无线局域网是计算机网络技术和无线通信技术相结合的产物，是利用无线媒介传输信息的计算机网络。在无线通信信道中，由于多径时延不可避免地存在符号间干扰，正交频分复用(OFDM)作为一种可以有效对抗符号间干扰(ISI)和提高频谱利用率的高速传输技术，引起了广泛关注。在无线局域网(WLAN)系统中，OFDM调制技术已经被采用作为其物理层标准，并且公认为是下一代无线通信系统中的核心技术。基于IEEE802.11a的无线局域网标准的物理层采用了OFDM技术，能有效的对抗多径信道衰落，达到54Mbps的速度，而未来而的IEEE802.11N将达到100Mbps的高速。因此，研发以OFDM为核心的原型机研究非常有必要。 本文在深入理解OFDM技术的同时，结合相应的EDA工具对系统进行建模并基于IEEE802.11a物理层标准给出了一种OFDM基带发射机系统的FPGA实现方案。整个设计采用目前主流的自顶向下的设计方法，由总体设计至详细设计逐步细化。在系统功能模块的FPGA实现过程中，针对Xilinx一款160万门的Spartan-3E XCS1600E芯片，依照：IEEE802.11a帧格式，对发射机系统各个模块进行了详细设计和仿真： (1)训练序列生成模块，包括长，短训练序列； (2)信令模块，包括卷积编码，交织，BPSK调制映射； (3)数据模块，包括加扰，卷积编码，删余，交织，BPSK/QPSK/16QAM/64QAM调制映射； (4)OFDM处理部分，包括导频插入，加循环前缀，IFFT处理； (5)对整个发射处理部分联调，并给出仿真结果另外，还完成了接收机部分模块的FPGA设计，并给出了相应的顶层结构与仿真波形。最后提出了改进和进一步开发的方向。
上传时间： 2013-04-24
上传用户：李彦东
MIMO(Multiple-Input Multiple-Out-put)系统是一项运用于802.11N的核心技术。本篇文章全面介绍了MIMO系统多天线技术。
上传时间： 2013-05-23
上传用户：LSPSL
搭建无线AP网络，我们都需要慎重！
上传时间： 2013-10-16
上传用户：元宵汉堡包
ralink最新rt3070 usb wifi 无线网卡驱动程序，支持802.11N draft2.0标准，极具参考价值
上传时间： 2014-01-09
上传用户：change0329
A decade ago, I first wrote that people moved, and networks needed to adapt to the reality that people worked on the go. Of course, in those days, wireless LANs came with a trade-off. Yes, you could use them while moving, but you had to trade a great deal of throughput to get the mobility. Although it was possible to get bits anywhere, even while in motion, those bits came slower. As one of the network engineers I worked with put it, “We’ve installed switched gigabit Ethernet everywhere on campus, so I don’t understand why you’d want to go back to what is a 25-megabit hub.” He un- derestimated the allure of working on the go.
上传时间： 2020-05-26
上传用户：shancjb
MIMO-OFDM is a key technology for next-generation cellular communications (3GPP-LTE, Mobile WiMAX, IMT-Advanced) as well as wireless LAN (IEEE 802.11a, IEEE 802.11N), wireless PAN (MB-OFDM), and broadcasting (DAB, DVB, DMB). This book provides a comprehensive introduction to the basic theory and practice of wireless channel modeling, OFDM, and MIMO, with MATLAB ? programs to simulate the underlying techniques on MIMO-OFDMsystems.Thisbookisprimarilydesignedforengineersandresearcherswhoare interested in learning various MIMO-OFDM techniques and applying them to wireless communications.
标签： Communications MIMO-OFDM Wireless MATLAB with
上传时间： 2020-05-28
上传用户：shancjb
该文档为IEEE802_11N标准下的4G关键技术解析讲解文档，是一份很不错的参考资料，具有较高参考价值，感兴趣的可以下载看看
上传时间： 2022-04-11
上传用户：hbsun
FU6831/11 是一款集成 8051 内核和电机控制引擎(ME)的电机驱动专用芯片，8051 内核处理常规事务，ME 处理电机实时事务，双核协同工作实现各种高性能电机控制。其中 8051 内核大部分指令周期为 1T 或 2T，芯片内部集成有高速运算放大器、比较器、Pre-driver(FU6811 除外)、高速 ADC、高速乘/除法器、CRC、SPI、I2C、UART、多种 TIMER、PWM 等功能，内置高压 LDO，适用于BLDC/PMSM 电机的方波、SVPWM/SPWM、FOC 驱动控制。预驱动类型为：FU6811 为 Gate Driver 输出；FU6831 为 3P3N Predriver 输出。
标签： FU6831
上传时间： 2022-07-09
上传用户：kid1423
Overview The MT7628 router-on-a-chip includes an 802.11N MAC and baseband,a 2.4 GHz radio and FEM,a 575/580MHz MIPS? 24K% CPU core,a 5-port 10/100 fast ethernet switch. The MT7628 includes everything needed to build an AP router from a single chip. The embedded high performance CPU can process advanced applications effortlessly, such as routing, security and VolP. The MT7628 also includes a selection of interfaces to support a variety of applications, such as a USB port for accessing external storage.Features· Embedded MIPS24KEc(575/580 MHz) with 64KBl-Cache and 32 KB D-Cache·2T2R 2.4 GHz with 300 Mbps PHY data rate· Legacy 802.11b/g and HT 802.11N modes·20/40 MHz channel bandwidth· Reverse Data Grant(RDG)· Maximal Ratio Combining(MRC)· Space Time Block Coding(STBC)· MCM 8 Mbytes DDR1 KGD(MT7628KN)
标签： mt7628
上传时间： 2022-07-18
上传用户：lw125849842
MT7688 family integrates a 1T1R 802.11N Wi-Fi radio,a 580MHz MIPS? 24KEcTM CPU,1-port fast Ethernet PHY, USB2.0 host, PCIe, SD-XC,I2S/PCM and multiple slow IOs. MT7688 provides two operation modes-IoT gateway mode and IoT device mode. In IoT gateway mode, the PCI Express interface can connect to 802.1lac chipset for 1lac dual-band concurrent gateway. The high performance USB2.0 allows MT7688 to add 3G/LTE modem support or add a H.264 ISP for wireless IP camera. For the IoT device mode, MT7688 supports eMC, SD-XC and USB 2.0. MT7688 can support the Wifi high quality audio via 192Kbps/24bits I2S interface and VolP application through PCM. In IoT device mode, it further supports PWM, SPI slave,3d UARI and more GPIOs. For IoT gateway, it canl connect to touch panel and BLE, Zigbee/Z-Wave and sub-1G RF for smart home control.
上传时间： 2022-07-24
上传用户：13692533910
