[系统设计方案] OFDM系统中一种抑制峰均功率比的安全算法
安全性低和较高的峰均功率比（ＰＡＰＲ）是正交频分复用无源光网络（ＯＦＤＭ－ＰＯＮ）系 统 所 面 临 的 主 要 挑 战，为此提出一种基于二维混沌加密的选择 性 映 射 （ＳＬＭ）方 案。该 方 案 利 用 二 维 Ｌｏｇｉｓｔｉｃ映 射 分 别 产 生 随 机 交 织 器和相位序列对 ＯＦＤＭ 信号进行加扰，达到系统加密的 同 时 降 低 ＰＡＰＲ 的 目 的。仿 真 结 果 显 示，与 传 统 ＳＬＭ 算 法和原始光 ＯＦＤＭ（Ｏ－ＯＦＤＭ）信号相比，所提出的方案可分别获得０．５ｄＢ和３．８ｄＢ的 ＰＡＰＲ 抑制增益。实验证明，７Ｇｂｉｔ／ｓ １６ＱＡＭ （Ｑｕａｄｒａｔｕｒｅ Ａｍｐｌｉｔｕｄｅ Ｍｏｄｕｌａｔｉｏｎ）Ｏ－ＯＦＤＭ 加 密 信 号 可 通 过 ２５ｋｍ 标 准 单 模 光 纤 在 强 度 调制／直接检测 ＯＦＤＭ－ＰＯＮ 系统中安全传输并且系统误码率性能得到改善。
Optical commnications; intensity modulation/direct detection; orthogonal frequncy divison mulitplexing passive optical network systems; selected maping; encryption; PAPR (2020-09-12, Others, 694KB, 下载2次)
[系统设计方案] resume_templates_and_cover_letter
IT相关专业毕业生求职文档（简历模板及求职信模板）
IT-related graduates employment documents (resume templates and cover letter templates) (2013-11-11, Others, 769KB, 下载3次)
[系统设计方案] topo
比较完善的网络普通图，在一般的企业当中均为适用，几乎万能。
Ordinary network diagram, which are in the general enterprise applies almost universal. (2013-04-09, Others, 52KB, 下载2次)
[系统设计方案] small-wireless-tranceiver-design
关于小型无线收发信机的设计的一些相关文献
small wireless tranceiver design (2013-04-03, Others, 3069KB, 下载2次)
[系统设计方案] CBIR-UML-Diagram
Here i am attaching the UML Diagrams of Content based image retrival which cn be help for the developing the project documentation.
It consits of 6 types of different uml diagrams like Usecase,class,sequence,colloboration,and activity so enjoy.........
Here i am attaching the UML Diagrams of Content based image retrival which cn be help for the developing the project documentation.
It consits of 6 types of different uml diagrams like Usecase,class,sequence,colloboration,and activity so enjoy.........
(2012-09-24, Others, 79KB, 下载7次)
[系统设计方案] guang-sheng-guang-pu
中红外光经过甲烷吸收
后，产生的声波信号经麦克风检测，由锁相放大器对信号进行采集并输入计算机进行处理。按信噪比为１计算，得到甲烷的探测极限为１８９ｎｍｏｌ·ｍｏｌ－１。
The mid-infrared light through the methane absorption, the acoustic signal generated by the microphone detected by a lock-in amplifier of the signal acquisition and input computer for processing. The SNR is calculated to give the methane detection limit 189nmolmol-1. (2012-09-07, Others, 594KB, 下载27次)
[系统设计方案] yancheng
盐城市城管局行政权利网上公开透明运行系统建设
Yancheng Urban Management Bureau Chief rights online open and transparent operation of the system construction (2012-05-07, Others, 144KB, 下载9次)
[系统设计方案] SystemView
提出了一种利用SystemView提供的自动c代码生成器开发具有消息反馈功能的复杂通
信仿真系统的实现方案，该方案解决了在单纯的SystemView仿真环境下无法实现闭环仿真的问题，同
时利用该方案实现的仿真系统具有运行速度快、动态性能好等特点。
Put forward a kind of use SystemView provide automatic c code generator development with news of the function of complex feedback
The implementation scheme of letter simulation system, the scheme in the simple solution SystemView simulation environment cannot achieve the question, with the loop simulation
Using the implementation of the simulation system has a fast operation, good dynamic performance etc. Characteristics.
