In this paper, a hybrid power domain non-orthogonal multiple accessing (NOMA) scheme by the superposition of orthogonal frequency division multiple accessing (OFDM) and index modulated OFDM (OFDM-IM) technologies is presented and named IM-NOMA. It is shown via both computer-based simulations and mathematical analysis that IM-NOMA outperforms the classical OFDM-NOMA in terms of bit error rate (BER) under a total power constraint and achievable sum rate. The system performance of IM-NOMA not only depends on the power difference between the overlapping users but also on features of the OFDM-IM signal. Hence, this scheme is robust against possible catastrophic error performance in case similar power is assigned to the users.

中文翻译：

---

具有 OFDM 和 OFDM-IM 的混合下行链路 NOMA，用于超 5G 无线网络

在本文中，提出了一种由正交频分多址(OFDM)和索引调制OFDM(OFDM-IM)技术叠加而成的混合功率域非正交多址(NOMA)方案，并将其命名为IM-NOMA。通过基于计算机的模拟和数学分析表明，IM-NOMA 在总功率约束和可实现的总速率下的误码率 (BER) 方面优于经典的 OFDM-NOMA。IM-NOMA 的系统性能不仅取决于重叠用户之间的功率差异，还取决于 OFDM-IM 信号的特征。因此，在类似的功率分配给用户的情况下，该方案对于可能的灾难性错误性能是稳健的。