Cramer-Rao Performance Bounds for NLOS Target Localization Behind L-shaped Corner

Non-line-of-sight (NLOS) targets detection is a crucial concern in both military and civilian applications. Currently, NLOS detection technique is generally focused on utilizing the significant multipath information such as distance, angle, etc., to achieve target localization, which ignores the influence of the multipath number on target localization accuracy. In this paper, the Cramer-Rao Lower Bound (CRLB) for estimation of target position in L-shaped NLOS environment is derived. Specifically, first, the electromagnetic (EM) wave propagation model for the L-shaped scenario via unmanned aerial vehicles (UAV)-borne radar is established to analyse the relationship between the radar altitude and target position. According to the distance relation, the target position is estimated by least squares method. Then, the CRLB is utilized to evaluate the effect of different multipath numbers on target localization accuracy. Finally, several simulations are conducted to indicate that the number of multipath is positively correlated with the accuracy of target localization.