Uplink transceiver for subcarrier index modulation OFDM in massive MIMO systems with imperfect channel state information

Abstract

In this paper, we propose the uplink transceiver for Subcarrier Index Modulation (SIM) OFDM in multiuser massive MIMO systems with imperfect channel state information (CSI). In the proposed scheme, the indexes of inactive subcarriers implicitly transmit information bits and the subcarriers activation process is only dependent on modulation order of M-QAM. To mitigate multiuser interference at the base station with imperfect CSI, an iterative detector based on the Generalized Approximate Message Passing (GAMP) algorithm is developed. Compared to the classical massive MIMO OFDM system, our proposed scheme can improve energy efficiency (EE) without sacrificing spectral efficiency (SE). In addition, the GAMP detector shows superior detection performance and lower computational complexity than Minimum Mean Square Error (MMSE) detector. The simulation results confirm the efficiency of our proposed scheme.