FDA-MIMO Radar With Long-Baseline Transmit Array Using ESPRIT

The frequency diverse array (FDA) multiple-input multiple-output (MIMO) radar combined with long-baseline transmit array (LBTA-FDA-MIMO) is presented for high accuracy direction-of-arrival (DOA) estimation, and the transmit array is designed in the form of a four-antenna interferometer in this letter. However, the ambiguities of both angle and range exist at the same time. To deal with this problem, a joint-disambiguation method based on ESPRIT is proposed and the uniqueness theorem is proved. The main idea of this method is that the unambiguous-rough-estimation for angle is used to solve the ambiguities of fine-estimation expressions coupled with angle and range. Compared with FDA-MIMO radar, the LBTA-FDA-MIMO radar significantly improves the angle estimation accuracy, and interestingly, it also improves the ranging accuracy via simulations.