Cooperation for Secure Communications in the MIMO Relay Wire-tap Channel

摘要

We tackle the problem of secure communications for the Multiple-Input Multiple-Output Relay Eavesdropper system. By establishing a lower bound on the secrecy capacity at which secure communications between the source and the destination are attainable, we prove that the introduction of a relay yields better security results that the conventional model i.e when no relay is introduced and the eavesdropper's channel incurs as little noise as the legitimate receiver. We make use of the singular value decomposition (SVD) and its generalization to decompose the whole system into parallel independent channels. At the source, the generalized singular value decomposition (GSVD) is performed to simultaneously diagonalize the channel matrices of the relay and the destination and independently code across the resulting parallel channels.