Date Added: Jun 2010
This paper investigates transmission strategies in a MIMO wiretap channel with a transmitter, receiver and wire-tapper, each equipped with multiple antennas. The secrecy rate between the transmitter and the legitimate receiver is chosen as the performance metric. In a departure from existing work, the wire-tapper is able to act either as a passive eavesdropper or as an active jammer, under a half-duplex constraint. The transmitter therefore faces a choice between allocating all of its power for data; and broadcasting artificial noise along with the information signal in order to selectively degrade the eavesdropper's channel.