Comparative performance of LMSTDE and ETDE for delay and Doppler estimation

The performance of two adaptive TDE systems, namely, the least mean square time delay estimator (LMSTDE) and the explicit time delay estimator (ETDE) are compared when the delay is linearly time-varied. While the (LMSTDE) interpolates filter coefficients to determine the time difference of a signal received at two separated sensors, the ETDE adapts and tracks the time delay explicitly. The convergence dynamics of these two approaches are analyzed when the delay is a linearly time-varying function due to relative motion between the signal source and the receivers. The merits of these methods in terms of parameter estimation and computational load are discussed. Simulation results show that the ETDE outperforms the LMSTDE for delay and Doppler estimation and its performance is comparable to the CRLB under noisy environment