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4g

4g通信技術(shù)是第四代的移動(dòng)信息系統(tǒng),是在3G技術(shù)上的一次更好的改良,其相較于3G通信技術(shù)來說一個(gè)更大的優(yōu)勢,是將WLAN技術(shù)和3G通信技術(shù)進(jìn)行了很好的結(jié)合,使圖像的傳輸速度更快,讓傳輸圖像的質(zhì)量和圖像看起來更加清晰。在智能通信設(shè)備中應(yīng)用4g通信技術(shù)讓用戶的上網(wǎng)速度更加迅速,速度可以高達(dá)100Mbps。[1]
  • 基于MTK7612/7628D的wifi 2.4g和5G開發(fā)資料

    基于MTK7612/7628D的wifi2.4g和5G開發(fā)資料AP-MT7628_IPAILNA_MT7612E_IPAILNA_V18_2L_SPI_DDR2_COCLOCK_WS3050_20150224.pdf

    標(biāo)簽: mt7628 wifi 5G

    上傳時(shí)間: 2022-07-04

    上傳用戶:xsr1983

  • SPI方式STM32F103與2.4g模塊NRF24L01收發(fā)通訊

    SPI方式STM32F103與2.4g模塊NRF24L01收發(fā)通訊           

    標(biāo)簽: spi stm32f103 nrf24l01 收發(fā)通訊

    上傳時(shí)間: 2022-07-05

    上傳用戶:

  • 4g移動(dòng)通信技術(shù)權(quán)威指南:LTE與LTE-Advanced.4g LTE.LTE

    PrefaceDuring the past years, there has been a quickly rising interest in radio access technologies for providingmobile as well as nomadic and fixed services for voice, video, and data. The difference indesign, implementation, and use between telecom and datacom technologies is also becoming moreblurred. One example is cellular technologies from the telecom world being used for broadband dataand wireless LAN from the datacom world being used for voice-over IP.Today, the most widespread radio access technology for mobile communication is digital cellular,with the number of users passing 5 billion by 2010, which is more than half of the world’s population.It has emerged from early deployments of an expensive voice service for a few car-borne users,to today’s widespread use of mobile-communication devices that provide a range of mobile servicesand often include camera, MP3 player, and PDA functions. With this widespread use and increasinginterest in mobile communication, a continuing evolution ahead is foreseen.This book describes LTE, developed in 3GPP (Third Generation Partnership Project) and providingtrue 4g broadband mobile access, starting from the first version in release 8 and through the continuingevolution to release 10, the latest version of LTE. Release 10, also known as LTE-Advanced,is of particular interest as it is the major technology approved by the ITU as fulfilling the IMTAdvancedrequirements. The description in this book is based on LTE release 10 and thus provides acomplete description of the LTE-Advanced radio access from the bottom up.Chapter 1 gives the background to LTE and its evolution, looking also at the different standardsbodies and organizations involved in the process of defining 4g. It also gives a discussion of the reasonsand driving forces behind the evolution.Chapters 2–6 provide a deeper insight into some of the technologies that are part of LTE and itsevolution. Because of its generic nature, these chapters can be used as a background not only for LTEas described in this book, but also for readers who want to understand the technology behind othersystems, such as WCDMA/HSPA, WiMAX, and CDMA2000.Chapters 7–17 constitute the main part of the book. As a start, an introductory technical overviewof LTE is given, where the most important technology components are introduced based onthe generic technologies described in previous chapters. The following chapters provide a detaileddescription of the protocol structure, the downlink and uplink transmission schemes, and the associatedmechanisms for scheduling, retransmission and interference handling. Broadcast operation andrelaying are also described. This is followed by a discussion of the spectrum flexibility and the associated

    標(biāo)簽: 4g 移動(dòng)通信

    上傳時(shí)間: 2022-07-08

    上傳用戶:

  • 2.4g小車遙控智能小車設(shè)計(jì)資料,包括遙控器資料,可移植添加重力感應(yīng)功能

    2.4g小車遙控智能小車設(shè)計(jì)資料,包括遙控器資料,可移植添加重力感應(yīng)功能

    標(biāo)簽: 遙控智能小車 重力感應(yīng)

    上傳時(shí)間: 2022-07-10

    上傳用戶:jason_vip1

  • 2.4g nRF24L01測試板原理圖和PCB源文件

    2.4g nRF24L01測試板原理圖和PCB源文件

    標(biāo)簽: nrf24l01 pcb

    上傳時(shí)間: 2022-07-10

    上傳用戶:

  • 聯(lián)發(fā)科MTK MT6735全模4g智能手機(jī)資料分享(原理圖和PCB).

    聯(lián)發(fā)科MTK MT6735全模4g智能手機(jī)資料分享(原理圖和PCB).

