And in - depth research is made in this thesis . after analyzing some practical issues , i design and implement a scrambling and conditional access system with full functions , appropriate size and certain application field 在此基础上，设计了相应的系统硬件和软件，完成了一个基于pc的、规模适中但功能完备的同密条件接收系统。
Whether exact synchronization can be achieved affects the performance of the simulcrypt system . in this thesis in - depth analyze is made to synchronization issues in simulcrypt system and some way are give 能否实现精确同步关系关系着条件接收系统的性能，论文对同步问题从系统构成、软硬件实现多个角度作了深入分析并提出了解决方案。
Arrange and produce a new software adapter , and design seven difference modules according to the function of conditional accessing system , according to the function need to achieve for each module , process a concrete analysis 提出了一个新的ca软件适配层;并根据条件接收系统的功能设计了七个适配模块,对每个模块需要实现的功能进行了分析。
In this thesis in - depth analyze is made to how to achieve high scrambling and multiplexing velocity . during the hardware implement , in - depth analyze is made to traditional distribute algorithm ( da ) and a improvement algorithm is made 加扰和复用是条件接收系统的关键，论文就如何提高系统加扰和复用速度作了深入分析并实现了硬件解决方案。
Different district will choose the conditional access system to carry on the program encryption , to develop a digital television receiving system , transplantation of different conditional access systems are needed for the different district 条件接收模块是由条件接收系统开发公司研制开发,再移植到数字电视接收系统中。地方广电局可以自己选择条件接收系统进行节目加密。
The ca system envolved in the three components . it " s intension is to scramble or descramble the streams which is the services requested by any users . so if the user pay the charge , he / she can get the service 有条件接收系统贯穿在这三部分构成的整个系统之中，目的就是根据每个用户申请的服务将相应的码流构成完善的加解扰系统，使每个用户在按时交费的基础上可以得到相应的服务，使广电网络真正成为一个能够自我积累发展的产业。
The products of our company mainly include digital tv conditional access system ( cas ) , subscriber management system ( sms ) , electronic program guide ( epg ) , stb , middleware , security broadcast monitoring facilities , data broadcast system , and data broadcast receiving card , etc 公司现阶段的产品主要包括数字电视条件接收系统( cas ) 、用户管理系统( sms ) 、电子节目指南( epg ) 、机顶盒、中间件、安全播出监测设备、数据广播系统和接收卡等。
Finally , studies the instruction system of cos upon a dedicated instruction of smartcos - xc . chapter 4 discusses the smartcos - xc and gives the design and implementing of a smart card file system framework . based on this , this paper gives a simulation of head - end encryption of entitlement control message ( ecm ) and entitlement management message ( emm ) , and implements the decryption of ecm and emm in the smart card 在对通用cos的研究的基础上,首先简单分析了smartcos - xc ,结合该cos ,论文针对有条件接收系统,按不同用途、不同类型分别设计并实现了存储用户授权及智能卡应用的文件体系结构,通过该cos的指令系统,设计并实现了模拟前端授权控制信息( entitlementcontrolmessage , ecm ) 、授权管理信息( entitlementmanagementmessage , emm )数据生成模块及用户端ecm 、 emm解密模块。
The essential intention of conditional access system ( cas ) is to achieve pay - tv of the digital broadcast system by means of subscriber management and authorization control . so cas is the key technology to realize the pay - tv and interact - tv . based on composite technology in transport layer , paper describes the production and structure of transport stream in mpeg - 2 standard , mpeg - 2 program special information and conditional access definition in service information from dvb standard 有条件接收系统( conditionalaccesssystem , cas ) ,其基本目的是通过对用户的授权控制和管理,实现数字广播电视系统的有偿服务,在为运营商带来经济上回报的同时,也能为用户提供更多、更高质量的服务内容,它是实现付费电视、交互电视的关键技术。
Conditional access ( ca ) is a technology used to control access to digital television ( dtv ) services to authorized users by encrypting the transmitted programming . an emm provides general information about the subscriber and the status of the subscription . the emm is sent with the ecm 数字电视用户管理系统通过对用户订购信息的记录与处理，形成用户数据库，并经由与条件接收系统的接口，向条件接收系统发送用户授权管理信息的基本数据，条件接收系统据此实现对用户收看数字电视节目的控制。
