A View of Information-Estimation Relations in Gaussian Networks

Séminaire le 9 Octobre 2017, 14h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Prof. Shlomo Shamai (Andrew and Erna Viterbi Department of Electrical Engineering)


This talk will focus on the recent applications of Information-Estimation Relations to Gaussian Networks. In the first part of the talk, we will go over recent connections between estimation theoretic and information theoretic measures. The estimation theoretic measures that would
be of importance to us are the Minimum Means p-th Error (MMPE) and its special case the Minimum Mean Square Error (MMSE). As will be demonstrated, the MMSE can be very useful in bounding mutual information via the I-MMSE relationship of Guo-Shamai-Verdu, and the MMPE can be used to bound the conditional entropy via the moment entropy inequality. In the second part of the talk, we will discuss several applications of Information-Estimation Relations in Gaussian noise networks. As the first application, we show how the I-MMSE relationship can be used to determine the behavior, for every signal-to-noise ratio (SNR), of the mutual information and the MMSE of the transmitted codeword for the setting of the Gaussian Broadcast Channel and the Gaussian Wiretap Channel. As a second application, the notion of the MMPE is used to generalize the Ozarow-Wyner lower bound on the mutual information for discrete inputs on Gaussian noise channels. A short outlook of future applications concludes the presentation.

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This work is in collaboration with R. Bustin, A. Dytso, H. Vincent Poor, Daniela Tuninetti, Natasha Devroye, and it is supported by the European Union's Horizon 2020 Research And Innovation Programme, grant agreement no. 694630.

Combined Optimal Activation and Transmission Control in Delay Tolerant Network

Séminaire le 4 Octobre 2017, 14h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Amar Prakash Azad, Inria Sophia Antipolis


Generalized Secrecy Capacity

Séminaire le 2 Octobre 2017, 11h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Matthieu Bloch


On the Degrees of Freedom of MISO Broadcast Channels with Partial CSIT

Séminaire le 20 Septembre 2017, 14h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Dr. Hamdi Joudeh (Imperial College London)


The multiple-input-single-output (MISO) broadcast channel (BC), in which a multi-antenna transmitter communicates with multiple uncoordinated single-antenna receivers, is an essential building block of modern wireless networks. In this channel, multiuser interference management is naturally carried out at the transmitter. This in turn requires highly accurate and up-to-date channel state information at the transmitter (CSIT), which is not always available in practice. While it is understood that the MISO BC is sensitive to CSIT inaccuracies, the capacity under such conditions remains largely a mystery. Hence, it is natural to resort to coarse approximations, e.g. the Degrees of Freedom (DoF), when studying such challenging problems. In this talk, I will review some recent (and not so recent) results in DoF studies of the MISO BC when only partial instantaneous CSIT is available. I will be focusing on tools used to derive achievability and converse result. I will also present some new DoF results for parallel MISO BCs (e.g. OFDM) with partial CSIT. Implications, insights and open problems are also discussed.

Bio: Hamdi Joudeh is a postdoctoral research associate in the Communications and Signal Processing Group, Department of Electrical and Electronic Engineering at Imperial College London. He received his PhD in Electrical Engineering and MSc in Communications and Signal Processing from Imperial College London, UK, in 2016 and 2011 respectively. His research interests are in the areas of wireless communications and multiuser information theory. He is currently serving as an associate editor for the EURASIP Journal on Wireless Communications and Networking.

Semantically-Secured Message-Key Trade-off over Wiretap Channels with Random Parameters

Séminaire le 4 Mai 2017, 14h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Alexander Bunin, Faculty of Electrical Engineering at the Technion-Israel Institute of Technology, Israel.


Modern communication systems usually present an architectural separation between error correction and data encryption. The former is typically realized at the physical layer by transforming the noisy communication channel into a reliable "bit pipe". The data encryption is implemented on top of that by applying cryptographic principles.

Physical layer security (PLS) rooted in information-theoretic principles, is an alternative approach to provably secure communication. This approach dates back to Wyner's celebrated 1975 paper on the wiretap channel (WTC). By harnessing randomness from the noisy communication channel and combining it with proper physical layer coding, PLS guarantees protection against computationally-unlimited eavesdroppers with no requirement that the legitimate parties share a secret key (SK) in advance. The eavesdroppers computational abilities are of no consequence here since the signal he/she observes from the channel carries only negligible information about the secret data.

