Wireless propagation channels and their impact of system design

Speaker: Andreas Molisch,
Lund UniversityAbstract: This talk has the central premise that a good understanding of the wireless propagation channel is vital for system design and simulation. This premise is emphasized by means of several examples from the areas of multi-antenna systems, co-operative communications, and ultrawideband (UWB) systems. In the multi-antenna case, we first present a number of channel measurement and modeling techniques. We then discuss the impact of the channels on the efficiency of antenna subset selection, a technique that reduces the complexity of MIMO systems by using only a small number of RF up/downconversion chains and connecting them adaptively to the "best" antenna elements. Next, we turn our attention to co-operative communications, and show how the correlation between fading at different nodes influences the optimum cooperation strategies. Finally, we explore UWB communications. After an overview of the special properties of UWB channels and their impact on Rake receivers, we explore in detail a new modulation format that is especially useful in heterogeneous networks. The modulation format can be received by transmitted-reference as well as coherent receivers, and gives almost-optimum performance for each of those receiver types. We will discuss both mathematically and intuitively the performance of this scheme in different propagation channels.Biography: Andreas F. Molisch is Professor and Chairholder for Radio Systems at Lund University, Sweden, and Deputy Director of the SSF National Center of Excellence for High-Speed Wireless Communications. He is simultaneously Distinguished Member of Technical Staff at Mitsubishi Electric Research Labs in Cambridge, MA, USA. Previously, he worked at the Technical University of Vienna, the Research Center for Telecommunications Vienna, and AT&T Bell Laboratories. His current research interests are measurement and modeling of wireless propagation channels, ultrawideband communications, MIMO systems, and cooperative communications. He has authored, co-authored, or edited four books (among them the recent textbook "Wireless Communications"), 11 book chapters, some 100 journal papers, and numerous conference contributions. He has been chairman of a number of international standardization groups, international conferences and symposia, and editor for IEEE journals. Dr. Molisch is a Fellow of the IEEE and recipient of several awards.Host: Robert Scholtz, scholtz@usc.edu

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos