The size of over complete dictionary seriously affects the computing speed of on-grid sparse algorithm. In the case of multi parameter estimation, to ensure accuracy of result, the required dictionary size will increase explosively by multiplication. Therefore, it is infeasible to estimate all parameters directly by on-grid methods. In this paper, the feasible sparse spectrum fitting (SpSF) algorithm for joint direction of arrival (DOA) and range estimation in collocated FDA-MIMO radar is introduced. Firstly, due to fact that receive spatial frequency only depends on angle, by reshaping data in receive spatial frequency domain for DOA estimation, a covariance fitting technique for data preprocessing is adopt and obtained DOA by SpSF. Next, range is calculated in transmit-receive spatial frequency domain by SpSF. In addition, to speed up computation with the increase of the targets, a high-speed method by replacing convex optimization with one-dimensional peak search approximation is proposed. Finally, several numerical simulations are carried out to verify the effectiveness of the proposed approach.

DOA-range estimation; FDA-MIMO; SpSF; high-speed