Roua Youssef, du département Électronique et du laboratoire Labsticc, a présenté ses travaux de thèse le 5 avril 2011 à Télécom Bretagne.
Résumé : Cooperative communication in wireless networks has recently been introduced as a new method to increase the throughput, the reliability and the robustness of the wireless system. The basic idea of cooperative communications is that all nodes in a network may help each other to transmit information to a destination. This thesis addresses cooperative coding schemes for wireless networks with relays. The main part of this thesis investigates the design of distributed serially concatenated codes for relay networks. In this work, scenarios where multiple sources communicate with a destination with the help of a relay are considered. The main contribution of this thesis is the construction of a powerful code distributed over all the nodes in the network. Time allocation between the sources and the relay is also addressed in order to improve the performance of the network. The proposed coding scheme achieves very low error rates and offers significant performance gains with respect to non-cooperation, even for a very large number of sources. Furthermore, it provides a high flexibility in terms of code rate, number of sources, overall system rate and error protection. The proposed distributed coding scheme fits well for applications such as sensor networks where each sensor deals with a small amount of information.
Mots-clés : achievable rates, cooperative communications, distributed coding, relay channel, serially concatenated codes, turbo codes.
Membres du jury : Lars Rasmussen, professeur, Royal Institute of Technology, Suède,
- Maryline Helard, professeur, INSA, Rennes,
- Alexandre Graell I Amat, maître de conférences, Chalmers University of Technology, Suède,
- Oliver Berder, maître de conférences, ENSSAT, Lannion,
- Christian Roland, maître de conférences, Université de Bretagne Sud,
- Catherine Douillard, professeur, Télécom Bretagne.