Reliable Transmission in FBMC-Based OTFS Systems With TF Domain Pilot-Aided Channel Estimation and Equalization

Orthogonal Time Frequency Space (OTFS) modulation can effectively support high-mobility communication scenarios. However, Orthogonal Frequency Division Multiplexing (OFDM) based OTFS suffers from high spectrum leakage. Implementing channel estimation and equalization that simultaneously supports both OTFS and OFDM also faces challenges. In this paper, we adopt Filter Bank Multi-Carrier (FBMC) modulation as an alternative to OFDM and propose a TF-domain pilot-aided channel estimation and equalization scheme, which can improve spectrum leakage and enhance compatibility. Specifically, first, based on the core function of the prototype filter, we choose the Hermite prototype filter with symmetric properties to construct the FBMC-based OTFS system, enhancing adaptability to dynamic channels. Second, considering the dynamic characteristics of fast time-varying channels, we construct Bessel fitting or priori information-assisted channel extrapolation mechanisms to achieve accurate tracking of channel parameters. Finally, we derive the criterion for determining the channel wide-sense stationarity time interval, which provides a basis for the update mechanism of prior information. Simulation results show that the proposed scheme can work robustly on doubly-selection channels. Compared to classical OTFS, FBMC-based OTFS significantly improves reliability in high mobility scenarios.