Frequency offset estimator for OFDM using a special preamble

In this letter,we design a special preamble composed of two OFDM training blocks with different numbers of identical parts. Based on the designed preamble, we propose a method to estimate frequency offset utilizing initial estimates from the two OFDM training symbols. By elaborately selecting the numbers of identical parts for the two training blocks, the proposed estimator provides a much larger estimate range than conventional estimators using identical parts. Computer simulations show that the proposed estimator exhibits superior estimate performance, while maintaining low computational complexity.