This thesis analyzed the error performance of mfsk and mpsk modulator in hf with optimal receiver , studied the shortcoming and strongpoint of several typical short - wave data transmission systems and their performance over fading and intersymbol interference channels . the theory and key technical of adaptive modem is discussed . in the last , an efficient modulation scheme - block coded modulation is introduced into hf radio systems to improve the efficiency of hf data transmission , this paper also proposes a hf data transmission system scheme composed of a block coded modulator and a decision feedback type adaptive equalizer 本文在对短波数传两种常见调制方式fsk及psk最佳解调性能分析的基础上,讨论了几种采用典型调制技术的短波数传系统(如时频调制、多进制频移键控慢跳频、 chess系统)原理、优缺点以及抗衰落和抗符号间干扰的性能;分析了自适应串行数传系统抗短波信道衰落和多径干扰的原理、关键技术;在本文的最后引入一种有望解决短波数传系统低效率状况的调制方式bcm -分组编码调制,给出了一个采用bcm技术与自适应均衡技术相结合的短波数传系统方案,并通过计算机模拟进行了初部验证。
The thesis also describes the implementation of the reliable multicast data transmission system with the adaptation of alc and the above three key schemes . this system is applied in zju remote education broadcast - television - online project , one of the zhejiang province 5112 projects , and zhejiang rural technology information project , one of zhejiang province ' s major technology development projects 本文最后论述了采用异步分层编码和上面三个关键技术的可靠组播数据传送系统的实现,并在杭州市“ 5112 ”项目?浙大远教广电在线项目和浙江省重大科技攻关项目?浙江省科技信息化村镇项目上得到了应用,实际运行效果良好。
Under this background and based on the assignment of researching and developing real - time transaction proto - type system of one of the five exchanges - shanghai future exchange , the dissertation is intended to research and implement the exchange message protocol ( xmp ) and message transaction protocol ( xtp ) which are designed to guaranteeing the security and reliability of the data transmission system and discusses the design and implement of the xmp and xtp 本文正是在这样的背景下,基于我国五大交易所之一?上海期货交易所的交易原型系统的研究和开发项目,研究实时交易系统中的数据通信协议:信息打包协议xmp ( exchangemessageprotocol )和交易协议xtp ( exchangetransactionprotocol ) ,并讨论了协议的设计和实现。
Network based data transmission security is one of the critical task in information security field . in this paper , a permutation code security algorithm based on the block cipher that is widely used in the data transmission system is put up after carefully studied the current encryption methods 基于网络的数据传输安全问题是信息安全领域的重要课题之一,本文在分析现有数据加密方法的基础上,在数据传输系统中应用一种基于分组密码新概念的新算法?排列码加密算法。
The thesis is composed of 9 parts : the background , significance , main topics and innovations in the thesis are introduced in chapter 1 ; in chapter 2 , the main function and performance of interface circuits are described from the view of system by using the example of gigabit ethernet ' s transceiver ; the transmission media ' s frequency characteristics and model are analyzed for the high - speed data transmission system in chapter 3 ; the line driver is presented in chapter 4 ; the equalization principles for high - speed data transmission system are introduced in chapter 5 ; a novel adaptive equalizer for 1000base - cx transceiver is presented in chapter 6 ; in chapter 7 , a fixed equalizer for 2 . 5gbps transceiver is described ; in chapter 8 , layout design and measured results are discussed ; at last , the conclusions are drawn in chapter 9 . during period of finishing the thesis , i read lots of literatures about the interface circuits in high - speed data transmission system , studied their principles and design techniques , and designed : 1 、 the line driver for 2 . 5gbps baseband copper cable transceiver ; 2 、 the fixed equalizer for 2 . 5gbps baseband copper cable transceiver ; 3 、 the fixed equalizer for 1 . 5gbps sata ( serial at attachment ) transceiver ; 4 、 an adaptive equalizer for 1000base - cx transceiver 论文由9部分组成:在第一章引言中介绍了论文的背景、意义、国内外研究现状,以及论文的主要内容和创新;第二章以千兆位以太网为例,从系统的角度介绍了高速数据传输系统接口电路的主要功能和性能指标;第三章分析了高速数据传输系统的传输介质的频率特性和模型;第四章描述了线驱动器的设计原理及其电路实现;第五章描述了高速数据传输系统的均衡原理;第六章描述了适用于1 . 25gbps基带铜缆收发器系统的自适应均衡器的设计原理和电路实现;第七章描述了适用于2 . 5gbps基带铜缆收发器系统和1 . 5gbps串行硬盘接口( sata )收发器系统的固定均衡器的设计原理及其电路实现;在第八章中分析了电路的版图设计及芯片测试结果;最后,第九章总结了全文。在完成论文期间,查阅了大量的有关高速数据传输系统接口电路方面的文献,较系统地学习了线驱动器、传输线和均衡器等方面的理论知识和电路设计原理,设计了用于: ( 1 ) 2 . 5gbps基带铜缆收发器系统的线驱动器; ( 2 ) 2 . 5gbps基带铜缆收发器系统的固定均衡器; ( 3 ) 1 . 5gbpssata系统的固定均衡器; ( 4 ) 1 . 25gbps基带铜缆收发器系统的自适应均衡器。