The improved gray scale and the coarse-fine PCM systems, two new digital TV bandwidth reduction techniques

Two new digital television bandwidth-reduction techniques are presented with experimental results. Each provides twice the efficiency of a conventional pulse code modulation (PCM) system with similar picture fidelity, and each is simple and feasible for present-day spacecraft Implementation. The Improved Gray Scale PCM system effectively eliminates, by an averaging process, the gray scale contouring effect encountered in low-bit digital TV systems. The Coarse-Fine PCM system is somewhat more complex, but provides a higher fidelity reproduction of the original picture. The basic principles of operation of these two new data-compression techniques are given along with comparative pictorial results.     

有线数字电视信道编码技术

在传输有线数字电视信号的过程中,为保证信号正常无误地传送,采用的核心技术就是有线数字电视信道编码技术。在介绍有线数字电视及信道编码的基础上,详细分析讨论了有线数字电视信道编码中的数据随机化、RS编码和卷积交织等技术的原理及其参数的意义。     

30/45 Mbps digital coding system for transmission of (4:2:2) digital component TV signals recommended by CCIR

In recent years, the digitalization of transmission links and studio equipment has progressed rapidly in many countries. Considering this background, CCIR has aimed at standardizing a unified high-efficiency bit-reduction coding system, which is indispensable for reducing the cost of digital transmission of TV programs. In this paper, the 30/45 Mbps coding system that we proposed in the expert group assembled for this standardization is presented. The design of this system is based on the 15/30 Mbps universal TV coding system that we developed to transmit two or four TV programs simultaneously through a single transponder of an INTELSAT satellite with 36-MHz bandwidth. First, details of the system configuration are given. Then, the system's coding performance using actual hardware and its transmission performance over an actual digital transmission link are presented. It is concluded that the coding system gives very high performance as well as multichannel sound signals. Finally, the necessity of improving the facility of the coding system for commercial use is discussed.     

数字电视技术分析

DVB—H手机电视技术从传统的数字电视技术演进而来并广泛应用于3G移动通信中，回顾数字电视技术的历史，比较ATSC 8-VSB、DVB—T COFDM和ISDB—T BST—OFDM3种不同调制方式的数字电视技术的优缺点，并分析3种传输系统在不同网络环境中的运行性能。     

实现手机电视的技术方式

DVB-H手机电视技术从传统的数字电视技术演进而来并广泛应用于3G移动通信中。回顾数字电视技术的发展历史,比较基于手机的流媒体业务、MBMS、DVB-H、MediaFLO和DVB-S不同调制方式的数字电视技术的优缺点,并分析5种传输系统在不同网络环境中的运行性能。     

Data compression systems for home-use digital video recording

The authors focus on image data compression techniques for digital recording. Image coding for storage equipment covers a large variety of systems because the applications differ considerably in nature. Video coding systems suitable for digital TV and HDTV recording and digital electronic still picture storage are considered. In addition, attention is paid to picture coding for interactive systems, such as the compact-disc interactive system. The relation between the recording system boundary conditions and the applied coding techniques is outlined. The main emphasis is on picture coding techniques for digital consumer recording     

数字移动电视单频网的建设

数字移动电视广播系统是我国广播电视综合覆盖体系中的重要组成部分,单频网(SFN)是目前地面数字电视广播系统覆盖最好的方法之一。介绍数字移动电视单频网建设中的一些经验和心得,包括合理指配单频网数字台站、选择合适的单频网传输模式、单频网时延的合理设置等。     

立体电视视频质量影响因素分析

从立体电视技术链的角度出发,首先分析了立体电视双目视差基本原理,然后分析了立体电视在视频采集制作、发端压缩编码、信道传输、收端解码和立体显示这5大环节中,现行技术对立体视频质量分别造成的影响以及已有的改进措施,最后展望了最新立体电视技术对于立体视频质量的提升。     

Coded channels. Digital television by satellite

Digital compression techniques will allow satellite TV broadcasting to continue to compete effectively with broadband cable. Instead of transmitting a continuously varying analogue electrical voltage to represent the picture, digital television converts each of the pixels that makes up a TV picture into a coded message. Provided that a receiver can decode the digital message, it can build up a completely new picture, dot by dot, on the screen, with perfect results. As digital compression of television signals becomes the norm, and broadcasters try to squeeze ten or more, services down the same bandwidth that used to carry just one analogue picture, lessons will be learned-about what is acceptable on different types of picture material. Variable rates of compression could perhaps be applied to different scenes in real time, and the channel bandwidth provided for each programme being transmitted over a satellite transponder could be varied dynamically according to the data rate that each scene requires. The author discusses these various aspects of data compression and channel coding     

Field test results of multi-channel digital tv transmission at 15 and 30 Mb/s through an intelsat satellite using a PSK/FDMA system

This paper describes field test results of multi-channel digital TV transmission using a PSK/FDMA system and the related subjective test results of received TV pictures. The picture quality of the multi-channel 15 or 30 Mb/s transmission for both NTSC and PAL systems through the INTELSAT POR satellite are subjectively evaluated for various bit-error rates. In addition, subjective evaluations were made at various values of earth-station e.i.r.p. to compare the picture quality of digital transmissions with that of current half-transponder FM transmission.     

