cfaed Seminar Series

cfaed Seminar Series

Y.-W. Peter Hong , National Tsing Hua University, Taiwan

Secret Communications in the Physical Layer - Impact of Training an Limited Channel State Informtion

15.06.2015 (Monday) , 16:00 - 17:30
TU Dresden, Barkhausenbuilding, BAR I/15 , Helmholtzstraße 18 , 01069 Dresden

Secrecy in wireless communications has become increasingly important due to the broadcast nature of wireless transmissions. In addition to conventional cryptography-based approaches, information-theoretic studies on physical layer secrecy have demonstrated the possibility of achieving confidentiality solely through coding and signal processing techniques. However, many of these studies rely on perfect knowledge of the channel state information (CSI) at the transmitter and/or the receiver, which is not attainable in practice. 

In this talk, Prof. Hong will describe his recent studies on the impact of training and limited channel state information (CSI) on the achievable secrecy rate. First, the impact of quantized channel feedback on the achievable secrecy rate will be discussed. In particular, by considering the artificial noise (AN) assisted beamforming system, the secrecy rate loss caused by quantized channel direction information will be analyzed and the scaling of the number of feedback bits that is needed in order to maintain a constant secrecy rate loss as the transmission power increases will be derived.

Secondly, the role of training and channel estimation in physical layer secrecy will be discussed and a class of secrecy-enhancing training-based channel estimation schemes, called discriminatory channel estimation (DCE), will be introduced. Two specific DCE schemes will be described, namely, the feedback-and-retraining and the two-way training based DCE schemes. These schemes rely on the insertion of AN in appropriately chosen subspaces during the training process and also on appropriate power allocation between training data and AN. Finally, the tradeoff between training and data transmission in physical layer secrecy transmissions will be discussed. Throughout these studies, we try to answer questions such as “Is conventional training favorable for secrecy?” and “How much training is enough for secrecy?”.

Y.-W. Peter Hong received his B.S. degree from National Taiwan University in 1999, and his Ph.D. degree from Cornell University in 2005, both in electrical engineering. He joined the Institute of Communications Engineering and the Department of Electrical Engineering at National Tsing Hua University, Hsinchu, Taiwan, in Fall 2005, where he is now a Full Professor. His research interests include cooperative communications, physical layer secrecy, distributed signal processing for sensor networks, and cross-layer designs for wireless networks.

Dr. Hong received the best paper award for young authors from the IEEE IT/COM Society Taipei/Tainan chapter in 2005, the best paper award among unclassified papers in MILCOM 2005, the Junior Faculty Research Award from the College of EECS and from National Tsing Hua University in 2009 and 2010, respectively, the IEEE Communication Society Asia-Pacific Outstanding Young Researcher Award in 2010, the Y. Z. Hsu Scientific Paper Award in 2001, the National Science Council (NSC) Wu Ta-You Memorial Award also in 2011, and the Chinese Institute of Electrical Engineering (CIEE) Outstanding Young Electrical Engineer Award in 2012.

His coauthored paper also received the Best Paper Award from the Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC) in 2013.
Dr. Hong is an Associate Editor for IEEE Transactions on Signal Processing and IEEE Transactions on Information Forensics and Security. He is also the 2014-2015 Distinguished Lecturer for Asia-Pacific Signal and Information Processing Association (APSIPA).

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