MIMO Gaussian Broadcast Channels with Confidential and Common Messages

TL;DR

This paper characterizes the secrecy capacity region of a MIMO Gaussian broadcast channel with two confidential messages and a common message, using advanced coding schemes and information-theoretic tools.

Contribution

It introduces a combined secret dirty-paper and superposition coding scheme that achieves the secrecy capacity region for this complex broadcast scenario.

Findings

Achieves the secrecy capacity region for the MIMO Gaussian broadcast channel with confidential messages.

Employs a channel-enhancement approach and extremal entropy inequality for proof.

Demonstrates the effectiveness of combined coding schemes in secure MIMO communications.

Abstract

This paper considers the problem of secret communication over a two-receiver multiple-input multiple-output (MIMO) Gaussian broadcast channel. The transmitter has two independent, confidential messages and a common message. Each of the confidential messages is intended for one of the receivers but needs to be kept perfectly secret from the other, and the common message is intended for both receivers. It is shown that a natural scheme that combines secret dirty-paper coding with Gaussian superposition coding achieves the secrecy capacity region. To prove this result, a channel-enhancement approach and an extremal entropy inequality of Weingarten et al. are used.