In-Phase and Quadrature Index Modulation Aided OTFS Transmission

Recently, orthogonal time frequency space modulation with index modulation (OTFS-IM) has been proposed, which can achieve better bit error rate (BER) performance than conventional OTFS. In this letter, a new transmission scheme, OTFS with in-phase and quadrature index modulation (OTFS-I/Q-IM), is presented to increase the spectral efficiency of OTFS-IM, in which additional information bits are carried through the grid index of OTFS block in in-phase and quadrature dimensions. Furthermore, the analytical expressions of average bit error probability (ABEP) and the maximum peak to average power ratio (PAPR) are derived to evaluate the performance of the proposed scheme. Simulation results demonstrate the enhanced performance of the proposed scheme in high-mobility scenarios.