分类：设计开发    下载：2    浏览：698    时间：2017-07-31

李园，孙雅东，黄超 (吉林大学通信工程学院，长春130012) 摘要：为了研究Ad Hoe网络DSR (Dynamic Source Routing)、DSDV (Destination Sequenced Distance Vector Rou— ting)、AODV (Ad hoe Demand Distance Vector Routing)3种路由协议的TCP(Transfer Control Protoco1)传输性能，在原理上对其进行了分析，并通过仿真实验予以验证。结果表明，DSDV适用于跳数较少的TCP连接，DSR和AODV适用于跳数较多的TCP连接，复杂场景中DSDV总体性能最优。 关键词：Ad Hoe 网络；TCP协议；路由协议

分类：设计开发    下载：2    浏览：477    时间：2017-08-03

射频(RF)电路的电路板布局应在理解电路板结构、电源布线和接地基本原则的基础上进行。本文探讨了相关的基本原则，并提供了一些实用的、经过验证的电源布线、电源旁路和接地技术，可有效提高RF设计的性能指标。考虑到实际设计中PLL杂散信号对于电源耦合、接地和滤波器元件的位置非常敏感，本文着重讨论了有关PLL杂散信号抑制的方法。为便于说明问题，本文以MAX2827 802.11a/g收发器的PCB布局作为参考设计。

分类：设计开发    下载：2    浏览：351    时间：2017-07-31

摘 要 无线Mesh网络中TCP流之间存在严重的传输不公平现象，难于获得高质量且公平的TCP服务．对无线Mesh网络中影响TCP性能的各层协议进行建模有助于TCP公平性影响因素的分析和改进协议的设计．利用Markov链对基于IEEE 802．1lb／g的无线Mesh网络中节点MAC层状态转换和TCP协议状态转换建模，并据此对TCP的延迟和吞吐量进行了理论分析．模拟实验结果与理论分析结果的对比证明了基于Markov链的无线Mesh网络TCP公平性建模与分析的正确性．根据建模分析总结的无线Mesh网络TCP公平性重要影响因素对改进无线Mesh网络TCP公平性研究有重要指导意义． 关键词 无线Mesh网络，TCP，公平性，Markov链

分类：设计开发    下载：2    浏览：369    时间：2017-08-12

来原：http://www.anywlan.com/thread-2855-1-1.html 2006年6月专题索引——OFDM与MIMO技术 评价：良 介绍802.11n标准及OFDM与MIMO技术原理。 [attach]779[/attach]

