3,897 research outputs found

    A survey of digital television broadcast transmission techniques

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    This paper is a survey of the transmission techniques used in digital television (TV) standards worldwide. With the increase in the demand for High-Definition (HD) TV, video-on-demand and mobile TV services, there was a real need for more bandwidth-efficient, flawless and crisp video quality, which motivated the migration from analogue to digital broadcasting. In this paper we present a brief history of the development of TV and then we survey the transmission technology used in different digital terrestrial, satellite, cable and mobile TV standards in different parts of the world. First, we present the Digital Video Broadcasting standards developed in Europe for terrestrial (DVB-T/T2), for satellite (DVB-S/S2), for cable (DVB-C) and for hand-held transmission (DVB-H). We then describe the Advanced Television System Committee standards developed in the USA both for terrestrial (ATSC) and for hand-held transmission (ATSC-M/H). We continue by describing the Integrated Services Digital Broadcasting standards developed in Japan for Terrestrial (ISDB-T) and Satellite (ISDB-S) transmission and then present the International System for Digital Television (ISDTV), which was developed in Brazil by adopteding the ISDB-T physical layer architecture. Following the ISDTV, we describe the Digital Terrestrial television Multimedia Broadcast (DTMB) standard developed in China. Finally, as a design example, we highlight the physical layer implementation of the DVB-T2 standar

    High definition systems in Japan

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    The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems

    Licenced to Thrive? Podcasting and Copyright Law in Canada

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    This article examines podcasting and its specific characteristics to see, first, where it fits within Canada’s copyright law, and second, how the licensing regime for musical works in Canada applies to podcasting. The discussion next turns to whether or not the current licensing regime for podcasting is desirable in light of the purpose of copyright in Canada, and with a view to the various interests at stake: those of artists, in being paid, and those of society, in enabling podcasters to access material in order to produce their work. An examination of the current and proposed licensing regime and its implications leads to the conclusion that it is not very feasible for amateur or non-commercial podcasters to operate legally in Canada if they use musical content, and that at the very least, podcasting should be covered by different tariffs than commercial Internet broadcasters or download services. The paper then goes on to explore suggestions that have been made to better serve the interests of rights holders, while also allowing more inexpensive access to users — the people who consume (listen to or watch) podcasts — in the online environment

    Orthogonal Pseudo-Random Sequence Enabled Cognitive and Emergency Communications

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    With the ever-increasing demands for the broadband mobile communications, it is becoming more and more difficult to accommodate all existing and emerging wireless services and applications due to the limited communication resources particularly radio spectrum. In addition, system parameters of wireless communications often need to be adapted due to the variation of channel characteristics and user demands. Cognitive communication is emerged as an effective technique, particularly to improve the utilization rate of limited communication resources adaptively according to the change in its operating conditions and requirements. To handle these challenges efficiently and reliably in cognitive radio scenario, cyclic prefix (CP) of the OFDM system is precoded in this thesis using pseudo-random sequence. This signaling link can effectively carry transmission parameters and system adaptation information. In first part of the thesis, mutual interference minimization and transmission power adaptation enabled by the additional signaling link are also investigated. In order to make use of this precoded cyclic prefix (PCP) signaling link, an efficient demodulation scheme is needed to reduce the implementation complexity. Therefore, a low complexity signaling demodulator along with a multipath combining technique to further improve the performance in real communication scenario like in multipath channel is proposed in the thesis. The final aspect of this thesis is the investigation of a robust communication system using digital television (DTV) transmitter identification watermark signal which is also a modulated pseudo-random sequence. The previous study on PCP signaling is thus extended to an emergency communication system using DTV watermark. It is found that watermark based communication system is more robust than the DTV broadcasting and can reach a much wider coverage with significantly increased network reliability, which is suitable for national emergency situations

    New Media Technologies in Europe: the Politics of Satellite, HDTV and DAB

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    It has been lhe tradition in Europe to develop media technologies at national level with close cooperation between the state and the private sector, and frequently with competition between different states and their industrial Infrastructures. The creation of new technologies mostly occurred within lhe electric, and later the electronics industry and included studio equipment, transmitters and receivers; it also included those industries supplying equipment to areas such as telecommunications. optics and the aerospace indus try. The state has always provided some of the central players. for example, Post Office administrations (Telecoms), research ministries, the military sector and in particular, the public service broadcasters

    ESA personal communications and digital audio broadcasting systems based on non-geostationary satellites

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    Personal Communications and Digital Audio Broadcasting are two new services that the European Space Agency (ESA) is investigating for future European and Global Mobile Satellite systems. ESA is active in promoting these services in their various mission options including non-geostationary and geostationary satellite systems. A Medium Altitude Global Satellite System (MAGSS) for global personal communications at L and S-band, and a Multiregional Highly inclined Elliptical Orbit (M-HEO) system for multiregional digital audio broadcasting at L-band are described. Both systems are being investigated by ESA in the context of future programs, such as Archimedes, which are intended to demonstrate the new services and to develop the technology for future non-geostationary mobile communication and broadcasting satellites

    Mapping Digital Media: United Kingdom

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    Examines trends in digital media access, consumption, and impact, including digital television uptake, Internet access, preferred news sources, effect on investigative journalism, the role of public interest journalism, and the regulatory environment
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