Cramér-Rao lower bound for time reversal range estimators in N-multipath scattering environments

As an improvement to the conventional radar range estimation based on a single forward propagation of the probing signal, the paper presents a time reversal (TR) based range estimation technique for radar tracking applications and develops the Cramér-Rao lower bounds (CRLB) for the conventional and TR range estimators in an N-multipath scattering environment, where N may assume any value. The CRLBs quantify possible improvement offered by the TR range estimator over the conventional approach. Stronger secondary multipath improves the performance of the TR range estimator as its CRLB decreases with a higher number of multipaths.