A Dual-Mode Index Modulation Scheme With Gray-Coded Pairwise Index Mapping

In this letter, we propose a single-carrier (SC) dual-mode (DM) index modulation scheme with Gray-coded pairwise index mapping. To improve the index error rate performance of DM schemes, we apply Gray-coding to the mapping of modulation patterns. The error propagation within each symbol group in DM schemes can also be avoided due to the pairwise pattern design. Moreover, the mapping ideas in the proposed scheme can be easily extended to other index modulation schemes to obtain better bit error rate performance. Simulation results demonstrate the performance advantage of the proposed scheme over conventional SC and DM schemes in frequency selective fading channels.