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     

The status of HDTV in Europe

High-definition television (HDTV) has been intensively developed in Europe since the early '80s, but no regular service has been started. The author reviews some ongoing European R & D activities in the field of high-definition (HD) technology and available and future technologies for HD communication are discussed. Finally, some applications of HD technology in the nonbroadcast area will be presented, including, HD teleconferencing, medical applications and telecinema services     

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     

The dawn of digital TV

The end of analog TV is at hand. Governments are setting firm dates and planning for the new broadcast TV. Although analog TV is being shutdown, it is observed that changing to digital TV costs much higher mainly because of its convenience in connectivity, crisp quality images and digital sounds. In the end, though, consumers are winners, with new and improved services available. They have access to HDTV's great pictures and sound. Thy have uniformly high-quality reception anywhere in a broadcast area, and additional services includes some within traditional broadcast channels but even more coming in the auctioned broadcast spectrum.     

Professional HDTV digital recorder

Some of the essential technology for record/playback systems in professional HDTV digital recorders is described. The full bandwidths of 1125/60 HDTV signals (30 MHz for luminance and 15 MHz each for the two color difference signals) were recorded. An 8-8 mapping channel code and integrated detection were used. A special phase locked loop (PLL) to cope with picture search functions was developed. At the high data rate of 148.5 Mb/s per channel and the high linear density of 0.345 μm per bit, the recorder operates with a word error rate of less than 10^-4      

The digital backlot [cinema special effects]

Special effects become more special thanks to digital processing at every level of filmmaking. Here, the author describes how Hollywood's nearly insatiable demands for novelty are being met with state-of-the-art graphics technology and innovative craftsmanship     

HDTV and the new digital television

Introduces a special section of IEEE Spectrum on HDTV and digital television. Mention is made of historical aspects first before a very brief run-down of the papers in the section     

HDTV evolves for the digital era

HDTV was created in an era of analog TV, seeking higher performance through the enhancements feasible in such an environment, such as higher resolution. The digital era is now in place, bringing compression and other processing enhancements, along with a new order of requirements, possibilities, and constraints for TV systems. HDTV in this era has a new meaning, with very different criteria being established. The paper traces the development of HDTV and details current work to establish HDTV systems appropriate for evolving and future digital application     

Compatible coding of digital interlaced HDTV

A compatible coding scheme for interlaced HDTV (high-definition television) is proposed. This scheme provides a standard definition signal and a second channel containing the additional information required to reach the HD resolution. The global scheme is of the pyramidal type: the standard TV is obtained by downsampling the HDTV signal by means of a field-based operation. The standard TV signal is coded, decoded, and upsampled. It is used as a prediction of the HD signal and the prediction error is coded in a second channel. In both branches, motion-compensated hybrid DCT coding is used. In addition, the DCT is taken within the frame     

浅谈数字HDTV技术

本文介绍了HDTV的基本概念、关键技术与标准、HDTV系统结构等内容。     

The congressional corral [digital media copying prevention]

For now, technologies for ripping, mixing, and burning digital technology are lawful to manufacture and distribute in the United States. But for how much longer? The motion picture industry among other groups of copyright holders, wants Congress to mandate that standard technical protection be installed in all digital media devices. In March 2002, Senator Ernest ("Fritz") Hollings (D-S.C.), with the endorsement of Senator Dianne Feinstein (D-Calif) and others, introduced legislation to do just that. His Consumer Broadband and Digital Television Promotion Act (CB DTPA) would give representatives of technology companies, copyright holders, and consumer groups 12 months to agree on such "standard technical measures". The act would require the Federal Communications Commission (FCC) to conduct a rulemaking that would lead to the requirement that a standard protection measure be embedded in every digital media device. This latter term is broadly enough defined to include general-purpose computers. Making or distributing digital media devices without the standard measure, or removing or altering the measure, would be illegal and, if done for profit, would be a felony.     

Channel coding scheme for in HDTV digital VCR

The authors have developed an experimental in HDTV digital videocassette recorder (VCR). The VCR can record HDTV digital base-band signals for more than 64 min on a in metal particle (MP) tape. An eight-to-eight modulation ( ) scheme has been developed for this VCR to realize high-density recording. In order to suppress sufficiently the low-frequency components and reduce the occurrence probability of long-run-lengths for the recording data sequence, a new conversion table and bit-rearrangement method have been introduced in this modulation scheme. This conversion table has been particularly structured to reduce run-length using the bit-rearrangement process. Three kinds of typical HDTV images were used to evaluate the performance compared with the scrambled-NRZ method. The run-length distribution and the frequency spectrum were calculated for each image. The results showed that the occurrence probability of long-run-lengths were well reduced and the low-frequency components along with the DC component were sufficiently suppressed. Cross-talk interferences and overwriting noises were also found to be much less than those for the scrambled-NRZ method.     

Extreme lawsuits [digital copyright]

Copyright owners concerned that digital technology can allow consumers to quickly make perfect copies of their works have increasingly considered adopting technology to limit that capability-technology that often limits viewing or hearing those works as well. The current fights over digital copyright are basically struggles over two questions. One is: how should the law protect copyright owners who control access to their works with measures such as encryption? The other asks whether you should be held liable for copyright violations if you make a product that can evade those control measures-but that also has legitimate uses. Answers to these questions are now emerging, if fitfully and confusingly, from a host of lawsuits, legislation, and business developments. Those answers will have far-reaching effects on everything from how we purchase music, movies, and other cultural works; what we can do with them after we buy them; and how future consumer electronics products are designed.     

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     

Multicarrier modem for digital HDTV terrestrial broadcasting

A digital modulation system using orthogonal frequency division and multiplexing (OFDM) is addressed in this paper. Such a system presents the advantage of coping with echoes more easily than classical single-carrier modems, thanks to the insertion of a guard interval between two symbols. The signal equalization is then achieved in the frequency domain. This OFDM modem is improved by using dual polarizations. In this configuration, it can convey a 70 Mbits/s (HDTV) bit stream in an 8 MHz UHF channel. Some experimental results relate field trials carried out in several countries with such equipment.