September Updates

(1) During 3rd – 4th September I have been visiting IRCICA Lille, hosted by Prof. Laurent Clavier and also discussing variance reduction methods for optimisation problems in information theory with Victor Elvira (IMT Lille Douai). I also dropped by at INRIA Lille to discuss ongoing projects on molecular communications with Valeria Loscri.

(2) On 12th September, Aline Roumy from INRIA Rennes will be presenting in our Information Theory Seminar in Lyon.

Title – Source coding under massive random access: theory and applications.

Abstract – In this presentation we will introduce a novel source coding problem allowing massive random access to large databases. Indeed, we consider a database that is so large that, to be stored on a single server, the data have to be compressed efficiently, meaning that the redundancy/correlation between the data have to be exploited. The dataset is then stored on a server and made available to users that may want to access only a subset of the data. Such a request for a subset of the data is indeedrandom, since the choice of the subset is user-dependent. Finally, massive requests are made, meaning that, upon request, the server can only perform low complexity operations (such as bit extraction but no decompression/compression). After describing the problem, information theoretical bounds of the source coding problem will be derived. Then two applications will be presented: Free-viewpoint Television (FTV) and massive requests to a database collecting data from a large-scale sensor network (such as Smart Cities).

Date – 12/09/2018.

(3) On 17th – 18th September, I am co-organizing a workshop on Molecular Communications in London, funded by the French Embassy in the UK. Speakers will include Weisi Guo, Adam Noel, Yansha Deng, Irene Otero-Muras, Bao Quoc Tang, Michael BarrosMauro Femminella, and myself. A summary of the workshop is available here.

(4) On 19th September, I will present a seminar in Kings College London, hosted by Yansha Deng. Below are the details:

Title –  Interference in Dynamic Wireless IoT Networks: Non-Gaussian Models and Information Theoretic Limits

Abstract – Two features of wireless IoT networks not present in cellular settings are: (i) small quantities of data transmission; and (ii) heterogeneous devices. The first feature implies that active transmitter sets in the network change rapidly and the second feature implies that the symbol duration for each device may vary throughout the network. A key consequence is that interference can be impulsive and not well modeled by Gaussian noise. Using a system setup based on a stochastic geometry model, we show that memoryless stationary additive isotropic alpha-stable noise channels arise in the point-to-point communication setting. Using this observation, we formally study the optimization problem for the capacity of this channel, establishing existence and uniqueness of optimal input distributions, and new achievable rates. We also briefly present some initial results on the impact of this new model for design and connections with recent results on the sensitivity of the capacity in non-Gaussian models.

Related Publications – 

Malcolm Egan, Laurent Clavier, Ce Zheng, Mauro de Freitas and Jean-Marie Gorce, “Dynamic interference in uplink SCMA for large-scale wireless networks without coordination,” accepted for publication in EURASIP Journal on Wireless Communications and Networking.

Malcolm Egan, Laurent Clavier, Mauro de Freitas, Louis Dorville, Jean-Marie Gorce and Anne Savard, “Wireless communication in dynamic interference”, Proc. IEEE Global Communications Conference (GLOBECOM), (2017).

Mauro de Freitas, Malcolm Egan, Laurent Clavier, Alban Goupil, Gareth W. Peters and Nourddine Azzaoui, “Capacity bounds for additive symmetric alpha-stable noise channels”, IEEE Transactions on Information Theory, vol. 63, no. 8, pp. 5115-5123, (2017).

Malcolm Egan, Mauro de Freitas, Laurent Clavier, Alban Goupil, Gareth W. Peters and Nourddine Azzaoui, “Achievable rates for additive isotropic alpha-stable noise channels”, In Proc. of the IEEE International Symposium on Information Theory, (2016).

Malcolm Egan, Samir M. Perlaza and Vyacheslav Kungurtsev, “Capacity Sensitivity in Additive Non-Gaussian Noise Channels”, accepted for publication in IEEE International Symposium on Information Theory (ISIT), (2017).

Malcolm Egan and Samir M. Perlaza, “Capacity approximation of continuous channels by discrete inputs”, in Proc. CISS 2018 (Invited Paper).