many typical machine learning tasks, deep learning algorithmsareverycostly interms ofenergyconsumption,duetotheirlargeamount of required computations and huge model sizes. Because of this, deep learning applications on battery-constrained wearables have only been possible through wireless connections with a resourceful cloud. This setup has several drawbacks. First, there are privacy concerns. Cloud computing requires users to share their raw data—images, video, locations, speech—with a remote system. Most users are not willing to do this. Second, the cloud-setup requires users to be connected all the time, which is unfeasible given current cellular coverage. Furthermore, real-time applications require low latency connections, which cannot be guaranteed using the current communication infrastructure. Finally, wireless connections are very inefficient—requiringtoo much energyper transferredbit for real-time data transfer on energy-constrained platforms.
標簽: Embedded_Deep_Learning Algorithms
上傳時間: 2020-06-10
上傳用戶:shancjb