一个Ku波段卫星转发器传输六路数字电视

在概述了卫星数字电视技术之后，本文着重讲解了通过亚卫２号一个Ｋｕ转发器采用多路单载波（ＭＣＰＣ）方式传递六路数字电视信号这一设计课题。     

卫星数字压缩编解码系统及其测试

本文简要地介绍了卫星数字压缩编解码系统特性及其设备检测的必要性检测方法与指标要求。     

卫星移动通信系统的比较和发展概况

国际移动通信标准的制订和系统设计曾受到20世纪90年代信息泡沫的严重影响,许多标准和系统存在着不合理现象,在应用中值得重视。文章在比较了多个卫星移动通信系统设计方案和运营状况的基础上,指出在卫星移动通信系统中应重视的几个设计参数,如多址方式的选择、卫星系统的可靠性等。     

卫星数字电视与采用小口径天线接收的可行性

卫星数字电视与采用小口径天线接收的可行性□黄唯金（中国兵器工业第二一二研究所７１００６５）摘要文中介绍了卫星数字电视系统的构成及功能，并通过计算证明了采用小口径天线接收的可行性。关键词卫星通讯数字压缩编码解码接收天线０引言随着卫星技术和数字压缩技术的...     

数字电视传输中的关键技术

本文主要介绍数字电视传输系统，包括系统的组成、内外信道的划分、卫星传输系统、有线电视传输系统、数字电视广播系统和有条件接收技术等内容。     

浅析数字电视地面广播国家标准DMB—TH及其应用前景

当今社会已经进入数字化时代，电视广播系统的全面数字化是大势所趋。相对于传统的固定接收模式的模拟电视，数字化电视不仅极大地改善了人们收看电视节目的质量，而且提供了更加人性化和更加方便自由的收看方式。目前，我国数字电视按信号传输方式可以分为地面无线传输数字电视、卫星传统数字电视、有线传输数字电视3类。数字电视地面广播虽然容易实现移动和便携接收的功能，但对整个技术系统的要求最高。它具备无数数字系统所共有的优点：与卫星接收相比，有实现容易、价格低廉的特点；与有线接收相比，不易受城市施工建设、自然灾害、战争等因素造成的断网影响。因此，数字电视地面广播技术给传统的收看电视方式带来了新的变化，孕育着创造一个新的移动电视市场的机遇，其应用前景将更加深远。     

MPEG-2卫星数据电脑接收与录制系统的使用

MPEG-2卫星数字电视节目接收系统是电视台获取电视节目素材的重要手段.扬州电视台为了接收与录制<体育界>和<娱乐现场>等通过卫星传输的MPEG-2数字电视节目,采用了北京亚太东方通信网络有限公司的MPEG-2卫星数据电脑接收与录制系统.     

多波段单路单脉冲跟踪接收系统研究

通过对多波段单路单脉冲接收系统信噪比和Ｃ／Ｎ值的分析,证明了在卫星跟踪接收系统中将信道支路与角跟踪支路合并的可行性。     

第八讲 数字机顶盒的使用

卫星数字电视的接收与调试比模拟卫星电视的接收与调试要复杂一些，造成这种现象的主要原因有3个：首先，接收卫星模拟信号只要输入下行频率即可(有些机器需要输入中频频率)，而接收卫星数字电视信号至少需要输入3个参数，即要输入接收信号的下行频率、极化方式和符码率。这3个参数若有1个出了差错，就很难接收到数字电视信号。其次，数字电视信号是压缩信号，接收数字电视信号是一个解压缩过程，需要一定的计算时间，如果不了解这一过程，有时     

数字卫星电视接收系统抗噪声性能的分析

分析卫星数字电视接收系统的性能以及卫星数字电视接收机中R-S解码器、卷积解码器和QPSK解调器等部分电路对系统抗噪声性能的贡献.     

卫星数字电视信号干扰检测与预警实现

随着数字通信技术的发展，广播电视由模拟向数字化全面过渡。卫星数字广播具有诸多优点，受到世界各国的广泛重视，同时也成为不法分子的攻击对象。新型专业卫星数字电视解码器（IRD）通过运行防止非法信号干扰的软件，实时分析卫星数字电视信号的特征，从而提前发现外来非法干扰信号并实施预警。分析卫星数字电视信号在受干扰过程中的信号特征，然后根据此特征提出对恶意干扰进行预警的一种实现算法。     

Measurement of the required cross-polar protection ratio in G-PALTV FM satellite transmissions planning

A measurement campaign using live TV broadcast satellite signals and receiving commercial equipment has been carried out to study the required cross-polar protection ratio at the receiving antenna in satellite transmission planning. This experiment provides useful and realistic conclusions for the optimum spectrum allocation of TV channels in broadcasting satellite systems, as for example, the frequency offset required between cross-polar channels depending on the cross-polar rejection at the receiving antenna, for a certain grade of video signal impairment due to the cross-polar channel interference effects, and taken also into account the noise contribution on the signal     

Study of the required crosspolar protection ratio in G-PAL TV FMsatellite transmissions planning

