Index Modulation Multiple-Access (IMMA): Efficient Techniques for Downlink Millimeter Waves Outdoor Channel

In this paper, we propose two new multiple-access schemes for downlink system based on the combination of orthogonal frequency division multiplexing (OFDM) with index modulation (IM), namely OFDM-IM. first proposed technique, namely, Index Modulation Multiple-Access (IMMA), OFDM subcarriers are divided into multiple sets and each set is assigned to a specific user, their data bits transmitted via OFDM-IM technique. On other hand, in second scheme, an extended version IMMA introduced where different users arranged pairs, pair shares block subcarriers. The allocated domains: domain constellation domain. focus paper 28 GHz transmission band as it has been considered initial deployment mm-waves wireless systems, due relatively lower location within mmwaves range hence characterized by attenuation. fluctuating ray model (FTR) was propagation outdoor millimeter waves channels. Simulation results demonstrate that both achieve improved average bit error rate (ABER) than classical OFDMA NOMA-IM techniques.