A Dual-hop Uplink IM-OFDMA System with Decode-and-Forward Relays

Due to the expected exploitation of high frequency bands to meet increasing demands on high data rates, multi-hop links are being under investigation as a solution for limited transmission distances over these bands. As such, many of recent transmission schemes are analyzed over multi-hop scenarios. To this end, in this paper, we design a dual-hop system of Index Modulation based Orthogonal Frequency Division Multiple Access (IM-OFDMA) with the help of decode-and-forward relays. Two different scenarios are considered, with single and multiple DF relays. Moreover, the average error rate is analyzed for the proposed system considering the two different scenarios. Our results indicate that the overall performance in the case of a single DF relay is governed by the performance of the second hop. Also, results reveal that a significant gain can be attained if a single relay is assigned to each user rather than one relay for all users.