Weekly Seminar: “OTFS: A New Generation of Modulation Addressing the Challenges of 5G”
A new two-dimensional modulation technique called Orthogonal Time Frequency Space (OTFS) modulation designed in the delay-Doppler domain is introduced as a waveform ideally suited to new 5G use cases. Through this design, which exploits full diversity over time and frequency, OTFS coupled with equalization converts the fading, time-varying wireless channel experienced by modulated signals such as OFDM into a time-independent channel with a complex channel gain that is roughly constant for all symbols. Thus, transmitter adaptation is not needed. This extraction of the full channel diversity allows OTFS to greatly simplify system operation and significantly improves performance, particularly in systems with high Doppler, short packets, and large antenna arrays. Simulation results indicate at least several dB of block error rate performance improvement for OTFS over OFDM in all of these settings which translates to significant spectral efficiency improvements.
Christian Ibars Casas is currently a Principal Engineer at Cohere Technologies, based in Santa Clara, CA, USA. Formerly, he was with the Next Generation Networks group at Intel Corporation, USA (2013-2016), and with the Centre Tecnologic de Telecomunicacions de Catalunya, Spain (2003-2013), as head of the Communications Systems Division and other positions. He has also held external lecturer appointments at Universitat Pompeu Fabra during 2006-2008, and several visiting appointments (visiting student at Stanford University, 2000, visiting scholar at Cisco Research Center, 2010, and Marie Curie Fellow at the University of Padova (2010-2011)). During his career, Christian has specialized in wireless communications systems, with a recent focus on 5fth Generation cellular systems. He participates in the standardization process of 3GPP since Release 13. He also participated in several projects funded by the the European Commission, European Space Agency, Spanish Government, and US National Science Foundation, such as Free Bits, IST-Winner, IST-WIP, IST-Coopcom, ICT-Exalted, ICT-Emphatic, and MIMOSat. He has published over 80 international journal and conference papers, and holds over 10 patents. Christian received degrees in electrical engineering from Universitat Politecnica de Catalunya, Spain, and Politecnico di Torino, Italy, in 1999, and a Ph. D. degree in electrical engineering from the New Jersey Institute of Technology, USA, in 2003.