数字电视技术入门——八、全数字高清晰度电视系统

高清晰度电视(HDTV)已经成熟的有日本的MUSE制HDTV、欧洲的HD-MAC制HDTV和美国的全数字化HDTV。前两种是模拟和数字混合型制式，其中日本的MUSE制式HDTV系统目前还在运行。     

美国对HDTV的研究

本文概述了美国HDTV的研究工作,包括现有电视制式兼容发展到HDTV的指导原则,研究所等机构在高级电视业务方面的工作及意见。并列表比较不同制式。     

MUSE家族发展的现状—HDTV MUSE制和兼容MUSE制

1.引言NHK已经开发了基于1125/60标准的MUSE制式,并通过WARC-BS或RARC-SAT分配的卫星频道广播了HDTV信号。为了建立日本的HDTV业务,已经使用广播和通信卫星做了各种传输试验。基于这些实验得到的结论,NHK已计划1989年6月开始每天1小时的实验广播。     

高清晰度电视接收系统

虽然日本于80年代初推出的高清晰度电视(HDTV)引起了世界许多国家的关注,但这种HDTV所占用的频带太宽,不能与现行制式兼容,因此HDTV标准没有成为世界统一标准。为此,日本NHK技术研究所于1984年6月推出了MUSE制HDTV系统。该系统采用时间压缩合成(TCI)技术,将高清晰度电视信号的基带压缩到8.1MHz,从而实现了与现行日本NTSC制相兼容的目标。在经过几年的试验性广播以后,于1991年11月25日正式以MUSE制HDTV方式(或称Hi-Vision)向全日本广播。     

HDTV光纤传输技术

预计HDTV将是下一代电视制式。本文阐述了HDTV光纤传输的主要技术、HDTV分配系统的概念以及日本在这方面的主要经验。在日本,已经研制了一种采用时间压缩多路格式的系统,并正在进行现场试验。另外还讨论了HDTV分配网络的设计思想以及将来的应用。高清晰度电视(HDTV)比NTSC 4 MHz制式提供了更多的真实感。因此,预计HDTV将是下一代电视制式。大多数的HDTV设备,如摄象机、CRT监视器、投影监视器、录象机以及信号处理器,已经完成了研制。于是     

美国数字高清晰度电视的最新发展：谈数字HDTV大联盟

一、数字HDTV大联盟的由来 1987年,美国联邦通信委员会(FCC)提出“重视先进电视系统”的报告,并成立了相应的组织机构。在其推动下,美国数字HDTV技术得到了迅速发展,在世界高清晰度电视发展领域遥遥领先。自1991年以来,已有4种全数字HDTV制式通过了美国先进电视顾问委员会(ATV)的测试,它们分别是:通用仪器公司和麻省理工学院提出的DigiCipher(数字密码)制式和CCDC(频道兼容)制式;AT&T和Zenith电子公司提出的DSC-HDTV制式;高级电视研究集团提出的ADTV(高级数字电     

数字压缩技术用于地面广播HDTV

设计数字HDTV制式的关键是压缩HDTV信源编码,使它能以6MHz带宽在地面广播的频道传送.信源编码的主要目标是在保证图像质量前提下,尽可能利用较少的几个比特再现图像.典型的信源编码是有损耗编码和无损耗编码的组合.本文结合美国四种用于地面广播的数字HDTV制式对这些压缩技术作了进一步的探讨.     

我国高清晰度电视(HDTV)的制式选定策略分析

本文在分析了国际上HDTV发展历史、HDTV技术要求和我国国情的基础上,提出了我国选定HDTV制式的依据。     

HDTV发展近况与研究对策

本文重点介绍了自美国推出HDTV数字制式以来,国际上美、日、欧角逐HDTV的发展近况,并探讨了我国的研究对策。     

HDTV多媒体大屏幕显示墙中制式变换的研究

本文介绍了HDTV多媒体大屏幕显示墙系统的组成及应用前景．重点阐述了HDTV分割器中制式变换的问题和制式变换的基本原理及解决方法。     

HDTV broadcasting systems

A brief overview of HDTV broadcasting in the USA, Japan, and Europe is given. The requirements for HDTV broadcast systems are examined. The issue of compatibility is discussed. Standardization activities for HDTV broadcasting are described. The Japanese MUSE (multiple sub-Nyquist sampling encoding) system and the European HD-MAC (high-definition multiplexed analog components) systems are examined with respect to their technical basis, underlying principle, and coding/decoding     

The Japanese scene [digital HDTV]

Japan is the only country, so far, to be actually broadcasting high-definition television services. MUSE (multiple sub-Nyquist sampling encoding) is the basis for systems applying bandwidth compression to the transmission of both analog and digital signals. It encodes a signal of 1125 lines and 60 fields per second, a high-definition television (HDTV) signal into an 8-Hz bandwidth. Experimental MUSE broadcasts started in 1990 and have continued ever since. Meanwhile, work has been in progress in areas other than MUSE. Enhanced-definition television, a terrestrial system, is entering its second generation. Integrated digital broadcasting looks to spin many services into a single digital thread for transmission over a single channel. Digital sound broadcasting and hierarchical television transmission will also come in for consideration. The MUSE system depends on digital technology for signal processing, but the HDTV signal that is broadcast is analog, the outcome of frequency modulation     

An HDTV Broadcasting System Utilizing a Bandwidth Compression Technique?MUSE

An HDTV broadcasting service on one satellite broadcast channel became available after the development of a transmission system called MUSE involving bandwidth compression. Using MUSE, a satellite channel of width 27 or 24 MHz in the 12 GHz band can carry an HDTV picture, digitally-coded four-channel sound and independent digital signal at about 100 Kb/s.     

