Subsample time delay estimation of chirp signals using FrFT

•A new subsample time delay estimator is proposed.•Use the phase of FrFT to achieve subsample resolution of time delay estimate.•The theoretic derivation of the algorithm is presented.•The validity and superiority are demonstrated via computer simulations.

A new subsample time delay estimator is proposed in this paper. It is evaluated based on the time delay property of the fractional Fourier transform and is suitable for processing chirp signals. The theoretic derivation of the algorithm is also presented. The validity and superiority to the fractional time delay estimator (FRTDE), the conventional direct correlator (DC) and the average magnitude squared fractional difference function (AMSFDF) estimator of this new time delay estimator are demonstrated via computer simulations.