Orthogonal frequency division multiplexing(OFDM) with index modulation (IM) is a multicarriertransmission technique for frequency-selective fading channels.Although it is energy and spectral efficient, its performancemay not be satisfactory as some active subcarriers can besuppressed by fading. In this letter, we consider trellis codedmodulation (TCM) for OFDM-IM in order to improve thedetection performance of active subcarriers by increasing theHamming distance between index symbols. We devise mappingrules for TCM for two cases and it is shown that the diversityorder can be improved, which results in a lower probability ofindex error.
- OFDM IM
- Trellis Coded Modulation