Hindawi Publishing

Displaying 161-200 of 1831 results

  • White Papers // Feb 2010

    Localized Multistreams for P2P Streaming

    Streaming video over the Internet, including cellular networks, has now become a commonplace. Network operators typically use multicasting or variants of multiple unicasting to deliver streams to the user terminal in a controlled fashion. P2P streaming is an emerging alternative, which is theoretically more scalable but suffers from other issues...

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  • White Papers // Feb 2010

    Hybrid Terrestrial-Satellite DVB/IP Infrastructure in Overlay Constellations for Triple-Play Services Access in Rural Areas

    This paper discusses the convergence of digital broadcasting and Internet technologies, by elaborating on the design, implementation, and performance evaluation of a hybrid terrestrial/satellite networking infrastructure, enabling triple-play services access in rural areas. At local/district level, the paper proposes the exploitation of DVB-T platforms in regenerative configurations for creating terrestrial...

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  • White Papers // Jan 2010

    Secure P2P Data Storage and Maintenance

    P2P data storage requires strong reliability and security assurances. Existing data storage solutions have been designed for centralized as well as distributed settings; yet they do not address the security and cooperation issues raised by self-organization. P2P systems also introduce new needs regarding data availability due to the dynamicity of...

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  • White Papers // Jan 2010

    Personalized Sports Video Customization Using Content and Context Analysis

    The authors present an integrated framework on personalized sports video customization, which addresses three research issues: semantic video annotation, personalized video retrieval and summarization, and system adaptation. Sports video annotation serves as the foundation of the video customization system. To acquire detailed description of video content, external web text is...

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  • White Papers // Jan 2010

    Mixed-Signal Parallel Compressive Spectrum Sensing for Cognitive Radios

    Wideband spectrum sensing for cognitive radios requires very demanding Analog-to-Digital Conversion (ADC) speed and dynamic range. In this paper, a mixed-signal parallel compressive sensing architecture is developed to realize wideband spectrum sensing for cognitive radios at sub-Nqyuist rates by exploiting the sparsity in current frequency usage. Overlapping windowed integrators are...

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  • White Papers // Jun 2009

    Interactive Digital Terrestrial Television: The Interoperability Challenge in Brazil

    This paper introduces different standards implemented in existing Digital Terrestrial Television Broadcasting systems to allow the fruition of interactive services and applications through digital Set Top Boxes. It focuses on the interoperability issue between the Brazilian and the European architectures. In fact, despite in Brazil the GEM specification has been...

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  • White Papers // Jun 2009

    Multiple Description Coding Using Data Hiding and Regions of Interest for Broadcasting Applications

    The authors propose an innovative scheme for Multiple Description Coding (MDC) with Regions Of Interest (ROI) support to be adopted in high-quality television. The scheme proposes to split the stream into two separate descriptors and to preserve the quality of the region of interest, even in case one descriptor is...

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  • White Papers // Jun 2009

    P2P and MPEG FGS Encoding: A Good Recipe for Multipoint Video Transmission on the Internet

    In the last years Peer-To-Peer (P2P) systems have gained ground for content sharing between communities, determining a real revolution on the Internet. The characteristics of P2P systems make them a very good choice for multimedia content distribution over IP networks. However, although P2P technology gives new opportunities to define an...

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  • White Papers // Mar 2009

    A Geometry-Inclusive Analysis for Single-Relay Systems

    Successful message relay, or the quality of the interuser channel, is critical to fully realize the cooperative benefits promised by the theory. This in turn points out the importance of the geometry of cooperative system. This paper investigates the impact of the relay's location on the system capacity and outage...

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  • White Papers // Apr 2009

    Implementing Statistical Multiplexing in DVB-H

    A novel technique for implementing Statistical Multiplexing (StatMux) of broadcast services over Digital Video Broadcasting for Handhelds (DVB-H) channels is proposed. DVB-H uses a time-sliced transmission scheme to reduce the power consumption used for radio reception part in DVB-H receivers. Due to the time-sliced transmission scheme, the implementation of known...

