Joint Beamforming and Antenna Position Design for Movable Antenna-Assisted uRLLC Systems

In this work, we investigate the joint optimization of beamforming and antenna position in movable antenna (MA)-assisted short packet transmission (SPT) for ultra-reliable low-latency communication (uRLLC) systems. In contrast to conventional uRLLC systems employing fixed-position antennas, MAs at the user side can dynamically adjust their positions within a limited region. Our objective is to jointly optimize the beamforming matrix and MA positions to maximize the sum rate of multiple uRLLC users, subject to a transmit power budget and a movement constrained region. Due to the non-convexity of the problem and the absence of a closed-form expression for the objective function, we propose an efficient alternating optimization algorithm based on successive convex approximation. Numerical results demonstrate that the proposed MA-assisted scheme outperforms competing schemes, achieving the better sum rate even at shorter blocklengths compared to the Shannon capacity formula obtained with the fixed-position antenna scheme.