Covert Communications with A Full-Duplex Receiver over Wireless Fading Channels

TL;DR

This paper introduces a novel covert communication scheme using a full-duplex receiver with artificial noise to hide transmissions from a warden, achieving positive covert rates even under strict detection constraints.

Contribution

It is the first to analyze full-duplex receivers with artificial noise for covert communications, deriving detection error rates and demonstrating unlimited covert rates under covertness constraints.

Findings

Artificial noise enables positive covert rates at any transmit power.

Optimal detection threshold for the warden is analytically derived.

Full-duplex receiver with controlled noise enhances covert communication capabilities.

Abstract

In this work, we propose a covert communication scheme where the transmitter attempts to hide its transmission to a full-duplex receiver, from a warden that is to detect this covert transmission using a radiometer. Specifically, we first derive the detection error rate at the warden, based on which the optimal detection threshold for its radiometer is analytically determined and its expected detection error rate over wireless fading channels is achieved in a closed-form expression. Our analysis indicates that the artificial noise deliberately produced by the receiver with a random transmit power, although causes self-interference, offers the capability of achieving a positive effective covert rate for any transmit power (can be infinity) subject to any given covertness requirement on the expected detection error rate. This work is the first study on the use of the full-duplex receiver with controlled artificial noise for achieving covert communications and invites further investigation in this regard.