EE Systems Seminar

Recent advances in energy harvesting technologies enable wireless devices to harvest the energy they need from the natural resources in their environment. This development opens the exciting new possibility to build wireless networks that are self-powered, self-sustainable and which have lifetimes limited by their hardware and not the size of their batteries.  However, energy harvesting also brings a fundamental shift in communication system design principles. In conventional systems, energy (or power) is a deterministic quantity continuously available to the transmitter and communication is typically constrained only in terms of average power. In harvesting systems, the energy available for communication is a stochastic rather than a deterministic process which has memory and is input-dependent. In this talk, we will investigate the information-theoretic capacity of this non-traditional communication system. We will characterize the capacity as an n-letter mutual information rate under various assumptions on the availability of energy arrival information and use these n-letter expressions to approximate the capacity in terms of a power allocation problem that has been extensively studied in the recent communication theory literature. We will then proceed to deriving an approximate solution to this power control problem for some energy profiles which will allow us to approximate the capacity with a simple and insightful formula within a constant gap independent of system parameters.

Bio:Ayfer Ozgur is an Assistant Professor in the Information Systems Laboratory at Stanford University since 2012. Before joining Stanford, she was a postdoctoral researcher and a Ph.D. student at EPFL, Switzerland. She received her Ph.D. degree from EPFL in 2009 and B.Sc. and M.Sc.degrees in electrical engineering and physics from Middle East Technical University, Turkey in 2001 and 2004 respectively. From 2001 to 2004, she worked as a hardware design engineer for the Defense Industries Research and Development Institute in Turkey. She received the EPFL Best Ph.D. Thesis Award in 2010 and the NSFCAREER Award in 2013. Her research interests are in wireless and network communication, information and coding theory