A critique of purely digital HDTV
Article Abstract:
Digital high-definition television (HDTV) technology may be feasible in the future, but the currently proposed digital HDTV transmission systems have very poor spectrum efficiency and need to demonstrate sufficient reliability. There is a 'stampede' in the direction of digital terrestrial HDTV broadcasting, and vital decisions are being made about it 'without adequate thought' or determination of the viability of proposed all-digital technologies. Several assertions about digital transmission are shown or claimed to be wrong, including the beliefs that digital modulation is the most efficient transmission method, digital systems are less susceptible to interference and more immune to noise than analog systems, digital transmission automatically removes ghosts and interoperability with nonbroadcast applications is simpler. The compression technologies that the proposed digital HDTV systems will use are all based on subband coding or the discrete Fourier transform, neither of which provide any advantages to digital transmission.
Publication Name: IEEE Spectrum
Subject: Engineering and manufacturing industries
ISSN: 0018-9235
Year: 1991
User Contributions:
Comment about this article or add new information about this topic:
WARC-92: setting the stage
Article Abstract:
The forthcoming 1992 World Administrative Radio Conference (WARC-92) to commence Feb 1992 in Torremolinos, Spain, will review and decide on a number of proposals for the allocation of radio frequency bands around the world. The allocations are defined by the Table of Frequency Allocations (TFA) of WARC's parent organization, the International Telecommunication Union (ITU). WARC's agenda was established in 1990 by ITU's Administrative Council. ITU member nations developed and submitted proposals that are refined through negotiations with other nations and in WARC committees before submission to the entire 1992 WARC assembly. Only member nations can send delegations to WARC to vote on the allocations. Frequency allocations have historically been awarded on a first-come basis, but developing countries persuaded the ITU to accommodate their needs on an equal basis. The output of WARC is the Final Acts document, which itemizes all agreements made at the conference.
Publication Name: IEEE Spectrum
Subject: Engineering and manufacturing industries
ISSN: 0018-9235
Year: 1992
User Contributions:
Comment about this article or add new information about this topic:
DOE labs: models for tech transfer
Article Abstract:
Department of Energy (DOE) national laboratories involved in weapons work are leading the foray into the commercial world. At the forefront are the Lawrence Livermore National Laboratory in California, Oak Ridge in Tennessee and New Mexico's Los Alamos and Sandia. These facilities have initiated cooperative research and development agreement (Crada) with private entities to streamline technology transfer from military applications to civilian production. Though they were goaded into signing Cradas by the National Competitiveness Technology Transfer Act, the labs will ultimately benefit since they will be free to concentrate on their core capabilities and enjoy additional resources. Two companies who hold Cradas are Radiant Technologies Inc and Plasma Physics Corp. The former deals in ferroelectric materials while the latter is working toward the production of silicon-on-defect-layers.
Publication Name: IEEE Spectrum
Subject: Engineering and manufacturing industries
ISSN: 0018-9235
Year: 1992
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Cache memory design: an evolving art. PC Jr.: misreading the market. Matrix printer: no pulleys, belts, or screws
- Abstracts: Aerospace & military: setting targets throughout the region. Small, low-cost earth stations: a major trend
- Abstracts: The case for object-oriented databases. Plotting made easy
- Abstracts: Linear control analysis on a PC. Editing made easy
- Abstracts: Designing circuit boards for manufacturability. Simulating EM fields