Dear Colleague,

On behalf of the IEEE Sweden VT/COM/IT Chapter in collaboration with Chalmers University of Technology, we would like to invite you to the following IEEE Technical hybrid seminar by Prof. Stefano Buzzi, University of Cassino and Lazio Meridionale, Cassino, Italy.

Title: Three applications of active reconfigurable intelligent Surfaces: massive MIMO emulation, user localization and target detection             

Time: 15:00-16:00 CET Wed Dec 14, 2022

Room: E2 Room 2503 Fredrik Lamm, EDIT building floor 3, Hörsalsvägen 11, Chalmers, Campus Johanneberg: Fredrik Lamm (chalmers.se)

Online Zoom: https://chalmers.zoom.us/j/66889766863, password: 872735 (alternative connections below)

Local host: Prof. Tommy Svensson, Chalmers University of Technology, Gothenburg, Sweden, tommy.svensson@chalmers.se.

Abstract: Active reconfigurable intelligent surfaces (RISs) are made of several reflective elements, each assisted by active loads (negative resistance), that reflect and amplify the incident signal instead of only reflecting it with a tunable phase shift as in the case of a passive RIS. The talk focuses on three different applications of active RISs: (a) emulation of massive MIMO antenna array with a not-so-large number of active antennas; (b) downlink UE localization and orientation estimation in wireless networks operating at mmWave carrier frequencies; and (c) radar target detection. For the first application, we show a configuration where an active RIS is placed at short distance from an array of active antennas: it is shown that this structure permits emulating massive MIMO systems performance wthout having to use a large number of antennas and RF chains for the digital beamforming. For the second application, we present and analyze the performance of the maximum likelihood estimators and of several suboptimal approximations. Finally, for the last scenario, we assume that an active RIS provides an independent additional look of a prospective target, and we design the radar system by selecting the power emitted by the radar, the number of RIS elements, and their amplification factor in order to maximize the detection probability for a fixed probability of false alarm and a common (among radar and RIS) power budget. Numerical results show the effectiveness of the proposed procedures and highlight the scenarios where active RISs well outperform passive ones.

Biography: Stefano Buzzi joined the University of Cassino and Lazio Meridionale, Italy in 2000, first as an Assistant Professor, then as an Associate Professor (since 2002) and, finally, since 2018, as a Full Professor. Since 2022 he is also affiliated with Politecnico di Milano, Italy.
He received the M.Sc. degree (summa cum laude)  in Electronic Engineering in 1994, and the Ph.D. degree in Electrical and Computer Engineering in 1999, both from the University of Naples “Federico II”. He has had short-term research appointments at Princeton University, Princeton (NJ), USA in 1999, 2000, 2001 and 2006. He is a former Associate Editor of the IEEE Signal Processing Letters and of the IEEE Communications Letters, has been the guest editor of four IEEE JSAC special issues, and from 2014 to 2020 he has been an Editor for the IEEE Transactions on Wireless Communications. He also serves regularly as TPC member of several international conferences.  
Dr. Buzzi’s research interests are in the broad field of communications and signal processing, with emphasis on wireless communications and beyond-5G systems.  He is currently the Principal Investigator of the EU-funded Innovative Training Network project METAWIRELESS, on the application of metasurfaces to wireless communications. He has co-authored about 170 technical peer-reviewed journal and conference papers.

Welcome!

Best regards,
Tommy Svensson, VT/COM/IT Sweden Chapter

==

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