Biography
Prof. P. Takis Mathiopoulos
Prof. P. Takis Mathiopoulos
University of Athens, Greece
Title: On the SINR Statistics of VFDM Cognitive Spectrum Sharing Systems
Abstract: 
An analytical precise approximation of the SINR statistics of the two-tier Vandermonde-subspace frequency division multiplexing (VFDM) cognitive spectrum sharing systems over frequency-selective Rayleigh fading channels is presented. It is shown that the gamma distribution provides the best fitting accuracy and that its use leads to simple, yet accurate, closed-form expressions for evaluating the ergodic capacity (EC) and average bit error probability (ABEP) performance of such systems. In deriving these expressions, the parameters of the gamma distribution have been obtained for various operating conditions of the considered VFDM system using distribution fitting. Furthermore, regression analysis has been used to obtain approximate analytical expressions for these parameters in relation to the system operating parameters. Performance evaluation results, obtained for various system implementations, including the standardized IEEE 802.11 and 3GPP LTE, are presented to demonstrate the validity of the proposed methodology. Its accuracy has been verified by means of computer simulations.
Biography: 

P. Takis Mathiopoulos is Professor of Telecommunications at the Department of Informatics and Telecommunications, University of Athens, Greece. Prior to that, he was with the Institute for Space Applications and Remote Sensing (ISARS) of the National Observatory of Athens, first as his Director (2000-2005) and then as Director of Research (2006-2014). From 1989 - 2003, he was a faculty member in the Department of Electrical and Computer Engineering, the University of British Columbia (UBC), where he was a Professor from 2000-2003, and was appointed ASI and Killam Research Fellow. From 2008-2013 he was appointed as Guest Professor at the Southwest Jiaotong University, China. He has been also appointed by the Government of PR of China as a Senior Foreign Expert at the School of Information Engineering, Yangzhou University (2014-2017) and by Keio University as a Visiting (Global) Professor in the Department of Information and Computer Science (2015-2016 and 2017-2018) under the Top Global University Project of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) Government of Japan.For the last 25 years he has been conducting research mainly on the physical layer of digital communication systems for terrestrial and satellite applications. His research spans many aspects, including channel characterization and measurements, modulation, coding, SIMO/MIMO, UWB, OFDM, software/cognitive radios, green communications, 5G and more recently the IoT.In addition, since 2010, he has been actively involved with research activities in the fields of remote sensing, LiDAR systems and photogrammetry. In these areas, he has co-authored more than 100 journal papers, mainly published in various IEEE journals, 1 book (edited), 4 book chapters and more than 120 conference papers, 2 of which received best paper awards. In December 2017, he has been presented by the Satellite and Space Communication Technical Committee of the IEEE Communications Society their 2017 award for outstanding contributions in the field of Satellite and Space Communications.  

Dr. Mathiopoulos has been or currently serves on the editorial board of several archival journals, including the IET Communications, and the IEEE TRANSACTIONS ON COMMUNICATIONS (1993 - 2005). Since 1993, he has served on a regular basis as a scientific advisor and a technical expert for the European Commission (EC). In addition, from 2001-2016 he has served as the Greek representative to high level committees in the European Commission (EC) and the European Space Agency (ESA). He has been a member of the TPC of more than 100 international conferences, as well as TPC Vice Chair for the 2006-S IEEE VTC and 2008-F IEEE VTC, Co-Chair of FITCE2011 and ICCC2017. He has delivered numerous invited presentations, including plenary lectures, and has taught many short courses all over the world.