In the nineteenth century, scientists, mathematician, engineers and innovators started investigating electromagnetism. The theory that underpins wireless communications was formed by Maxwell. Early demonstrations took place by Hertz, Tesla and others. Marconi demonstrated the first wireless transmission. Since then, the range of applications has expanded at an immense rate, together with the underpinning technology. The rate of development has been incredible and today the level of technical and commercial maturity is very high. This success would not have been possible without understanding radio- wave propagation. This knowledge enables us to design successful systems and networks, together with waveforms, antennal and transceiver architectures. The radio channel is the cornerstone to the operation of any wireless system.
標簽: LTE-Advanced Generation Next and
上傳時間: 2020-05-27
上傳用戶:shancjb
Today, our everyday life is almost impossible to detach from the influence of wireless mobile communication technologies. This global trend is growing exponentially, and the mobile-only data traffic is expected to exceed stationary data traffic. However, for further development of mobile communication, there is a major obstacle to overcome, which is the resource-paucity of portable devices relative to stationary hardware.
標簽: LTE-Advanced Mechanism DRX
上傳時間: 2020-05-27
上傳用戶:shancjb
This books attempts to provide an extensive overview on Long-Term Evolution (LTE) networks. Understanding LTE and its Performance is purposely written to appeal to a broad audience and to be of value to anyone who is interested in 3GPP LTE or wireless broadband networks more generally. The aim of this book is to offer comprehensive coverage of current state-of-the-art theoretical and techno- logical aspects of broadband mobile and wireless networks focusing on LTE. The presentation starts from basic principles and proceeds smoothly to most advanced topics. Provided schemes are developed and oriented in the context of very actual closed standards, the 3 GPPP LTE.
標簽: Performance LTE and its
上傳時間: 2020-05-27
上傳用戶:shancjb
用DirectX制作高級動畫-[Advanced.Animation.with.DirectX]
標簽: DirectX Animation Advanced with
上傳時間: 2013-05-23
上傳用戶:eeworm
當今,移動通信正處于向第四代通信系統發展的階段,OFDM技術作為第四代數字移動通信(4G)系統的關鍵技術之一,被包括LTE在內的眾多準4G協議所采用。IDFT/DFT作為OFDM系統中的關鍵功能模塊,其精度對基帶解調性能產生著重大的影響,尤其對LTE上行所采用的SC_FDMA更是如此。為了使定點化IDFT/DFT達到較好的性能,本文采用數字自動增益控制(DAGC)技術,以解決過大輸入信號動態范圍所造成的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,并重點關注近年來為了改善其性能而興起的數字化AGC技術,它們主要用于壓縮ADC輸入動態范圍以防止其飽和。針對基帶處理中具有累加特性的定點化IDFT/DFT技術,進一步分析了AAGC技術和基帶DAGC在實施對象,實現方法等上的異同點,指出了基帶DAGC的必要性。 其次,根據LTE協議,搭建了從調制到解調的基帶PUSCH處理鏈路,并針對基于DFT的信道估計方法的缺點,使用簡單的兩點替換實現了優化,通過高斯信道下的MATLAB仿真,證明其可以達到理想效果。仿真結果還表明,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進行調制,也能達到在SNR高于17dB時,硬判譯碼結果為極低誤碼率(BER)的效果。 再次,在所搭建鏈路的基礎上,通過理論分析和MATLAB仿真,證明了包括時域和頻域DAGC在內的基帶DAGC具有穩定接收鏈路解調性能的作用。同時,通過對幾種DAGC算法的比較后,得到的一套適用于實現的基帶DAGC算法,可以使IDFT/DFT的輸出SNR處于最佳范圍,從而滿足LTE系統基帶解調的要求。針對時域和頻域DAGC的差異,分別選定移位和加法,以及查表的方式進行基帶DAGC算法的實現。 最后,本文對選定的基帶DAGC算法進行了FPGA設計,仿真、綜合和上板結果說明,時域和頻域DAGC實現方法占用資源較少,容易進行集成,能夠達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IQ數據,使之滿足基帶解調性能。
上傳時間: 2013-05-17
上傳用戶:laozhanshi111
MAX+PLUS II Advanced Synthsis ALtera的一個免費HDL綜合工具,安裝后可以直接使用,是MaxplusII的一個插件,用這個插件進行語言綜合,比直接使用MaxplusII綜合的效果好
標簽: Advanced Synthsis 10.230 PLUS
上傳時間: 2013-05-27
上傳用戶:feichengweoayauya
·Advanced ASIC Chip Synthesis Using Synopsys Design Compiler,Physical Compiler and Primetime
標簽: nbsp Synthesis Advanced Synopsys
上傳時間: 2013-04-24
上傳用戶:alia
[PIC項目實戰:基于PIC18].Advanced.PIC.Microcontroller.Projects.in.C
標簽: PIC Microcontroller Advanced Projects
上傳時間: 2013-11-21
上傳用戶:二驅蚊器
針對固定碼長Turbo碼適應性差的缺點,以LTE為應用背景,提出了一種幀長可配置的Turbo編譯碼器的FPGA實現方案。該設計可以依據具體的信道環境和速率要求調節信息幀長,平衡譯碼性能和系統時延。方案采用“自頂向下”的設計思想和“自底而上”的實現方法,對 Turbo編譯碼系統模塊化設計后優化統一,經時序仿真驗證后下載配置到Altera公司Stratix III系列的EP3SL150F1152C2N中。測試結果表明,系統運行穩健可靠,并具有良好的移植性;集成化一體設計,為LTE標準下Turbo碼 ASIC的開發提供了參考。
上傳時間: 2013-10-28
上傳用戶:d815185728
為滿足TD-LTE系統對實時性的要求,通過對媒體接入控制(MAC)層和物理層之間的實時性研究以及對操作系統Nucleus PLUS的機制分析,實現了MAC層子幀調度。根據TD-LTE無線綜合測試儀中的設計要求,詳細介紹了Nucleus PLUS任務循環調度以及MAC子幀調度的流程設計。在實現MAC層基本功能的同時滿足了TD-LTE對系統實時性、子幀同步與任務資源管理的需求。
上傳時間: 2013-11-10
上傳用戶:royzhangsz