Outage Performance of Two-Hop OFDM With Index Modulation and Multi-Carrier Relay Selections

In this letter, we propose a two-hop orthogonal frequency-division multiplexing with index modulation (OFDM-IM) system, which is assisted by multiple relays and employs multi-carrier relay selection to enhance the system reliability. In particular, two commonly used multi-carrier relay selection schemes are considered, i.e., bulk and per-subcarrier relay selections, and the decode-and-forward relaying is adopted as the forwarding protocol for the proposed system. The analysis of average outage probability of the proposed system is given in closed form and substantiated by numerical results generated by Monte Carlo simulations. By the analytical and numerical results provided, we can observe that the full diversity (equal to the number of relays) can be achieved by applying both bulk and per-subcarrier relay selections in two-hop OFDM-IM systems.