在車載自組網中，路由協議很大程度上決定了整個網絡的性能。如何有效的利用車流信息提高傳輸質量是改善路由性能的一個關鍵問題。本文基于速度-密度線性模型，提出了一種實時車流密度的路由協議RVDR（Real-time Vehicle Density Routing）。該協議通過與鄰居節點交換的速度信息，對相關道路車流密度進行預測，并給出基于車流密度信息的路徑選擇方法。仿真結果表明，與現有協議相比，RVDR協議在實時性和高效性等性能方面得到改進。
上傳時間： 2014-07-10
上傳用戶：ZJX5201314
摘 要： 針對非同分布的Nakagami信道，基于矩生成函數MGF(Moment Generation Function)的分析方法，提出正交空時分組碼系統STBC(Space-Time Block Coding)的一種快速性能評估算法，不需要涉及超幾何函數積分運算，可在中高信噪比時，快速準確地估計STBC系統的符號錯誤概率性能。在平坦瑞利衰落信道下的計算機仿真表明，該算法與已有的STBC系統的近似估計算法相比，具有較優的性能。 關鍵詞： 正交空時分組碼； MIMO； MGF； 誤符號率
上傳時間： 2014-12-29
上傳用戶：如果你也聽說
為提升虛擬儀器傳輸速率與實時性能，擴展監測范圍，在VC的軟件平臺上設計了一種全功能虛擬示波器。與傳統虛擬示波器相比，該系統采用嵌入式系統完成信號采集，采用工業以太網為傳輸介質，通過線性插值算法和多線程編程思想，實現波形顯示、參數計算、頻譜分析以及波形存儲及回放功能。實驗結果表明，該虛擬示波器可以實現20 kHz采樣頻率下的波形精確顯示，達到預期的各項指標。 Abstract: o enhance the transfer rate and real-time of virtual instrument performance， expand scope of monitoring， this paper uses the VCs software platform to design a fully functional virtual oscilloscope. Compared with traditional virtual oscilloscope， this system adopts the embedded system to complete the data acquisition， industrial Ethernet as the transmission medium used by the linear interpolation algorithm and multi-threaded programming ideas， namely to achieve waveform display， parameter calculation， spectrum analysis and waveform storage and playback. Experimental results show that the virtual oscilloscope can accurately display the waveform with 20kHz sampling frequency， and achieve the desired targets.
上傳時間： 2013-11-25
上傳用戶：wbwyl
The field of microelectromechanical systems (MEMS), particularly micromachinedmechanical transducers, has been expanding over recent years, and the productioncosts of these devices continue to fall. Using materials, fabrication processes, anddesign tools originally developed for the microelectronic circuits industry, newtypes of microengineered device are evolving all the time—many offering numerousadvantages over their traditional counterparts. The electrical properties of siliconhave been well understood for many years, but it is the mechanical properties thathave been exploited in many examples of MEMS. This book may seem slightlyunusual in that it has four editors. However, since we all work together in this fieldwithin the School of Electronics and Computer Science at the University of Southampton,it seemed natural to work together on a project like this. MEMS are nowappearing as part of the syllabus for both undergraduate and postgraduate coursesat many universities, and we hope that this book will complement the teaching thatis taking place in this area.