Multimedia services in the HDTV MUSE system

Experimental equipment to investigate multimedia service functions for application to MUSE (multiple sub-Nyquist sampling encoding) HDTV broadcasting has been developed. This system is called the multimedia MUSE system. Programs have also been produced to evaluate service functions of the system taking into account the capacity of the transmission path. This paper describes the configuration of the multimedia MUSE System, service examples, and evaluation of transmission capacity making use of test programs. Our studies reveal that multimedia broadcasting services can be provided when storage memory is installed for achieving interactive viewing and multimedia programs are appropriately configured. In addition, the services described here will provide the basic concept for multimedia broadcasting in future digital broadcasts     

Sound Transmission for HDTV Using Baseband Multiplexing into MUSE Video Signal

A coding system developed for sound transmission accompanying the MUSE system HDTV picture is described.     

FM-FDM optical CATV transmission experiment and system design forMUSE HDTV signals

FM-FDM (frequency division multiplexing) optical transmission equipment has been developed for 34-channel MUSE HDTV (high-definition television) signals to realize optical CATV (cable television) systems. The equipment uses an LD (laser diode) with a 1.3 μm wavelength, a single-mode optical fiber, and an avalanche photodiode (APD). A good picture is received after a 42 km transmission. A part of the multiplexed signals is distorted near or below the threshold of an LD. When the number of transmission channels is small and the total optical modulation depth is large, this nonlinearity governs the power ratio of an FM signal to one distortion component-the DU ratio. However, when the number of transmission channels is large, the DU ratio is determined by the effective optical modulation depth rather than the total optical modulation depth. Furthermore, the method of system design is clarified for an optical trunk line CATV system. If no restriction on the transmission bandwidth of optical devices exists, approximately 30 km transmission of 100-channel MUSE HDTV signals is available with a received CN ratio of 17.5 dB     

HDTV传输的调制技术

本文旨在阐述高清晰度电视（ＨＤＴＶ）传输的调制技术，并对其国际现状作一较全面的概括。文中扼要地分析了ＨＤＴＶ传输的基本原理，在突出全数字式地面广播的情况下，简述了三种传输调制技术的思想和特点，最后，比较三种ＨＤＴＶ传输的调制技术并分析它们的发展趋势。     

A codec for HDTV signal transmission through terrestrial and satellite digital links

A codec for digital transmission of HDTV is described. The bit-rate compression algorithm is based on advanced techniques such as spatial discrete cosine transform (DCT), temporal differential PCM (DPCM), variable length coding. The codec is designed to operate with both the interlaced studio systems 1125/60 and 1250/50, and, thanks to the inherent flexibility of the packet structure, a wide range of line bit-rates can be used as a compromise between video quality and bit-rate constraints of the digital transmission link. The flexibility of the HDTV codec is highlightened through examples of applications over satellite digital links in practical situations.     

High-definition television systems

Fifteen years ago, in 1970, the NHK (the Japan Broadcasting Corporation) forecast today's information society and started research and development of a high-resolution and wide-screen television system which we now call high-definition television (HDTV) system, to produce a new television system most suitable to the creation of "video culture of the future." Wide ranging studies have been carried out by NHK on the establishment of desirable picture quality, picture aspect, and signal standards for transmission. The provisional HDTV system proposed by NHK based on the result of many studies and the performances of the system are described. Early in 1984, the MUSE system has been developed by NHK and the desirable HDTV information can be compressed with 8 MHz and packed with this system. Thanks to the development of the MUSE system, there is the potential of HDTV broadcasting via satellite and early introduction of HDTV into package media such as video discs and videotapes. The NHK's HDTV system was designed to match many other applications. Many kinds of HDTV equipment have been developed in Japan and HDTV is approached and studied in the relation to various aspects such as electrocinematography, printing, and medicine. NHK has been working on the development of the entire broadcasting system of HDTV to unite the whole world into one "television community" in the coming generation by a worldwide single standard. Video engineers all over the world should be aware of the importance of every possible effort toward the establishment of a global HDTV system.     

Hierarchical NTSC compatible HDTV system architecture — A North American perspective

High definition television (HDTV) has become a major world-wide event in the television arena. Since the early 1980s, when HDTV was first demonstrated by Japan, a number of alternative systems have emerged. These systems clearly reflect the business and political objectives of the particular countries or organizations. In North America, which is the largest single consumer market in the world, technical, business and political considerations are shaping the evolution of HDTV. This paper describes a possible advanced television (ATV) architecture for North America and defines its functional modules and corresponding interfaces. The developed model is recommended as a design tool for standardizing ATV in North America and analysing interrelationships of the functional modules on the economic basis. The paper proposes an ‘hierarchical’ ATV emission system with full NTSC compatibility and HDTV quality. Solutions are recommended for terrestrial broadcast, CATV and satellite. This work describes a total systems approach to HDTV called HDS-NA (high definition system for North America). The two emission signals of HDS-NA: HDMAC-60 and HDNTSC are characterized. RF alternatives for the terrestrial broadcast of HDTV are also discussed.