Secure Transmission with Multiple Antennas II: The MIMOME Wiretap Channel

The capacity of the Gaussian wiretap channel model is analyzed when there are multiple antennas at the sender, intended receiver and eavesdropper. The associated channel matrices are fixed and known to all the terminals. A computable characterization of the secrecy capacity is established as the saddle point solution to a minimax problem. The converse is based on a Sato-type argument used in other broadcast settings, and the coding theorem is based on Gaussian wiretap codebooks. At high signal-to-noise ratio (SNR), the secrecy capacity is shown to be attained by simultaneously diagonalizing the channel matrices via the generalized singular value decomposition, and independently coding across the resulting parallel channels. The associated capacity is expressed in terms of the corresponding generalized singular values. It is shown that a semiblind "masked" multi-input multi-output (MIMO) transmission strategy that sends information along directions in which there is gain to th...

• Type: Journal
• Year: 2010
• Where: CORR
• Authors: Ashish Khisti, Gregory W. Wornell
• Keywords: Channel Matrices, CORR 2010, Education, Gaussian Wiretap, Secrecy Capacity