Three Artificial-Noise-Aided Secure Transmission Schemes in Wiretap Channels

• Published in: IEEE transactions on vehicular technology Vol. 67; no. 4; pp. 3669 - 3673
• Main Authors: Yan, Shihao, Yang, Nan, Land, Ingmar, Malaney, Robert, Yuan, Jinhong
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Artificial noise; Complexity theory; Encoding; Network security; Optimization; Physical layer security; power allocation; Redundancy; secure transmission; Signal to noise ratio; Upper bounds; wiretap code rates; Wiretapping
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2017.2779508

We examine the secrecy performance of three artificial-noise-aided secure transmission schemes, namely, the partially adaptive, fully adaptive, and on-off schemes. To this end, we provide new analysis to facilitate the optimization of the fraction <inline-formula><tex-math notation="LaTeX">\phi</tex-math> </inline-formula> of the transmit power allocated to the useful signal and redundancy rate <inline-formula> <tex-math notation="LaTeX">R_{\rm{E}}</tex-math></inline-formula>. Surprisingly, our examination indicates that the partially adaptive scheme, in which only the codeword rate <inline-formula><tex-math notation="LaTeX">R_{\rm{B}} </tex-math></inline-formula> varies with the instantaneous channel gains, significantly outperforms the on-off scheme, in which both <inline-formula><tex-math notation="LaTeX">R_{\rm{B}}</tex-math> </inline-formula> and <inline-formula><tex-math notation="LaTeX">R_{\rm{E}}</tex-math></inline-formula> vary. This performance gain can be characterized in terms of a higher average secrecy rate, subject to an upper bound on the secrecy outage probability. Furthermore, our results also demonstrate that the partially adaptive scheme can achieve almost the same secrecy performance as the fully adaptive scheme, which is of a much higher complexity, where <inline-formula><tex-math notation="LaTeX">\phi</tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">R_{\rm{B}}</tex-math></inline-formula>, and <inline-formula><tex-math notation="LaTeX"> R_{\rm{E}}</tex-math></inline-formula> all vary with the instantaneous channel gains.