HDTV技术动向

1.引言 HDTV(高清晰度电视)正以CCIR(国无线电咨询委员会)为中心,向国际统一标准方向发展。与此时,HDTV实用化工作也在全世界进行。     

全球性高清晰度电视的射频频率要求

一、引言高清晰度电视(HDTV)是一种新技术,它将使现有的电视制式发生巨大变化。HDTV在各国被广泛发展成为最重要的未来广播制式之一。根据广泛的心理物理学研究,HDTV新的扫描格式:屏幕宽高比为16:9,扫描线数超过1000条。采用这些新格式,就临场感和图像清晰度而言,比现有电视制式有完全不同的图像效果。由于其明显的潜在优势,预计HDTV将不仅用于广播而且用于各种工业领域。本文介绍HDTV发展现状及根据CCIR报告的W-HDTV卫星广播制式的各种问题。     

新名词介绍——ATV

ATV是Advance Television的缩写,在日本译成下一代电视,高画质电视或高级电视。这词是从现行制式的改良到建立新的制式过程中,各种电视广播的图象质量改善的总称。按照CCIR的报告(报告1077和报告801-2)ATV包括以下3种内容:(1)Enhanced Television(2)Extended Definition Television(3)HDTV。     

数字电视的有关国际标准

1　引言自1948年提出视频数字化概念后,经过将近40年的探索,于1982年提出了电视演播室数字编码的国际标准(CCIR601号建议);又于1984年提出了第一个实用化的、适应于会议电视和可视电话要求的H.261标准;1993年公布了活动图像的编码压缩标准MPEG-1;1994年发表了MPEG-2标准,该标准向下兼容MPEG-1,向上兼容HDTV的图象质量;1999年公布了MPEG-4标准;今后还计划发表MPEG-7标准。下面将上述国际标准逐一介绍。2　CCIR601号建议为了便于国际间的节目交换,为消除数字设备之间的制式差别和为625行电视系统与525行电视系统之间兼容,在1982…     

数字电视发展概况

1标准 1.1数字电视信号编码压缩标准1 948年有人提出视频信号可以数字化。 1982年提出CCIR601号建议,它是数字化演播室标准。 1990年提出H.261标准,它是会议电视和可视电话标准。 1991年3月提出JPEG标准,它是静止图像传输标准。 1991年11月提出MPEG-1标准,它是活动图像传输标准。 1993年11月提出MFEG-2标准,它是电视图像(包括HDTV)传输标准。 1999年提出MPEG-4标准,它是低码率的可视电话传输标准。     

CCIR493──最可靠的短波选呼系统

近年来，我国短波用户日渐关注CCIR493数字选呼系统。凡使用过这一系统的用户普遍反映其呼通率高、无差错、组网能力强、便于管理。很多大型的短波网络已经或计划采用这一优秀系统。专家认为，推广CCIR493选呼系统能够改变短波领域的混乱状况，促进我国短波应用向高层次的多功能网络方向发展，更好地利用频谱资源。本文仅从使用角度对CCIR493系统作粗浅介绍，使新接触者对它有一个概况性了解。一、CCIR493选呼信令的发展过程CCIR493协议的核心是DSC全数字化选择呼叫技术（英文全称DigitalSelectiVeCall）。这项技术最早出现在60…     

基于FPGA和ADV7123的CCIR显示接口的设计和应用

数字图像在CCIR接口监视器上正确、完整地显示,涉及到图像存储、时序的构建、数字图像的制式转换和数字图像的模拟处理.提出一种能够广泛应用的CCIR接口方案,详细阐述了把逐行扫描的CCD图像数据通过SRAM存储转换成隔行扫描方式的数据格式,采用FPGA设计了CCIR制式的复合同步和消隐时序信号、介绍了视频D/A转换器的使用和该电路设计中的电磁兼容问题.该方案可以广泛用于各种数字视频系统、高分辨率彩色图像处理和视频再现等.     