分类：设计开发    下载：2    浏览：429    时间：2017-08-04

PCB原理图

分类：设计开发    下载：2    浏览：535    时间：2017-08-25

这是较早期的SDK，最新的SDK请搜索本站下载，同时本站也有MTK相关编译教程下载。

分类：设计开发    下载：2    浏览：811    时间：2017-08-25

1 SDK History .................................................................................................................................. 9 2 Version History........................................................................................................................... 14 3 Overview of the Ralink AP Demo Board ................................................................................. 15 3.1 RT2880 .................................................................................................................................. 15 3.2 RT3052 .................................................................................................................................. 19 3.3 RT3883 .................................................................................................................................. 21 3.4 RT3352 .................................................................................................................................. 24 3.5 RT5350 .................................................................................................................................. 26 3.6 RT6855 .................................................................................................................................. 29 3.7 RT6856 .................................................................................................................................. 30 3.8 MT7620 .................................................................................................................................. 32 4 AP SDK source code overview ................................................................................................ 36 5 Tool-chain ................................................................................................................................... 37 5.1 Install toolchain ...................................................................................................................... 37 5.2 Install LZMA Utility................................................................................................................. 37 5.3 Install mksquashfs utility ....................................................................................................... 37 6 Boot loader ................................................................................................................................. 39 6.1 Uboot Configuration .............................................................................................................. 39 6.2 Build the uboot Image ........................................................................................................... 40 6.3 Burn the uboot image ........................................................................................................... 40 7 User Library ................................................................................................................................ 42 7.1 Library Configuration............................................................................................................. 42 7.2 Library Porting ........................................................................................................................ 42 7.3 Build user library .................................................................................................................... 43 8 User Application......................................................................................................................... 44 8.1 Ralink Proprietary Applications ........................................................................................... 44 8.1.1 ATED ............................................................................................................................. 44 8.1.2 REG ............................................................................................................................... 44 8.1.3 FLASH ........................................................................................................................... 44 8.1.4 GPIO .............................................................................................................................. 45 8.1.5 MII_MGR ....................................................................................................................... 45 8.1.6 MTD ............................................................................................................................... 46 8.1.7 NVRAM.......................................................................................................................... 47 8.1.8 SPICMD ........................................................................................................................ 48 8.1.9 I2CCMD ......................................................................................................................... 48 8.1.10 Script .............................................................................................................................. 49 8.2 goahead ................................................................................................................................. 49 8.3 nvram library .......................................................................................................................... 49 8.4 wsc_upnp ............................................................................................................................... 49 8.5 iptables ................................................................................................................................... 49 8.6 ntpclient .................................................................................................................................. 49 8.7 mtd-utils ................................................................................................................................. 50 8.8 ppp-2.4.2 ................................................................................................................................ 50 8.9 bridge-utils .............................................................................................................................. 50 8.10 wireless_tools ......................................................................................................................... 50 8.11 inadyn ..................................................................................................................................... 50 8.12 zebra-0.95a_ripd .................................................................................................................... 50 8.13 wpa_supplicant-0.5.7 ............................................................................................................ 51 8.14 totd-1.5 ................................................................................................................................... 51 8.15 samba-3.0.2 ........................................................................................................................... 51 8.16 radvd-1.0 ................................................................................................................................ 51 8.17 pptp-client ............................................................................................................................... 51 8.18 rp-l2tp-0.4 ............................................................................................................................... 51 8.19 ctorrent-dnh3.2 ...................................................................................................................... 52 8.20 dhcp6 ...................................................................................................................................... 52 8.21 dnsmasq-2.40 ........................................................................................................................ 52 8.22 igmpproxy ............................................................................................................................... 52 8.23 matrixssl-1.8.3 ........................................................................................................................ 52 8.24 rp-pppoe-3.8 ........................................................................................................................... 53 8.25 usb_modeswitch-0.9.5 .......................................................................................................... 53 8.26 Port new user application ..................................................................................................... 53 9 Linux Kernel ............................................................................................................................... 56 9.1 Linux configuration ................................................................................................................ 56 9.2 Change Flash/DRAM Size ................................................................................................... 58 9.3 Change Switch Controller in RT2880 Platform ................................................................. 58 9.4 Update User/Kernel default settings ................................................................................... 59 9.5 Compile Linux image ............................................................................................................ 60 9.6 Port new Linux kernel module ............................................................................................. 60 9.7 Execute commands at boot up time ................................................................................... 62 9.8 Add new files in RootFs ........................................................................................................ 62 9.9 Image DownSize ................................................................................................................... 62 10 Flash Layout and Firmware Upgrade ...................................................................................... 66 10.1 Flash Layout ........................................................................................................................... 66 10.2 Firmware Upgrade................................................................................................................. 67 10.2.1 By Uboot........................................................................................................................ 67 10.2.2 By WebUI ...................................................................................................................... 68 11 FAQ ............................................................................................................................................. 70 11.1 RT2880 Default password/UART/networking setting ...................................................... 70 11.2 System requirements for the host platform........................................................................ 70 11.3 How to add new default parameter in flash ....................................................................... 71 11.3.1 Example 1 ..................................................................................................................... 71 11.3.2 Example 2 ..................................................................................................................... 71 11.4 Enable Ethernet Converter Feature .................................................................................... 72 11.5 Change RF chip from RT2820 to RT2850 on the RT2880 platform .............................. 74 11.6 How to change the Ethernet MAC address ....................................................................... 74 11.7 How to configure GPIO ports ............................................................................................... 75 11.8 Use GPIO to turn on LED ..................................................................................................... 76 11.9 Use LED firmware to turn on LED ...................................................................................... 80 11.10 How to start the telnet server ............................................................................................... 83 11.10.1 busybox setting ............................................................................................................ 83 11.10.2 Linux setting .................................................................................................................. 83 11.11 11n bit rate derivation ........................................................................................................... 84 11.12 How to build a single image for the flash programmer .................................................... 87 11.13 How to power down the RT3x5x build-in 10/100 PHYs ................................................... 89 11.14 How to power down the RT6855/RT6856 build-in 10/100 PHYs ................................... 90 11.15 How to enable NFS client ..................................................................................................... 91 11.16 How to add a new language to the web UI ........................................................................ 92 11.17 How to enable watchdog ...................................................................................................... 93 11.18 How to enable USB storage on the RT305x platform ...................................................... 94 11.19 How to enable USB automount on the RT305x platform ................................................ 95 11.20 How to enable software QoS ............................................................................................... 96 11.21 Software QoS information .................................................................................................... 99 11.21.1 Software QoS – Preface ............................................................................................. 99 11.21.2 Software QoS – Concept ............................................................................................ 99 11.21.3 Software QoS – Usage ............................................................................................... 99 11.22 How to enable USB Ethernet (example for ASIX AX88XXX) ....................................... 103 11.23 How to build a single image for the RT2880 8M flash platform .................................... 104 11.24 How to start a printer server (example for HP officejet 4355) ....................................... 105 11.25 How to force the RT3052 link speed ................................................................................ 107 11.26 How to verify IGMP snooping function ............................................................................. 109 11.27 EHCI/OHCI USB Power Saving ........................................................................................ 110 11.28 Auto-frequency and Power Saving ................................................................................... 111 11.29 Concurrent AP porting Guide ............................................................................................ 116 11.30 SuperDMZ usage guide ..................................................................................................... 125 11.31 How to support IPv6 Ready Logo ..................................................................................... 126 11.32 How to enable iPerf tool ..................................................................................................... 128 11.33 How to enable ebtables ...................................................................................................... 129 11.34 How to enable IPv6 Rapid Deployment (6rd) .................................................................. 129 11.35 How to enable IPv6 DS-Lite ............................................................................................... 133 11.36 How to modify flash layout ................................................................................................. 137 11.37 How to reduce Linux FW size. ........................................................................................... 140 11.38 How to change internal GSW PHY Base Address. ........................................................ 141 11.39 How to support new USB 3G dongle ................................................................................ 141 11.40 How to enable USB 3G dongle function .......................................................................... 142

