Two discrete-time phase delay estimators

Two simple discrete-time methods for estimating the phase-shift between two real sinusoidal signals in noise are proposed. The first estimator removes the bias of the recently proposed quadrature delay estimator (QDE) by utilizing all in-phase and quadrature-phase components of the received signals. While the phase estimate of the second method is given by the phase difference of the discrete-time Fourier transforms of two complex sinusoids derived from the real signals. The performances of the two estimators are evaluated by comparing with the QDE as well as the performance bound.