Compressed Sensing-Based Channel Estimation for OTFS in Continuous Delay-Doppler Domain

Orthogonal time frequency space (OTFS) modulation offers significant performance advantages over orthogonal frequency division multiplexing (OFDM) in doubly dispersive channels. Estimating the delay-Doppler (DD) channel response of the receiver is necessary for OTFS signal detection. In this paper, we propose a two-stage channel estimation method. First, the Orthogonal Matching Pursuit (OMP) algorithm is used for integer delay-Doppler coarse estimation, and then the Fibonacci Search method is employed to estimate the fractional delay and Doppler. Simulation results show that the proposed method outperforms other channel estimation methods in terms of normalized mean square estimation error (NMSE) performance. The estimation accuracy of a one percent DD resolution can be obtained through a small number of iterations.