Multiuser Diversity for Secrecy Communications Using Opportunistic Jammer Selection: Secure DoF and Jammer Scaling Law

• Published in: IEEE transactions on signal processing Vol. 62; no. 4; pp. 828 - 839
• Main Authors: Lee, Jung Hoon, Choi, Wan
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 15.02.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Detection, estimation, filtering, equalization, prediction; Exact sciences and technology; Information, signal and communications theory; Interference channels; Jamming; Multiuser diversity; opportunistic jammer selection; physical layer security; Receiving antennas; secure DoF; Security; Signal and communications theory; Signal, noise; Telecommunications and information theory; Transmitters; Wireless communication; secure DoF; Multiple access; Wireless telecommunication; Transmitter; Jamming; Multiuser diversity; Scaling law; Transmitting antenna; Gaussian signal; Signal processing; opportunistic jammer selection; Selection criterion; Safety; physical layer security; Receiving antenna; Secrecy
• ISSN: 1053-587X; 1941-0476
• DOI: 10.1109/TSP.2013.2293979

In this paper, we propose opportunistic jammer selection in a wireless security system for increasing the secure degrees of freedom (DoF) between a transmitter and a legitimate receiver (say, Alice and Bob). There is a jammer group consisting of S jammers among which Bob selects K jammers. The selected jammers transmit independent and identically distributed Gaussian signals to hinder the eavesdropper (Eve). Since the channels of Bob and Eve are independent, we can select the jammers whose jamming channels are aligned at Bob, but not at Eve. As a result, Eve cannot obtain any DoF unless it has more than KNj receive antennas, where Nj is the number of each jammer's transmit antenna, and hence KNj can be regarded as defensible dimensions against Eve. For the jamming signal alignment at Bob, we propose two opportunistic jammer selection schemes and find the scaling law of the required number of jammers for target secure DoF by a geometrical interpretation of the received signals.