A study including simulation and a measurement campaign using live TV broadcast satellite signals and receiving commercial equipment has been carried out to investigate the required cross-polar protection ratio at the terrestrial receiving antenna for satellite transmission planning. This experiment provides useful and realistic results for efficient channel allocation in the spectrum band of broadcast satellite systems. Among them is the frequency offset required between cross-polar channels, depending on the cross-polar rejection at the receiving antenna, for a certain degree of video signal impairment due to the cross-polar channel interference effect, and taking into account the noise contribution to the signal. A worst case in frequency offset value, i.e., larger subjective impairment of the picture at equal carrier to noise ratio (CNR), has been detected around 5 MHz (near the chroma carrier in G-PAL system 4.43 MHz) only for high values of CNR. Different subjective degradation of the image due to cross-polar channel interference and noise has been observed, and their particular contributions to impairment have been evaluated     

数字卫星电视播放系统实现方案

对现有的数字卫星电视标准进行比较的基础上设计了一种卫星电视播放系统,并阐述了系统的实现过程.系统采用支持BDA的硬件架构,结合基于DirectShow软件系统的设计方法,简化了播放系统的编写,提高了通用性,适合对新业务的开发与升级.     

Effective multi-program broadcasting of prerecorded video using VBR MPEG-2 coding

The tradeoff between picture quality and bandwidth usage is a prominent issue in the world of broadcasting. Since broadcasters are able to transmit multiple streams simultaneously in a channel, they face the challenge of guaranteeing the contracted picture quality required by each of the transmitted video streams while maximizing the number of video streams carried in each channel. We have developed an easy to implement MPEG-2 based multi-program video coding system suitable for digital TV broadcast, video on demand, and high definition TV over broadcast satellite networks with limited bandwidth. Compared to present broadcast systems and for the same level of contracted picture quality, our system greatly increases the number of video streams transmitted in each channel. As a result, either a large number of transponders can be freed to carry real-time broadcasting or the level of picture quality can be significantly increased. By switching from tape storage to video server technology, the need for numerous playback (VTR) systems at the headend is eliminated. In addition, the most of the complete MPEG-2 encoders are replaced by much less complex MPEG-2 transcoders. All this means a much more cost-effective solution for broadcast stations.     

A hybrid architecture for analog video broadcast and B-ISDNservices in customer premises networks

The use of SCM (subcarrier multiplexing) transmission to deliver broadcast analog video signals within a CPN (customer premises network) as an overlay to an all-digital B-ISDN (broadband integrated services digital network) is considered. The feasibility of a proposal where the analog and digital signals are carried on different wavelengths is shown. An architecture for an optical CPN, termed H-Bus and incorporating emerging broadband SONET and ATM (asynchronous transfer mode) standards, is taken as a baseline for the delivery of switched digital, two-way voice, data, and video services. An optical overlay for the distribution of analog, broadcast video services using subcarrier multiplexing is considered. Several key alternatives associated with the delivery of broadcast video services are assessed, including signal quality, number of simultaneous channels, number of user terminals to be served, and modulation format. These issues are considered in terms of their impact on the interface with the public local exchange network and on the complexity, topology, and cost of the CPN     

Broadcasting by satellites

As a result of recent advances in signal processing technology and standards for video compression systems there has been a dramatic increase in interest in commercial applications. This paper reviews the current broadcasting situation from a number of viewpoints relevant to the future development of the available technologies. After a review of the context, which includes alternative new broadcasting technologies as well as alternative media capable of competing with satellite, digital technology is given a wide ranging assessment with particular attention paid to the direct broadcasting to the home by satellite application currently receiving considerable attention world-wide. The possible system architectures and subsystem design features are highlighted with the European Baseline Satellite Broadcasting specification developed by the European Digital Video Broadcasting Project gaining special attention. For completeness a brief review of the digital audio broadcasting system (DAB) is also given. In addition to the applications for direct broadcasting, applications in the professional domain for distributing television signals from studios to terrestrial transmitters, satellite up-link sites or cable heads or for satellite news gathering (SNG) are examined. Features of existing commercially available hardware to support these services are described briefly.     

Bidirectional WDM passive optical network for simultaneous transmission of data and digital broadcast video service

We have demonstrated an easily upgradable bidirectional passive optical network for the simultaneous transmission of wavelength-division-multiplexing channels and digital broadcast video signals. The proposed network could transmit 15 2.5-Gb/s downstream channels, 15 155-Mb/s upstream channels, and one broadcast signal consisting of more than 70 digital video channels.     

利用安捷伦ADS产生DVB-S数字卫星电视信号--ADS仪表连接应用

在数字卫星电视接收系统的开发过程中,为了验证接收系统的正确性,(即接收系统是否可以正常工作,是否可以正常地播放出图像)需要一个卫星信号源,要求它应该能够产生具有卫星编码的活动图像信息,从而使接收系统工作于符合DVB标准的数字卫星系统中.本文将阐述如何利用安捷伦ADS仿真软件和ESG E4438C矢量信号发生器,产生出带有图像信息的DVB-S数字卫星电视信号.     

浅谈数字播出通路与导播应急操作

电视节目的安全播出无疑是任何一个电视台最重要的工作之一,而导播对播出事故的判断及应急操作又是安全播出工作中最关键的环节.以广东电视台卫星频道为例,通过对数字播出通路的简介,阐述数字播出通路的结构、数字信号传输过程及与之相关的播出设备,进而说明熟悉数字播出通路结构对导播在事故判断及应急操作的作用,并提出改良建议.