Sensing Aided Covert Communications: Turning Interference into Allies

TL;DR

This paper presents a novel radar-assisted covert communication method that leverages sensing to enhance secrecy, employing advanced channel prediction and robust beamforming to ensure undetectability against adversaries.

Contribution

It introduces a joint radar and communication design framework utilizing sensing for covert transmission, including algorithms for perfect and imperfect CSI scenarios, outperforming traditional methods.

Findings

Accurate adversary tracking achieved

Enhanced covert transmission rate demonstrated

Proposed algorithms ensure covertness under various conditions

Abstract

In this paper, we investigate the realization of covert communication in a general radar-communication cooperation system, which includes integrated sensing and communications as a special example. We explore the possibility of utilizing the sensing ability of radar to track and jam the aerial adversary target attempting to detect the transmission. Based on the echoes from the target, the extended Kalman filtering technique is employed to predict its trajectory as well as the corresponding channels. Depending on the maneuvering altitude of adversary target, two channel state information (CSI) models are considered, with the aim of maximizing the covert transmission rate by jointly designing the radar waveform and communication transmit beamforming vector based on the constructed channels. For perfect CSI under the free-space propagation model, by decoupling the joint design, we propose an efficient algorithm to guarantee that the target cannot detect the transmission. For imperfect CSI due to the multi-path components, a robust joint transmission scheme is proposed based on the property of the Kullback-Leibler divergence. The convergence behaviour, tracking MSE, false alarm and missed detection probabilities, and covert transmission rate are evaluated. Simulation results show that the proposed algorithms achieve accurate tracking. For both channel models, the proposed sensing-assisted covert transmission design is able to guarantee the covertness, and significantly outperforms the conventional schemes.