Overview on the Concepts of MIMO, Multiuser MIMO, and Massive MIMO

In this opening talk, the basic fundamentals underlying the MIMO concept are explained. It will be shown how multiple reflections in indoor and urban environments can be effectively used to create additional independent channels that can serve the purposes of diversity and/or spatial multiplexing. Extending this concept for a base station to serve multiple users gives rise to Multiuser MIMO, in which both the number of served users and that of the array elements are very moderate. 

Massive MIMO on the other hand uses large antenna arrays to produce very narrow multiple beams that are capable of simultaneously establishing independent channels between the base station and a number of mobile or stationary users. 

The usually used deterministic and stochastic models for representing mobile wireless channels (linear time-varying systems) will be explained emphasizing the massive-MIMO aspects. Sample massive-MIMO systems that have been recently developed will be presented and discussed.

------------------

Prof. Abbas Omar received the B.Sc., M.Sc. and Doktor-Ing. degrees in electrical engineering in 1978, 1982 and 1986, respectively. He has been professor of electrical engineering since 1990 and director of the Chair of Microwave and Communication Engineering at the University of Magdeburg, Germany since 1998. He joined the Petroleum Institute in Abu Dhabi as a Distinguished Professor in 2012 and 2013 as an organizer of the research activities for the Oil and Gas Industry in this area. In 2014 and 2015 he chaired the Electrical and Computer Engineering at the University of Akron, Ohio, USA. Dr. Omar authored and co-authored more than 450 technical papers extending over a wide spectrum of research areas. His current research fields cover the areas of microwave, magnetic-resonance, and acoustic imaging, microwave and millimeter-wave material characterization, phased arrays and beamforming, massive MIMO, indoor positioning, subsurface tomography and ground penetrating radar, and field theoretical modeling of microwave systems and components. He is IEEE Fellow.