Cooperative Secret Communication with Artificial Noise in Symmetric Interference Channel

TL;DR

This paper investigates how cooperative artificial noise can improve secrecy rates in symmetric Gaussian interference channels, identifying optimal power control strategies and the impact of power constraints.

Contribution

It introduces a method for optimizing power and artificial noise parameters for secrecy in interference channels, revealing the critical power threshold for optimal strategies.

Findings

Existence of a critical power value $P_c$ determining optimal strategies.

Artificial noise enlarges the secrecy rate region.

Time-sharing surpasses max-min point above $P_c$.

Abstract

We consider the symmetric Gaussian interference channel where two users try to enhance their secrecy rates in a cooperative manner. Artificial noise is introduced along with useful information. We derive the power control and artificial noise parameter for two kinds of optimal points, max-min point and single user point. It is shown that there exists a critical value $P_c$ of the power constraint, below which the max-min point is an optimal point on the secrecy rate region, and above which time-sharing between single user points achieves larger secrecy rate pairs. It is also shown that artificial noise can help to enlarge the secrecy rate region, in particular on the single user point.