Mixed far-field and near-field source localization based on subarray cross-cumulant

This paper presents a new algorithm for mixed far-field and near-field source localization using a uniform linear array (ULA). Firstly, the ULA is divided into two overlapping subarrays to construct two special cross-cumulant matrices of the subarray outputs, which are only characterized by directions-of-arrival (DOAs) of the sources. Then, the shift invariance structure in the cumulant domain is derived, and the DOAs of all sources are estimated by the TLS-ESPRIT method. Finally, with the estimated DOAs, the range estimates of near-field sources are obtained via one-dimensional search, and the types of sources are also distinguished. The developed algorithm involves neither DOA search nor parameter pairing. Furthermore, it exhibits a higher localization accuracy than the traditional methods. Simulation results are presented to demonstrate the performance of the proposed algorithm.