上傳時間： 2013-10-16
上傳用戶：朗朗乾坤
Contents 1 Introduction 1 2 Glosary 1 2.1 Concepts 1 2.2 Abbreviations and acronyms 4 3 Capabilities 6 4 Technical Description 6 4.1 General 6 4.2 Service oriented Allocation of Resources on the Abis interface (SARA) 8 4.3 Configuration of dedicated PDCHs in Packet Switched Domain (PSD) 10 4.4 Handling of Packet Data traffic 15 4.5 Channel selection in Cicuit Switched Domain (CSD) 19 4.6 Return of PDCHs to Cicuit Switched Domain (CSD) 22 4.7 Main changes in Ericsson GSM system R10/BSS R10 24 5 Engineering guidelines 24 6 Parameters 26 6.1 Main controlling parameters 26 6.2 Parameters for special adjustments 26 6.3 Value ranges and default values 28 7 References 29
上傳時間： 2013-11-12
上傳用戶：ainimao
User ManualRev. 1.2SmartRF® CC2420DK: Packet Sniffer for IEEE 802.15.4 and ZigBee Table of contents1 INTRODUCTION...............................................................................................31.1 HARDWARE PLATFORM.......................................................................................31.2 SOFTWARE.........................................................................................................32 USER INTERFACE..........................................................................................42.1 MENUS AND TOOLBARS.......................................................................................62.2 SETUP................................................................................................................62.3 SELECT FIELDS...................................................................................................72.3.1 Tips............................................................................................................72.4 PACKET DETAILS.................................................................................................72.5 ADDRESS BOOK..................................................................................................92.5.1 Tips............................................................................................................92.6 DISPLAY FILTER................................................................................................102.7 TIME LINE.........................................................................................................103 HELP....................................................................................................................114 TROUBLESHOOTING..................................................................................125 GENERAL INFORMATION........................................................................135.1 DOCUMENT HISTORY........................................................................................135.2 DISCLAIMER......................................................................................................135.3 TRADEMARKS...................................................................................................136 ADDRESS INFORMATION........................................................................14
上傳時間： 2014-01-14
上傳用戶：zhangyi99104144
A Computer-On-Module, or COM, is a Module with all components necessary for a bootable host computer, packaged as a super component. A COM requires a Carrier Board to bring out I/O and to power up. COMs are used to build single board computer solutions and offer OEMs fast time-to-market with reduced development cost. Like integrated circuits, they provide OEMs with significant freedom in meeting form-fit-function requirements. For all these reasons the COM methodology has gained much popularity with OEMs in the embedded industry. COM Express® is an open industry standard for Computer-On-Modules. It is designed to be future proof and to provide a smooth transition path from legacy parallel interfaces to LVDS (Low Voltage Differential Signaling) interfaces. These include the PCI bus and parallel ATA on the one hand and PCI Express and Serial ATA on the other hand.
上傳時間： 2013-11-05
上傳用戶：Wwill
We all know the benefits of using FieldProgrammable Gate Arrays (FPGAs): no NRE, nominimum order quantities, and faster time-tomarket.In an ideal world, designs would never needto be changed because of design errors, but we allknow that sometimes this is necessary.
上傳時間： 2013-11-04
上傳用戶：leixinzhuo
The use of the Wind River VxWorks Real-Time Operating System (RTOS) on Virtex™-4embedded PowerPC™ processors continues to be a popular choice for high performanceFPGA designs. The introduction of the Wind River Workbench design environment has enableda new and easier way for designers to control the configuration of the VxWorks kernel. Thisguide shows the steps required to build and configure a ML403 Embedded DevelopmentPlatform to boot and run the VxWorks RTOS. A VxWorks bootloader is created, programmedinto Flash, and used to boot the design. The concepts presented here can be scaled to anyPowerPC enabled development platform.
上傳時間： 2013-10-26
上傳用戶：agent
The NCV7356 is a physical layer device for a single wire data linkcapable of operating with various Carrier Sense Multiple Accesswith Collision Resolution (CSMA/CR) protocols such as the BoschController Area Network (CAN) version 2.0. This serial data linknetwork is intended for use in applications where high data rate is notrequired and a lower data rate can achieve cost reductions in both thephysical media components and in the microprocessor and/ordedicated logic devices which use the network.The network shall be able to operate in either the normal data ratemode or a high-speed data download mode for assembly line andservice data transfer operations. The high-speed mode is onlyintended to be operational when the bus is attached to an off-boardservice node. This node shall provide temporary bus electrical loadswhich facilitate higher speed operation. Such temporary loads shouldbe removed when not performing download operations.The bit rate for normal communications is typically 33 kbit/s, forhigh-speed transmissions like described above a typical bit rate of83 kbit/s is recommended. The NCV7356 features undervoltagelockout, timeout for faulty blocked input signals, output blankingtime in case of bus ringing and a very low sleep mode current.
上傳時間： 2013-10-24
上傳用戶：s藍莓汁
