Objet: Stage de Master Recherche à l'INSA Rennes, laboratoire IETR
Sujet: Fundamental bounds for communications with reconfigurable intelligent surfaces
Encadrement: Prof. Philippe Mary et Dr. Luc Le Magoarou
Début: Idéalement le 1er Février 2025
Durée: 6 mois
Title: Fundamental bounds for communications with reconfigurable intelligent surfaces
Laboratory: IETR: Institut d’électronique et des technologies du numérique (https://www.ietr.fr)
Starting date: February 1st, 2025 – duration: 6 months
Topic
This work will be carried out as part of the "Sustainable, Secured, Sovereign and Intelligent Networks (RIS3)" project (https://ris3.insa-rennes.fr), at the IETR laboratory on the INSA Rennes campus.
The integration of reconfigurable surfaces (also called reconfigurable intelligent surfaces (RIS)) into future wireless communication networks has attracted a great deal of academic and industrial interest in recent years [1]. These devices, incorporating small elementary radiative circuits, can be controlled to modify the phase of the incident wave in order to focus it towards the end-user.
This technology allows to control the propagation environment in the sense that multi-paths are no longer undergone but exploited. Numerous works in the literature demonstrate the potential benefits of this technology in terms of achievable throughput, user coverage and energy efficiency [2,3]. On the other hand, the control of wavefronts impacting the reconfigurable device requires information from the end-user, in order to agilely change the properties of the radiating surface. The amount of data to be transmitted back to the transmitter and the reconfigurable surface will depend on the time and coherence bandwidth of the channel, as well as the number of users to be served. Few studies have addressed the information overhead involved in controlling these surfaces, except in [4,5]. The authors consider only a single Tx-surface-Rx link, and in [4], the amount of information required to operate the smart surface is not studied. The authors in [5] adopt an information-theoretic approach to propose joint "data-control" encoding to maximize the end-to-end throughput. The authors show that joint encoding maximizes the achievable throughput of the system, compared to the case where control is done separately. However, several issues are still opened as the fundamental limits with imperfect channel state information or with finite block length packets.
This internship aims at studying the fundamental limits of communication with a reconfigurable surface and to quantify the amount of information needed to optimally operate these devices in various environments. We will focus more specifically onto the following tasks:
T1: Prepare a rigorous state of the art on theoretical works dealing with channels with state by studying in particular [5, 6].
T2: Recover the results in [5] and define the tradeoff between the control rate and the information rate.
T3: Extend the results to the epsilon-capacity notion.
T4: Write the internship report and, if the results are satisfying, a first conference paper.
This internship could be pursued in a PhD thesis on the same topic, fully funded (funding already acquired) according to the quality of the candidate work.
Key skills
The candidate should be pursuing a MSc degree or equivalent in one of the following fields: information and communication theory, signal processing, applied mathematics. He or she should be comfortable with one or more of the following programming languages: Matlab, Python or C/C++ and with Linux operating system. A strong spirit of curiosity and strong interest in mathematical developments are expected.
Keywords
Information theory, probability, convex and non-convex optimization, intelligent reconfigurable surfaces.
How to apply
Email a motivation letter to the people listed below, explaining your interest to the topic and why you think you have the background to address it. Please, attach the following documents:
- A CV with a complete list of projects / internships / courses related to the topic.
- Academic records up to date.
- The contact of one or two referees.
Applications will be evaluated as they are received until one candidate is selected. Only short-listed candidates will be contacted.
Deadline to apply: 16 December 2024
Environment and added-values of the offer
The intern will be part of the RIS3 project team, and will evolve in a stimulating research environment with renowned experts in communication theory, signal processing and machine learning for wireless communications. In addition, the intern will be paid around 700€ / month and a fully founded PhD position would be possible according to the candidate’s work.
References
[1] M. Di Renzo et al., "Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead," IEEE Journal on Selected Areas in Communications, vol. 38, no. 11, pp. 2450-2525, Nov. 2020.
[2] N. Shlezinger, et al., "Dynamic Metasurface Antennas for Uplink Massive MIMO Systems," IEEE Transactions on Communications, vol. 67, no. 10, pp. 6829-6843, Oct. 2019.
[3] Z. Yang et al., "Energy-Efficient Wireless Communications with Distributed Reconfigurable Intelligent Surfaces," IEEE Transactions on Wireless Communications, vol. 21, no. 1, pp. 665-679, Jan. 2022.
[4] A. Zappone, et al., "Overhead-Aware Design of Reconfigurable Intelligent Surfaces in Smart Radio Environments," IEEE Transactions on Wireless Communications, vol. 20, no. 1, pp. 126-141.
[5] R. Karasik, et al. "Beyond max-SNR: Joint encoding for reconfigurable intelligent surfaces", In Proc. IEEE Int. Symp. Inf. Theory, 2020.
[6] T. Weissman, "Capacity of Channels With Action-Dependent States," in IEEE Transactions on Information Theory, vol. 56, no. 11, pp. 5396-5411, Nov. 2010.
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Contacts:
Philippe Mary and Luc Le Magoarou
INSA de Rennes / IETR UMR CNRS – 6164
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Web sites:
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