Flexible construction of girth-six QC-LDPC Codes
標(biāo)簽： construction girth-six Flexible QC-LDPC
上傳時(shí)間： 2017-09-27
上傳用戶(hù)：gaojiao1999
信息化社會(huì)的到來(lái)以及IP技術(shù)的興起，正深刻的改變著電信網(wǎng)絡(luò)的面貌以及未來(lái)技術(shù)發(fā)展的走向。無(wú)線通信技術(shù)的發(fā)展為實(shí)現(xiàn)數(shù)字化社區(qū)提供了有力的保證。而視頻通信則成為多媒體業(yè)務(wù)的核心。如何在環(huán)境惡劣的無(wú)線環(huán)境中，實(shí)時(shí)傳輸高質(zhì)量的視頻面臨著巨大的挑戰(zhàn)，因此這也成為人們的研究熱點(diǎn)。 對(duì)于無(wú)線移動(dòng)信道來(lái)說(shuō)，網(wǎng)絡(luò)的可用帶寬是有限的。由于多徑、衰落、時(shí)延擴(kuò)展、噪聲影響和信道干擾等原因，無(wú)線移動(dòng)通信不僅具有帶寬波動(dòng)的特點(diǎn)，而且信道誤碼率高，經(jīng)常會(huì)出現(xiàn)連續(xù)的、突發(fā)性的傳輸錯(cuò)誤。無(wú)線信道可用帶寬與傳輸速率的時(shí)變特性，使得傳輸?shù)目煽啃源鬄榻档汀?視頻播放具有嚴(yán)格的實(shí)時(shí)性要求，這就要求網(wǎng)絡(luò)為視頻的傳輸提供足夠的帶寬.有保障的延時(shí)和誤碼率。為了獲得可接受的重建視頻質(zhì)量，視頻傳輸至少需要28Kbps左右的帶寬。而且視頻傳輸對(duì)時(shí)延非常敏感。然而無(wú)線移動(dòng)網(wǎng)絡(luò)卻無(wú)法提供可靠的服務(wù)質(zhì)量。 基于無(wú)線視頻通信面臨的挑戰(zhàn)，本文在對(duì)新一代視頻編碼國(guó)際標(biāo)準(zhǔn)H.264/AVC研究的基礎(chǔ)上，主要在提高其編碼效率和H.264的無(wú)線傳輸抗誤碼性能，以及如何在嵌入式環(huán)境下實(shí)現(xiàn)H.264解碼器進(jìn)行了研究。 結(jié)合低碼率和幀內(nèi)刷新，提出一種針對(duì)感興趣區(qū)的可變幀內(nèi)刷新方法。實(shí)驗(yàn)表明該方法可以使用較少的碼率對(duì)感興趣區(qū)域進(jìn)行更好的錯(cuò)誤控制，以提高區(qū)域圖像質(zhì)量，同時(shí)能根據(jù)感興趣區(qū)及信道的狀況自動(dòng)調(diào)整宏塊刷新數(shù)量，充分利用有限的碼率。 為了有效的平衡編碼效率和抗誤碼能力的之間的矛盾，筆者提出了一種自適應(yīng)FMO(Flexible Macroblock Order)編碼方法，可根據(jù)圖像的復(fù)雜度自適應(yīng)地選擇編碼所需的FMO模式。仿真結(jié)果表明這種FMO編碼方式完全可行，且在運(yùn)動(dòng)復(fù)雜度頻繁變化時(shí)效果更加明顯，完全可應(yīng)用在環(huán)境惡劣的無(wú)線信道中。 在對(duì)嵌入式PXA270硬件結(jié)構(gòu)和X264研究的基礎(chǔ)上，基本實(shí)現(xiàn)了基于H.264的嵌入式解碼，在PXA270基礎(chǔ)上進(jìn)行環(huán)境的配置，定制WirtCE操作系統(tǒng)，并編譯、產(chǎn)生開(kāi)發(fā)所用的SDK和下載內(nèi)核到目標(biāo)機(jī)。利用開(kāi)發(fā)工具EVC實(shí)現(xiàn)在PC機(jī)上的實(shí)時(shí)開(kāi)發(fā)和在線仿真調(diào)試，最終實(shí)現(xiàn)了對(duì)無(wú)差錯(cuò)H.264碼流實(shí)時(shí)解碼。
標(biāo)簽： 264 ARM 無(wú)線傳輸 差錯(cuò)控制
上傳時(shí)間： 2013-06-18
上傳用戶(hù)：也一樣請(qǐng)求
The LTC®1966 is a true RMS-to-DC converter that uses aDS computational technique to make it dramatically simplerto use, significantly more accurate, lower in powerconsumption and more Flexible than conventional logantilogRMS-to-DC converters. The LTC1966 RMS-to-DCconverter has an input signal range from 5mVRMS to1.5VRMS (a 50dB dynamic range with a single 5V supplyrail) and a 3dB bandwidth of 800kHz with signal crestfactors up to four.