Two fundamental questions in PLS are those of the best achievable transmission rate of a secret message (SM) over a noisy channel, and the highest attainable SK rate that distributed parties can agree upon. Our work studies the trade-off between SM and SK rates simultaneously achievable over a state-dependent wiretap channel WTC with non-causal channel state information (CSI) at the encoder. This model subsumes all other instances of CSI availability as special cases, and calls for an efficient utilization of the state sequence both for reliability and security purposes. We derive an inner bound on the SM-SK capacity region based on a novel superposition coding scheme. Our inner bound improves upon the previously best known SM-SK trade-off result by Prabhakaran et al., and to the best of our knowledge, upon all other existing lower bounds for either SM or SK for this setup. The results are derived under the strict semantic-security metric that requires negligible information leakage for all message-key distributions. The achievability proof uses the strong soft-covering lemma for superposition codes.
The talk is based on joint work with: Z. Goldfeld and H. H. Permuter (Ben-Gurion University of the Negev, Israel), S. Shamai (Technion - Israel Institute of Technology), P. W. Cuff (Princeton University) and P. Piantanida (CentralSupelec).
The work of A. Bunin and S. Shamai has been supported by the European Union's Horizon 2020 Research And Innovation Programme, grant agreement no. 694630.

Some results on the existence of equilibria and stability of dc linear networks with constant power loads.

Séminaire le 13 Juillet 2016, 11h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Prof. Robert Griñó, Polytechnic University of Catalonia


The presentation will show some results on the existence of equilibria in dc electrical networks that supply to constant power loads (CPLs). Specifically, a necessary condition for the existence, which is also sufficient for the case one and two CPLs, will be presented. Besides, a sufficient condition, based on the negative imaginary systems concept, that assures local stability for all the range of possible equilibria will be shown for the case of a dc linear network with a single ideal or finite-bandwidth CPL.

Topological Interference Management

Séminaire le 28 Juin 2016, 14h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Dr Syed Ali Jafar


Abstract:

Studies of the degrees of Freedom (DoF) of wireless communication networks often focus on clever ways to exploit an abundance of channel knowledge which is rarely available in practice while ignoring topological aspects that are the basis of most robust interference management schemes. Topological interference management refers to a complementary perspective where the focus is on exploiting network topology under limited channel knowledge. Progress in this direction includes the discovery that optimal interference avoidance is essentially the index coding problem, that interference alignment plays a central role in this problem even though no precise knowledge of channel realizations is available, a new set of conditions for the approximate optimality of treating interference as noise, novel outer bounds based on aligned image sets, and connections to network coding problems such as distributed storage repair, multiple unicasts and private information retrieval. This talk will summarize the advances in the broad area of topological interference management and highlight some of the key open problems.

Biography:

Syed Ali Jafar received his B. Tech. from IIT Delhi, India, in 1997, M.S. from Caltech, USA, in 1999, and Ph.D. from Stanford, USA, in 2003, all in Electrical Engineering. His industry experience includes positions at Lucent Bell Labs, Qualcomm Inc. and Hughes Software Systems. He is a Professor in the Department of Electrical Engineering and Computer Science at the University of California Irvine, Irvine, CA USA. His research interests include multiuser information theory, wireless communications and network coding.

Dr. Jafar received the Blavatnik National Laureate in Physical Sciences and Engineering in 2015, the UCI Academic Senate Distinguished Mid-Career Faculty Award for Research in 2015, the School of Engineering Mid-Career Excellence in Research Award in 2015, the School of Engineering Maseeh Outstanding Research Award in 2010, the ONR Young Investigator Award in 2008, and the NSF CAREER award in 2006. His co-authored papers received the IEEE Information Theory Society Best Paper Award in 2009, IEEE Communications Society Best Tutorial Paper Award in 2013, IEEE Communications Society Heinrich Hertz Award in 2015, IEEE Signal Processing Society Young Author Best Paper Award (to student co-authors) in 2015, an IEEE GLOBECOM Best Paper Award in 2012 and an IEEE GLOBECOM Best Paper Award in 2014. Dr. Jafar received the UC Irvine EECS Professor of the Year award five times, in 2006, 2009, 2011, 2012, and 2014, from the Engineering Students Council and the Teaching Excellence Award in 2012 from the School of Engineering. He was a University of Canterbury Erskine Fellow in 2010 and an IEEE Communications Society Distinguished Lecturer for 2013-2014. Dr. Jafar was recognized as a Thomson Reuters Highly Cited Researcher and included by Sciencewatch among The World's Most Influential Scientific Minds in 2014 and again in 2015. He served as Associate Editor for IEEE Transactions on Communications 2004-2009, for IEEE Communications Letters 2008-2009 and for IEEE Transactions on Information Theory 2009-2012. Dr. Jafar was elevated to IEEE Fellow, Class of 2014, for contributions to analyzing the capacity of wireless communication networks.

Mismatched decoding

Séminaire le 22 Octobre 2015, 11h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Dr. Guillen i Fabregas


This talk will review the mismatched decoding problem. In particular, the talk will review the fundamental limits of mismatched channel-decoder pairs in a point-to-point setup, with particular focus on random coding ensembles, achievable information rates and the corresponding error exponents.

