The Secrecy Capacity Region of the Gaussian MIMO Multi-Receiver Wiretap Channel

In this paper, we consider the Gaussian multiple-input multiple-output (MIMO) multi-receiver wiretap channel in which a transmitter wants to have confidential communication with an arbitrary number of users in the presence of an external eavesdropper. We derive the secrecy capacity region of this channel for the most general case. We first show that even for the single-input single-output (SISO) case, existing converse techniques for the Gaussian scalar broadcast channel cannot be extended to this secrecy context, to emphasize the need for a new proof technique. Our new proof technique makes use of the relationships between the minimum-mean-square-error and the mutual information, and equivalently, the relationships between the Fisher information and the differential entropy. Using the intuition gained from the converse proof of the SISO channel, we first prove the secrecy capacity region of the degraded MIMO channel, in which all receivers have the same number of antennas, and th...

• Type: Journal
• Year: 2011
• Where: TIT
• Authors: Ersen Ekrem, Sennur Ulukus
• Keywords: MIMO Channel, Noise Covariance Matrices, Secrecy Capacity Region, TIT 2011