標(biāo)簽： 真有效值 轉(zhuǎn)換器 自動(dòng)調(diào)節(jié)
上傳時(shí)間： 2013-10-12
上傳用戶(hù)：qilin
提出一種基于凌陽(yáng)單片機(jī)的步進(jìn)電機(jī)加減速的控制方法。采用凌陽(yáng)科技推出的16位結(jié)構(gòu)工控單片機(jī)SPMC75F2413A為控制器，由Allegro公司生產(chǎn)的兩相步進(jìn)電機(jī)專(zhuān)用驅(qū)動(dòng)器件SLA7042M構(gòu)成步進(jìn)電機(jī)的驅(qū)動(dòng)電路，在傳統(tǒng)的3段直線加減速控制算法基礎(chǔ)上增加至7段S形曲線加減速過(guò)程，控制步進(jìn)電機(jī)的啟動(dòng)和停止。實(shí)驗(yàn)結(jié)果表明，該控制方法克服了直線加減速中不連續(xù)、易造成系統(tǒng)沖擊的問(wèn)題，整個(gè)系統(tǒng)實(shí)現(xiàn)柔性控制，電機(jī)啟動(dòng)、停止連續(xù)性能提高30%。 Abstract: The method of controlled stepping motor is referred based on SPMC75F2413A MCU， which adopts the 16 knots SPMC75F2413A MCU as the controller. The special-purpose actuation chip SLA7042M of two stepping motor produced by Allegro Corporation constituted to actuation electric circuit. The purpose of increasing to seven section of S shape curve based on the traditional three sections of straight line is to control the start and stop process of stepping motor. The experimental results show that the control method solves easy to pull-out and overshot problems. The overall system realizes Flexible control， and the performance of motor start or stop continuity is increased 30%
標(biāo)簽： 凌陽(yáng)單片機(jī) 步進(jìn)電機(jī) 減 控制方法
上傳時(shí)間： 2013-12-08
上傳用戶(hù)：jiangfire
出了一種利用ATmega8單片機(jī)對(duì)ISD2500系列語(yǔ)音芯片進(jìn)行控制的智能語(yǔ)音系統(tǒng)，此系統(tǒng)使用靈活，易于功能升級(jí)，具有良好的應(yīng)用前景。提供了硬件連接電路和關(guān)鍵源程序。 Abstract: An intelligent voice system using ISD2500 series voice chips based on ATmega8 MCU is described.This system is Flexible and easy to upgrade for users,and it has pretty good using foreground. The circuit diagram and the key program are also provided.
標(biāo)簽： ATmega8 2500 ISD 智能語(yǔ)音
上傳時(shí)間： 2014-01-22
上傳用戶(hù)：Artemis
Virtex-5, Spartan-DSP FPGAs Application Note This application note demonstrates how efficient implementations of Digital Up Converters(DUC) and Digital Down Converters (DDC) can be done by leveraging the Xilinx DSP IPportfolio for increased productivity and reduced time to development. Step-by-step instruction is given on how to perform system-level trade off analysis and develop the most efficient FPGA implementation, thus allowing engineers a Flexible, low-cost and low-power alternative to ASSP technologies.
標(biāo)簽： Spartan-DSP Virtex FPGAs Ap
上傳時(shí)間： 2013-10-23
上傳用戶(hù)：raron1989
1.The C Programming Language is a powerful, Flexible andpotentially portable high-level programming language. 2.The C language may be used successfully to create a programfor an 8-bit MCU, but to produce the most efficient machinecode, the programmer must carefully construct the C Languageprogram.3.The programmer must not only create an efficient high leveldesign, but also pay attention to the detailed implementation.
標(biāo)簽： FREESCALE 單片機(jī) 編程 教程
上傳時(shí)間： 2013-12-27
上傳用戶(hù)：huanglang
Luminary Micro Stellaris™ microcontrollers that are equipped with an analog-to-digital converter(ADC), use an innovative sequence-based sampling architecture designed to be extremely Flexible,yet easy to use. This application note describes the sampling architecture of the ADC. Sinceprogrammers can configure Stellaris microcontrollers either through the powerful StellarisFamilyDriver Library or through direct writes to the device's control registers, this application note describesboth methods. The information presented in this document is intended to complement the ADCchapter of the device datasheet, and assumes the reader has a basic understanding of howADCsfunction.
標(biāo)簽： Microcontr Stellaris Using the
上傳時(shí)間： 2013-10-14
上傳用戶(hù)：blans
winCE msdn講座 XP Embedded Now and the future Windows XP Embedded Developmentand Deployment Model OverviewWindows XP Embedded Component ModelWindows XP Embedded Studio Tools Microsoft WindowsXP Embedded Product Highlights Componentized version of Windows XP Professional~ 12,000 components and updates as of Service Pack 2Flexible localizationSame binaries and API as Windows XP ProfessionalHotfixes and service packsEmbedded Enabling FeaturesRuns on standard PC hardwareSupports boot on hard drives, compact flash, DiskOnChipand read-only mediaSupport for remote install and remote bootHeadless device and remote management supportIntegration with Microsoft management tools
上傳時(shí)間： 2013-10-31
上傳用戶(hù)：jrsoft
The AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer with 8Kbytes of Flash programmable and erasable read only memory (PEROM). The deviceis manufactured using Atmel’s high-density nonvolatile memory technology and iscompatible with the industry-standard 80C51 and 80C52 instruction set and pinout.The on-chip Flash allows the program memory to be reprogrammed in-system or by aconventional nonvolatile memory programmer. By combining a versatile 8-bit CPUwith Flash on a monolithic chip, the Atmel AT89C52 is a powerful microcomputerwhich provides a highly-Flexible and cost-effective solution to many embedded controlapplications.
上傳時(shí)間： 2013-11-10
上傳用戶(hù)：1427796291
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