Bio:
Albert Guillén i Fàbregas was born in Barcelona in 1974. In 1999 he received the Telecommunication Engineering Degree and the Electronics Engineering Degree from Universitat Politècnica de Catalunya and Politecnico di Torino, respectively, and the Ph.D. in Communication Systems from Ecole Polytechnique Fédérale de Lausanne (EPFL) in 2004.
Since 2011 he has been a Research Professor of the Institució Catalana de Recerca i Estudis Avançats (ICREA) at the Department of Information and Communication Technologies,
Universitat Pompeu Fabra. He is also an Adjunct Researcher at the Department of Engineering, University of Cambridge, where he was a Reader and a Fellow of Trinity Hall. He has held appoinments at the New Jersey Institute of Technology, Telecom Italia, European Space Agency (ESA), Institut Eurecom, University of South Australia, as well as visiting appointments at TelecomParisTech (Paris), Universitat Pompeu Fabra, University of South Australia, Centrum Wiskunde & Informatica and Texas A&M University in Qatar. His research interests are in information theory, coding theory and communication theory. Dr. Guillén i Fàbregas received the Starting Grant from the European Research Council, the Young Authors Award of the 2004 European Signal Processing Conference, the 2004 Best Doctoral Thesis Award from the Spanish Institution of Telecommunications Engineers, and a Research Fellowship of the Spanish Government to join ESA. He is an Associate Editor of the IEEE Transactions on Information Theory and of the Foundations and Trends in Communications and Information Theory, Now Publishers. He is also a Senior Member of IEEE,  a member of theYoung Academy of Europe and was an Editor of the IEEE Transactions on Wireless Communications (2007-2011).

Fronthaul Compression for Cloud Radio Access Networks: An Information Theoretic View

Séminaire le 28 Septembre 2015, 14h00 à CentraleSupelec (Gif-sur-Yvette) Amphi F3-09
Prof. Shlomo Shamai, EE Department, Technion-Israel Institute of Technology


Cloud radio access networks (C-RANs) emerge as appealing architectures for next-generation wireless/cellular systems whereby the processing/decoding is migrated from the local base-stations/radio units (RU) to a control/central units (CU) in the *cloud*. This is facilitated by fronthaul links connecting the RUs to the managing CUs. We focus on oblivious processing at the RU, and hence the fronthaul links carry digital information about the baseband signals, in the uplink from the RUs to the CU and vice versa in the downlink. The high data rate service demands in C-RANs, imply that even with fast (optical) front hauls, let alone for heterogeneous fronhauls, efficient compression of the basedand signals is essential. In this talk we focus on advanced robust signal processing solutions, emerging by network information theoretic concepts, and review also the basic approaches to this cloud network. Multi-hop fronthaul topologies are also discussed. Analysis and numerical results illustrate the considerable performance gains to be expected for different cellular models. Some interesting theoretical directions conclude the presentation.

Multicast IP

Séminaire le 5 Juillet 2015, 12h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Antthony Busson


An Example of Hardware/Software Partitioning in SDR Systems: the Software

Séminaire le 3 Juin 2014, 16h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Lorenzo Vangelista, Carlo Fantozzi, Daniele Vogrig


Conflicts and Incentives in Wireless Cooperative Relaying: A Distributed Market Pricing Framework

Séminaire le 3 Août 2013, 16h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Lin Chen


Amplification paramétrique d'images et transformée de Fourier

Séminaire le 8 Avril 2013, 12h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Eric Lantz


Adaptive Passivity–based Control for Maximum Power Extraction of Stand–alone Windmill Systems

Séminaire le 4 Avril 2012, 16h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Romeo Ortega, Fernando Mancilla–David and Mohsen Soltani


Mother Nature Knows Best:Results on Wireless Networks Based on Analogies with Physics

Séminaire le 2 Mars 2012, 10h00 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Stavros Toumpis


Analysis of K-tier Heterogeneous Cellular Networks

Séminaire le 17 Février 2012, 11h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Harpreet S. Dhillon


Optimal Activation and Transmission Control in Delay Tolerant Network

Séminaire le 14 Décembre 2011, 11h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Amar Prakash Azad


Automobiles as Testbed for Designing High Performance Controllers

Séminaire le 1 Décembre 2011, 11h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Stefano Di Gennaro


On Interference Channels with Source-Cooperation and Cognition

Séminaire le 14 Octobre 2011, 16h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Daniela Tuninetti (Ph.D.)


Channel Polarization in Wiretapping andPermuted Parallel Channels

Séminaire le 4 Octobre 2011, 10h30 à CentraleSupelec (Gif-sur-Yvette) Salle du conseil du L2S - B4.40
Shlomo Shamai


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