Carlo Basile

The US HDTV standard

This standard for digital high-definition television has been submitted to the Federal Communications Commission for its approval. Based as it is on the MPEG-2 video compression and transport protocol, multiple transmission formats, Dolby AC-3 digital audio, and vestigial sideband digital modulation, this HDTV system will supply the home with superb images and spectacular sound while also, as part of the National Information Infrastructure (NII), relaying digital data. An HDTV system employing multiple transmission formats, digital compression, packetization, and modulation techniques is a marked advance over current world television standards such as NTSC, PAL, or SECAM. >

Advanced digital HDTV transmission system for terrestrial video simulcasting

Transmission aspects of the advanced digital high definition television (AD-HDTV) system, for terrestrial simulcast delivery of HDTV are described. In AD-HDTV, two quadrature-amplitude-modulated (QAM) carriers, with different power spectral densities, are employed in a frequency division multiplex (FDM) mode within the standard 6-MHz channel. The resulting spectral shaping allows a larger power to be transmitted, compared to that for a single QAM carrier, for the same level of perceptual interference into cochannel NTSC. The coded video data are split into high-priority (HP) data and standard-priority (SP) data, and the vital information is sent on the appropriate QAM carrier, resulting in a robust audio and video transmission system. The availability is higher in scenarios where the carrier-to-noise ratio (CNR) is above the threshold for HP reception but below the threshold for SP reception; this is important in fringe areas. The NTSC planning factors, suitably modified for HDTV delivery, are used to estimate the coverage area for AD-HDTV. The calculated AD-HDTV coverage area of 54.5 miles is comparable to that for NTSC transmission. >

Channel Matching Techniques for 2-Channel Television

Interest and progress in the area of high definition television (HDTV) has led to a wider aspect ratio image as an integral part of the evolutionary process. Encoder systems decompose the wide aspect ratio source image into a center 4:3 image and two side panels, maintaining compatibility with existing standards (NTSC) for the center picture. Transmission schemes then transmit the center image over a standard 6 Mhz TV channel (channel 1) and the panel information over another channel (channel 2). Decoders which accept the center and panel information recombine the signals to construct the original wider image. An example of this technique is utilized in the two channel ENTSC System [1]. Due to linear distortions, various parameters such as hue, saturation, black level, gain and static time delay must be normalized in both video signals before recombination of the wide aspect ratio picture. A description of techniques which employ insertion of a training signal at the transmitter and a microprocessor at the receiver, used to control these parameters is presented in this paper.

Digital video and the national information infrastructure

Abstract This paper gives an overview of the efforts in the United States to build high-speed networks for the delivery of digital video services to the homes of consumers. It details the obstacles that need to be overcome for digital video service to commence and the various network architectures and technologies that have been, and presently are being considered. The applications are described that will be enabled by such an infrastructure, termed the NII, as are two digital video services oriented market trials — one being conducted by a cable operator and the second by a telephone company.

An HDTV MAC format for FM environments

The system-level architecture for the encoding and decoding of an HDTV (high-definition TV) satellite MAC (multiplexed analog component) signal format suitable for FSS (fixed satellite service) and DBS (direct broadcast service) applications is discussed. A baseband signal processing scheme for video information is shown, the digital data channel capacity is derived, and an analysis of signal-to-noise issues is presented. A decoder consisting of multiple horizontal and vertical signal processing blocks, which does not require frame memory and is therefore not very complex, is described. The horizontal, vertical, and temporal resolution delivered by this system is well tailored to the human visual system. The hardware has been built and used to demonstrate the picture quality, which has proved to be excellent. A digital data channel has been incorporated within the HDTV format. The channel capacity is a minimum of 1.375 Mb/s and research suggests that a doubling of this capacity to 2.75 Mb/s is possible with acceptable performance. The unweighted luminance S/N has been calculated to be 22 dB+C/N, using the suggested transmission parameters. >

Baseband video processing and the transmission of HDTV signals

The authors address the key concerns in the formulation of new HDTV (high-definition television) systems. The starting point is the derivation of basic definitions of resolution parameters of television systems. Having established the means of representing the static and dynamic resolution of a television system, the authors discuss baseband encoding and decoding methods in terms of spatial and temporal filtering of source images as a means of efficient bandwidth reduction. A method for delivery of HDTV via satellite is detailed, and a simulcast technique for transmission HDTV in a terrestrial environment is presented. The sampling, filtering, subsampling, and transmission packaging provides a high-definition system for the North American HDS/NA. Interference issues are of primary concern when utilizing a taboo channel for terrestrial broadcast, and techniques for minimizing their effects, exploited in HDS/NA, are discussed. >

Grand alliance MPEG‐2‐based video decoder with parallel processing architecture

A practical and unique hardware architecture for video bitstream source decoding and video postprocessing of a Moving Pictures Expert Group (MPEG‐2)‐based high‐definition television (HDTV) compressed bitstream has been implemented to impose minimal limitations on the video source coding algorithm. The Grand Alliance (GA) MPEG‐2‐based HDTV codec achieves a high degree of source and channel coding efficiency while preserving the delivery of high‐resoultion picture quality in a variety of video input and output formats in bandwidth‐limited channels. The video source decoder hardware architecture necessary to achieve the data decoding and ensuing video postprocessing poses numerous technologic challenges to the system designer, who must tradeoff minimizing codec constraints with the eventual commercialization of a video decoder for a consumer television receiver product. The powerful and flexible coding algorithm necessary to satisfy the HDTV picture quality and transmission channel bandwidth limitation requirements results in an encoder‐output bitstream that necessitates high throughout decoding. Although the transmitted bitstream is of constant rate due to rate buffering, bistreams internal to the codec are both peaky and bursty. An intelligent distributive parallel processing decoding architecture has been developed to dynamically partition the MPEG‐2 bitstream into a number of decodable subset bitstreams, while placing minimal constraints on the encoding algorithm. This architecture allows for high‐speed, efficient decoding of the bitstream, and can be a prelude to the development of a cost‐effective consumer product. Further architecture refinements can be explored, including implementation in VLSI.

A New NTSC Co-Channel Interference Rejection Filter with Coded 6-VSB Modulation for Improved ATV Coverage

The Advanced Television Systems Committee (ATSC) advanced television (ATV) standard and its service area predictions assume the use of a comb filter at the receiver However, such a filter is not required by the ATV standard. There are also unresolved questions about the efficacy of the comb filter. We describe a new system, including an NTSC co-channel interference rejection filter with coded 6-level digital vestigial sideband (6-VSB) modulation, of comparable complexity, which offers improved ATV service area. Coverage analysis results demonstrate that the system provides much better co-channel performance today, with a comparable carrier-to-noise (C/N) threshold and better threshold performance when NTSC transmission ceases in the future. The new system obviates concerns about the reliability of the comb filter under conditions of noise, interference, and multipath.