The Ziv-Zakai bound (ZZB) provides a general mean-square error analytical baseline to evaluate time delay estimation (TDE) techniques for a wide range of time-bandwidth products and signal-tonoise ratios, but generally can only be numerically evaluated. The Weiss-Weinstein bound (WWB) further improves characterization of the attainable system performance, for narrowband and wideband signals with small to moderate fractional bandwidth. Similar to the WWB, here we nd a simpli ed closed-form ZZB for TDE with ultra-wideband (UWB) signals. The resulting simpli ed bound is found over disjoint segments, separated by thresholds that characterize different regions of ambiguity. The closed-form simpli ed bound can be analytically studied, and approaches both the ZZB and the TDE performance of a maximum likelihood estimator.
INDEX TERMSUltra-wideband, time delay estimation, Ziv-Zakai bound, WeissWeinstein bound.