    標(biāo)簽: mtk mt6735 4g智能手機(jī)

    上傳時(shí)間: 2022-07-10

    上傳用戶:

  • XN297L-2.4g無線收發(fā)模塊-原理圖PCBXN297驅(qū)動(dòng)源碼

    XN297L-2.4g無線收發(fā)模塊-原理圖PCBXN297驅(qū)動(dòng)源碼

    標(biāo)簽: 無線收發(fā)模塊 pcbxn297

    上傳時(shí)間: 2022-07-10

    上傳用戶:1208020161

  • STM32407 USB驅(qū)動(dòng)4g模塊代碼

    STM32407 USB驅(qū)動(dòng)4g模塊代碼                        

    標(biāo)簽: stm32407 usb 4g模塊

    上傳時(shí)間: 2022-07-22

    上傳用戶:shjgzh

  • 2.4gHz天線選型及設(shè)計(jì)(英文).rar

    這是在網(wǎng)上找的關(guān)于2.4g天線的設(shè)計(jì)方法,對于在設(shè)計(jì)2.4g天線的同事應(yīng)該有點(diǎn)幫助

    標(biāo)簽: 2.4 GHz 天線

    上傳時(shí)間: 2013-06-16

    上傳用戶:古谷仁美

  • LTE系統(tǒng)中基帶DAGC的應(yīng)用研究及FPGA實(shí)現(xiàn).rar

    當(dāng)今,移動(dòng)通信正處于向第四代通信系統(tǒng)發(fā)展的階段,OFDM技術(shù)作為第四代數(shù)字移動(dòng)通信(4g)系統(tǒng)的關(guān)鍵技術(shù)之一,被包括LTE在內(nèi)的眾多準(zhǔn)4g協(xié)議所采用。IDFT/DFT作為OFDM系統(tǒng)中的關(guān)鍵功能模塊,其精度對基帶解調(diào)性能產(chǎn)生著重大的影響,尤其對LTE上行所采用的SC_FDMA更是如此。為了使定點(diǎn)化IDFT/DFT達(dá)到較好的性能,本文采用數(shù)字自動(dòng)增益控制(DAGC)技術(shù),以解決過大輸入信號動(dòng)態(tài)范圍所造成的IDFT/DFT輸出信噪比(SNR)惡化問題。 首先,本文簡單介紹了較為成熟的AAGC(模擬AGC)技術(shù),并重點(diǎn)關(guān)注近年來為了改善其性能而興起的數(shù)字化AGC技術(shù),它們主要用于壓縮ADC輸入動(dòng)態(tài)范圍以防止其飽和。針對基帶處理中具有累加特性的定點(diǎn)化IDFT/DFT技術(shù),進(jìn)一步分析了AAGC技術(shù)和基帶DAGC在實(shí)施對象,實(shí)現(xiàn)方法等上的異同點(diǎn),指出了基帶DAGC的必要性。 其次,根據(jù)LTE協(xié)議,搭建了從調(diào)制到解調(diào)的基帶PUSCH處理鏈路,并針對基于DFT的信道估計(jì)方法的缺點(diǎn),使用簡單的兩點(diǎn)替換實(shí)現(xiàn)了優(yōu)化,通過高斯信道下的MATLAB仿真,證明其可以達(dá)到理想效果。仿真結(jié)果還表明,在不考慮同步問題的高斯信道下,本文所搭建的基帶處理鏈路,采用64QAM進(jìn)行調(diào)制,也能達(dá)到在SNR高于17dB時(shí),硬判譯碼結(jié)果為極低誤碼率(BER)的效果。 再次,在所搭建鏈路的基礎(chǔ)上,通過理論分析和MATLAB仿真,證明了包括時(shí)域和頻域DAGC在內(nèi)的基帶DAGC具有穩(wěn)定接收鏈路解調(diào)性能的作用。同時(shí),通過對幾種DAGC算法的比較后,得到的一套適用于實(shí)現(xiàn)的基帶DAGC算法,可以使IDFT/DFT的輸出SNR處于最佳范圍,從而滿足LTE系統(tǒng)基帶解調(diào)的要求。針對時(shí)域和頻域DAGC的差異,分別選定移位和加法,以及查表的方式進(jìn)行基帶DAGC算法的實(shí)現(xiàn)。 最后,本文對選定的基帶DAGC算法進(jìn)行了FPGA設(shè)計(jì),仿真、綜合和上板結(jié)果說明,時(shí)域和頻域DAGC實(shí)現(xiàn)方法占用資源較少,容易進(jìn)行集成,能夠達(dá)到的最高工作頻率較高,完全滿足基帶處理的速率要求,可以流水處理每一個(gè)IQ數(shù)據(jù),使之滿足基帶解調(diào)性能。

    標(biāo)簽: DAGC FPGA LTE

    上傳時(shí)間: 2013-05-17

    上傳用戶:laozhanshi111

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