Post date: 25-feb-2017 8:56:23
Title: Ambient Backscatter Communications
Date: 15-12-2016
Aula: 301 Aulario III
Material: pdf slides
Speakers: Riku Jänttiis
Riku Jänttiis an Associate Professor (tenured) in Communications Engineering and the head of the department of Communications and Networking at Aalto University School of Electrical Engineering, Finland. He received his M.Sc (with distinction) in Electrical Engineering in 1997 and D.Sc (with distinction) in Automation and Systems Technology in 2001, both from Helsinki University of Technology (TKK). Prior to joining Aalto (formerly known as TKK) in August 2006, he was professor pro tem at the Department of Computer Science, University of Vaasa. Prof. Jäntti is a senior member of IEEE and associate editor of IEEE Transactions on Vehicular Technology. He is also IEEE VTS Distinguished Lecturer (Class 2016). The research interests of Prof. Jäntti include radio resource control and optimization for machine type communications,cloud based Radio Access Networks, spectrum and co-existence management and RF Inference.
Abstract:
One of the limiting factors of connecting things to the Internet using wireless technologies is the availability of energy. One solution is provided by the modulated back-scattering (MBS) systems used in RFIF, where the nodes (tags) modulate their information onto a carrier generated by a reader and the reader decodes the modulated information. The RFID reader illuminates a tag with a constant amplitude carrier wave at some fixed frequency. Recently MBS concept has been extended to ambient backscatter (AB) through applying a modulated signal instead of an unmodulatd carrier. The prior work have focused on the mono-static case, where the transmitter and the receiver are co-located and only the backscattered information needs to be decoded. In this talk, we consider the bi-static case where the receiver need to decode both the original transmitted information as well as the message generated by the AB node. We show that the capacity of a MIMO system with AB exceeds that of the MIMO system alone. The excess capacity can be achieved by the MMO system alone by using the AB node as a passive relay or be shared between the two systems. We also discuss the impact of channel estimation errors on the achievable data rate.