Rotatable Antenna Enabled Covert Communication

TL;DR

This paper introduces a rotatable antenna system for covert wireless communication, optimizing beamforming and rotation to enhance covertness and outperform benchmarks.

Contribution

It proposes a novel RA-enabled covert communication framework with an efficient optimization algorithm for beamforming and rotation angle design.

Findings

Significantly improved covertness performance compared to benchmarks

Effective optimization of beamforming and rotational angles

Demonstrated robustness through simulation results

Abstract

Unlike conventional fixed-antenna architectures, rotatable antenna (RA) has shown great potential in enhancing wireless communication performance by exploiting additional spatial degrees of freedom (DoFs) in a cost-effective manner. In this letter, we propose a novel RA-enabled covert communication system, where an RA array-based transmitter (Alice) sends covert information to a legitimate user (Bob) in the presence of multiple wardens (Willies). To maximize the covert rate, we optimize the transmit beamforming vector and the rotational angles of individual RAs, subject to the constraints on covertness, transmit power, and antenna rotational range. To address the non-convex formulated problem, we decompose it into two subproblems and propose an efficient alternating optimization (AO) algorithm to solve the two subproblems iteratively, where the second-order cone programming (SOCP) method and successive convex approximation (SCA) approach are applied separately. Simulation results demonstrate that the proposed RA-enabled covert communication system can provide significantly superior covertness performance to other benchmark schemes.