Rate-splitting multiple access (RSMA) is a multiple access technique generalizing conventional techniques, such as, space-division multiple access (SDMA), non-orthogonal multiple access (NOMA), and physical layer multi-casting, which aims to address multi-user interference (MUI) in multiple-input multiple-output (MIMO) 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 problem to find the optimal subcarrier and power allocation for downlink transmission in a two-user system using RSMA and OFDM and propose a weighted minimum mean-square error (WMMSE)-based algorithm to obtain a solution. The sum-rate performance of the proposed OFDM-RSMA scheme is compared with that of conventional orthogonal frequency division multiple access (OFDMA) and OFDM-NOMA by numerical results. It is shown that the proposed OFDM-RSMA outperforms OFDM-NOMA and OFDMA under ICI in diverse propagation channel conditions owing to its flexible structure and robust interference management capabilities.
翻译:速率分割多址接入(RSMA)是一种泛化传统技术(如空分多址(SDMA)、非正交多址接入(NOMA)和物理层多播)的多址接入技术,旨在解决多输入多输出(MIMO)系统中的多用户干扰(MUI)问题。本研究利用RSMA的干扰管理能力,应对正交频分复用(OFDM)波形中的子载波间干扰(ICI)问题。我们针对采用RSMA与OFDM的两用户下行链路系统,提出最优子载波与功率分配的问题,并设计了一种基于加权最小均方误差(WMMSE)的算法获取解。通过数值结果,将所提OFDM-RSMA方案的和速率性能与传统正交频分多址(OFDMA)及OFDM-NOMA进行对比。结果表明,得益于其灵活的结构与稳健的干扰管理能力,所提OFDM-RSMA在不同传播信道条件下受ICI影响时,均优于OFDM-NOMA与OFDMA。