In this paper, we propose a novel orthogonal frequency division multiplexing with index modulation (OFDM-IM) scheme, which we call Q-ary multi-mode OFDM-IM (Q-MM-OFDM-IM). In the proposed scheme, Q disjoint M-ary constellations are used repeatedly on each subcarrier, and a maximum-distance separable code is applied to the indices of these constellations to achieve the highest number of index symbols. A low-complexity subcarrier-wise detection is shown possible for the proposed scheme. Spectral efficiency (SE) and the error rate performance of the proposed scheme are further analyzed. It is shown that the proposed scheme exhibits a very flexible structure that is capable of encompassing conventional OFDM as a special case. It is also shown that the proposed scheme is capable of considerably outperforming the other OFDM-IM schemes and conventional OFDM in terms of error and SE performance while preserving a low-complexity structure.

中文翻译：

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带索引调制的 Q-ary 多模 OFDM

在本文中，我们提出了一种新的带有索引调制的正交频分复用 (OFDM-IM) 方案，我们将其称为 Q-ary 多模 OFDM-IM (Q-MM-OFDM-IM)。在所提出的方案中，在每个子载波上重复使用Q个不相交的M-ary星座，并且对这些星座的索引应用最大距离可分离码以获得最大数量的索引符号。对于所提出的方案，低复杂度的子载波方式检测被证明是可能的。进一步分析了所提出方案的频谱效率（SE）和误码率性能。结果表明，所提出的方案展示了一种非常灵活的结​​构，能够将传统的 OFDM 作为一种特殊情况。