Dr. Rui Dinis

Future wireless systems are expected to provide huge growth in user bit rates and overall required bit rates, and the same might be expect for beyond 5G systems. This means a substantial spectral efficiency increase, which must be achieved while maintaining or even improving the power efficiency. To accomplish this one needs to employ new transmission techniques, with the most promising ones based on the use of a large number of antennas. For this reason, massive MIMO (Multiple-Input and Multiple-Output) schemes, involving tens or even hundreds of antennas, are a key component of 5G, since they allow high-capacity gains, while enabling significant power savings. Clearly, the evolution beyond 5G will involve even more antennas.

A new and revolutionary technique able to improve substantially the performance of wireless communication networks is to smartly changing the propagation characteristics of the wireless channel through the use of RIS (Reconfigurable Intelligent Surfaces), which are made of a large number of low cost passive reflecting elements able to independently change the amplitude and/or phase of the incident signal so as to achieve specific propagation effects. LIS (Large Intelligent Surfaces) are the natural evolution of massive MIMO schemes. They will employ many thousands of antenna elements, allowing huge capacity gains, as well accurate positioning and efficient energy harvesting techniques. However, the implementation of these techniques involves considerable challenges.

In this talk we give an overview of potentialities and challenges of systems with a huge number of antennas. We start by making an overview on the evolution from MIMO to massive MIMO, and its extension to RIS and LIS and cell free systems. Then we present the main features of those systems, as well as the implementation constraints and challenges, as well as potential solutions.

Biography:

Rui Dinis (Senior Member, IEEE) received the Ph.D. degree from the Instituto Superior Técnico (IST), Technical University of Lisbon, Portugal, in 2001, and the Habilitation degree in telecommunications from the Faculdade de Ciências e Tecnologia (FCT), Universidade Nova de Lisboa (UNL), in 2010. He was a Researcher with the Centro de Análise e Processamentode Sinal (CAPS), IST, from 1992 to 2005, and a Researcher with the Instituto de Sistemas e Robótica (ISR), from 2005 to 2008. From 2001 to 2008, he was a Professor with IST. In 2003, he was an Invited Professor with Carleton University, Ottawa, Canada. Since 2009, he has been a Researcher with the Instituto de Telecomunicações (IT). He is currently an Associate Professor with the FCT–UNL. He has been actively involved in several international research projects in the broadband wireless communications area, such as RACE project MBS, ACTS project SAMBA, and IST projects B-BONE and C-MOBILE, and many national projects, most of them as a nuclear researcher and/or in charge of his research centre in multi-institutional projects. He was involved in pioneer projects on the use of mm-waves for broadband wireless communications (international projects MBS and SAMBA). He has published six books, over 100 journal articles and book chapters, and over 300 conference papers (of which five received best papers’ awards), and over 18 patents (attributed or pending). His main research activities are on modulation and transmitter design, nonlinear effects on digital communications and receiver design (detection, equalization, channel estimation and carrier synchronization), with emphasis on frequency-domain implementations, namely for MIMO systems and/or OFDM and SC-FDE modulations. He is also working on cross-layer design and optimization involving PHY, MAC, and LLC issues, and indoor positioning techniques. He is or was with the Organizing Committee of several international conferences, such as the IEEE conferences ICT’2014, VTC’2017-Fall, VTC’2018-Spring, and ISWCS’2018. He is also the President of VTS Portugal Chapter, since 2016 and a member of several technical committees of the IEEE Communications Society, such as SPCE, RCC, WC, and CT. He is an Editor of IEEE Transactions on Wireless Communications, IEEE Transactions on Communications, IEEE Transactions on Vehicular Technology and Physical Communication (Elsevier).