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
Wireless communications has become a field of enormous scientific and economic interest. Recent success stories include 2G and 3G cellular voice and data services (e.g., GSM and UMTS), wireless local area networks (WiFi/IEEE 802.11x), wireless broadband access (WiMAX/IEEE 802.16x), and digital broadcast systems (DVB, DAB, DRM). On the physical layer side, traditional designs typically assume that the radio channel remains constant for the duration of a data block. However, researchers and system designers are increasingly shifting their attention to channels that may vary within a block. In addition to time dispersion caused by multipath propagation, these rapidly time-varying channels feature frequency dispersion resulting from the Doppler effect. They are, thus, often referred to as being “doubly dispersive.”
标签： Time-Varying Channels
上传时间： 2020-06-01
上传用户：shancjb
Power Electronics is one of modern and key technologies in Electrical and Electronics Engineering for green power, sustainable energy systems, and smart grids. Especially, the transformation of existing electric power systems into smart grids is currently a global trend. The gradual increase of distributed generators in smart grids indicates a wide and important role for power electronic converters in the electric power system, also with the increased use of power electronics devices (nonlinear loads) and motor loadings, low cost, low-loss and high-performance shunt current quality compensators are highly demanded by power customers to solve current quality problems caused by those loadings.
标签： Electronics Parallel Filters Power
上传时间： 2020-06-07
上传用户：shancjb
The term “ smart grid ” defi nes a self - healing network equipped with dynamic optimiza- tion techniques that use real - time measurements to minimize network losses, maintain voltage levels, increase reliability, and improve asset management. The operational data collected by the smart grid and its sub - systems will allow system operators to rapidly identify the best strategy to secure against attacks, vulnerability, and so on, caused by various contingencies. However, the smart grid fi rst depends upon identifying and researching key performance measures, designing and testing appropriate tools, and developing the proper education curriculum to equip current and future personnel with the knowledge and skills for deployment of this highly advanced system.
上传时间： 2020-06-07
上传用户：shancjb
软件开发人员必备工具书，，目录如下Welcome to Software Construction [1]1.1 What Is Software Construction?1.2 Why Is Software Construction Important?1.3 How to Read This Book......7.1 Valid Reasons to Create a Routine7.2 Design at the Routine Level7.3 Good Routine Names7.4 How Long Can a Routine Be?7.5 How to Use Routine Parameters7.6 Special Considerations in the Use of Functions7.7 Macro Routines and Inline RoutinesDefensive Programming [5.6 + new material]8.1 Protecting Your Program From Invalid Inputs8.2 Assertions8.3 Error Handling Techniques8.4 Exceptions8.5 Barricade Your Program to Contain the Damage caused by Errors8.6 Debugging Aids8.7 Determining How Much Defensive Programming to Leave in Production Code8.8 Being Defensive About Defensive ProgrammingThe Pseudocode Programming Process [4+new material]9.1 Summary of Steps in Building Classes and Routines9.2 Pseudocode for Pros9.3 Constructing Routines Using the PPP9.4 Alternatives to the PPP......
上传时间： 2021-12-08
上传用户：20125101110
入室抢劫事件屡见不鲜,针对此现象进行分析不难发现,造成失窃事件的极大原因是人们慵懒和意识差等不良性格造成习惯性不锁门.本文以STC89C52单片机为基础,设计了一种基于人体红外传感器的自动关门锁门装置,来解决此类问题.The incidents of burglary are so common. It is not difficult to find that the main reason for the burglary is the habit of unlocking of doors caused by people's laziness and poor consciousness. Based on the single chip microcomputer of STC89C52, a device used with infrared sensor of human body is introduced in this paper, which can achieve the effect of automatic closing and locking doors.
上传时间： 2022-03-27
上传用户：canderile
电学中的测量技术涉及范围非常广,电流测量在电学计量中占有非常重要的位置。如何精确地进行电流测量是精密测量的一大难题。传统的电流检测电路多采用运算放大芯片与片外电流检测电路相结合的方式,电路集成度很低,需要较多的接口和资源才能完成对电路的检测。本文把所有电路部分都集成在一块芯片上,包括检测电阻,运算放大器电路及模拟转数字转换电路,从而在电路内部可以进行电流检测,使电路更好的集成化。前置电路使用二级共源共栅结构的运算放大器,减小沟道长度调制效应造成的电流误差。10位SAR ADC中采用电容驱动能力强的传输门保证了模数转化器的有效精度。比较器模块采用再生锁存器与迟滞比较器作为基础单元组合解决精密测量的问题。本设计可以作为嵌入芯片内的一小部分而检测芯片中的微小电流1mA~100mA,工作电压在1.8v左右,电流检测精度预期达到10uA的需求。The measurement technology in electricity involves a wide range,and current measurement plays a very important position in electrical measurement.How to accurately measure current is a big problem in precision measurement. The traditional current detecting circuit adopts the combination of the operational amplifier chip and theoff-chip current detecting circuit, The circuit integration is very low, and more interfaces and resources are needed tocomplete the circuit detection.This topic integrates all the circuit parts into one chip, including detection resistance, operational amplifier circuit andanalog to digital conversion circuit. Highly integrated circuit makes the external resources on the chip more intensive,so that current detection can be carried out inside the circuit, so that the circuit can be better integrated. Thefront-end circuit of this project uses two-stage cascade operational amplifier and cascade tube to reduce the currenterror caused by channel length modulation effect. In 10-bit SAR ADC, the transmission gate with strong capacitivedriving ability ensures the effective accuracy of the analog-to-digital converter. Comparator module uses regenerativelatch and hysteresis comparator as basic unit to solve the difficult problem of precision measurement. This topic can beused as a small part of the embedded chip to detect the micro-current in the chip 1 mA~100 mA, the working voltageis about 1.8v, and the current detection accuracy is expected to reach the requirement of 10 uA.
上传时间： 2022-04-03
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Abstract: A sliding mode observer and fractional-order phase-locked loop (FO-PLL) method is proposed for the sensorless speed control of a permanent magnet synchronous motor (PMSM).The saturation function is adopted in order to reduce the chattering phenomenon caused by the sliding mode observer. In this proposed FO-PLL, method, a regulable fractional order r is involved, which means that the FO-PLL provides an extra degree of freedom. In fact, the conventional phase-locked loop (PLL) applied in sensorless PMSM control can be seen as a special case of the proposed FO-PLL. By selecting a proper fractional order r a better performance may be achieved. The computer simulation results demonstrate the effectiveness of the proposed method.Key words: fractional calculus; fractional order phase-locked loop; sensorless control; sliding mode observer; permanent magnet synchronous motor; speed controll
上传时间： 2022-06-18
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