Improved Algebraic Solution for Elliptic Localization in Distributed MIMO Radar

In this paper, the problem of locating a target in a distributed multiple-input multiple-output radar system using bistatic range measurements is addressed. An algebraic closed-form two-stage weighted least squares solution for the considered problem is developed and analyzed. In the first stage, we establish a set of linear equations by eliminating the nuisance parameters first and then we apply a weighted least squares estimator to determine the target position estimate. In the second stage, in order to improve the localization performance and refine the solution of the first stage, an estimate of the target position estimation error is obtained. The final solution is obtained by subtracting the solution of the second stage from the solution of the first stage. The Cramer-Rao lower bound (CRLB) for target localization accuracy is developed in the case of Gaussian distribution. The proposed method is shown to be an approximately unbiased estimator, which is able to attain the CRLB accuracy under small noise conditions. Numerical simulations are included to examine the algorithm's performance and corroborate the theoretical developments.