Efficient Signal Detection for MIMO-SIM-OFDM Systems

In this paper, a pair of detectors based on the local search (LS) and M algorithms are proposed for the multiple-input multiple-output subearrier-index modulation orthogonal frequency division multiplexing (MIMO-SIM-OFDM) systems. Specifically, the M algorithm is employed in the LS algorithm to avoid the local optimal solution in the first proposed detector, which is named as enhanced LS (E-LS) detector. Furthermore, a threshold is employed to the E-LS detector to reduce the complexity in the second proposed detector, which is named as low-complexity E-LS (LC-E-LC) detector. Simulation results show that the proposed detectors can obtain a flexible tradeoff between performance and complexity, compared to the traditional maximum likelihood (ML) and log-likelihood ratio (LLR) detectors.