Gaussian MIMO Broadcast Channels with Common and Confidential Messages

TL;DR

This paper characterizes the full capacity region of a two-user Gaussian MIMO broadcast channel with both common and confidential messages, revealing the limits of secure communication in such systems.

Contribution

It provides the complete capacity region for the Gaussian MIMO broadcast channel with common and confidential messages, and explores its relation to the non-confidential case.

Findings

Derived the entire capacity region for the channel.

Established connections with the non-confidential capacity region.

Enhanced understanding of secure MIMO broadcast communications.

Abstract

We study the two-user Gaussian multiple-input multiple-output (MIMO) broadcast channel with common and confidential messages. In this channel, the transmitter sends a common message to both users, and a confidential message to each user which is kept perfectly secret from the other user. We obtain the entire capacity region of this channel. We also explore the connections between the capacity region we obtained for the Gaussian MIMO broadcast channel with common and confidential messages and the capacity region of its non-confidential counterpart, i.e., the Gaussian MIMO broadcast channel with common and private messages, which is not known completely.