分类：设计开发    下载：2    浏览：929    时间：2017-08-02

郑 军，樊 艳 (浙江林学院浙江临安311300) 摘要：TR—UWB系统采用自相关接收检测技术作为一种非最优接收机，其结构简单、性能优良。对TR—UWB系统的自相关接收检测技术进行改进，通过合并有限数目多径信号以提高接收信号能量，同时对接收信号做平均处理抑制噪声，从而提高系统性能。采用高斯近似法得到系统的误码率，最后在多径信道环境下进行仿真，验证了接收机性能的改进和误码率分析的正确。 关键词：TR—UWB；自相关接收机；多径；噪声抑制

分类：设计开发    下载：2    浏览：803    时间：2017-08-02

【文件原名】：支持VoWLAN的PCF轮询调度算法研究 Research on PCF Polling Scheduling Algorithm Supporting VoWLAN Applications 【资料成文时间】：2005年 【语言】：中文 【页数】：3 【作者】：万泉, 杜明辉 【文件格式】：pdf 【摘要或目录】：就802. 11 WLAN中MAC层点协调功能(PCF)状态下点协调器(PC)对各个站点分配媒体访问权的轮询机制进行分析并加以改进,通过引入不同优先级的业务区分机制,提出一种新的轮询调度算法,从而提高站点数据接入服务的性能,以满足VoIP over WLAN应用的QoS需求. 关键词: VoWLAN, 服务质量保证, 点协调功能, 分布式协调功能, 轮询

