Rate splitting multiple access (RSMA) is regarded as an essential and powerful physical-layer (PHY) paradigm for next generation communication systems. Under such a system, users employ successive interference cancellation (SIC), allowing them to decode a portion of the interference and treat the remainder as noise. However, a problem is that current RSMA systems rely on fixed-position antenna arrays, limiting their capacity to fully exploit spatial freedom. This constraint restricts beamforming gain, which substantially degrades RSMA performance. To address this problem, we propose an movable antenna (MA)-aided RSMA scheme that allows the antennas at the base station (BS) to adjust their positions dynamically. Our target is to maximize the system's sum rate of both common and private messages by jointly optimizing the MA positions, beamforming matrix, and common rate allocation. To tackle the formulated non-convex problem, we employ fractional programming (FP) and develop a two-stage, coarse-to-fine-grained search algorithm to obtain suboptimal solutions. Numerical results demonstrate that, with appropriate antenna adjustments, the MA-enabled system significantly enhances the overall performance and reliability of RSMA when employing the proposed algorithm compared to fixed-position antenna configurations.

翻译：速率分割多址接入（RSMA）被视为下一代通信系统中一项关键且强大的物理层范式。在此类系统中，用户采用连续干扰消除技术，使其能够解码部分干扰并将剩余部分视为噪声。然而，当前RSMA系统依赖于固定位置天线阵列，限制了其充分利用空间自由度的能力。这一约束限制了波束成形增益，从而显著降低了RSMA性能。为解决此问题，我们提出了一种可移动天线辅助的RSMA方案，允许基站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，最大化系统公共消息与私有消息的和速率。为处理所构建的非凸优化问题，我们采用分式规划技术，并开发了一种从粗到细的两阶段搜索算法以获得次优解。数值结果表明，与固定位置天线配置相比，采用所提算法时，通过适当的天线调整，MA赋能系统能显著提升RSMA的整体性能与可靠性。