Signal Model and Statistical Analysis for the Sequential Sampling Pulse Radar Technique

For high-accuracy radar-based range measurement two commonly applied radar principles are frequency-modulated continuous-wave (FMCW) and pulse radars. In many applications, e.g. liquid level gauging or short-range automotive applications, the latter radar principle is based on sequential sampling together with a cross correlation technique to alleviate the high demands on the sampling stage as well as the high power consumption of a standard pulse radar. The systempsilas mode of operation is well-known. In this paper we present a detailed derivation and discussion of the resulting intermediate frequency (IF) signal model. Furthermore, a derivation and comparison of the best possible round-trip delay time (RTDT) respectively range estimation variances using FMCW, standard pulse, and the advanced pulse radar concept is given by means of the corresponding Cramer-Rao lower bounds (CRLBs). Asymptotically optimal and suboptimal estimators are derived and compared regarding their range estimation variance, threshold level, and computational complexity. Simulation and measurement results show the applicability of the derived bounds and estimators in practice.