分类：设计开发    下载：2    浏览：471    时间：2017-07-29

王春东1,2，王秀峰1 (1. 南开大学信息科学技术学院，天津 300071；2. 天津理工大学计算机科学与工程系，天津 300191) 摘要：研究了在基于802.11的系统中，如何通过信号强度进行移动设备的室内定位。在研究并实现最大群中心定位算法MCCPA的基础之上，给出了一种利用移动终端的历史位置信息对定位结果进行修正的室内定位算法(MMCCPA)。其主要思想是，在给定前一时间使用者所在位置的条件下，将使用者出现在特定范围的概率列入考量加以修正，并作为对环境因素影响的调整，这样不仅减少计算量，而且明显提高了位置估算的正确率。 关键词：无线网络；信号强度；定位算法；802.11；历史记录 Research on 802.11-based Indoor Positioning Algorithm WANG Chundong1,2, WANG Xiufeng1 (1. College of Information Science Technology, Nankai University, Tianjin 300071; 2. Dept. of Computer Science & Engineering, Tianjin University of Technology, Tianjin 300191) 【Abstract】This paper focuses on how to position the mobile device indoor by using signal strength in 802.11-based system. It introduces a802.11-based positioning system called the maximal cluster centered positioning algorithm (MCCPA). The MCCP system locates mobile objects viacollecting the sensed power strengths of the mobile objects to multiple wireless access points. Based on realizing MCCPA, the paper gives a newalgorithm named MMCCPA to correct the positioning results by using the history record information of mobile devices. The main idea of MMCCPAis that it also considers the probability of users’ appearance in the specific area in order to correct results, as an adjustment to the environmentfactors, so as to increase the preciseness and decrease the count quantity.The experimental results show that the location information provided byMMCCPA assures higher correctness than MCCPA. 【Key words】Wireless networks; Signal strength; Positioning algorithm; 802.11; History record

分类：设计开发    下载：2    浏览：450    时间：2017-07-29

王 军1,2,3，王宏1，徐皑冬1，周侗1 （1. 中国科学院沈阳自动化研究所，沈阳 110016；2. 中国科学院研究生院，北京 100039； 3. 沈阳化工学院计算机科学与技术学院，沈阳 110142） 摘 要：EPA是我国第一个拥有自主知识产权的现场总线标准，现已正式成为IEC的PAS文件。作者在参与开发出“基于无线局域网的EPA网络控制系统”的相关设备后，分析和探讨了为适应不同需要的EPA若干无线与有线网段集成的方案。同时，提出了一种符合EPA标准的无线现场总线设备结构的实现模型。从而为实现了EPA进一步向无线工业现场总线进军提供了一定的理论基础。 关键词：EPA；集成模式；无线现场总线 Research of Integrated Wired/Wireless Fieldbus on EPA WANG Jun1,2,3, WANG Hong1, XU Aidong1, ZHOU Tong1 (1.Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016; 2. Graduate School, Chinese Academy of Sciences, Beijing 100039; 3. School of Computer Science & Technology, Shenyang Institute of Chemical Technology, Shenyang 110142) 【Abstract】The EPA profile that is the first industry Ethernet profile of China is constituted. It has been a PAS in IEC. After the authordevelopedequipment of EPA network control system on WLAN, the paper analyses and expatiates some methods for an integrated hybrid(wired/wireless) EPAfieldbus to adapt to different conditions, and provides a model of wireless fieldbus equipment framework on EPA. It provides some theoryfoundation for EPA occupying more market on wireless fieldbus. 【Key words】EPA; Integration mode; Wireless fieldbus

分类：设计开发    下载：2    浏览：436    时间：2017-07-29

刘军, 郭伟, 肖百龙, 黄飞 ( 电子科技大学通信抗干扰技术国家级重点实验室, 四川成都610054) 摘要: 通过分析IEEE 802. 11 DCF 的分组发送过程, 获得了RTS 和基本方式下分组传输的时间开销。给出了以最小化传输时间开销代价为优化目标的最优RTS 门限的计算公式。通过对当前信道分组发送的成功概率Ps 的预测, 实现了最优RTS 门限的计算, 并给出了一个具体的自适应RTS 门限调整算法, 使终端能自动调整其RTS 门限以达到或接近最优值。仿真表明自适应RTS 门限调整算法有效减小了MAC 分组传送的时间开销, 提高了信道的传输效率。 关键词: 无线局域网; 802. 11 DCF; RTS 门限; 分组成功传送概率; 自适应RTS 门限调整