Radio Astronomy and Spectrum Management: The Impact of WARC-79

As a valid use of the radio spectrum and an official radio service, radio astronomy was very much a part of the 1979 World Administrative Radio Conference (WARC-79). The allocation of frequency bands is vitally important for the sustained health of the science. WARC-79 provided first the impetus for astronomers, worldwide, to examine the allocation requirements of radio astronomy and then the opportunity to communicate those needs to the regulatory community. The characteristics of radio astronomy, the criteria for interference-free operation, possibilities for sharing with other radio services, and the need for frequency-band allocations are discussed because all bear directly on an evaluation of the Conference. The Final Acts of WARC-79 are examined from the viewpoint of their impact on radio astronomy.     

The Impact of WARC-79 on the Broadcasting-Satellite Service

The World Administrative Radio Conference, Geneva, Switzerland, 1979 (WARC-79) decided many of the international issues facing the Broadcasting-Satellite service (BSS) and adopted Resolutions and Recommendations dealing with most of the others. This paper identifies the BSS issues considered at WARC-79, describes the actions taken during the Conference, indicates the current status of subsequent WARC-mandated activities involving the BSS, and assesses the potential impact of the WARC on future BSS systems.     

WARC-79 Changes to the Technical Radio Regulations

The WARC-79 met to revise and reorder the International Radio Regulations. This encompassed consideration of some 1300 pages of text over a two and one third month period by approximately eighteen hundred people. Approximately fourteen thousand proposals were presented. Technical proposals were considered within Committee 4 which was chaired by N. Morishima of Japan. This paper will identify those sections of the Radio Regulations considered in the Technical Committee, the important changes, and the implications thereof.     

The Impact of WARC-79 on Space Applications

Prior to the 1979 World Administrative Radio Conference (WARC-79), no frequency bands were allocated for remotesensing measurements. Actions taken by the WARC insure that frequencies will be available for such use, and that operations can be conducted without harmful interference on a worldwide basis for the benefit of all nations. Allocations employed for transfer of scientific data from spacecraft in all regions of space from near-Earth orbit to deep-space planetary ranges were significantly improved. New global allocations for Earth exploration-satellites will permit worldwide acquisition of Earth exploration data both via direct transmission and via relay satellites. New allocations for meteorological satellite data transmission will permit wide-band applications such as direct reception of highresolution picture data by users. Satellite-aided search and rescue systems will benefit from WARC decisions to allocate frequencies exclusively for emergency radiobeacon systems using space techniques. Bands to provide links between the satellite and Earth were designated for distress and safety operations. Time and frequency services with accuracies in the 10- to 50-ps range, needed to meet future system requirements for precise time and frequency information, will be possible because of WARC actions to allocate frequency bands with suitable bandwidth for these services. The search for communications from extraterrestrial intelligence was afforded a degree of protection near several spectral lines of basic physical interest.     

基于盲源分离的短波频谱管理监测研究

常规无线电频谱监测中,对同频段频谱相互重叠的混合信号缺乏有效的监测手段,盲源分离能在不需要已知源信号和传播信道的情况下,实现对接收混合信号的分离,得到纯净的源信号,是实现监测这种混合信号的有效方法,所以考虑将盲源分离应用到频谱管理监测中。介绍了盲源分离的基本概念,对短波频谱管理监测的盲源分离算法进行了分析,着重对该技术在电磁频谱管理监测中的应用进行了仿真,为频谱管理监测提供了技术支持。     

Impact of WARC-79 on the Studies of International Radio Consultative Committee (CCIR)

The CCIR provided the main technical bases for the World Administrative Radio Conference, 1979, including terminology; technical bases for allocation, regulation, and for the provision for new services; characteristics of equipment and emissions; radio wave propagation and noise data. The WARC specified CCIR studies to be carried out for a number of future radio conferences to be held in the 1980-1986 time period, including a conference in 1983 to plan satellite broadcasting in the region of the Americas and a world conference in 1984/1986 concerning the geostationary satellite orbit. Additional studies set out for technical radio regulations included, for example, determination of coordination area around an Earth station in the bands from 1 to 40 GHz shared between space and terrestrial services, and other technical criteria for frequency band sharing. Over the next few years, because of the intense schedule of ITU administrative radio conferences, CCIR studies related to frequency sharing and other radio regulations will increase markedly.     

广播型网格的用户兴趣图谱

用户兴趣图谱是实现智能代理与主动服务的基本依据.而广播型网格的用户兴趣图谱有其自身的特点.本文研究了UCL(Uniform Content Locator)在广播型网格中接收端的应用机制,建立了UCL解析、数据流控制和UCL应用机制,提出了建立基于UCL的用户兴趣图谱的方法,分析了信息的媒体结构与本体结构的特点,研究了相互间转换和在用户肖像模型建立过程中的作用.利用实验建立的广播网格环境验证了该方法的有效性.     

短波组网协作频谱感知技术研究

短波通信由于通信距离远、顽存性强等优点而广泛应用于军事通信领域。为增强短波组网通信的抗干扰性能,将信道感知技术与短波组网相融合,提出了一种基于协作感知技术的网络频率自适应技术。该技术在初始组网时,能正确、快捷的从频率库中选出适用于整个网络的最佳工作频率;在网络运行过程中,根据频率的质量变化情况,及时地调整工作频率。 OPNET仿真表明,该协作感知技术有效,对通信性能改善明显。     

Satellite Beam Optimization for the Broadcasting Satellite Service

In view of the forthcoming ITU Regional Administrative Radio Conference for the planning of the Broadcasting Satellite Service at 12 GHz for the American Continent to be held in 1983, there is a need for a means to transfer the service quality requirements for a Broadcasting Satellite Service into a consistent set of satellite and receiving terminal parameters.     

基于DRM 数字调幅广播的高频外辐射源雷达实验研究

该文介绍了利用新近研制的全数字主被动一体化高频地波雷达系统,开展我国首次基于DRM (Digital Radio Mondiale)数字调幅广播的高频外辐射源雷达(HF Passive Bistatic Radar, HFPBR)实验研究的情况。论述了该体制雷达的理论、关键技术、探测设备和外场实验,给出了不同条件下(包括地波模式、天波模式、天地波混合传播模式)的典型探测结果,在国际上首次从实验上证实了利用DRM 广播信号实现超视距无源探测的技术可行性,为该探测技术的发展奠定了理论与实验基础。      

卫星多媒体数据广播业务分析及实现

首先简要分析了卫星多媒体数据广播业务的市场及其应用环境，接下来介绍了其技术和商业特点、实现的方法，最后阐述了卫星多媒体数据广播的市场策略及其相关的资金投入与成本牧益。在介绍卫星多媒体数据广播业务的实现方法时，具体说明了卫星多媒体广播的价值链、平台的功能要求、内容的创建以及技术平台的实现等。     

数字调幅广播外辐射源雷达信号性能研究

DRM数字调幅广播作为取代传统中短波模拟调幅广播的新标准在全球获得迅猛发展,针对DRM广播新体制高频外辐射源雷达,首先参照DRM信号结构从理论上仿真研究了DRM信号的模糊函数特性,重点分析了模糊函数中副峰产生的机理并提出了副峰抑制的方法;然后结合我国首次获得的DRM外辐射源雷达实测数据处理对理论分析结果和副峰抑制方法进行了验证。结果表明:经过副峰处理后的DRM信号具有良好的图钉状模糊函数,是一种理想的高频外辐射探测机会照射源,为后续目标探测研究奠定了基础。     

交互式移动多媒体广播业务的购买与保护

介绍了在交互式移动多媒体广播中起关键作用的服务购买与保护技术IPDC SPP,它专门针对资源受限的移动终端进行了优化.其中重点介绍遵从该规范的OSF机制,包括OSF的流程以及架构.最后介绍一种符合OSF规范的J2ME平台上的AES加密算法.     

紧急广播概况及我国开展紧急广播业务的相关建议

紧急广播是一种利用广播通信系统向公众通告紧急事件的业务,自从美国"911"事件后,各国逐渐重视这项广播业务.本文介绍了美国、欧洲和日韩的紧急广播概况,以及我国针对突发事件应对机制颁布的法令.根据国外现有紧急广播系统的特点和我国相关法令对紧急广播的要求,对我国将来开展紧急广播业务提出相关建议,供决策者参考.     

播出系统的科学管理

通过对播出系统现有设备的构成分析 ,针对播出设备在常规使用中所存在的一些故障隐患 ,提出系统设备构成的改进方案 ,说明加强播出系统的科学化规范化管理对确保安全优质播出的重要作用     

播出系统的科学管理

通过对播出系统现有设备的构成分析，针对播出设备在常规使用中所存在的一些故障隐患，提出系统设备构成的改进方案，说明加强播出系统的科学化规范化管理对确保安全优质播出的重要作用。     

浅议广电客服的发展与完善

结合张家港广电信息网络有限公司客服中心实际情况,提出广电客服改进的措施及如何提高客服人员的业务能力,使客户服务工作得到完善,最终让客户满意,从而进一步提升公司形象。     

用频谱分析方法实现多音并行HF MODEM

探讨了多音并行ＨＦ ＭＯＤＥＭ的原理，采用频谱分析的方法实现全数字化多音并行ＨＦ ＭＯＤＥＭ，其中解调、同步和多普勒频移补偿都是通过ＦＦＴ来完成。本方案已经在计算机上模拟实现。