The Gaussian Many-to-One Interference Channel with Confidential Messages

TL;DR

This paper analyzes the Gaussian many-to-one interference channel with confidential messages, deriving achievable rates and bounds, and demonstrating that nested lattice codes can ensure secrecy with a constant gap to the upper bound under strong interference.

Contribution

It introduces the use of nested lattice codes for secrecy in interference channels and establishes a constant-gap result between achievable and upper bound rates under strong interference.

Findings

Nested lattice codes provide secrecy in interference channels.

A sum rate upper bound is established for strong interference.

The gap between achievable and upper bound rates is constant under certain conditions.

Abstract

We investigate the $K$-user many-to-one interference channel with confidential messages in which the $K$th user experiences interference from all other $K-1$ users, and is at the same time treated as an eavesdropper to all the messages of these users. We derive achievable rates and an upper bound on the sum rate for this channel and show that the gap between the achievable sum rate and its upper bound is $\log_2(K-1)$ bits per channel use under very strong interference, when the interfering users have equal power constraints and interfering link channel gains. The main contributions of this work are: (i) nested lattice codes are shown to provide secrecy when interference is present, (ii) a secrecy sum rate upper bound is found for strong interference regime and (iii) it is proved that under very strong interference and a symmetric setting, the gap between the achievable sum rate and the upper bound is constant with respect to transmission powers.