In this letter, we investigate the performance of Max Minimum Fairness (MMF) for uplink Rate-Splitting Multiple Access (RSMA) in short-packet communications. Specifically, considering a Single-Input Single-Output (SISO) Multiple Access Channel (MAC), we optimize the transmit power allocation between the splitting user messages to maximize the minimum rate among users with Finite Blocklength (FBL) constraints. To tackle this problem, we propose a Successive Convex Approximation (SCA)-based approach. Additionally, we introduce a low-complexity scheme to design the decoding order at the receiver. Numerical results show that RSMA outperforms conventional transmission schemes such as Non-orthogonal Multiple Access (NOMA) in terms of MMF.

翻译：在本文中，我们研究了短包通信中上行链路速率分裂多址接入（RSMA）的最大最小公平性（MMF）性能。具体而言，考虑单输入单输出（SISO）多址接入信道（MAC），我们在有限块长（FBL）约束下，优化分裂用户消息之间的发射功率分配，以最大化用户间的最小速率。为解决该问题，我们提出了一种基于逐次凸近似（SCA）的方法。此外，我们引入了一种低复杂度方案来设计接收端的解码顺序。数值结果表明，在MMF性能方面，RSMA优于传统传输方案（如非正交多址接入（NOMA））。