Non-orthogonal multiple access (NOMA) has been widely nominated as an emerging spectral efficiency (SE) multiple access technique for the next generation of wireless communication network. To meet the growing demands in massive connectivity and huge data in transmission, a novel index modulation aided NOMA with the rotation of signal constellation of low power users (IM-NOMA-RC) is developed to the downlink transmission. In the proposed IM-NOMA-RC system, the users are classified into far-user group and near-user group according to their channel conditions, where the rotation constellation based IM operation is performed only on the users who belong to the near-user group that are allocated lower power compared with the far ones to transmit extra information. In the proposed IM-NOMA-RC, all the subcarriers are activated to transmit information to multiple users to achieve higher SE. With the aid of the multiple dimension modulation in IM-NOMA-RC, more users can be supported over an orthogonal resource block. Then, both maximum likelihood (ML) detector and successive interference cancellation (SIC) detector are studied for all the user. Numerical simulation results of the proposed IM-NOMARC scheme are investigate for the ML detector and the SIC detector for each users, which shows that proposed scheme can outperform conventional NOMA.

翻译：非正交多址接入（NOMA）已被广泛提名为下一代无线通信网络中一种具有潜力的频谱效率（SE）多址技术。为满足海量连接与大容量数据传输日益增长的需求，本文针对下行链路提出了一种新型低功率用户星座旋转辅助的索引调制NOMA方案（IM-NOMA-RC）。在所提出的IM-NOMA-RC系统中，用户根据信道条件分为远用户组和近用户组，其中基于旋转星座的IM操作仅应用于近用户组中分配功率低于远用户组的用户，用于传输额外信息。在IM-NOMA-RC中，所有子载波均被激活以向多个用户传输信息，从而实现更高的频谱效率。借助IM-NOMA-RC中的多维调制技术，可在单个正交资源块上支持更多用户。随后，针对所有用户分别研究了最大似然（ML）检测器和串行干扰消除（SIC）检测器。通过数值仿真对所提IM-NOMA-RC方案中每个用户采用ML检测器和SIC检测器的性能进行了验证，结果表明所提方案优于传统NOMA。