ABSTRACT Time difference of arrival (TDOA) estimation is a critical parameter estimation stage of TDOA localisation in wireless monitoring networks, and its result directly determines the positioning accuracy of the signal source. However, the existing TDOA estimation methods based on orthogonal matching pursuit (OMP) only consider the scenario of circular signal and are prone to the degradation of estimation performance due to atom misselection under small samples and low signal‐to‐noise ratio (SNR). To address this issue, this paper proposes a loop matching pursuit multistation TDOA estimation algorithm based on noncircular signal. Firstly, by combining the noncircular characteristic of the radiation source signal, an extended data model is constructed by using multistation received data and their conjugate. Then, based on the time‐domain sparsity of the time difference, an extended time‐domain dictionary set is built by discretising the time grid. In addition, the support set is optimised via atom loop deletion and addition to reconstruct the sparse coefficients. Finally, the TDOA estimation is obtained from the correspondence between the time difference value and the sparse coefficient. Furthermore, the Cramer–Rao bound (CRB) for TDOA estimation of a noncircular source is derived, thereby providing a quantitative theoretical lower bound for the estimation accuracy of the new algorithm. The simulation experiment results verify the superiority of the proposed algorithm under small samples and low SNR.
Wang et al. (Thu,) studied this question.