Archives des séminaires

Le 05/03/2020 Towards Formal Verification in Automotive

Auteur(s) & Affilliation(s) du séminaire :

Yasmine Assioua

Présentation du séminaire :

In the automotive, softwares are more and more present  However, during the development lifecycle, errors and flaws can be introduced and lead to failures. Due to the lack of automatic and formal means, verifying that the softwares are bug free and compliant with the requirements is challenging. In this presentation we propose an approach inspired by formal methods that helps analyse and validate the developped softwares.

Contact(s) :

Le 06/02/2020 Impact of Security Measures on Performance Aspects in SysML Models

Auteur(s) & Affilliation(s) du séminaire :

Zoor Maysam

Présentation du séminaire :

Impact of Security Measures on Performance Aspects in SysML Models
As embedded systems becomes more connected and prone to attacks, security turns out to be 
a certain andmandatory dimension to take into consideration during system modeling. However adding 
security featurescan lead to decline in performance. In this paper, the trade-off between security and performance
 requirementsis considered. To do so, the paper defines a method to automatically assess the impact of security 
measures on system performance. The method applies to system modeled at a high level of abstraction with 
SysML. 



Contact(s) :

Zoor Maysam

Le 23/01/2020 From markdownn to slideshows with pandoc

Auteur(s) & Affilliation(s) du séminaire :

Pacalet Renaud

Présentation du séminaire :

Pandoc is a computer program written in Haskell (a functional programming language) that 
converts documents from one of many possible input formats (docx, epub, html, json, latex, 
markdown, odt...) and to one of many possible output formats (beamer, docx, epub, html, 
latex, markdown, odt, pdf, pptx, slidy...) 
 
In this talk we will present pandoc, its internal representation of documents and its 
processing flow. We will then show how to produce beamer/PDF or HTML/javascript presentations
from markdown inputs. Finally, we will show how the lua scripting language, the pandoc templates 
and the beamer templates can be used to customize pandoc in order to produce advanced presentations 
in the Telecom Paris style.

Contact(s) :

Pacalet Renaud

Le 15/01/2020 [ComNum] Multiple access with finite payloads and many users

Auteur(s) & Affilliation(s) du séminaire :

Yuri Polyanskiy

Présentation du séminaire :

in 3C14 at 10am

Abstract:

One of the next frontiers in communication technology is to re-think methods of sharing
spectrum among wireless transmitters. In this talk, I will discuss recent results on
characterizing the fundamental tradeoff between the density of users (ratio of active users and the number of degrees of freedom available per frame) and 
the minimal required energy-per-bit (Eb/N0). In the regime of interest for the Internet-of-Things, 
the payload of each user is about 100 data bits. This is too small for the asymptotic Shannon theory to provide any guidance and thus we needed to develop new tools for analysis.
A surprising discovery is existence of coded-access schemes that are able to almost perfectly reject
the multi-user interference, so that increasing the density of users
(without increasing space-time-frequency resources) does not lead to
any deterioration of service. Practically important is that known
MAC architectures are not capable of attaining this effect. A similar analysis and effects
arise in the problem of (unsourced) random-access over the AWGN channel, which we will
discuss as well.

Contact(s) :

Wigger Michele

Le 14/01/2020 [ComNum PhD seminar] DNN assisted Sphere Decoder

Auteur(s) & Affilliation(s) du séminaire :

Askri Aymen

Présentation du séminaire :

in 3C41 at 2pm

Abstract

For a wide class of MIMO space-time transmission schemes, Maximum Likelihood decoding requires us to solve an integer least-squares problem. The sphere decoder (SD) algorithm is one of the optimal decoders that require high complexity. Our work addresses this issue by using artificial intelligence to reduce the computational complexity. To that end, we train a feedforward neural network (NN) to predict the number of lattice points inside the sphere. Since the number of lattice points is intelligently learnt by a NN, the SD algorithm starts the tree search with a radius that allows a small number of points falling inside the sphere. This results in a significant complexity reduction.

