Do you have a mobile phone? We think you probably do, one way or another. We would also guess that you might use it for many diff erent things in the course of your everyday life—as a telephone certainly, but also as an address book, as a clock or watch, as a camera, or now as a connection to your computer, email and the internet. Th ere will be a range of people you use it to contact (or not), and various strategies you use to take calls—or send texts, or take photos, or receive emails, or search online (or not, in diff erent situations). Th ere are also likely to be a range of social relation- ships in your life that your mobile phone helps to maintain—or disrupts, or inter- venes in, or makes possible, or complicates, or just plain helps to handle.
标签： Communications Introduction Mobile Media New An to
上传时间： 2020-05-30
上传用户：shancjb
This book is about multipoint cooperative communication, a key technology to overcome the long-standing problem of limited transmission rate caused by inter- point interference. However, the multipoint cooperative communication is not an isolated technology. Instead, it covers a vast range of research areas such as the multiple-input multiple-outputsystem, the relay network, channel state information issues, inter-point radio resource management operations, coordinated or joint transmissions, etc. We suppose that any attempt trying to thoroughly analyze the multipoint cooperative communication technology might end up working on a cyclopedia for modern communication systems and easily get lost in discussing all kinds of cooperative communication schemes as well as the associated models and their variations.
标签： Communication Multi-point Cooperative Systems
上传时间： 2020-05-31
上传用户：shancjb
Optical wireless communication is an emerging and dynamic research and development area that has generated a vast number of interesting solutions to very complicated communication challenges. For example, high data rate, high capacity and minimum interference links for short-range communication for inter-building communication, computer-to-computer communication, or sensor networks. At the opposite extreme is a long-range link in the order of millions of kilometers in the new mission to Mars and other solar system planets.
标签： Communication Wireless Optical Systems
上传时间： 2020-05-31
上传用户：shancjb
Welcome to the world of wireless communications and the logical extension to the broadband architectures that are emerging as the future of the industry. No aspect of communications will be untouched by the wireless interfaces;no part of our working environment will be left untouched either. As the world changes and the newer technologies emerge, we can expect to see more in the line of untethered communications than in the wired inter- faces.
标签： Broadband Wireless Handbook
上传时间： 2020-06-01
上传用户：shancjb
干耦合超声检测方法由于无需在待检测材料表面涂抹水或油等液体耦合剂，操作方便，移动灵活，适用于固体火箭发动机壳体、飞机机翼等一些对结构完整性要求较高且需要长期使用或贮存的部件。当利用干耦合方法对复合材料平板结构进行检测时，激发出的Lamb波携带有大量结构或缺陷的信息，如缺陷的类型、大小、位置等，采用合理的分析方法提取出信号中的有用信息，就能对材料中的损伤做出评估。