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  • White Papers // Mar 2009

    Adaptive Error Resilience for Video Streaming

    Compressed video sequences are vulnerable to channel errors, to the extent that minor errors and/or small losses can result in substantial degradation. Thus, protecting compressed data against channel errors is imperative. The use of channel coding schemes can be effective in reducing the impact of channel errors, although this requires...

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  • White Papers // Feb 2009

    Implementing a DVB-T/H Receiver on a Software-Defined Radio Platform

    Digital multimedia broadcasting is available in more and more countries with various forms. One of the most successful forms is Digital Video Broadcasting for Terrestrial (DVB-T), which has been deployed in most countries of the world for years. In order to bring the digital multimedia broadcasting services to battery-powered handheld...

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  • White Papers // Feb 2009

    Intra-Skip in Inter-Frame Coding of H.264/AVC

    In inter-frame coding of H.264/AVC standard, not only seven inter-partition modes but also intra-modes are taken into account for seeking the best coding mode so as to maintain higher encoding efficiency by sacrificing the speed of H.264/AVC encoder. Aiming at intra-skip, this paper proposes a novel mathematical model for intra-skip...

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  • White Papers // Feb 2009

    Exploiting Redundancy in an OFDM SDR Receiver

    Common OFDM system contains redundancy necessary to mitigate interblock interference and allows computationally effective single-tap frequency domain equalization in receiver. Assuming the system implements an outer error correcting code and channel state information is available in the receiver, the authors show that it is possible to understand the cyclic prefix...

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  • White Papers // Feb 2009

    Multiband Antennas for SDR Applications

    The authors present multiband antennas configurations for SDR applications. Using a composite folded dipole structure as starting point, they derived more complex antenna configurations to support multiple communication protocols for mobile application with linear and circular polarizations. Prototypes as single antenna with circular polarization, tunable single antenna with PIN diode...

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  • White Papers // Feb 2009

    Low-Cost Transceiver Architectures for 60 GHz Ultra Wideband WLANs

    Millimeter-wave multi-port transceiver architectures dedicated to 60 GHz UWB short-range communications are proposed in this paper. Multi-port circuits based on 90 degree? hybrid couplers are intensively used for phased antenna array, millimeter-wave modulation and down-conversion, as a low-cost alternative to the conventional architecture. This allows complete integration of circuits including...

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  • White Papers // Jan 2009

    3G Long Term Evolution Baseband Processing With Application-Specific Processors

    Data rates in the upcoming 3G Long Term Evolution (LTE) standard will be manifold when compared to the current universal mobile telecommunications system. Implementing receivers conforming with the high-capacity transmission techniques is challenging due to the complexity and computational requirements of algorithms. In this paper, the Software Defined Radio (SDR)...

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  • White Papers // Jan 2009

    Software-Defined Radio Demonstrators: An Example and Future Trends

    Software-defined radio requires the combination of software-based signal processing and the enabling hardware components. In this paper, the authors present an overview of the criteria for such platforms and the current state of development and future trends in this area. This paper will also provide details of a high-performance flexible...

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  • White Papers // Oct 2008

    Statistical Time-Frequency Multiplexing of HD Video Traffic in DVB-T2

    Digital Video Broadcast-Terrestrial 2 (DVB-T2) is the successor of DVB-T standard that allows a two-dimensional multiplexing of broadcast services in time and frequency domains. It introduces an optional Time-Frequency Slicing (TFS) transmission scheme to increase the flexibility of service multiplexing. Utilizing Statistical Multiplexing (StatMux) in conjunction with TFS is expected...

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  • White Papers // Oct 2008

    New Adaptive Algorithms for GOP Size Control With Return Channel Suppression in Wyner-Ziv Video Coding

    The authors present novel algorithms for adaptive GOP size control in distributed Wyner-Ziv video coding, where an H.264 video codec is used for intracoding of key frames. The proposed algorithms rely on theoretical calculations to estimate the bit rate necessary for the successful decoding of Wyner-Ziv frames without the need...

