The MIMOME Channel

The MIMOME channel is a Gaussian wiretap channel in which the sender, receiver, and eavesdropper all have multiple antennas. We characterize the secrecy capacity as the saddle-value of a minimax problem. Among other implications, our result establishes that a Gaussian distribution maximizes the secrecy capacity characterization of Csisz{'a}r and K{"o}rner when applied to the MIMOME channel. We also determine a necessary and sufficient condition for the secrecy capacity to be zero. Large antenna array analysis of this condition reveals several useful insights into the conditions under which secure communication is possible.

💡 Research Summary

The paper studies the Gaussian wire‑tap channel in which the transmitter, legitimate receiver, and eavesdropper each have multiple antennas – the so‑called MIMOME (multiple‑input multiple‑output multiple‑eavesdropper) channel. The authors’ main contribution is an exact characterization of the secrecy capacity as the saddle‑point value of a minimax optimization problem.

Channel model. The transmitter has (n_t) antennas, the legitimate receiver (n_r) antennas, and the eavesdropper (n_e) antennas. The received vectors are
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