無線局域網是計算機網絡技術和無線通信技術相結合的產物，是利用無線媒介傳輸信息的計算機網絡。在無線通信信道中，由于多徑時延不可避免地存在符號間干擾，正交頻分復用(OFDM)作為一種可以有效對抗符號間干擾(ISI)和提高頻譜利用率的高速傳輸技術，引起了廣泛關注。在無線局域網(WLAN)系統中，OFDM調制技術已經被采用作為其物理層標準，并且公認為是下一代無線通信系統中的核心技術。基于IEEE802.11a的無線局域網標準的物理層采用了OFDM技術，能有效的對抗多徑信道衰落，達到54Mbps的速度，而未來而的IEEE802.11N將達到100Mbps的高速。因此，研發以OFDM為核心的原型機研究非常有必要。 本文在深入理解OFDM技術的同時，結合相應的EDA工具對系統進行建模并基于IEEE802.11a物理層標準給出了一種OFDM基帶發射機系統的FPGA實現方案。整個設計采用目前主流的自頂向下的設計方法，由總體設計至詳細設計逐步細化。在系統功能模塊的FPGA實現過程中，針對Xilinx一款160萬門的Spartan-3E XCS1600E芯片，依照：IEEE802.11a幀格式，對發射機系統各個模塊進行了詳細設計和仿真： (1)訓練序列生成模塊，包括長，短訓練序列； (2)信令模塊，包括卷積編碼，交織，BPSK調制映射； (3)數據模塊，包括加擾，卷積編碼，刪余，交織，BPSK/QPSK/16QAM/64QAM調制映射； (4)OFDM處理部分，包括導頻插入，加循環前綴，IFFT處理； (5)對整個發射處理部分聯調，并給出仿真結果另外，還完成了接收機部分模塊的FPGA設計，并給出了相應的頂層結構與仿真波形。最后提出了改進和進一步開發的方向。
上傳時間： 2013-04-24
上傳用戶：李彥東
MIMO(Multiple-Input Multiple-Out-put)系統是一項運用于802.11N的核心技術。本篇文章全面介紹了MIMO系統多天線技術。
上傳時間： 2013-05-23
上傳用戶：LSPSL
搭建無線AP網絡，我們都需要慎重！
上傳時間： 2013-10-16
上傳用戶：元宵漢堡包
ralink最新rt3070 usb wifi 無線網卡驅動程序，支持802.11N draft2.0標準，極具參考價值
上傳時間： 2014-01-09
上傳用戶：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.
上傳時間： 2020-05-26
上傳用戶：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.
標簽： Communications MIMO-OFDM Wireless MATLAB with
上傳時間： 2020-05-28
上傳用戶：shancjb
該文檔為IEEE802_11N標準下的4G關鍵技術解析講解文檔，是一份很不錯的參考資料，具有較高參考價值，感興趣的可以下載看看
上傳時間： 2022-04-11
上傳用戶：
FU6831/11 是一款集成 8051 內核和電機控制引擎(ME)的電機驅動專用芯片，8051 內核處理常規事務，ME 處理電機實時事務，雙核協同工作實現各種高性能電機控制。其中 8051 內核大部分指令周期為 1T 或 2T，芯片內部集成有高速運算放大器、比較器、Pre-driver(FU6811 除外)、高速 ADC、高速乘/除法器、CRC、SPI、I2C、UART、多種 TIMER、PWM 等功能，內置高壓 LDO，適用于BLDC/PMSM 電機的方波、SVPWM/SPWM、FOC 驅動控制。預驅動類型為：FU6811 為 Gate Driver 輸出；FU6831 為 3P3N Predriver 輸出。
標簽： FU6831
上傳時間： 2022-07-09
上傳用戶：
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)
標簽： mt7628
上傳時間： 2022-07-18
上傳用戶：
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.
上傳時間： 2022-07-24
上傳用戶：
