Subcarrier Index Modulation OFDM for multiuser MIMO systems with iterative detection

Abstract

In this paper, we propose Subcarrier Index Modulation (SIM) OFDM for multiuser uplink transmission in MIMO systems. In the proposed scheme, information bits are divided into two parts according to the quadrature amplitude modulation order: the first part of bits are mapped to the indexes of inactive subcarriers implicitly carrying information, the remaining part of bits are mapped onto the signal constellation. To mitigate multiuser interference at the base station, an iterative detector based on the Generalized Approximate Message Passing (GAMP) algorithm is developed. Compared to the classical multiuser OFDM system, our proposed scheme can lower the peak to average power ratio (PAPR), improve both the energy efficiency (EE) and detection performance without sacrificing the spectral efficiency (SE). The simulation results confirm the efficiency of our proposed scheme.