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## Invitation To A Talk by Martina Cardone, Ph.D., University of Minnesota, USA

TIME: | 22 November 2017, 11:00 AM |

PLACE: | Room MAR 0.007, Marchstr. 23, 10587 Berlin |

TITLE: | Reconciling Optimality and Complexity over Wireless Relay Networks |

**ABSTRACT:**

Information theory designs near-optimal relaying schemes assuming no complexity constraints. 5G systems are envisaged to deploy cooperative relaying at a large scale, using low-complexity schemes. In this talk, we discuss some approaches to achieve near-optimal rate performance over complexity-constrained relay networks. We consider a wireless network where the communication from a base station to a mobile user is assisted by N half-duplex relays. For such a network, a constant-gap capacity approximation involves an optimization over the 2^N possible listen/transmit relays configuration states. We leverage intrinsic structural properties of such networks and we show a surprising result: at most N + 1 states, out of the 2^N possible ones, suffice for a constant-gap capacity approximation for a class of half-duplex relay networks, which includes the practically relevant Gaussian noise case. We next design a polynomial-time algorithm that allows to compute the at most N + 1 active states sufficient for constant-gap capacity approximation for Gaussian half-duplex relay networks where the N relays are arranged in a line. The algorithm uses similarities between network states in half-duplex and edge coloring in a graph and achieves a rate that provides a closed-form expression for the approximate capacity.

**BIO:**

Martina Cardone received her B.Sc. in Telecommunications Engineering from Politecnico di Torino, Italy in 2009. She obtained her M.Sc. degrees in Telecommunications Engineering from Politecnico di Torino, Italy and Télécom ParisTech, France in 2011 as part of a double degree program. In 2015, she received her Ph.D. in Electronics and Communications from Télécom ParisTech (with work done at Eurecom in Sophia Antipolis, France), where she worked with Professor Raymond Knopp and Professor Daniela Tuninetti. From July 2015 to August 2017 she was a post-doctoral research fellow in the Electrical and Computer Engineering department at the University of California, Los Angeles, where she worked with Professor Christina Fragouli. She is currently a post-doctoral associate in the Electrical and Computer Engineering department at the University of Minnesota and she will be joining the same department as a tenure-track Assistant Professor as of January 2018. She regularly serves on the Technical Program Committee of IEEE workshops and conferences. Her main research interests are in network information theory, wireless networks, security and network coding. She was the recipient of the Qualcomm Innovation Fellowship in 2014 and she received the second prize in the Outstanding Ph.D. Thesis Award at Télécom ParisTech (among the 85 theses defended in 2015).