用于DRM接收机的信道估计算法

DRM(Digital Radio Mondial)规定了一种应用于30MHz以下地面广播的数字声音广播系统,能够高质量地传输声音、数据及静止图片等。DRM系统采用正交频分复用和多电平调制技术,为保证接收信号质量,在接收机中需要进行信道均衡。根据DRM系统发射信号的特点,设计了一种信道估计算法,兼顾了复杂程度和均衡精度,并且对载波频偏不敏感。     

Digital Radio Mondiale (DRM) digital sound broadcasting in the AM bands

The paper describes the new world-wide broadcasting system Digital Radio Mondiale/spl trade/ (DRM/spl trade/) for the long, medium and short wave bands. It is originated by the goal of the consortium members to develop a flexible and efficient audio and data broadcasting standard. Better sound quality, more reliable reception in combination with additional service information make DRM a promising successor to analogue AM. Achieving good audio quality becomes a challenging task due to the limited bandwidth of 9 or 10 kHz, especially in often strongly impaired channels. Many other requirements, which were the basis for the system development, are illustrated. The article gives an overview of the system architecture, including the components for multiplexing, modulation, channel coding and source coding. Important receiver aspects, such as synchronization and channel estimation, are also described.     

无线广播发展探索

随着电子科学技术不断地更新换代,无线电调幅广播正在逐步向数字中短波音频广播(DRM)和数字音频广播(DAB)直播卫星发展。     

创新的中国数字调频广播技术方案——CDRadio与HD Radio的简介与比较

数字化正对中国广播电视行业产生着深刻的影响,传统的FM音频广播也面临着数字化改造.在DAB,HD Radio,DRM及CDRadio几种先进数字音频广播技术方案中重点比较了HD Radio与CDRadio.中国数字调频广播技术方案CDRadio实现了真正的带内数模混叠同播,并通过使用非规则频谱分配、LDPC纠错编码、时...     

数字调幅广播的DRM与IBOC技术

分别介绍了由国际电联(ITU)推荐的世界数字无线电组织DRM和美国iBiquity数字公司带内同频IBOC2个可实现30MHz以下地面数字音频广播的系统方案的技术要点和指标,并对2个方案进行了对比研究,提出了对发展中国数字调幅广播的建议。     

几种数字广播技术的特点及其应用

目前数字广播技术发展迅速,为此介绍国际上几种发展较为成熟的数字广播,如数字声音广播（DAB）、数字多媒体广播（DMB）、数字卫星声音广播（DSB）、数字调幅声音广播（DRM）等,尤其是网上数字广播利用互联网的优势,实现了全球覆盖,受众自由选择节目,扩展了信息容量,实现了同步交流,极大地拓展了广播的功能,展现出美好前景。     

基于软件无线电的中短波接收机设计

目前广播系统正由模拟体制向数字化体制过渡,数字版权管理（DRM,Digital Radio Mondiale）系统就是针对30 MHz以下频段的数字广播标准。作为软件无线电的核心技术之一,数字接收机技术得到了越来越普遍的应用。介绍了一种基于软件无线电的中短波接收机的硬件系统结构,这种软件无线电接收机结构可以同时解码音频和数据流,兼容目前的模拟调幅广播和数字调幅广播标准。重点讨论了电调滤波器的设计,最后使用EDA软件进行仿真,并给出了仿真结果。     

DRM短波数字广播技术及监测

在HF频段开展的短波声音广播业务,是各国对文化、政策进行区域或全球宣传的有利工具。自短波广播出现以来,HF频谱资源日趋紧张。随着科技的进步,听众对高品质声音广播的需求增大。国际电信联盟顺应时代和科技的发展,研发并制定了世界数字广播系统,由此,短波广播迈入数字化的进程不断加快。本文就短波数字广播的调制技术及监测进行分析和介绍。     

Summary of conclusions of the 1992 World Administrative RadioConference

The major decisions made at the conference are briefly described. Additional frequency bands for shortwave (HF) radio broadcasting were agreed upon. Frequency allocations were made to support a number of US proposals, to provide advanced mobile radio services using low Earth orbit satellites. Allocations for land based mobile services adopted at WARC '92, in the range 1700 to 2600 MHz, are meant to foster improved mobile services that can be used worldwide. An allocation was also made to support commercial telephone service between passengers flying on aircraft and individuals on the ground. Allocations were made for sound broadcasting from satellites, as well as for providing a means to accommodate a complementary terrestrial-based digital audio broadcasting service. New frequency allocations to support space activities were agreed upon, and an allocation was made to the fixed satellite service in the band 13.75 to 14.0 GHz     

CD by radio-digital radio broadcasting

Engineers have been looking at ways of broadcasting a digital radio service to the general public, which would ideally have the following features: sound quality comparable with that of the CD; reliable reception to all listeners in the coverage area; capability of offering coverage of all listeners; capability of fixed, mobile and portable reception using simple low grains antennas; simple push-button programme selection-no tuning; frequency efficiency, so that many services can be provided in any spectrum available; and capability of operation from terrestrial transmitters and/or satellite. The author describes the requirements of a digital audio broadcasting system regarding intersymbol interference and then discusses COFDM, coded-orthogonal frequency division multiplex. The author also discusses low-bit-rate sound, terrestrial transmission, satellite broadcasting, receivers, frequency allocation and system testing     

Technical advances in digital audio radio broadcasting

The move to digital is a natural progression taking place in all aspects of broadcast media applications from document processing in newspapers to video processing in television distribution. This is no less true for audio broadcasting which has taken a unique development path in the United States. This path has been heavily influenced by a combination of regulatory and migratory requirements specific to the U.S. market. In addition, competition between proposed terrestrial and satellite systems combined with increasing consumer expectations have set ambitious, and often changing, requirements for the systems. The result has been a unique set of evolving requirements on source coding, channel coding, and modulation technologies to make these systems a reality. This paper outlines the technical development of the terrestrial wireless and satellite audio broadcasting systems in the U.S., providing details on specific source and channel coding designs and adding perspective on why specific designs were selected in the final systems. These systems are also compared to other systems such as Eureka-147, DRM, and Worldspace, developed under different requirements.     

调频频段数字音频广播系统研究及覆盖干扰分析

2013年国家新闻出版广电总局颁布了调频频段数字音频广播系统的信道标准和复用标准,标志着中国调频频段模拟广播数字化技术已经确定。主要介绍了调频频段数字音频广播系统的相关技术及其传输性能,并结合实验室的测试结果讨论了调频频段数字音频广播的覆盖和干扰问题。     

数字调幅广播系统(DAM)中应用Turbo码的分析

描述了一个利用MATLAB设计的仿真平台,用于分析Turbo码应用于AM频段数字音频广播系统的性能,简要说明了平台中使用的Turbo码的编、解码算法。利用此平台以DRM(全球数字广播)系统的参数和AWGN信道为例进行仿真,结果表明,在所分析的情况下,应用Turbo码可以得到较好的性能,并在技术上有一定的可实现性。     

基于WRM的流媒体数字版权管理(DRM)系统实现

为了解决媒体文件的版权问题，Windows Media Rights Manager（MRM）提供了对数字权限管理（DRM）的支持，可实现对数字媒体文件的加密保护。该文简要介绍了Micmsoft的DRM技术原理及工作流程，叙述了如何采用DRM技术保护网站上的音频和视频资料。重点描述了如何基于Windows Media Rights Manager SDK创建认证服务器。提供认证许可的发放及身份的验证，如何基于Windows Media Rights Manager SDK创建一个DRM系统来生成密钥，打包、加密和发行数字媒体内容。     

ATSC Video and Audio Coding

In recent decades, digital video and audio coding technologies have helped revolutionize the ways we create, deliver, and consume audiovisual content. This is exemplified by digital television (DTV), which is emerging as a captivating new program and data broadcasting service. This paper provides an overview of the video and audio coding subsystems of the Advanced Television Systems Committee (ATSC) DTV standard. We first review the motivation for data compression in digital broadcasting. The MPEG-2 video and AC-3 audio compression algorithms are described, with emphasis on basic concepts, system features, and coding performance. Next-generation video and audio codecs currently under consideration for advanced services are also presented.     

省级CDR全数字音频广播试验分析

随着我国广播电视无线数字化的不断推进,调频广播也逐渐进入数字化进程,开展全数字音频广播试验工作,符合未来广播业务发展的方向。本文结合河北广播电视台全数字音频广播试验,对全数字音频广播节目集成平台、传输系统、发射系统的搭建步骤进行了总结,对全数字音频广播实地路测数据、收听效果对比测试数据、实际覆盖效果进行了重点分析,为今后相关部门开展全数字音频广播覆盖工程提供参考和借鉴。     

基于流媒体技术的智能小区数字音频播放系统

介绍了流媒体技术的基本原理、网络传输协议及其传播方式,分析了传统智能小区数字音频播放系统中的不足,在原有基础上利用流媒体技术设计和实现了一个功能更为完善的数字音频播放系统。实验表明,该系统在音频服务器和录播终端均为PIII800M的PC机,网络为10Mb带宽LAN条件下完全满足智能小区音频播放要求。     

Authenticated content distribution framework for digital rights management systems with smart card revocation

The growing features of multimedia distribution across multiple smart devices have attained significant attention of many industries and users. In this context, digital rights management (DRM) is the system, which tries to ensure authorized content distribution. For much diverse and productive research in content distribution, DRM is paying attention to provide a better DRM protocol according to current requirements. But the violation of copyright protection of digital content (video, audio, and secret documents) still has a significant issue of concern. Not only solely copyright protection but also stolen smart cards which keep the license and more specific information of a user is also an attentive concern of DRM users. In this paper, we introduced an authenticated key agreement protocol which maintains secure and authorized content distribution with successful smart card revocation. Moreover, the proposed scheme has simulated under AVISPA tool, which informally confirms the security of the protocol. The formal proof security is given in the random oracle model and then done the performance evaluation. The comparison with the relevant existing schemes shows the advantage of the proposed scheme. It identified that the proposed protocol achieves all the desirable security and performance attributes with valid smart card revocation.     

数字多媒体广播（DMB）

简要介绍了数字音频广播（DAB）的新发展——数字多媒体广播（DMB）的特点入其中新技术的应用和发展前景。