Uplink rate-splitting multiple access (RSMA) requires optimization of decoding order and power allocation, while decoding order is a discrete variable, and it is very complex to find the optimal decoding order if the number of users is large enough. This letter proposes a low-complexity user pairing-based resource allocation algorithm with the objective of minimizing the maximum latency. Closed-form expressions for power and bandwidth allocation for a given latency are first derived. Then a bisection method is used to determine the minimum latency and optimal resource allocation. Finally, the proposed algorithm is compared with unpaired RSMA using an exhaustive method to obtain the optimal decoding order, unpaired RSMA using a suboptimal decoding order, paired non-orthogonal multiple access (NOMA) and unpaired NOMA. The results show that our proposed algorithm outperforms NOMA and achieves similar performance to unpaired RSMA. In addition, the complexity of the proposed algorithm is significantly reduced.

翻译：上行速率分裂多址接入（RSMA）需要优化解码顺序和功率分配，而解码顺序是一个离散变量，当用户数量足够大时，寻找最优解码顺序极为复杂。本文提出一种基于用户配对的低复杂度资源分配算法，以最小化最大时延为目标。首先推导出给定延迟条件下功率和带宽分配的闭式表达式。然后采用二分法确定最小时延及最优资源分配。最后，将所提算法与使用穷举法获得最优解码顺序的非配对RSMA、使用次优解码顺序的非配对RSMA、配对非正交多址接入（NOMA）以及非配对NOMA进行比较。结果表明，所提算法性能优于NOMA，且与未配对RSMA性能相近。此外，所提算法的复杂度显著降低。