RSMA-Enabled Covert Communications Against Multiple Spatially Random Wardens

TL;DR

This paper explores covert communication in a multi-user RSMA system with randomly located wardens, deriving analytical expressions, formulating an ECT maximization problem, and demonstrating RSMA's advantages through simulations.

Contribution

It introduces a novel RSMA-based covert communication framework considering random wardens and imperfect CSI, with analytical derivations and an AO-GA optimization approach.

Findings

RSMA outperforms conventional multiple access schemes in covert communication scenarios.

The proposed AO-GA algorithm effectively maximizes effective covert throughput.

Analytical expressions accurately predict system performance under various conditions.

Abstract

This work investigates covert communication in a rate-splitting multiple access (RSMA)-based multi-user multiple-input single-output system, where the random locations of the wardens follow a homogeneous Poisson point process. To demonstrate practical deployment scenarios, imperfect channel state information at the transmitter is considered. Closed-form expressions for the statistics of the received signal-to-interference-plus-noise ratio, along with the analytical formulations for the covertness constraint, outage probability, and effective covert throughput (ECT), are derived. Subsequently, an ECT maximization problem is formulated under covertness and power allocation constraints. This optimization problem is addressed using an alternating optimization-assisted genetic algorithm (AO-GA). Simulation results corroborate the theoretical analysis and demonstrate the superiority of RSMA over conventional multiple access schemes, as well as the effectiveness of the proposed AO-GA.