Joint Subsample Time Delay and Echo Template Estimations for Ultrasound Signals

In ultrasound applications, the signal obtained from a real data acquisition system is corrupted by noise and the echoes may have subsample time delays, which in some cases, compromises scatterer localization. Most time delay estimation (TDE) techniques require a precise signal template, otherwise localization deteriorate. In this paper, we propose an alternate scheme that jointly estimates an echo template and time delays for several echoes from noisy measurements. Reinterpreting existing methods from a probabilistic perspective, we extend their functionalities through a joint application of a maximum likelihood estimator (MLE) and a maximum a posteriori (MAP) estimator. Finally, we present simulated results to demonstrate the superiority of the proposed method over traditional ones.