Moving target localization in passive distributed MIMO radar systems with unknown transmitter positions

This paper investigates the problem of moving target localization in passive distributed multiple-input multiple-output (MIMO) radar systems with unknown transmitter positions. Using the angle of arrival (AOA), differential time delay (DTD) and differential frequency shift (DFS) measurements, an efficient localization method is proposed to jointly estimate the positions and velocities of the target and the transmitters. The proposed method provides a closed-form solution without requiring precise time synchronization or the transmission of raw signals among receivers. Theoretical analysis shows that introducing DFS measurements can improve position estimation accuracy and that increasing the number of transmitters further enhances target localization performance. Moreover, this method is proven to achieve the Cram$\acute{\text{e}}$r–Rao lower bound (CRLB) accuracy under small error conditions. Simulation results validate the theoretical development and show that the proposed method outperforms the existing methods.