Iterative Hard Thresholding Algorithm-Based Detector for Compressed OFDM-IM Systems

A low-complexity iterative hard thresholding (IHT) algorithm-based detector is proposed for the compressed orthogonal frequency division multiplexing with index modulation (OFDM-IM) system. To improve recovery accuracy and reduce the number of iterations, detection is embedded into the iterations of the IHT algorithm, and the block energy information is used to identify subblocks that are more likely to be error-recovered. Compared with the existing methods for improving spectral efficiency, the new method does not expand the detection search space and not need extra pseudo-inverse calculations during iterations. Theoretical and simulation results show that the proposed scheme can considerably reduce computational complexity while improving spectral efficiency and preserving significant BER performance gain.