Post date: 05-may-2017 6:07:48

Title: Visible Light Communications

Date: 22-May-2017

Aula: Lab 3204

Material youtube video pdf slides

Speaker: Máximo Morales Céspedes received the B.Sc., and M.Sc., and Ph.D. degrees from the Universidad Carlos III de Madrid, Spain, in 2010, 2012, 2015, respectively, all in electrical engineering, with a specialization in Multimedia and Communications. In 2012 he was finalist of the IEEE Region 8 Student Paper Contest. From 2015 to 2017 he has been working as a postdoctoral fellow with the Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM) at Universite Catholique de Louvain.

Currently, he is with the Department of Signal Theory and Communications, Universidad Carlos III de Madrid, Spain. His research interests are interference management, hardware implementations, MIMO techniques and signal processing applied to wireless communications.

Abstract: The use of light-emitting diodes (LED) for ambient illumination leads to visible light communi- cations (VLC) as a promising technology for providing both constant lighting and high-speed wireless services in indoor environments. Since multiple LED sources can transmit to several users, this scenario naturally forms a multiple user multiple-input single-output (MU-MISO) system. In this sense, transmit precoding (TPC) schemes based on channel state information at the transmitter (CSIT) originally devised for radio-frequency (RF) systems have been proposed for their implementation in VLC. However, beyond providing CSIT or the need for cooperation among transmitters, which also result challenging in RF systems, there exist several constraints such as the non-negativity of the transmitted signal or providing constant illumination that hamper the performance of TPC schemes in VLC. Taking into consideration these constraints, this paper explores the use of Blind Interference Alignment (BIA) for achieving multiplexing gain without CSIT or cooperation. To do that, we devise the concept of reconfigurable photodetector that allows to switch among distinct and linearly independent channel responses. Simulation results show that the proposed BIA approach achieves a similar performance as TPC schemes for VLC systems even without considering the costs of providing CSIT and cooperation.