Carrier frequency offset estimation for OFDM systems with subcarriers

In this paper, we propose an iterative CFO estimator using a specific pattern of alternating pilots and subcarriers in training OFDM block. One major advantage of the proposed estimator is its simple structure. The proposed method estimates the CFO in an iterative fashion based on the signals at the subcarriers and use of the estimated CFO to correct the carrier frequency for the next iteration. It is found that with the proposed scheme, the final estimation accuracy depends only on the signal to noise ratio and is insensitive to the initial frequency offset. Simulation results demonstrate that the algorithm can achieve relatively high estimation accuracy within a few iterations in frequency-selective fading channels.