Misspecified Cramér-Rao Bound for Terahertz Automotive Radar Range Estimation

High-resolution information about a host vehicle's surroundings is essential for autonomous driving and advanced driver assistance systems (ADAS). This requires radar systems with high-resolution range, Doppler, azimuth, and elevation capabilities. Terahertz (THz) frequency band radar systems could provide nearly-optical resolution while compact and lightweight. However, frequency-selective range-dependent attenuation of the THz propagation channel challenges the implementation of automotive radars at this frequency band. Estimating the parameters of the THz channel can be computationally complex. Therefore, a flat channel model is conventionally considered for the THz radar range estimator. This work investigates the influence of this assumption on the THz radar range performance estimation via the misspecified Cramér-Rao bound (MCRB). The ability of the proposed approach to evaluate the influence of the frequency-selective misspecification on the radar range estimation accuracy and detection range is evaluated via simulations.