A Novel Blind CFO Estimator for RCP-OTFS Systems

Orthogonal time frequency space (OTFS) modulation is widely recognized as a key modulation technique for sixth-generation (6G) communication systems. However, it is a challenging task to estimate the carrier frequency offset (CFO) in OTFS system. In this paper, a blind carrier frequency offset (CFO) estimator based on cyclic prefix (CP) is proposed for fractional CFO estimation in RCP-OTFS system. The proposed method derives a cost function based on the correlation between received OTFS frame and remodulated received OTFS frame, and achieves CFO estimation by minimizing the theoretical mean square error (MSE). Simulation results demonstrate that the proposed estimator outperforms other estimators in terms of accuracy and range of estimation, while exhibiting robustness to different modulation orders.