Low complexity frequency offset estimator for OFDM with time-frequency training sequence

A ratio-adjustable time-frequency training sequence and the corresponding carrier frequency offset (CFO) estimator are proposed for orthogonal frequency division multiplexing (OFDM) systems over frequency-selective fading channels. The proposed method estimates the coarse and fine CFO through the training sequence in frequency domain and time domain separately. Computation complexity can be greatly decreased by employing predefined lookup table. Simulation results show that the proposed estimator has better performance with almost the same overhead compared with Lei´s method in (2004).