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Presenter: Dr. Wei Xu - Associate Professor, National Mobile Communications Research Laboratory (NCRL), Southeast University, China
Supervisor: Dr. Xiaodai Dong

Date: Tue, September 23, 2014
Time: 11:00:00 - 12:00:00
Place: EOW 430

ABSTRACT

Abstract:

High peak-to-average-power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) degrades the performance in optical wireless communication systems. This paper proposes a modified asymmetrically-clipped optical OFDM (ACO-OFDM) with low PAPR via introducing a recoverable upper-clipping (RoC) procedure. Even though some information is clipped by a predetermined peak threshold, the clipped error information is kept and repositioned in our proposed scheme, named RoC-ACO-OFDM, instead of simply being dropped in conventional schemes. The proposed method makes full use of the specific structure of ACO-OFDM signals in time domain where a half of the positions are forced to zeros within an OFDM symbol. The zero-valued positions are utilized to carry the clipped error information. Moreover, we accordingly presented an optimal MAP detection for the RoC-ACO-OFDM system. To facilitate the usage of RoC-ACO-OFDM in practical applications, an efficient detection method is further developed with near optimal performance. Simulation results show that the proposed RoC-ACO-OFDM achieves a significant PAPR reduction while maintaining a competitive bit-error rate performance compared with the conventional schemes.

Biography:

Wei Xu received his B.Sc. degree in electrical engineering in 2003 and his M.S. and Ph.D. degrees in communication and information engineering in 2006 and 2009, respectively, all from Southeast University, Nanjing, China. He is currently an Associate Professor at the National Mobile Communications Research Laboratory (NCRL), Southeast University. Between 2009 and 2010, he was a postdoctoral research fellow with the Department of Electrical and Computer Engineering, University of Victoria, Canada. Dr. Xu is an Editor for the IEEE COMMUNICATIONS LETTERS. He has been involved in Technical Program Committees for a number of international conferences including the IEEE Global Communications Conference (Globecom), the IEEE Wireless Communications and Networking Conference (WCNC), the IEEE Vehicular Technology Conference (VTC), etc. He has co-authored more than 80 papers and has four patents granted. He is the co-recipient of the Best Paper Award at the IEEE International Symposium on Microwave, Antenna, Propagation, and EMC Technologies for Wireless Communications. He was elected Core Team Member of the Jiangsu Innovation Team in 2012. His research interests include communication theory, cooperative communications, and signal processing and optimization theory for wireless communications.