Movable-Antenna Enhanced RSMA Short-Packet Transmission for URLLC Services
Xiong Li, Zhiqiang Du, Qimei Cui, Yanzhao Hou, Ji Zhang, Xiaofeng Tao
Abstract
Rate-Splitting Multiple Access (RSMA)is a powerful technology to enhance spectral efficiency in short packet Ultra-Reliable and Low-Latency Communication (URLLC) systems with Finite Blocklength (FBL) codes.Enhancing system performance requires larger antenna arrays to meet increasingly stringent QoS requirements, which is very costly. To overcome this limitation, we propose a novel movable antennas (MAs)-assisted RSMA short packet transmission schemes to realize more flexible beamforming and higher spatial multiplexing gains with a small number of MAs. We formulate a sum rate maximization problem for the joint optimization of beamforming and antenna position under the specified URLLC requirements. An alternating optimization (AO) algorithmis developed to address this challenging high-dimensional non-convex optimization problem.Specifically, the Successive Convex Approximation (SCA) methodis utilized to design the beamforming matrix. Additionally, we proposeda novel worst position neighborhood variation-oriented particle swarm optimization (WPNVPSO) to optimize the MA positions efficiently.Numerical results demonstrate our proposed design outperforms other benchmarks by achieving high data rates with lower latency and higher reliability, while utilizing fewer antennas.