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  • White Papers // Nov 2008

    Live Broadcasting of High Definition Audiovisual Content Using HDTV Over Broadband IP Networks

    The current paper focuses on validating an implementation of a state-of-the art AudioVisual (AV) technologies setup for live broadcasting of cultural shows, via broadband Internet. The main objective of the work was to study, configure, and setup dedicated audio-video equipment for the processes of capturing, processing, and transmission of extended...

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  • White Papers // Oct 2008

    Turbo Decoder for Low-Power Ultrawideband Communication Systems

    A new method to reduce the computational complexity of the turbo decoding in UltraWideBand (UWB) Orthogonal Frequency Division Multiplexing (OFDM) system is proposed. Existing stopping techniques for turbo decoding process using constrained decoding assume fixed Signal-to-Noise Ratio (SNR) for all the OFDM symbol bits so they fail to yield an...

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  • White Papers // Oct 2008

    Evolving the Convergence of Telecommunication and TV Services Over NGN

    The convergence of telecommunication, cable TV, and broadcast networks towards the Internet technology will enable the provision of emerging multimedia services as well as the integration of rich communication capabilities with TV services. However, enabling efficient delivery of interactive personalized multimedia services with mobility support requires an advanced overlay control...

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  • White Papers // Mar 2010

    Advances in 3DTV: Theory and Practice

    Being a goal over decades, the extension of television, and visual communications in general, to the Third Dimension (3DTV) has been almost reached. Currently, 3D motion pictures are shown in theaters and the first 3D broadcasts are being planned to initiate in the next few years. Albeit the progress, state...

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  • White Papers // Jan 2010

    Flexible Human Behavior Analysis Framework for Video Surveillance Applications

    The authors study a flexible framework for semantic analysis of human motion from surveillance video. Successful trajectory estimation and human-body modeling facilitate the semantic analysis of human activities in video sequences. Although human motion is widely investigated, they have extended such research in three aspects. By adding a second camera,...

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  • White Papers // Jan 2010

    RTSP-based Mobile Peer-to-Peer Streaming System

    Peer-to-peer is emerging as a potentially disruptive technology for content distribution in the mobile Internet. In addition to the already well-known peer-to-peer file sharing, real-time peer-to-peer streaming is gaining popularity. This paper presents an effective real-time peer-to-peer streaming system for the mobile environment. The basis for the system is a...

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  • White Papers // Jan 2010

    Automatic TV Broadcast Structuring

    TV broadcast structuring is needed to precisely extract long useful programs. These can be either archived as part of the authors' audiovisual heritage or used to build added-value novel TV services like TVoD or Catch-up-TV. First, the problem of digital TV content structuring is positioned. Related work and existing solutions...

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  • White Papers // Dec 2009

    Robust MMSE Transceiver Designs for Downlink MIMO Systems with Multicell Cooperation

    The Robust-Generalized Iterative Approach (Robust-GIA), Robust-Fast Iterative Approach (Robust-FIA), and Robust-Decoder Covariance Optimization Approach (Robust-DCOA) are proposed for designing MMSE transceivers of downlink multicell multiuser MIMO systems with per-cell and per-antenna power constraints and possibly imperfect channel state information. The Robust-DCOA is the most restrictive but is always optimum, the...

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  • White Papers // Dec 2009

    A Scalable Multiple Description Scheme for 3D Video Coding Based on the Interlayer Prediction Structure

    The most recent literature indicates Multiple Description Coding (MDC) as a promising coding approach to handle the problem of video transmission over unreliable networks with different quality and bandwidth constraints. Furthermore, following recent commercial availability of auto stereoscopic 3D displays that allow 3D visual data to be viewed without the...

