On Cooperative Relaying Schemes for Wireless Physical Layer Security

• Published in: IEEE transactions on signal processing Vol. 59; no. 10; pp. 4985 - 4997
• Main Authors: Jiangyuan Li, Petropulu, Athina P., Weber, S.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Cooperation; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Exact solutions; Information, signal and communications theory; Jamming; Mathematical analysis; Mathematical models; Maximization; Node cooperation; Noise; Optimization; Physical layer; physical layer based security; Protocols; Relaying; Relays; secrecy rate; Security; semi-definite programming; Signal and communications theory; Signal, noise; Studies; Telecommunications and information theory; Transmission; Wireless networks; Relaying; Wireless telecommunication; physical layer based security; Transmission protocol; Cooperative systems; semi-definite programming; Jamming; Exact solution; Analytical method; Signal processing; Wireless network; Numerical simulation; Routing protocols; Safety; Node cooperation; secrecy rate; Secrecy
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2011.2159598

We consider a cooperative wireless network in the presence of one or more eavesdroppers, and exploit node cooperation for achieving physical (PHY) layer based security. Two different cooperation schemes are considered. In the first scheme, cooperating nodes retransmit a weighted version of the source signal in a decode-and-forward (DF) fashion. In the second scheme, referred to as cooperative jamming (CJ), while the source is transmitting, cooperating nodes transmit weighted noise to confound the eavesdropper. We investigate two objectives: i) maximization of the achievable secrecy rate subject to a total power constraint and ii) minimization of the total power transmit power under a secrecy rate constraint. For the first design objective, we obtain the exact solution for the DF scheme for the case of a single or multiple eavasdroppers, while for the CJ scheme with a single eavesdropper we reduce the multivariate problem to a problem of one variable. For the second design objective, existing work introduces additional constraints in order to reduce the degree of difficulty, thus resulting in suboptimal solutions. Our work raises those constraints, and obtains either an analytical solution for the DF scheme with a single eavesdropper, or reduces the multivariate problem to a problem of one variable for the CJ scheme with a single eavesdropper. Numerical results are presented to illustrate the proposed results and compare them to existing work.