Efficient signal detector design for OTFS with index modulation

In this paper, efficient signal detectors are designed for Orthogonal Time Frequency Space (OTFS) modulation with Index Modulation (IM) systems. Firstly, the Minimum Mean Squared Error (MMSE) based linear equalizer and its corresponding soft-aided decision are studied for OTFS-IM. To further improve the performance, a Vector-by-Vector-aided Message Passing (VV-MP) detector and its associated soft-decision are proposed, where each IM symbol is considered an entire vector utilized for message calculation and passing. Simulation results are shown that the OTFS-IM system relying on the proposed detectors is capable of providing considerable Bit Error Rate (BER) performance gains over the OTFS and Orthogonal Frequency Division Multiplex (OFDM) with IM systems.