A sine wave delay estimator

In the paper a novel open-loop solution of a sine wave sub sample time delay estimator operating in the discrete time domain is presented. The proposed solution is based on a concept of Hilbert transforming the reference-noised signal in order to estimate the phase difference relative to the received signal whose initial phase and delay are unknown. The engineered estimator works well around the normalized centre frequency equal to 0.25 of sampling rate (typical of some sonar or USG applications) with SNR (signal to noise ratio) higher than 15 dB. It allows for some slight detuning of the received signal from the above mentioned centre frequency. The performance of the time delay estimator is analysed and illustrated by the results of its operation in presence of noise.