(2011-05-29, Others, 324KB, 下载3次)
[系统设计方案] Web-Portal
企业内部门户系统设计与实现:门户设计论文
Enterprise system design and implementation of internal doors, gates design paper
(2011-03-01, Others, 4448KB, 下载3次)
[系统设计方案] A_method_based_on_Leo_satellite_communications_tim
摘 要:定时恢复是数字接收机中的关键技术,基于某特定LEO低轨卫星通信系统应用,重点研究了异步时钟采
样恢复法的工作原理,提出了一种改进的Gardner定时误差检测算法,给出了整个定时环路的具体实现方案,并针对其
性能进行了分析。仿真结果表明,在大多普勒加速度的卫星信道环境下,该方案能够满足系统设计的要求,且实现结
构简单、优化,可大幅降低算法复杂度,在较高信噪比的情况下,具有更加优化的性能。
Abstract: The timing recovery is a key technology in the digital receiver, based on a particular application of LEO LEO satellite communication system, focus on the asynchronous sampling clock recovery method works, a modified Gardner timing error detection algorithm, given a concrete realization of the regular loop programs, and analyzed for its performance. Simulation results show that the acceleration of the satellite channels in large Doppler environment, the program can meet the requirements of system design and realization of simple structure, optimization, can significantly reduce the complexity of the algorithm, in the case of high SNR, with more optimized performance. (2010-12-31, Others, 398KB, 下载15次)
[系统设计方案] Technical_Specifications_of_Protection_for_Smart_S
国家电网公司企业标准,智能变电站继电保护技术规范,著名的441文件
State Grid Corporation of corporate standards, technical specifications intelligent substation relay protection, the famous 441 documents (2010-10-18, Others, 889KB, 下载21次)
[系统设计方案] PCA82C250yingrongzhinan_cn
PCA82C250 CAN 收发器应用指南 中文版
PCA82C250 CAN Transceiver Application Guide Chinese Version (2010-03-03, Others, 474KB, 下载44次)
[系统设计方案] RFIDandsupchain
RFID和供应链方面的硕士论文，本文基于以上问题，提出了在供应链管理领域中的RFID的技术全链应用方式，阐述
了在供应链的始端—生产制造企业，至供应链末端—零售企业上各个环节RFID技
术的使用方法及因此可带来的收益。
RFID and supply chain master' s thesis, this article based on the above issue, in the supply chain management RFID technology in the field of application of the whole chain approach described in the beginning of the end of the supply chain- manufacturing enterprises, to the end of the supply chain- retail businesses on all aspects of RFID technology, the use of methods and thus can bring benefits. (2010-01-30, Others, 7405KB, 下载12次)
[系统设计方案] EMIEMC-shejimiji
EMIEMC设计秘籍。EMC工程师需要具备那些技能？从企业产品需要进行设计、整改认证的过程看，EMC工程师
必须具备以下八大技能。该资料详细说明了设计过程，感谢作者
EMC engineers need to have those skills? From enterprise products require the design, look at the process of rectification and certification, EMC engineers must have the following eight skills. The information detailed description of the design process, thanks author (2010-01-26, Others, 678KB, 下载4次)
[系统设计方案] DesignandDSPrealizationofan0FDMreceiver
设计了一个OFDM接收机，并采用1fI公司的TMS320C6416芯片进行实现。在假设理想
同步的前提下，该系统进行了FFT变化、使用了Ls(最小二乘法)进行信道估计，并且采用了
QPSK算法进行解调。最后将接收机输出数据与发端数据进行比较，在不同信噪比情况下计算其
误码率，得出了比较理想的结果。
An OFDM receiver is designed in山is paper and realized on the platform of the 1MS32OC6416 chip
of the TI company．Under the assumption of ideal synchronization．n叩transformation is realized in the system
wit}l LS method implemented in the channel estimation module and QPSK used in the demodulation module．
Finally，BER is calculated in different cases of SNR and the result is achieved as expected． (2009-09-01, Others, 238KB, 下载30次)
