Performance analysis of the estimation of time delay and Doppler stretch by wideband ambiguity function

In this paper, the performance of estimation of time delay and Doppler stretch by the wideband ambiguity function method (WBAF) is investigated. The comparison between the present result and that of Qu Jin et al. (see IEEE Trans., vol. SP-43, no. 4, p. 904-16, 1995) shows that the present result is more exact. Then we propose a modified returned signal model, and using the model we evaluate the maximum likelihood estimation (MLE) performance of the time delay and Doppler stretch, which shows that when the phase angle of the reflection coefficient φ₀ is known, the MLE performance is similar to the result given by Qu Jin et al. in the case that φ₀ is unknown. The result also demonstrates that WBAF method is an asymptotically optimal one