Successive Interference Cancellation Detector for IM-OFDMA Systems

Index Modulation Orthogonal Frequency Division Multiple Access (IM-OFDMA) is a spectral-efficient uplink multiple access scheme that has been recently proposed. IM-OFDMA relies on the index modulation concept and allows for multiple users to simultaneously share the same spectrum resources. It has been demonstrated that IM-OFDMA outperforms its conventional and recent counterparts in terms of the error performance and the number of served users. However, as IM-OFDMA employs a joint maximum likelihood detection to decode the received signals, it suffers from the computational complexity required at the receiver. The computational complexity becomes serious challenge especially at a large number of users, a large number of frequency subcarriers or a high modulation order. Therefore, this paper aims to reduce the computational complexity of the detection process in IM-OFDMA systems by employing the Successive Interference Cancellation (SIC) detection method. Specifically, the implementation of SIC in IM-OFDMA is in detail described, followed by the analysis of the error performance and the reduction of the computational complexity. Our results reveal that the SIC detector can reduce the computational complexity with a significant percentage as compared to the maximum likelihood detection. Also, the results show that the impact on the error performance is minimal if the served users in each frequency chunk are carefully selected.