Accurate Doppler Factor Estimation with Signal Phase-Matching for OFDM System

The major problem in applying OFDM to underwater channels is that it is vulnerable to carrier frequency offset(CFO) caused by transceiver mismatch and/or Doppler shifts.And the loss of orthogonality due to the CFO effects must be compensated before the demodulation with discrete Fourier transform.A novel CFO estimation technique for OFDM communications is proposed over an underwater acoustic channel.The intrinsic structure information of OFDM signals is exploited to derive a CFO estimator based on signal-phase-matching(SPM) principle.Simulation results show that the main advantages of the proposed technique are computation simplicity and high accuracy.