A Novel Channel Estimation Scheme for OTFS

Orthogonal time frequency space (OTFS) modulation is an emerging multicarrier technique designed in the delay-Doppler domain. It converts a time-varying channel into a 2D invariant channel in the delay-Doppler domain through 2D transformations, resulting in better performance gain over orthogonal frequency division multiplexing (OFDM) in high-mobility scenarios. In this paper, we first derive the feasibility of threshold aided channel estimation for OTFS systems. Considering the poor performance of classical threshold aided scheme with a single impulse under a high noisy condition, we further propose a novel channel estimation scheme based on priori channel information, i.e., maximum Doppler shift and maximum multipath delay, with multiple impulses to extract the diversity gain so as to improve the performance. In addition, the specific method for threshold selection is given on the basis of Statistical Signal Processing. The simulation results indicate that the proposed scheme can achieve better channel state information over the classical scheme.