Time delay estimation using fractional Fourier transform

The need for time delay estimation (TDE) between two signals arises quite often in many areas such as radar, sonar, etc. Several TDE techniques have been proposed in the literature using various signal transforms such as the conventional Fourier transform and the Hilbert transform. In this paper, use of the fractional Fourier transform (FRFT) for TDE is proposed. Some of the proposed estimators use the magnitude of the FRFT of the signals, whereas others depend on the phase angle of it. The problem of TDE in the statistical framework is also generalized using the FRFT and the maximum likelihood (ML) estimator for the time delay is obtained. To validate the proposed approach, simulation results for some of the proposed estimators are presented.