Asymptotically Efficient Target Localization From Bistatic Range Measurements in Distributed MIMO Radars

In this letter, the problem of target localization from bistatic range (BR) measurements in distributed multiple-input multiple-output radar systems is investigated. By introducing nuisance parameters, a pseudolinear set of BR equations is established. Then, a closed-form localization algorithm is developed, based on this pseudolinear set of equations and multistage weighted least squares estimation. This solution is shown analytically to attain the Cramer-Rao lower bound under the small Gaussian noise assumption. Simulations are included to support the theoretical studies. Unlike the existing studies where the variance of BR measurements is assumed to be independent of the corresponding transmitter-to-target and target-to-receiver distances, we consider the more realistic distance-dependent noise model. The positioning accuracy of the proposed algorithm is shown to outperform the existing closed-form methods under this distance-dependent noise model.