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.
標簽： Amplify-and-Forward Relaying
上傳時間： 2020-05-26
上傳用戶：shancjb
When the authors of this book asked me to write the foreword of their work on the digital enterprise, I immediately thought that it was one more document on a fashionable topic in the technology and the business world of the 21st Century often addressed by consulting firms, some of which have aspired to become experts on the subject. However, a more careful observation reveals that an issue more important than the sole subject of the digital enterprise is: “Is your company fully operational?”, because this is the real topic.
標簽： Digital_Transformation_Informatio n_System
上傳時間： 2020-05-27
上傳用戶：shancjb
Wireless Fidelity (Wi-Fi) networks have become mainstream over the last few years. What started out as cable replacement for static desktops in indoor networks has been extended to fully mobile broadband applications involving moving vehicles, high-speed trains, and even airplanes.
標簽： Technologies Emerging Wireless Theory LANs in
上傳時間： 2020-05-27
上傳用戶：shancjb
In this paper we revisit hybrid analog-digital precoding systems with emphasis on their modelling and radio-frequency (RF) losses, to realistically evaluate their benefits in 5G system implementations. For this, we decompose the analog beamforming networks (ABFN) as a bank of commonly used RF components and formulate realistic model constraints based on their S-parameters. Specifically, we concentrate on fully-connected ABFN (FC-ABFN) and Butler networks for implementing the discrete Fourier transform (DFT) in the RF domain. The results presented in this paper reveal that the performance and energy efficiency of hybrid precoding systems are severely affected, once practical factors are considered in the overall design. In this context, we also show that Butler RF networks are capable of providing better performances than FC-ABFN for systems with a large number of RF chains.
標簽： Analog-Digital Precoding Hybrid
上傳時間： 2020-05-27
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
If you would like to follow along with some of the steps outlined in this book, we recommend that you deploy Live Communications Server 2005 SP1 on a physical or virtual server running Microsoft Windows Server 2003. To run Communicator 2005, you will need a physical or virtual PC running Windows XP or Windows Server 2003. To fully test Microsoft Office integration with Communicator 2005, you need to be running Microsoft Office 2003 with Service Pack 2.
標簽： Communications Professional Server Live
上傳時間： 2020-05-31
上傳用戶：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).
標簽： Gyroscopes Vibratory Coriolis
上傳時間： 2020-06-06
上傳用戶：shancjb
Of the various applications that satellites have been used for, one of the most promising is that of global positioning. Made possible by Global Navigation Satellite Systems, global positioning enables any user to know his or her exact position on Earth. Nowadays, the only fully functioning system is the American Global Positioning System (GPS). However, the European system, known as Galileo, is expected to be operative in 2012.
上傳時間： 2020-06-09
上傳用戶：shancjb
MIT App Inventor is an innovative beginner’s introduction to programming and app creation that transforms the complex language of text-based coding into visual, drag-and- drop building blocks. The simple graphical interface grants even an inexperienced novice the ability to create a basic, fully functional app within an hour or less.
標簽： Arduino Android using and MIT app
上傳時間： 2020-06-09
上傳用戶：shancjb
The PW4554 is a cost-effective, fully integrated high input voltage single-cell Li-ion battery charger.The charger uses a CC/CV charge profile required by Li-ion battery. The charger accepts an inputvoltage up to 24V but is disabled when the input voltage exceeds the OVP threshold, typically 6.8V,to prevent excessive power dissipation. The 24V rating eliminates the over-voltage protection circuitrequired in a low input voltage charger
標簽： pw4554
上傳時間： 2022-02-11
上傳用戶：
