Sparse FDA-MIMO Design for Target Localization

Multiple input multiple output (MIMO) radar with frequency diverse array (FDA-MIMO) is capable of providing both the angle and range information of targets. To extend aperture while reducing interelement mutual coupling and system cost, a sparse FDA-MIMO is designed with which closed-form angle estimation can be fulfilled. If the transmit and receive arrays have the same geometry, the virtual aperture at an optimized frequency shift can be four times that of the physical transmit/receive array. To implement closed-form initial range estimation, non-uniform frequency increments have also been designed from the perspective of co-frequency. The uniform degree of freedom (uDOF) of the virtual frequency increment set can be larger than the element number of the transmit/receive array. With paired angle and range estimates, improved range re-estimation is further realized in a computationally efficient way. Simulation results have validated the efficacy of the sparse FDA-MIMO based angle and range estimation, in terms of accuracy and computational efficiency.