The Application of Cooperative Transmissions to Secrecy Communications

Şennur Ulukuş, Ersen Ekrem

Zhiguo Ding, Kin Kwong Leung, Dennis Goeckel +1 more

Information theoretic security has recently emerged as an effective physical layer approach to provide secure communications. The outage performance of such a secrecy communication system is considered in this paper, since it is an important criterion to measure whether users' predefined quality of service can be met. Provided that the legitimate receiver and eavesdropper have the same noise power, many existing secure schemes cannot achieve outage probability approaching zero, regardless of how large the transmission power is. By introducing cooperative transmission into secrecy communication systems, it will be shown here that outage probability approaching zero can be achieved. In particular, scenarios with single-antenna nodes and multiple-antenna nodes will both be addressed, and the optimal design of beamforming/precoding will be investigated. Explicit expressions of the achievable outage probability and diversity-multiplexing tradeoff will be developed to demonstrate the performance of the proposed cooperative secure transmission schemes, and numerical results are presented.

Ersen Ekrem, Şennur Ulukuş

Xiangyun Zhou, Lingyang Song, Yan Zhang

The exploitation of user cooperation has been recognized as an important technique to improve the robustness of secure transmissions, where various studies have shown that a careful use of relaying can improve the receptional reliability of the legitimate receivers and decrease eavesdropping capabilities at the same time. In this chapter, a detailed review will be provided to illustrate how to integrate relay transmissions with secrecy communications. Simpler scenarios with single-antenna nodes will be investigated first, where two secure transmission strategies, cooperative jamming and relay chatting, will be focused particularly. Then scenarios with multiple-antenna nodes will be considered, and the design of precoding becomes of interest, where the cases with and without channel information at the transmitters will be discussed separately.

João Luiz Rebelatto, Richard Demo Souza, Rodrigo Tsuneyoshi Kaido +2 more

We evaluate the secrecy performance of a multiple access cooperative network where the destination node is wiretapped by a malicious and passive eavesdropper. We propose the application of the network coding technique as an alternative to increase the secrecy at the destination node, on the top of improving the error performance of the legitimate communication, already demonstrated in the literature. Network coding is leveraged by assuming that the legitime cooperative nodes are able to perform non-binary linear combinations of different frames before the transmission. Different scenarios with and without channel state information (CSI) at the transmitter side are evaluated. The effectiveness of the proposed schemes is evaluated in terms of secrecy outage probability through theoretic and numerical analyses. It is shown that, even when the legitimate transmitters do not have any CSI, the secrecy can be increased through the use of network coding when compared to the direct transmission and traditional cooperative techniques.

Hsinying Liang, Cheng‐Ying Yang, Min‐Shiang Hwang