上传时间： 2021-10-18
上传用户：
1. Preface2. The concept2.2. Prescience 2.3. Reading guide 2.4. Abbreviations 2.5. Version management3. Hardware3.2. ESP32 3.3.2. Hardware schema 3.3.3. DHT22 and level shifter 3.3.4. Geekcreit® ESP32 Development Board4. Software4.2. Installatie van GIT 4.3. Installatation of the ESP32 Core 4.4. Installation of the Xtensa and ESP32 Tools 4.5. Python 4.5.1. Install Python 4.5.2. Installation of pySerial and EspTool 4.6. Test the software installation5. The ESP32 IoT project 5.1.1. WiFi connection 5.1.2. Setup date and time 5.1.3. MQTT connection 5.1.4. Determining temperature and humidity 5.2. IOT_ESP32_Project source6. Test6.2. ESP32, NodeJS, MongoDB en Mosca 6.2.1. Start MongoDB 6.2.2. Start NodeJS Express serve and Mosca broker 6.2.3. Start the ESP32 6.2.4. Start an Chrome browser
上传时间： 2022-04-05
上传用户：kingwide
TMS320F28027 DSP为控制芯片设计的中小功率投切无冲击UPS+软硬件设计源码本文重点研究UPS主电路中蓄电池投切时的实现方法和蓄电池升压电路的实现。主要研究内容如下：1）介绍了UPS系统，给出了系统框图，分析了各个部分的功能，并对其中重要的环节—蓄电池的投切和升压电路做详细分析。2）仿真研究。利用PSIM仿真软件搭建起系统的仿真模型，并对蓄电池的投切和蓄电池升压电路给出仿真结果。通过结果说明该方法正确性。3）硬件实验。以TMS320F28027 DSP为控制芯片，搭建硬件实验平台，给出了实验结果和结论。1. 系统方案 详细说明系统设计的整体思路，用模块的形式指出系统设计的各个关键点，并指出其中使用的关键算法当市电正常时，蓄电池不给逆变器提供能量，通过硬件关断此通道；通过一级Boost升压电路，逆变器输出正弦波经滤波器滤波后供给负载。当市电出现故障时或市电的电能质量在UPS要求的范围之外时，整流桥停止工作，蓄电池输出电压经过两级Boost升压电路将电压抬升至略低于单级Boost输出电压，经逆变器开始给负载提供能量。当输出短路或蓄电池的电压低于允许值时，UPS停止工作，以防止损坏逆变器或者蓄电池。当输出过载时，如果过载是瞬时的，则可以通过控制允许这种情况出现，如果过载时间比较长，则就需要通过转换开关由UPS转到市电给负载供电。
标签： tms320f28027 dsp
上传时间： 2022-05-05
上传用户：trh505
基于DSP28035的高速永磁无刷直流电机驱动系统，包括论文和软硬设计资料。摘要参赛作品为基于DSP28035的高速永磁无刷直流电机驱动系统。该系统以一台额定转速60 krpm的高速永磁无刷直流电机、交错并联的Buck电路以及全桥电路为硬件平台，以DSP28035为控制核心，实现了调压调速功能和基于坐标变换的无位置传感器新技术。为实现该系统要求，本作品充分利用了DSP28035的资源例如：CLA模块，模拟比较器、HPWM模块以及AD转换模块等。AbstractThis work is the drive system for a high speed permanent magnet burshless dc motor based on DSP28035. The hardware platform consists of a BLDC motor(rated speed is 60000rpm), a Buck circuit and an inverter. Under the control of DSP28035, this system can achieve the goal of adjusting the motor’s speed with voltage and the function of sensorless control based on the coordinate transformation. By making full use of resources of the core, such as CLA, analog comparator, HPWM and AD converters, the whole system can meet the requirements.1 引言高速永磁无刷直流电机驱动系统由于基波频率较高（一般在1kHZ以上），利用逆变桥斩波进行调速的控制方式通常会受到开关管开关频率的限制，因此该系统多采用三相全桥前级加Buck电路进承担调压调速的功能，而三相全桥主要承担逻辑换相的功能。然而，传统Buck电路所需电感的体积较大，增加了系统的体积，降低了系统的功率密度。
上传时间： 2022-05-08
上传用户：bluedrops
应广单片机 MINI-C编程指南.Mini-c总结文档一、缺点:（一）函数不能带参数.解决方法:通过A或全局变量进行参数传递;（二）不能使用for循环解决方法:用while循环代替for循环.（三）数组和指针功能弱化解决方法:① 使用rom查表② 使用ram查表（四）不支持全局变量定义同时进行初始化解决方法: 在初始化的时候记得对全局变量进行初始化. （五）Bit变量只支持写入0,或1,不支持直接bit变量取反解决方法 :if(uBitFlag){ uBitFlag=0;}Else{ uBitFlag=1; } 二、优点:（一）函数不带参数,可以节省堆栈空间（二）支持ROM查表（三）.delay时间非常准确,无需手工计算（四）支持bit变量,节省ram空间,支持字,字节拆分.（五）烧录支持滚动码写入.（六）端口配置可以使用脚本（七） 代码自动生成
标签： 单片机
上传时间： 2022-06-17
上传用户：
发那科dnc网络加工 网络加工 在线加工传输软件，欢迎下载
上传时间： 2022-07-04
上传用户：qingfengchizhu
