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

Datum

16.06.2015

Zeit

11:00 - 12:30

Sprecher

Y.-W. Peter Hong

Zugehörigkeit

National Tsing Hua University, Taiwan

Serie

cfaed Seminar Series

Sprache

en

Hauptthema

Elektro- u. Informationstechnik

Andere Themen

Elektro- u. Informationstechnik

Beschreibung

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?”.

Links

• https://cfaed.tu-dresden.de/index.php/cfaed-seminar-series/sem_hong_limited-channel-state-information.html

Letztmalig verändert: 05.06.2015, 12:23:16