Digital video broadcasting

A new kind of “wireless video” is currently entering consumers' homes-digital television. The term digital video broadcasting (DVB) is used as a synonym for digital television in many countries of the world. Whereas one may tend to think that digital television means just a new, digital, form of signal representation not necessarily affecting the information content of what one has always called TV, the truth is that digital television becomes multiple-channel data broadcasting. This article reviews some of the results of the work in the worldwide DVB Project and explains some of the fundamental concepts behind the work of this group. It then concentrates on the terrestrial transmission system (DVB-T) as one example of the many transmission technologies DVB has developed over the last few years. The COFDM modulation scheme which is a key ingredient of DVB-T is described in some detail. The performance of the system is presented. The use of DVB for data broadcasting and the accompanying return channel technologies are explained     

全数字电视制作系统的设计考虑

在全数字电视制作系统的设计中，选择数字编码方式和接口形成是关键。本文通过对分量数字与复合数字，串行数字传输与并行数字传输的分析比较，以及考虑到先建立的数字制作系统必须能与后建立的全台数字化大系统联网运行，最后选定了分量数字和串行数字接口方式。     

数字电视传输中的HFC网络技术

讨论有线电视网络中传输数字电视存在的问题,并对HFC网络建设和维护等技术问题进行探讨。     

Coded orthogonal frequency division multiplex [TV broadcasting]

Technological evolution and the ever-increasing demand for higher-quality services give broadcasters a strong incentive to completely digitize their broadcasting networks. This digitization, which is already well advanced in many program production areas and transmission links, now has to be extended to complete the last link in the broadcast chain; i.e., from broadcast transmitter to consumer receivers. It is therefore necessary to develop wholly new techniques for the broadcasting of digitally coded TV programmes. Thus an efficient baseband digital coding must be combined with a robust digital modulation and channel coding scheme that can meet the requirements of every mode of broadcast reception. This article presents the research work related to the coded orthogonal frequency division multiplex (COFDM) technology, which has now been completed in the field of digital radio (DAB), and which is under progress in the field of digital terrestrial TV     

NICAM728数字声电视广播

NICAM 728数字声电视广播系统是由BBC研究开发的,它可用于I、B、G、H等制式的电视系统,除传送电视图像和模拟调频单声信号外,还可传送两路高质量数字编码声音信号。目前,已有不少国家和地区采用了NICAM 728系统,一些国家也正在研究并考虑NICAM 728的应用。本文详细介绍了NICAM 728基带编码方案,调制、传输参数,以及系统的总体轮廊。     

数字电视数字广播技术与传输标准探析

当前数字电视数字广播技术为我国电子技术领域带来了新的影响,为模拟信号向数字信号转换提供技术支持。使用数字电视技术对信号进行处理与分析,有效保证了数字信号传输的安全性。根据数字电视数字广播传输的标准需求,并结合国家标准的系统框架处理流程,对关键技术的细节进行研究,并对数字电视数字广播传输的相关问题进行探析。     

唐山有线数字电视平台的组成及应用

以唐山有线数字电视网络体系结构设计为例,从数字电视前端播控平台、市区传输网络、机顶盒接收三方面入手,阐述了数字电视系统的传输工作流程以及部分网络设备的工作原理。     

DVB系统原理与Systemview仿真实现

数字视频广播DVB（Digital Video Broadcasting）标准是欧洲数字电视的传输标准,它包括数字信源压缩编码、节目数据流的统计复用、信道纠错编码、调制等数字传输链路各相关环节所采用的技术及接口标准。本文在介绍DVB技术原理的基础上,深入探讨了DVB系统的构成及调制、解调原理,并在Systemview下对该系统进行了完整仿真。通过信号观察窗对比信号波形发现,输入输出基本一致,说明该系统在通常信噪比条件下可以满足可靠传输的基本要求,达到了预期目的,证明了系统的可靠性。     

广播电视技术发展地面数字电视传输技术分析

对地面数字电视传输技术的基本背景进行了阐述,结合显著提高音画质量、大幅扩充通信量级、兼容更多终端设备以及保有更广发展前景四个部分,分析了地面数字电视传输技术的优越效益;最后,从做好传输系统架设工作、实现传输质量持续提升以及注重技术策略优化创新三个角度入手,研究了地面数字电视技术的实践要点。