Enhancing Covert Communication in Relay Systems Using Multi-Antenna Technique

TL;DR

This paper investigates how multi-antenna techniques can significantly improve covert communication performance in relay systems by developing theoretical models and optimizing system parameters under covertness constraints.

Contribution

It introduces a comprehensive theoretical framework for covert performance analysis in relay systems with multi-antenna configurations and proposes optimal design strategies for maximizing covert throughput.

Findings

Multi-antenna techniques enhance covert throughput in relay systems.

Theoretical models for single and multi-antenna scenarios are developed.

Numerical results confirm performance improvements with multi-antenna setups.

Abstract

This paper exploits the multi-antenna technique to enhance the covert communication performance in a relay system, where a source S conducts covert communication with a destination D via a relay R, subjecting to the detections of transmissions in the two hops from a single-antenna warden W. To demonstrate the performance gain from adopting the multi-antenna technique, we first consider the scenario when S, R and D all adopt single antenna, and apply hypothesis testing and statistics theories to develop a theoretical framework for the covert performance modeling in terms of detection error probability (DEP) and covert throughput. We then consider the scenario when S, R and D all adopt multiple antennas, and apply the hypothesis testing, statistics and matrix theories to develop corresponding theoretical framework for performance modeling. We further explore the optimal designs of the target rate and transmit power for covert throughput maximization under above both scenarios, subjecting to the constraints of covertness, reliability and transmit power. To solve the optimization problems, we employ Karushi-Kuhn-Tucker (KKT) conditions method in the single antenna scenario and a search algorithm in the multi-antenna scenario. Finally, we provide extensive numerical results to illustrate how the multi-antenna technique can enhance the covert performance in two-hop relay systems.