基于μPSD3234的10kW广播发射机微控制器的系统设计

针对广播发射机使用时的特定要求,本文选用高速SOC51单片机作为广播发射机微控制器的主控芯片,对整个监控系统的输入输出接口电路,人机交互等外围模块的硬件电路,远程通信电路和实时时钟电路进行了详细的硬件设计。软件设计部分给出了主程序流程图和子程序的设计思路。投入使用后的广播发射机控制系统具有稳定可靠性高,实时性强,操作简单和界面友好等特点,真正实现了广播发射机播放的自动化和智能化的要求。     

局域网在广播电视系统中的应用

结合东阳广播电视台的局域网建设,介绍了应用于电视非线性编辑、广播音频制作和播出、办公3个领域的网络系统的结构、功能和特点,并指出现行网络在适应性上的不足和发展方向,以及系统间彼此隔离的安全措施.     

声像管理系统――播出系统设计方案详解

随着各行业信息化建设进程的加快,多媒体资源的数字化管理工作被越来越多的单位所重视,为了解决行业用户大量多媒体资料数字化保存、检索和共享发布所面临的问题,提出了声像管理系统。结合某单位在声像管理系统方面的应用实践,详细分析了声像管理系统中播出环节的系统设计、网络架构、业务功能。该媒资系统的实践给媒资系统构建方法,甚至业务的拓展以及异构系统间的互通提供了很好的应用经验。     

数字视频广播中可靠组播的实现

数字视频广播是一种新型的电视广播技术,它和计算机技术相融合,利用现有的有线电视网络实现大范围远距离的可靠内容的广播.由于不是所有的主机都需要这些报文,因此IP广播浪费了网络资源,而将IP组播技术用于数字视频广播,能有效地利用网络资源.     

A new generation of modems for power efficient radio systems

A new class of generalized intersymbol-interference and jitter-free (GIJF) modulated signals is introduced. Computer simulation and hardware experimental research results demonstrate that our proposed new generation of signals and modulators leads to significant performance improvements in non-linearly amplified broadband radio systems. For increased power efficiency, non-linear amplification is required in most commercial satellite and terrestrial microwave systems. In particular, we demonstrate that the 3 dB envelope fluctuation of currently used offset raised-cosine overlapped QPSK systems is reduced to 0-5 dB, and that the BER performance is improved by approximately 1 dB. These significant technical performance advantages are expected to lead to more economical implementations of digital transmission systems.     

Optimal algorithms for dissemination of information in some interconnection networks

The problems of gossiping and broadcasting in one-way communication mode are considered for some prominent families of graphs. The complexity is measured as the number of communication rounds in the gossip and broadcast algorithms. The main result of the paper is the precise estimation of the gossip-problem complexity in cycles. To obtain this result a new combinatorial analysis of gossiping in cycles is developed. This analysis leads to an optimal lower bound on the number of rounds, and also to the design of an optimal algorithm for gossiping in cycles. The optimal algorithm for gossiping is later used to design new, effective algorithms for gossiping in important families of interconnection networks (cube connected cycles, butterfly networks). Furthermore, a new, effective algorithm for broadcasting in shuffle-exchange networks is developed.On leave from Comenius University, Bratislava, Czechoslovakia.     

数字电视简介

对数字电视信号的取样、量化、编码、信源的编码、信道的编码以及信号的传输的整个过程作了较简单阐述。     

通过低层音频服务实现的动态交互式播放

讨论了以Ｓｏｕｎｄ Ｂｌａｓｔｅｒ声音卡为基础，通过对波形音频输出的低层音频服务来实现的声音动态交互式播放，并给出了一个实用的在Ｗｉｎｄｏｗｓ环境下编制的高炮击模拟训练声音动态交互播放的实例。     

Satellites for communications and broadcasting: The evolving european market

The paper traces the development of the market for communications and direct broadcasting satellites in Europe, since the original specification of the European Communications Satellite (ECS) in 1977. It reviews the experiments undertaken on the Orbital Test Satellite (OTS) and the way in which demonstrations with this satellite have influenced the way in which ECS is being developed. It continues by considering the impact of television on the market, first cable television and its distribution requirements, then direct broadcasting by satellite, where the introduction of homes into the customer configuration will bring with it programme content as a salient feature in market development. Finally it speculates on the possibilities for the future, both in terms of the effect of new and higher frequencies on satellite communications systems, and the possible effects that interaction from small earth-stations could have on satellite design.     

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.