研究HDTV传输的新体制

本文在回顾和分析国际上HDTV现状和发展的基础上，提出我国发展HDTV的基本设想。本文指出在地面HDTV广播中采用扩展频谱（SS）传输体制的方案（HDTV／SS）将是形成具我国特色的HDTV工业的明智选择。     

高清晰度电视（HDTV）的压缩编码

本文简述HDTV压缩编码的发展;介绍HDTV的140兆比特/秒传输,数字/模拟混合型HDTV卫星广播,以及全数字HDTV地面广播中采用的图像压缩编码原理;并简要展望其发展前景。     

用于都灵冬运会的60GHz、伪无延迟HDTV传输系统

NHK进行HDTV的研究开发已有40年。在日本,尤其自从分别于2000年和2003年播出数字卫星广播和数字地面广播后,HDTV节目日益受欢迎。HDTV现场制作变得很普通,HDTV设备的数量也稳定增长。     

The evolution of HDTV in the work of the CCIR

The development of television system standards in the CIR (International Radio Consultative Committee) is reviewed. Background and results of the extraordinary meeting on high-definition television (HDTV) of CCIR Study Group II are presented. The arguments for a global studio standard for HDTV are examined as are the proposals for achieving this objective. The evolution toward digital systems and the preparation of emission/transmission standards is summarized. Cost, size, weight, and time frame are seen to be major constraints     

HDTV standards

An overview of relevant International Radio Consultative Committee (CCIR) activities in the area of high-definition television (HDTV) standardization is presented. The status of the CCIR standards with respect to chromaticity and signal format, picture characteristics, picture scanning characteristic, and analog and digital representation is discussed. It is concluded that the achievement of a single unambiguous parameter set requiring no quality impairing conversions in international program exchange remains doubtful     

High definition television systems

High definition television (HDTV) services will play the most important role in the digital television systems for the future. HDTV is already broadcast daily in Japan and advanced television (ATV) standards will soon be established in the US. The hardware systems for two HDTV systems, the 1125/60 and 1250/50 systems, have already been developed. Their outlines are described in the paper. Signal processing of HDTV is mainly carried out by digital methods on both the studio and receiver sides. The principles of processing are the same as for conventional television but the higher clock frequency and larger quantity of information require more sophisticated hardware. Digital signal processing methods are the key technology in HDTV broadcasting systems regardless of whether modulation is analog or digital. Some broadcasting systems are already practical use while others, are experimental. The author discusses these systems. The aim of the article is to present a global scope of the HDTV technology     

全数字HDTV的图像质量

本文从图像压缩编码的角度，讨论不同全数字ＨＤＴＶ方案的图像质量，从讨论结果中可以看出：经过编码／解码后全数字ＨＤＴＶ的重建图像质量，将接近或非常接近ＣＣＩＲ７０９建议的演播室图像质量。     

Modulation for terrestrial broadcasting of digital HDTV

The digital modulation methods used by the DigiCipher, DSC-HDTV, ADTV, and ATVA-P digital high-definition television (HDTV) systems are discussed. Three of the systems use a quadrature amplitude modulation method and the fourth uses a vestigial sideband modulation method. The channel equalization and spectrum sharing of the digital HDTV systems is discussed     

高清晰度电视技术的非广播应用

本文主要依据有关的最新CCIR文件,归纳了高清晰度电视技术/高分辨率图像技术的非广播应用,并叙述了有关设备和器件的开发情况。作者根据这些引述的信息,提出了一些见解。     

The challenges of digital HDTV

The characteristics of digital high-definition television (HDTV) and its advantages over analog and hybrid systems are described. The issues to be addressed in using digital transmission in the terrestrial broadcast environment are examined. Four proposed digital HDTV systems are discussed, and their similarities and differences are highlighted. Key techniques are the use of complex compression coding and motion compensation algorithms     

An Experimental HDTV Digital VTR with a Bit Rate of 1.188 Gbps

This paper describes the technical details of an experimental HDTV digital VTR with a bit rate of 1.188 Gbps. This newly developed machine satisfies the proposed parameter values in the CCIR Report 801. The basic technologies developed to achieve such an ultra-high speed recording are: metal particle tape and Sendust sputtered type head, a high performance head assembly, and parallel signal processing. Using 8 recording heads, the recording rate per channel is 148.5 Mbps and the minimum recording wavelength is 0.69 pm. The error control mechanism, based on Reed-Solomon product code, worked sufficiently well with the overhead for parity, sync code and ID code in the blanking period. Even after 20th generation dubbing, no picture quality degradation has been observed.