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Sullivan G.J.,Microsoft | Ohm J.-R.,RWTH Aachen | Han W.-J.,Gachon University | Wiegand T.,Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut | Wiegand T.,TU Berlin
IEEE Transactions on Circuits and Systems for Video Technology | Year: 2012

High Efficiency Video Coding (HEVC) is currently being prepared as the newest video coding standard of the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. The main goal of the HEVC standardization effort is to enable significantly improved compression performance relative to existing standards-in the range of 50% bit-rate reduction for equal perceptual video quality. This paper provides an overview of the technical features and characteristics of the HEVC standard. © 1991-2012 IEEE.

Boche H.,TU Munich | Schubert M.,Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut
IEEE Transactions on Information Theory | Year: 2011

Many solutions and concepts in resource allocation and game theory rely on the assumption of a convex utility set. In this paper, we show that the less restrictive assumption of a logarithmic hidden convexity is sometimes sufficient. We consider the problems of Nash bargaining and proportional fairness, which are closely related. We extend the Nash bargaining framework to a broader family of log-convex sets. We then focus on the set of feasible signal-to-interference-plus-noise ratios (SINRs), for the cases of individual power constraints and a sum power constraint. Under the assumption of log-convex interference functions, we show how Pareto optimality of boundary points depends on the interference coupling between the users. Finally, we provide necessary and sufficient conditions for strict log-convexity of the feasible SINR region. © 2011 IEEE.

Butt M.M.,Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut
IEEE Wireless Communications Letters | Year: 2012

This work addresses the problem of data scheduling over fading channels in a deadline (strict delay) constrained multiuser system where a certain amount of data loss can be tolerated. We propose a scheme which schedules the users based on their instantaneous channel conditions and backlog of the packets stored in the buffer. The scheme is analyzed in large user limit. Numerical results demonstrate the energy-performance trade-offs and quantify the gain in energy efficiency for the proposed scheme. © 2012 IEEE.

Bach H.-G.,Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut
ECS Transactions | Year: 2013

High-bit rate fiber networks, remote antenna driving, and measurement applications need a variety of high-performance photodetectors, exhibiting ultra-high frequencies or bandwidths. Based on waveguide-integrated detectors, three special detector types are presented, which address flexible coupling to subsequent electronics (bias-feeding detector), clock extraction capability (narrowband photodetectors) and free space radiation into the sub-THz range (self-biased pin-antenna chip). © The Electrochemical Society.

Penna F.,Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut | Garello R.,Polytechnic University of Turin
IEEE Transactions on Wireless Communications | Year: 2012

In this paper we propose a decentralized approach for cooperative signal detection, based on peer-to-peer collaboration among sensor nodes. The proposed method combines belief propagation, implemented in a distributed fashion through the exchange of local messages to and from neighboring nodes, with a Neyman-Pearson framework, that allows control over the false-alarm rate of each node. At the same time, nodes gradually learn their degree of correlation with neighbors, and clusters of nodes under homogeneous conditions are formed automatically. The performance of the resulting "Neyman-Pearson belief propagation" (NP-BP) algorithm is shown to be nearly equivalent to that of cooperative energy detection applied separately at each cluster. Thanks to its decentralized structure, NP-BP provides improved robustness, flexibility, and scalability compared to traditional, centralized schemes. In addition, its ability to adaptively form clusters makes the algorithm suitable for heterogeneous or time-varying radio environments. © 2002-2012 IEEE.

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