Movable-Antenna Enabled Covert Communication

Conventional multi-antenna technology with fixed position antenna (FPA) array cannot make full use of the spatial degree of freedom offered by wireless channels. This letter proposes a novel covert communication system empowered by movable-antenna (MA) array, in which a transmitter equipped with a linear MA array sends covert information to a legitimate user while being monitored by multiple single and FPA wardens. With the aim of maximizing the covert rate, we jointly design the transmit beamforming and antenna position considering the constraints of covertness, transmitter’s power as well as antenna position. Despite the non-convexity of the optimization problem, we solve two subproblems in an iterative manner by means of the block coordinate descent algorithm. Numerical results indicate that the proposed MA array scheme can provide superior covertness performance in comparison with the conventional FPA array especially when a small number of antennas is adopted at the transmitter.