CITI seminar – Ioannis Krikidis (Univ. Cyprus) – 13/02 at 11:30

Title: Wireless Powered Communications: Overview, Recent Results, and Challenges

Date and Place: 13 / 02 / 2020 10:30 in TD-C

Speaker: Ioannis Krikidis (Univ. Cyprus)

Host: Maracas


Conventional energy-constrained wireless systems such as sensor networks are powered by batteries and have limited lifetime. Wireless power transfer (WPT) is a promising technology for energy sustainable networks, where terminals can harvest energy from dedicated electromagnetic radiation through appropriate electronic circuits. The integration of WPT technology into communication networks introduces a fundamental co-existence of information and energy flows; radio-frequency signals are used in order to convey information and/or energy. The efficient management of these two flows through sophisticated networking protocols, signal processing/communication techniques and network architectures, gives rise to a new communication paradigm called wireless powered communications (WPC). In this talk, we discuss the principles of WPC and we highlight its main network architectures as well as the fundamental trade-off between information and energy transfer. Several examples, which deal with the integration of WPC in modern communication systems, are presented.


Dr. Ioannis Krikidis received the diploma in Computer Engineering from the Computer Engineering and Informatics Department (CEID) of the University of Patras, Greece, in 2000, and the M.Sc and Ph.D degrees from Ecole Nationale Superieure des Telecommunications (ENST), Paris, France, in 2001 and 2005, respectively, all in electrical engineering. From 2006 to 2007 he worked, as a Post-Doctoral researcher, with ENST, Paris, France, and from 2007 to 2010 he was a Research Fellow in the School of Engineering and Electronics at the University of Edinburgh, Edinburgh, UK. He is currently an Associate Professor at the Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus. His current research interests include wireless communications, cooperative networks, 4G/5G communication systems, wireless powered communications, and secrecy communications. I. Krikidis is an IEEE Fellow (class 2019) and he has received the prestigious ERC consolidator grant.


CITI seminar – Mari Kobayashi (TU Munich) – 13/02 at 10:30

Title: Joint State Sending and Communications: Theory and Vehicular Applications

Date and Place: 13 / 02 / 2020 10:30 in TD-C

Speaker: Mari Kobayashi (TU Munich)

Host: Maracas


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.


Mari Kobayashi received the B.E. degree in electrical engineering from Keio University, Yokohama, Japan, in 1999, and the M.S. degree in mobile radio and the Ph.D. degree from École Nationale Supérieure des Télécommunications, Paris, France, in 2000 and 2005, respectively. From November 2005 to March 2007, she was a postdoctoral researcher at the Centre Tecnològic de Telecomunicacions de Catalunya, Barcelona, Spain. In May 2007, she joined the Telecommunications department at CentraleSupélec, Gif-sur-Yvette, France, where she is now a professor. She is the recipient of the Newcom++ Best Paper Award in 2010, and IEEE Comsoc/IT Joint Society Paper Award in 2011, and ICC Best Paper Award in 2019. Since September 2017, she is on a sabbatical leave at Technical University of Munich (TUM) as an Alexander von Humboldt Experienced Research Fellow (till April 2019) and August-Wihelm Scheer Visiting Professor (since August 2019).


PhD Defence: “Simultaneous Information and Energy Transmission”, Nizar Khalfet, Emilie du Chatelet Amphitheater, INSA, 13th of February 2020 at 14h


Simultaneous Information and Energy Transmission


In this thesis, the fundamental limits of simultaneous information and energy transmission (SIET) are studied from two perspectives: the asymptotic and non-asymptotic block-length regimes. In the asymptotic block-length regime, the fundamental limits on SIET in the two-user Gaussian interference channel (G-IC) with and without feedback are characterized. More specifically, an achievable and converse region in terms of information and energy transmission rates (in bits per channel use and energy-units per channel use, respectively) are identified. In both cases, with and without feedback, an achievability scheme based on power-splitting, common randomness, rate splitting, block-Markov superposition coding, and backward decoding is presented. Finally, converse regions for both cases are obtained using some of the existing outer bounds on information transmission rates, as well as a new outer bound on the energy transmission rate. For the finite block-length regime, the case of a transmitter simultaneously sending information to a receiver and energy to an energy harvester through the binary symmetric channel has been studied. Given a finite number of channel uses (latency constraint) as well as tolerable average decoding error probability and energy shortage probability (reliability constraints), two sets of information and energy

transmission rates are presented. One consists in rate pairs for which the existence of at least one code achieving such rates under the latency and reliability constraints is proved (achievable region). The second one consists in a set whose complement contains the rate pairs for which there does not exist a code capable of achieving such rates (converse region). These two sets approximate the information-energy capacity region, which allows analyzing the trade-offs among performance, latency, and reliability in SIET systems.




  • Dr. Samson Lasaulce, CNRS, France. Reviewer.
  • Dr. Ioannis Krikidis, University of Cyprus, Cyprus. Reviewer.
  • Dr. Marie Kobayashi, CentraleSupelec, France. Examiner.
  • Dr. Jean-Marie Gorce, INSA de Lyon, France. Supervisor.
  • Dr. Samir M. Perlaza, INRIA, France. Advisor.