Precoded Index Modulation (PIM) for Multi-Input Multi-Output OFDM

In this paper, we extend the idea of Index modulated orthogonal frequency division multiplexing (IM-OFDM) to the MIMO scenario and propose the precoded index modulation for multi-input multi-output OFDM (PIM- MIMO-OFDM) for downlink transmission. Based on the channel state information (CSI) at the transmitter, PIM-MIMO-OFDM jointly selects the active elements of the receiver-side space-frequency OFDM subblocks. The co-channel interference (CCI) among receive antennas therefore can be completely eliminated. Low-complexity maximum likelihood (ML) and suboptimal detectors are proposed to achieve linear detection complexity. Both analytical and numerical results are provided to show that PIM-MIMO-OFDM achieves significantly improved bit error rate (BER) performance when compared with precoded MIMO-OFDM (P-MIMO-OFDM).