The Experts below are selected from a list of 14853 Experts worldwide ranked by ideXlab platform
Y C Chung - One of the best experts on this subject based on the ideXlab platform.
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Bidirectional WDM passive optical network for simultaneous transmission of data and Digital Broadcast video service
Journal of Lightwave Technology, 2003Co-Authors: E. S. Son, Jongdeog Kim, K. H. Han, Y C ChungAbstract:We have demonstrated an easily upgradable bidirectional passive optical network for the simultaneous transmission of wavelength-division-multiplexing channels and Digital Broadcast video signals. The proposed network could transmit 15 2.5-Gb/s downstream channels, 15 155-Mb/s upstream channels, and one Broadcast signal consisting of more than 70 Digital video channels.
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Spectrum-sliced bidirectional passive optical network for simultaneous transmission of WDM and Digital Broadcast video signals
Electronics Letters, 2001Co-Authors: D. K. Jung, K. H. Han, Hyunsoo Kim, Y C ChungAbstract:A bidirectional WDM passive optical network based on the spectrum-slicing technique for both broadband switched services and Digital Broadcast video services is demonstrated. This network is capable of providing a 155 Mbit's baseband signal and 30 Digital video signals to each subscriber. The upstream channels also operate at 155 Mbit/s
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Bidirectional passive optical network for the transmission of WDM channels with Digital Broadcast video signals
Optical Fiber Communication Conference and Exhibit, 1Co-Authors: E. S. Son, K. H. Han, J.k. Kim, Y C ChungAbstract:We have demonstrated a bidirectional PON for the transmission of 2.5-Gbps WDM channels and >70 Digital Broadcast video signals. This network could be implemented cost-effectively using a single strand of fiber for bidirectional transmission, LEDs for upstream channels, and one receiver for the detection of both the video and baseband signals (5622 Mbps). In addition, the capacity of the proposed network could be upgraded easily by changing the RF filter or using an additional WDM filter and a receiver.
M. Bard - One of the best experts on this subject based on the ideXlab platform.
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Future transmitter/receiver diversity schemes in Broadcast wireless networks
IEEE Communications Magazine, 2006Co-Authors: Yue Zhang, John Cosmas, Yong-hua Song, M. BardAbstract:An open diversity architecture for a cooperating Broadcast wireless network is presented that exploits the strengths of the existing Digital Broadcast standards. Different diversity techniques for Broadcast networks that will minimize the complexity of Broadcast systems and improve received SNR of Broadcast signals are described. Resulting Digital Broadcast networks could require fewer transmitter sites and thus be more cost effective with less environmental impact. Transmit diversity is particularly investigated since it obviates the major disadvantage of receive diversity being the difficulty of locating two receive antennas far enough apart in a small mobile device. The schemes examined here are compatible with existing Broadcast and cellular telecom standards, and can be incorporated into existing systems without change
Martin Vetterli - One of the best experts on this subject based on the ideXlab platform.
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Combined multiresolution source coding and modulation for Digital Broadcast of HDTV
Signal Processing-image Communication, 1992Co-Authors: Kannan Ramchandran, Martin VetterliAbstract:Abstract A practical end-to-end all-Digital multiresolution system is demonstrated that employs joint source-channel coding and modulation in order to achieve efficient Broadcast of Digital HDTV. The threshold effect plaguing single resolution systems is softened by a stepwise graceful degradation. This can be used to increase the coverage and robustness of the Digital Broadcast system. This approach is seen as an alternative to traditional single resolution Digital transmission systems which are not designed for Broadcast situations, and which suffer from the threshold effect. This paper highlights the benefits of using an embedded multiresolution modulation constellation over a modulation scheme that resorts to time or frequency multiplexing of the Broadcast resolutions. Besides showing coding results and simulations of transmission effects, the paper discusses the trade-offs between low and high resolution coverage.
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Multiresolution coding techniques for Digital television: A review
Multidimensional Systems and Signal Processing, 1992Co-Authors: Martin Vetterli, Kamil Metin UzAbstract:Multiresolution decompositions for video coding are reviewed. Both nonrecursive and recursive coding schemes are considered. In nonrecursive schemes, it is shown that pyramid structures have certain advantages over subband or wavelet techniques, and a specific spatiotemporal pyramid coding of HDTV is discussed in some detail. It is shown that recursive, DPCM like schemes will incur a slight loss of optimality due to a restricted form of prediction if multiresolution decomposition with compatible decoding is required. Compatibility and transmission issues are also discussed. Multiresolution transmission for Digital Broadcast TV is introduced. This, when combined with multiresolution source coding, achieves spectrum efficiency, robustness and graceful degradation under channel impairments.
K. Krishnapillai - One of the best experts on this subject based on the ideXlab platform.
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First steps toward providing a system for converged Digital Broadcast and cellular telecommunications services
IEEE Communications Magazine, 2004Co-Authors: O. Benali, D. Gorrec, M. Guiraudou, Georges Martinez, B. Mazieres, S. Butterfield, J. Cosmos, M. Haque, T. Itegaki, K. KrishnapillaiAbstract:This article provides the motivation to develop a converged Digital Broadcast and mobile telecommunications system. It then gives an overview of the main subsystems required to efficiently provide converged Broadcast and cellular services.
Jim Martin - One of the best experts on this subject based on the ideXlab platform.
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BROADNETS - Simulation study of the spectral capacity requirements of Switched Digital Broadcast
2007 Fourth International Conference on Broadband Communications Networks and Systems (BROADNETS '07), 2007Co-Authors: Jiong Gong, Daniel A. Vivanco, Jim MartinAbstract:Switched Digital Broadcast (SDB) is a new method of distributing video programming. Compared with traditional Broadcast methods, it reduces spectrum requirements by taking advantage of the fact that not all program channels are being viewed by subscribers at the same time. The actual spectrum savings depends on human TV watching behavior, the popularity of delivered TV programs, streaming bit-rate composition and subscriber group size. We have developed a simulation model of an SDB system that allows us to explore the impact of these factors, in particular subscriber’s channel flipping behavior, on the capacity requirement. Our subscriber viewing model ranges from intense, correlated channel flipping behavior to minimal flipping behavior representing DVR usage. Our results suggest that frequent channel flipping has little effect on the spectrum requirements under normal viewing assumptions.
