Simulations on the key technique of spread spectrum communications are studied here , according to the characteristic of lduwarc system , issues concerning pseudo - noise codes , spread spectrum method , correlation receiving and synchronization . we also design an error correction code for the system 论文还对扩频通信的关键技术进行了仿真研究,针对远程声遥控系统的特点,讨论了扩频码、扩频方式、相关接收和同步问题,同时讨论了适合远程声遥控系统的纠错编码技术。
Above all , [ 12 : 8 ] harming error correction theory is mentioned in this paper . the edac circuit designed by vhdl can works normally at different frequency of the cpu clock such as 66mhz 50mhz 40mhz 33mhz . the edac function of the circuit can also be disabled by software tool . meanwhile , some basic devices such as and logic , or logic , not logic and some small scale integrated circuits are also integrated in the fpga 本论文阐述了12 , 8汉明码纠错设计过程,采用vhdl语言实现纠错编码器( edac ) ,本设计能够适应cpu时钟信号clk2的不同频率,如66mhz 、 50mhz 、 40mhz 、 33mhz ,并且能够通过软件的控制使fpga的纠错编码功能关闭。
A method about how to design a real - time edac circuit based on aerospace computer which cantains 386ex cpuis is described in this paper . the main subject of this paper concentrates on the design of the edac ( error dectection and correction ) circuit which can accomplish the function that correct the errors of the data in sram 本课题实现了基于386excpu航天计算机的实时edac ( errordetectionandcorrection )电路的设计,即采用纠错编码设计来完成对sram中的数据进行纠错的功能。本课题的研究工作建立在第一轮386excpu航天计算机最小系统设计成功的基础之上。
In fact , the mobile channel is one of the most unpredictable channels , so people are seeking for advanced techniques like error control coding . for example ; in the proposals of ieee 802 . 11n of next generation wlan the ldpc code is presented . at the present , ldpc code is a hot topic with sparse parity - check matries , the performance is near shannon limit and complexity is low 为此,人们不断地研究和寻找多种先进的通信技术以提高移动通信的性能,纠错编码就是这样一种技术。如在下一代高速wlan的ieee802 . 11n的提案中,都提到了采用低密度校验码( lower - densityparity - checkcode , ldpccode ) 。
In next mobile communication system to suffice more and more high - speed data service and demand of qos ( quality of service ) many new wireless link layer transport technologies are going to be used such as mimo ( multiple input multiple output ) , ofdm ( orthogonal frequency division multiplexing ) , channel coding and acm ( adaptive coding modulation ) etc . low density parity check ( ldpc ) codes were first discovered in 1960 ’ s which belong to linear block codes with their parity matrix being sparse 下一代移动通信系统为了满足移动用户对高速、宽带数据传输业务不断增长和更高服务质量的要求,采用了许多新的无线链路传输技术,包括多天线发射和接收技术、正交频分复用技术、信道纠错编码技术和自适应编码调制技术等。上世纪60年代提出的低密度校验码,是一种校验矩阵为稀疏矩阵的线性分组码。