[系统设计方案] simplex_wireless_calling_system
单工无线呼叫系统分发射和接收两大部分。发射部分采用锁相环式频率合成器技术， MC145152和MC12022芯片组成锁相环，将载波频率精确锁定在35MHz，输出载波的稳定度达到4×10-5，准确度达到3×10-5，由变容二极管V149和集成压控振荡器芯片MC1648实现对载波的调频调制；末级功放选用三极管2SC1970，使其工作在丙类放大状态，提高了放大器的效率，输出功率达到设计要求。接收部分以超大规模AM/FM立体声收音集成芯片CXA1238S为主体，灵敏度、镜像抑制、信噪比等各项性能指标均达到设计要求；音频功率放大器采用集成芯片LM386，电压放大倍数最大为200。采用PT2262/2272编码/解码电路实现了数据传输业务以及对台号的选择等功能；音频输入和数据输入可自动转换；AT89S52作为整个系统的控制部分，程序设计采用C语言在KEIL51的编译器上编程实现；显示采用128×64点阵型液晶显示。经测试，整机功能齐全，各项性能指标符合系统要求，接收波形稳定，无明显失真。
The simplex wireless-calling system consists of two parts: transmit part and receive part.The transmit part adopts the phase-locked loop pattern of frequency synthesizing technology and uses the MC145152 and MC12022 chips to compose the phase-locked loop.It locks the frequency of the carrier-wave at 35MHz.The stabilization of the carrier-wave can be 4×10-5,the accuracy can be 3×10-5.The frequency modulation and the confection of the carrier-wave are realized by the capacity-changing diode V149 and the integration voltage-control oscillator MC1648 chip.The end power amplifier uses the audion 2SC1970 to make it work in the third magnifying state,it improves the efficiency of the magnifier and the power of the output reaches the design demand.The receive part uses the super cosmically AM/FM dimensional sound stereo radio reception integration chip CXA1238S as the main part.The sensitivity、the mirror-control restrain、the SNR and every capability index all reach the design demand.The audio (2009-08-30, Others, 612KB, 下载156次)
[系统设计方案] wuliuxitong
优秀本科毕业论文－现代物流企业综合管理系统
Outstanding undergraduate thesis- a modern logistics enterprise integrated management system (2008-12-22, Others, 57KB, 下载51次)
[系统设计方案] HardwareManualofHuawei
华为作为国内最有名的IT民营企业，对员工的培训非常严格，贡献一份华为硬件规范手册，希望对大家有用！
Huawei as the most well-known private enterprise IT, the training of its staff very strict norms contribute to a Huawei hardware manual, useful for all of us hope! (2008-11-21, Others, 767KB, 下载7次)
[系统设计方案] zujiajishu
目前
通用的组播协议以及组播组网的基本方案并针对组播业务需求和运营过程中
面临的问题提出了电信级的可运营可管理的“受控组播”解决方案包括信源
管理用户管理和组播安全控制等方面的内容
The current common multicast group multicast protocols as well as the basic program and network for multicast business needs and operational process issues faced by the telecommunications operator class can be managed, controlled multicast solutions include source manage user management and multicast security control of the content (2007-11-11, Others, 124KB, 下载12次)
[系统设计方案] 11111.files
汽车娱乐电子推动了功能和容量的快速发展，促使设计人员在性能、成本和灵活性上做出综合考虑。与其他汽车电子领域不同，多媒体图形应用高度可视化， 其需求多变，在许多情况下甚至还没有建立标准。汽车设计人员需要一个能够提供最灵活、性能最佳而成本可控的解决方案。可编程逻辑，特别是现场可编程门阵列 （FPGA）便是这样的解决方案。
automobile electronic entertainment functions and promote the rapid development of the capacity to promote design in performance, cost and flexibility make comprehensive consideration. And other areas of Automotive Electronics, multimedia graphics application of highly visual, their needs are ever-changing in many cases have not even established standards. Automobile designers need to be able to provide a most flexible, performance and the best cost-controlled solutions. Programmable logic, in particular field programmable gate array (FPGA) is such a solution. (2007-02-02, Others, 79KB, 下载8次)