During the past years, there has been a quickly rising interest in radio access tech- nologies for providing mobile as well as nomadic and fixed services for voice, video, and data. The difference in design, implementation, and use between telecom and datacom technologies is also getting more blurred. One example is cellular technologies from the telecom world being used for broadband data and wireless LAN from the datacom world being used for voice over IP.
上傳時間： 2020-05-26
上傳用戶：shancjb
Duringthe past years, there has been a quickly rising interest in radio access technologies for providing mobile as well as nomadic and fixed services for voice, video, and data. This proves that the difference in design, implementation, and use between telecom and datacom technologies is also becoming more blurred. What used to be a mobile phone used for voice communication is today increasingly becoming the main data communication device for end-users, providing web browsing, social networking, and many other services.
標簽： LTELTE-Advanced 4G
上傳時間： 2020-05-26
上傳用戶：shancjb
An acronym for Multiple-In, Multiple-Out, MIMO communication sends the same data as several signals simultaneously through multiple antennas, while still utilizing a single radio channel. This is a form of antenna diversity, which uses multiple antennas to improve signal quality and strength of an RF link. The data is split into multiple data streams at the transmission point and recombined on the receive side by another MIMO radio configured with the same number of antennas. The receiver is designed to take into account the slight time difference between receptions of each signal, any additional noise or interference, and even lost signals.
標簽： Understanding_the_Basics_of_MIMO
上傳時間： 2020-06-01
上傳用戶：shancjb
基于TMS320F28335的超聲波流量計硬件原理圖+軟件源碼本文以TMS320F28335 處理器為核心，設計一種用于管道流量測量的超聲波流量計。系統硬件由核心板，超聲波發射和接收電路，切換電路，超聲換能器，基于ADS805 的高速信號采集電路，人機交互以及電源等模塊構成。采用時差法進行管道流量測量，時差測量采用SCOT 加權的廣義互相關時延估計算法。本論文設計的超聲波流量計具有測量速度快、準確性好、成本低等優點。關鍵字：C2000，超聲波，流量，廣義互相關算法AbstractA kind of ultrasonic flowmeter using for the pipe flow measurement is designed based onTMS320F28335 in this paper. The system hardware consists of the following parts: the core board,ultrasonic signal transmitter and receiver circuits, switch circuit, ultrasonic transducer, signalacquisition circuit based on ADS805, human-computer interaction module and power supplymodule, etc. The system use the method of time difference for pipeline flow measurement and thetime difference is calculated by the time-delay algorithm of SCOT weighted generalizedcross-correlation. The ultrasonic flowmeter has the features of high testing speed, high precisionand low cost, etc.Keywords: C2000,Ultrasonic, Flow, Generalized Cross-Correlation Algorithm
標簽： tms320f28335 超聲波流量計
上傳時間： 2022-05-06
上傳用戶：
PrefaceDuring the past years, there has been a quickly rising interest in radio access technologies for providingmobile as well as nomadic and fixed services for voice, video, and data. The difference indesign, implementation, and use between telecom and datacom technologies is also becoming moreblurred. One example is cellular technologies from the telecom world being used for broadband dataand wireless LAN from the datacom world being used for voice-over IP.Today, the most widespread radio access technology for mobile communication is digital cellular,with the number of users passing 5 billion by 2010, which is more than half of the world’s population.It has emerged from early deployments of an expensive voice service for a few car-borne users,to today’s widespread use of mobile-communication devices that provide a range of mobile servicesand often include camera, MP3 player, and PDA functions. With this widespread use and increasinginterest in mobile communication, a continuing evolution ahead is foreseen.This book describes LTE, developed in 3GPP (Third Generation Partnership Project) and providingtrue 4G broadband mobile access, starting from the first version in release 8 and through the continuingevolution to release 10, the latest version of LTE. Release 10, also known as LTE-Advanced,is of particular interest as it is the major technology approved by the ITU as fulfilling the IMTAdvancedrequirements. The description in this book is based on LTE release 10 and thus provides acomplete description of the LTE-Advanced radio access from the bottom up.Chapter 1 gives the background to LTE and its evolution, looking also at the different standardsbodies and organizations involved in the process of defining 4G. It also gives a discussion of the reasonsand driving forces behind the evolution.Chapters 2–6 provide a deeper insight into some of the technologies that are part of LTE and itsevolution. Because of its generic nature, these chapters can be used as a background not only for LTEas described in this book, but also for readers who want to understand the technology behind othersystems, such as WCDMA/HSPA, WiMAX, and CDMA2000.Chapters 7–17 constitute the main part of the book. As a start, an introductory technical overviewof LTE is given, where the most important technology components are introduced based onthe generic technologies described in previous chapters. The following chapters provide a detaileddescription of the protocol structure, the downlink and uplink transmission schemes, and the associatedmechanisms for scheduling, retransmission and interference handling. Broadcast operation andrelaying are also described. This is followed by a discussion of the spectrum flexibility and the associated
上傳時間： 2022-07-08
上傳用戶：
