Simple and Low Complexity GD-HL Detector for OFDM-IM

In OFDM-IM scheme, the maximum likelihood (ML) detector becomes impractical for large number of active subcarrier index combinations and active subcarriers due to the exponentially growing decoding complexity. In this paper, a simple and low complexity GD-HL (greedy detection-hard limiting) detector based on greedy detection and hard-limiting idea is proposed. The computational complexity and the BER performance of GD-HL detector are analyzed. Computer simulation results demonstrate that the BER of GD-HL detector can approach, even reach the performance of optimal ML detector in the case of high-order modulation. The analysis show that the decoding complexity of the GD-HL is much lower and it doesn't grow with the increase of modulation order. These features make it more beneficial for OFDM-IM systems competing different channel conditions.