 

 

Contact(s) :

Ciblat Philippe

Le 29/11/2019 [ComNum/GTO] Improving Hard-decision FEC Decoding via Soft-aided Algorithms

Auteur(s) & Affilliation(s) du séminaire :

Alex Alvarado

Présentation du séminaire :

in 3C14 at 10:30am

Abstract: We discuss soft-aided algorithms to improve the performance of hard-decision FEC decoding. Special attention is paid to the soft-aided bit-marking (SABM) algorithm we recently introduced. Results and analysis for both staircase and product codes is presented.

Bio:  Alex Alvarado received received his M.Sc. degree from Universidad Técnica Federico Santa María, Valparaíso, Chile, in 2005 and the PhD degree from Chalmers University of Technology, Gothenburg, Sweden, in 2011. Dr. Alvarado is Associate Professor in the Signal Processing Systems group at Eindhoven University of Technology (TU/e), The Netherlands. Previously, he held postdoctoral positions at University College London and at the University of Cambridge, in the United Kingdom. Dr. Alvarado's research has received multiple awards, including Best Paper Awards at the 2018 Asia Communications and Photonics Conference and at the 2019 OptoElectronics and Communications Conference, and Best Poster Awards at the 2009 IEEE Information Theory Workshop and at the 2013 IEEE Communication Theory Workshop. He is also recipient of the 2015 IEEE Transactions on Communications Exemplary Reviewer Award, and the 2015 Journal of Lightwave Technology Best Paper Award. Dr. Alvarado is a senior member of the IEEE and served as an associate editor for IEEE Transactions on Communications. Since 2018, he serves in the OFC subcommittee Digital and Electronic Subsystems. He also served in the ECOC 2019 subcommittee Theory of Optical Communications. His general research interests are in the areas of digital communications, coding, and information theory.

 

 

Contact(s) :

Wigger Michele

Le 22/10/2019 [ComNum] Some fundamental bounds in joint source-channel coding

Auteur(s) & Affilliation(s) du séminaire :

Prof. Yuval Kochman, Hebrew University of Jerusalem

Présentation du séminaire :

in A301 at 2pm

Abstract:

Suppose that Alice wants to convey to Bob the results of k iid fair coin flips, using n times an iid binary symmetric channel (that is, in each use Alice's inout is flipped with probability e). We measure the performance by the expected Hamming distortion D, i.e., the probability that Bob's guess of a coin flip after seeing the channel outputs is wrong. Let D*(k, r, e) be the optimal attainable expected distortion, where r=n/k. For any fixed r, as k tends to infinity the optimum is attained by the separation principle: Alice and Bob should use the concatenation of optimal compression and digital communication. However, other approaches, known collectively as joint source-channel coding (JSCC) may be superior in terms of finite-blocklength performance (D* for limited k) and robustness (the performance when Alice does not know e). For r=1, a simple scalar (k=1) scheme attains D* universally over all e, but in general there are many open questions regarding the fundamental bounds of JSCC. We present some old and new results, and in particular show a surprising connection: an impossibility bound on robustness leads to a finite-blocklength bound.
Based in part on joint work with Or Ordentlich and Yury Polyanskiy.

Contact(s) :

Wigger Michele

Le 03/10/2019 [ComNum] Joint State Sensing and Communications: Theory and Vehicular Applications

Auteur(s) & Affilliation(s) du séminaire :

Prof. Mari Kobayashi (TUM & CentraleSupelec)

Présentation du séminaire :

in A301 at 10am

Abstract:

We consider a communication setup where transmitters wish to simultaneously sense network states and convey messages to intended receivers. The scenario is motivated by joint radar and vehicular communications where the radar and data applications share the same bandwidth.  First, I present a theoretical framework to characterize the fundamental limits of such a setup for memoryless channels with i.i.d. state sequences. Then, I present our recent work on joint radar and communication using Orthogonal Time Frequency Space (OTFS).  Although restricted to a simplified scenario with a single target, our numerical examples demonstrated that two modulations provide as accurate radar estimation as Frequency Modulated Continuous Waveform (FMCW), a typical automotive radar waveform,  while providing a non-negligible communication rate for free.

 

 

Contact(s) :

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