Spectrum sharing is not typically used in current cellular networks, because it only provides a slight performance improvement while requiring heavy coordination among different cellular operators. However, these problems can be potentially overcome in millimeter-wave (mmWave) networks, thanks to beamforming both at the base stations and at the terminals. In this talk, we discuss some joint beamforming and cell association optimization problems and characterize the performance gain that can be obtained when spectrum sharing is used, as a function of the underlying beamforming and coordination strategies. Our performance analysis reveals that beamforming, especially at the mobile users, can substantially reduce the need for coordination and simplify the implementation of spectrum sharing. These benefits are more prominent at higher mmWave frequencies (for example, 73 GHz) due to the possibility of having larger antenna arrays, which motivates a hybrid spectrum sharing approach. Furthermore, while interoperator coordination can be neglected in the large-antenna regime, intra-operator coordination can still bring gains by balancing the network load. The results shown will allow us to draw broad conclusions and to gain useful insights on the feasibility of spectrum sharing at mmWave networks.
Biography: Michele Zorzi received the Laurea and Ph.D. degrees in electrical engineering from the University of Padova in 1990 and 1994, respectively. From 1992 to 1993, he was on leave at UCSD, working on multiple access in mobile radio networks. In 1993, he joined the faculty of the Dipartimento di Elettronica e Informazione, Politecnico di Milano, Italy. After spending three years with the Center for Wireless Communications, UCSD, in 1998, he joined the School of Engineering, University of Ferrara, Italy, where he became a Professor in 2000. Since 2003, he has been with the faculty of the Information Engineering Department, University of Padova. His current research interests include performance evaluation in mobile communications systems, random access in wireless networks, ad hoc and sensor networks, Internet of Things, energy-constrained communications protocols, cognitive networks, and underwater communications and networking. Dr. Zorzi was the Editor-in-Chief of IEEE WIRELESS COMMUNICATIONS from 2003 to 2005 and the Editor-in-Chief of the IEEE TRANSACTIONS ON COMMUNICATIONS from 2008 to 2011. He is the founding Editor-in-Chief of the IEEE TRANSACTIONS ON COGNITIVE COMMUNICATIONS AND NETWORKING. He has also been an Editor for several journals and a member of the Organizing or the Technical Program Committee for many international conferences and the Guest Editor for special issues of IEEE PERSONAL COMMUNICATIONS, the IEEE WIRELESS COMMUNICATIONS, IEEE NETWORK, and the IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS. He served as a Member-at-Large of the Board of Governors of the IEEE Communications Society from 2009 to 2011, and as its Director of Education and Training in 2014-15. He is a Fellow of the IEEE.
