Ziv-Zakai lower bound for UWB based TOA estimation with multiuser interference

The aim of this paper is to derive a Ziv-Zakai lower bound (ZZLB) for the time of arrival (TOA) estimation in single-path (SP) additive white Gaussian noise (AWGN) channels and in the presence of multiuser interference (MUI). Time-hopping pulse position modulated (TH-PPM) ultra-wideband (UWB) signals are considered. Following a classical approach and extending it for the scenario under consideration, we compute the ZZLB by converting the related estimation problem into a binary detection one. To obtain the bit error rate (BER) of the corresponding detection problem, we both consider the exact handling of the MUI and the modeling of the MUI by means of a Gaussian approximation (GA).We compare the performance of the single-user maximum likelihood (ML) TOA estimator with the bounds.