Rate-splitting multiple access (RSMA) is a multiple access scheme to mitigate the effects of the multi-user interference (MUI) in multi-antenna systems. In this study, we leverage the interference management capabilities of RSMA to tackle the issue of inter-carrier interference (ICI) in orthogonal frequency division multiplexing (OFDM) waveform. We formulate a sum-rate maximization problem to find the optimal subcarrier and power allocation for downlink transmission in a two-user system using RSMA and OFDM. A weighted minimum mean-square error (WMMSE)-based algorithm is proposed to obtain a solution for the formulated non-convex problem. We show that the marriage of rate-splitting (RS) with OFDM provides complementary strengths to cope with peculiar characteristic of wireless medium and its performance-limiting challenges including inter-symbol interference (ISI), MUI, ICI, and inter-numerology interference (INI). The sum-rate performance of the proposed OFDM-RSMA scheme is numerically compared with that of conventional orthogonal frequency division multiple access (OFDMA) and OFDM-non-orthogonal multiple access (NOMA). It is shown that the proposed OFDM-RSMA outperforms OFDM-NOMA and OFDMA in diverse propagation channel conditions owing to its flexible structure and robust interference management capabilities.

翻译：速率分裂多址接入（RSMA）是一种用于缓解多天线系统中多用户干扰（MUI）影响的多址接入方案。本研究利用RSMA的干扰管理能力，解决正交频分复用（OFDM）波形中的载波间干扰（ICI）问题。我们构建了一个和速率最大化问题，以确定采用RSMA和OFDM的两用户下行链路传输的最优子载波与功率分配方案。针对该非凸问题，提出了一种基于加权最小均方误差（WMMSE）的算法进行求解。研究表明，将速率分裂（RS）与OFDM相结合，能够提供互补优势，有效应对无线介质的独特特性及其性能限制性挑战，包括符号间干扰（ISI）、MUI、ICI以及参数间干扰（INI）。通过数值仿真，将所提OFDM-RSMA方案的和速率性能与传统正交频分多址接入（OFDMA）及OFDM-非正交多址接入（NOMA）进行了对比。结果表明，所提OFDM-RSMA因其灵活的结构和强大的干扰管理能力，在各种传播信道条件下均优于OFDM-NOMA和OFDMA。