Secure Degrees of Freedom of Wireless X Networks Using Artificial Noise Alignment
2015 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 63, no 7, 2632-2646 p.Article in journal (Refereed) Published
The problem of transmitting confidential messages in M x K wireless X networks is considered in which each transmitter intends to send one confidential message to every receiver. In particular, the secure degrees of freedom (SDOF) of the considered network are studied based on an artificial noise alignment (ANA) approach, which integrates interference alignment and artificial noise transmission. At first, an SDOF upper bound is derived for the M x K X network with confidential messages (XNCM) to be K(M-1)/K+M-2. By proposing an ANA approach, it is shown that the SDOF upper bound is tight when K = 2 for the considered XNCM with time-/frequency-varying channels. For K >= 3, it is shown that SDOF of K(M-1)K+M-1 can be achieved, even when an external eavesdropper is present. The key idea of the proposed scheme is to inject artificial noise into the network, which can be aligned in the interference space at receivers for confidentiality. Moreover, for the network with no channel state information at transmitters, a blind ANA scheme is proposed to achieve SDOF of K(M-1)K+M-1 for K, M >= 2, with reconfigurable antennas at receivers. The proposedmethod provides a linear approach to secrecy coding and interference alignment.
Place, publisher, year, edition, pages
2015. Vol. 63, no 7, 2632-2646 p.
Secure degrees of freedom, artificial noise, interference alignment, wireless X network
IdentifiersURN: urn:nbn:se:kth:diva-172174DOI: 10.1109/TCOMM.2015.2434378ISI: 000358210000019ScopusID: 2-s2.0-84937459731OAI: oai:DiVA.org:kth-172174DiVA: diva2:846623
QC 201508172015-08-172015-08-142015-08-17Bibliographically approved