Rate splitting multiple access (RSMA) is regarded as a crucial and powerful physical layer (PHY) paradigm for next-generation communication systems. Particularly, users employ successive interference cancellation (SIC) to decode part of the interference while treating the remainder as noise. However, conventional RSMA systems rely on fixed-position antenna arrays, limiting their ability to fully exploit spatial diversity. This constraint reduces beamforming gain and significantly impairs RSMA performance. To address this problem, we propose a movable antenna (MA)-aided RSMA scheme that allows the antennas at the base station (BS) to dynamically adjust their positions. Our objective is to maximize the system sum rate of common and private messages by jointly optimizing the MA positions, beamforming matrix, and common rate allocation. To tackle the formulated non-convex problem, we apply fractional programming (FP) and develop an efficient two-stage, coarse-to-fine-grained searching (CFGS) algorithm to obtain high-quality solutions. Numerical results demonstrate that, with optimized antenna adjustments, the MA-enabled system achieves substantial performance and reliability improvements in RSMA over fixed-position antenna setups.

翻译：速率分割多址接入（RSMA）被视为下一代通信系统关键且强大的物理层范式。特别地，用户采用连续干扰消除（SIC）技术解码部分干扰，同时将剩余干扰视为噪声。然而，传统的RSMA系统依赖于固定位置的天线阵列，限制了其充分利用空间分集的能力。这一约束降低了波束成形增益，并显著损害了RSMA性能。为解决此问题，我们提出了一种可移动天线（MA）辅助的RSMA方案，允许基站（BS）处的天线动态调整其位置。我们的目标是通过联合优化MA位置、波束成形矩阵和公共速率分配，最大化公共消息与私有消息的系统总速率。为处理该非凸优化问题，我们应用分式规划（FP）方法，并开发了一种高效的两阶段、由粗到精的搜索（CFGS）算法以获得高质量解。数值结果表明，通过优化的天线调整，支持MA的系统在RSMA中相比固定位置天线配置实现了显著的性能和可靠性提升。