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Optimization of Cognitive Networks with Multiuser Detection and Retransmission-Based Error Control

Speaker: Marco Levorato,
University of PadovaAbstract: The original cognitive rationale proposed by Mitola in his Ph.D. thesis has found several applications in wireless networks. In a widely investigated scenario, unlicensed cognitive terminals, namely secondary users, access licensed bands with the aim of improving channel usage of wireless networks. Secondary users are required to adopt smart strategies in order to generate a limited interference to the owners of the bandwidth, namely primary users. Most prior work investigated this scenario with a channel sensing approach, by which the secondary users access the channel in frequency/time slots left unused by the primary users. Other work considers the superposition of secondary and primary users' signals with an interference temperature approach.In this work, we address the optimization of a multiuser detection cognitive wireless network with multiple primary and secondary users, where transmissions by the various nodes of the network can be superposed in time and frequency. We model outage events in the network due to interference and fading and we assume that the nodes implement retransmission-based error control. The main contribution of our analysis is the accurate modeling of the interaction among the stochastic processes tracking the evolution of the nodes in the network. In fact, due to interference the operations of each users influences the evolution of the state of the others.Biography: Marco Levorato received both the BSc (Electronics and Telecommunications Engineering) and the MSc (Telecommunications Engineering) summa cum laude from the University of Ferrara (Italy) in 2002 and 2005, respectively. He received a Ph.D. degree from the doctoral School of Information Engineering, University of Padova in 2008. In 2008 he has been a visiting student at the University of Southern California, Los Angeles, under the supervision of Prof. Urbashi Mitra. Since 2009 Dr. Levorato is a post-doctoral research fellow at the University of Padova. His research interests mainly focus on wireless networking, especially in the stochastic modeling of MIMO networks, cooperating systems, error control protocols and cognitive networks.Host: Urbashi Mitra, ubli@usc.edu, EEB 540, x04667

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

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos