Pilot-Aided Channel Estimation Based on MDCFT for OTFS in High Dynamic Environment

Orthogonal time frequency space (OTFS) modulation has gained significant attention due to its robustness against severe Doppler effects in dual-dispersion channels. However, conventional OTFS channel estimation algorithms are tailored for scenarios with constant Doppler shifts within the OTFS frame, struggling to address rapidly changing Doppler conditions, such as satellite maneuvering and adjacent space vehicles. This letter presents a pilot-aided channel estimation algorithm based on modified discrete Chirp Fourier transform (MDCFT) specifically tailored for high -dynamic environments characterized by uniform Doppler variations. We first establish the OTFS input-output relationship under high dynamic environments. Subsequently, we propose a channel estimation algorithm based on MDCFT, estimating the channel parameters by correlating the channel impulse response of the received pilot in the delay Doppler (DD) domain with our proposed algorithm. Simulation results show that the bit error rate (BER) performance of OTFS detection using our proposed algorithm outperforms that of conventional methods in high dynamic environments.