Massive MIMO: Bringing the Magic of Asymptotics to Wireless Networks

Prof. Emil Björnson
Dept. of Electrical Engineering, Linköping University, Sweden

Friday, 11 July 2014, 14:15 – 15:00

Venue
University of Luxembourg
Interdisciplinary Center for Security Reliability and Trust (SnT)
Room: Weicker Building – Ground Floor, Room B001.
4, rue Alphonse Weicker, L-2721 Luxembourg.

Abstract
The use of access points with very many antennas has emerged as one of the key technologies for beyond-4G wireless systems. It is known as massive MIMO (multiple-input multiple-output), very large MIMO, and full-dimensional MIMO. The main idea is to capitalize on asymptotic behaviors of random matrices by deploying hundreds of antenna elements to serve tens of user devices in parallel. With such an excessive number of service antennas, as compared to the number of users, one can achieve strong signals by exploiting the large arrays gain offered by coherent beamforming. In addition, there will be little interference because the users’ channels become almost orthogonal and the unavoidable interference leakage is likely to “disappear” in unused parts of the high-dimensional beam space.
In this talk, I describe the basic characteristics of massive MIMO and clarify the role that this technology might play in the wireless evolution. Basic properties around channel acquisition, overhead signaling, asymptotic behaviors, and deployment scenarios are reviewed (without going into any deep mathematical details). Moreover, I describe recent research findings on how to exploit the excessive number of service antennas to achieve seemingly magic results; almost everything seems to get easier and better when you go large!

Biography
Emil Björnson received a Master degree in Engineering Mathematics from Lund University, Sweden, in 2007. He received a Ph.D. degree in Telecommunications from the Department of Signal Processing at KTH Royal Institute of Technology, Sweden, in 2011. From 2012-2014 he has been a joint postdoc at the Alcatel-Lucent Chair on Flexible Radio, Supélec, France, and the Department of Signal Processing at KTH. From 2014 on, Dr. Björnson is an Assistant Professor at Linköping University, Sweden.
He is the first author of the book “Optimal Resource Allocation in Coordinated Multi-Cell Systems” and has received three best paper awards: IEEE WCNC 2014, IEEE CAMSAP 2011, and WCSP 2009.