Comparing Minimum Codeword Distances and Error Performance for Index Modulation and Maximum Distance Separable Coded Modulation

Index modulation (IM) that embeds information into combinations of activated codeword elements have desirable properties in terms of error performance, low-complexity implementation, and compatibility with existing communication techniques. However, a recent modulation concept based on a simple maximum distance separable (MDS) code, i.e., MDS modulation, achieves better performance than IM while preserving a low-complexity structure. In this paper, we conduct further numerical comparisons among the MDS and IM techniques to comprehend to what extent the MDS methods can outperform the IM methods in terms of distance properties and bit error rate (BER) performance. Our numerical distance comparisons show that the MDS techniques are more beneficial than the IM techniques when η > 2, where η is spectral efficiency (SE) per codeword element. Moreover, our BER results support the distance results and show the effectiveness of the MDS techniques against the IM techniques for a wide range of SE.