A Novel Frequency Offset Estimation Algorithm with Wide Range and High Accuracy for OFDM System

The carrier frequency offset estimation of Orthogonal Frequency Division Multiplexing (OFDM) has always been a research focus. However, the Capturing-range and the accuracy of frequency offset estimations, as a pair of contradictions, have not been satisfactorily solved in many studies. In order to solve this problem, a frequency offset estimation algorithm with wide range and high accuracy was proposed in this paper. The basic idea of this algorithm: step 1, conjugate multiply the received training sequence by the local-saved training sequence, step 2, conduct short delay related operations to obtain a wider range of estimation, step 3, conduct long delay related operations to ensure a higher estimation accuracy, step 4, get the final frequency offset estimation by simple operations of the two estimates result. Moreover, the noises are reduced during the related operation process. Results from theoretical analysis and computer simulations showed that the accuracy of the frequency offset estimation algorithm proposed in this paper was 1 or 2 orders of magnitude higher than that of the traditional algorithm in the Gaussian channel and the 60GHz multipath channel.