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  • White Papers // Dec 2009

    Spatial Domain Resource Sharing for Overlapping Cells in Indoor Environment

    As microcell wireless systems become more widespread, intercell interference among the access points will increase due to the limited frequency resource. In the overlapping cell scenario, radio resources should be shared by multiple cells. Although time and frequency resource sharing has been described in many papers, there is no detailed...

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  • White Papers // Dec 2009

    A Video Browsing Tool for Content Management in Postproduction

    The authors propose an interactive video browsing tool for supporting content management and selection in post-production. The approach is based on a process model for multimedia content abstraction. A software framework based on this process model and desktop and Web-based client applications are presented. For evaluation, they apply two TRECVID...

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  • White Papers // Dec 2009

    An Optimized Dynamic Scene Change Detection Algorithm for H.264/AVC Encoded Video Sequences

    Scene change detection plays an important role in a number of video applications, including video indexing, semantic features extraction, and, in general, pre- and post-processing operations. This paper deals with the design and performance evaluation of a dynamic scene change detector optimized for H.264/AVC encoded video sequences. The detector is...

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  • White Papers // Dec 2009

    ipProjector: Designs and Techniques for Geometry-Based Interactive Applications Using a Portable Projector

    The authors propose an interactive projection system for a virtual studio setup using a single self-contained and portable projection device. The system is named ipProjector, which stands for Interactive Portable Projector. Projection allows special effects of a virtual studio to be seen by live audiences in real time. The portable...

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  • White Papers // Jan 2010

    Utilizing Context in Location-Aware Short-Range Wireless Communication

    The authors discuss how a short-range wireless communication service implemented for modern mobile communication devices can provide additional value for both the consumer and the service/product provider. When used as an information search tool, such systems allow services and products being promoted at the location they are available. For the...

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  • White Papers // Nov 2009

    Phase-Shift Cyclic-Delay Diversity for MIMO OFDM Systems

    It is well known that a Multiple-Input-Multiple-Output (MIMO) transmission system can provide benefits on throughput and reliability in multipath fading channels over single-antenna systems. These benefits are now being realized; MIMO transmission schemes have been adopted in most wireless standards including 3GPP Long-Term Evolution (LTE), 3GPP LTE-Advanced, WiMax, and IEEE...

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  • White Papers // Dec 2009

    Statistical Skimming of Feature Films

    The authors present a statistical framework based on Hidden Markov Models (HMMs) for skimming feature films. A chain of HMMs is used to model subsequent story units: HMM states represent different visual-concepts, transitions model the temporal dependencies in each story unit, and stochastic observations are given by single shots. The...

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  • White Papers // Jan 2010

    Frequency-Based Optimization Design for Fractional Delay FIR Filters with Software-Defined Radio Applications

    Software-defined radio represents a major change in the design paradigm for radios, in which most of the functionality is made through programmable signal processing devices, giving the radio the ability to change its operating parameters to accommodate new features and capabilities. A software-defined radio platform is designed to make mobile...

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  • White Papers // Dec 2009

    A Compact Representation for 3D Animation Using Octrees and Affine Transformations

    This paper presents a new and compact 3D representation for nonrigid objects using the motion vectors between two consecutive frames. The authors' method relies on an Octree to recursively partition the object into smaller parts. Each part is then assigned a small number of motion parameters that can accurately represent...

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  • White Papers // Nov 2009

    Intercell Interference Coordination through Limited Feedback

    The authors consider the applications of multicell transmission schemes to the downlink of future wireless communication networks. A multicell Multiple-Input Multiple Output-(MIMOs) based scheme with limited coordination among neighboring Base Stations (BSs) is proposed to effectively combat the intercell interference by taking advantage of the degrees of freedom in the...

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  • White Papers // Dec 2009

    Q-Feed" -An Effective Solution for the Free-Riding Problem in Unstructured P2P Networks

    This paper presents a solution for reducing the ill effects of free-riders in decentralised unstructured P2P networks. An autonomous replication scheme is proposed to improve the availability and enhance system performance. Q-learning is widely employed in different situations to improve the accuracy in decision making by each peer. Based on...

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