A novel low-complexity frequency offset estimator for OFDM systems

The frequency offset estimation is one of the most important tasks in orthogonal frequency division multiplexing (OFDM) systems. To estimate frequency offset, a periodogram-based estimator has been proposed by Ren. The method consists of three estimation steps and gives an accurate result. However, in the second and third estimation steps, the maximum frequency offset range that can be estimated is limited to a subcarrier spacing. This range is insufficient compared with the overall signal bandwidth, making the first estimation step require high complexity. In this paper, we propose a low-complexity frequency offset estimation method, which can efficiently extend the estimation ranges without loss of accuracy.