The invention discloses an underdetermined DOA
estimation method based on target space diversity, and aims at LFMCW
system radar. The method comprises the following steps: carrying out two-dimensionalFFT on each path of array antenna receiving
signal by utilizing the characteristics of an LFMCW
system radar; selecting one path of
signal to carry out two-dimensional
constant false alarm rate CFARdetection so as to acquire distance and speed information of the target; wherein each path of
signal is divided into target subspaces according to the distribution of a target in a distance-speed space; and finally, performing DOA
estimation on each target subspace. By means of the characteristics of the LFMCW
radar, diversity is conducted on incident target signals in the distance-speed space, more target DOAs can be estimated when the number of array elements is fixed, the overall performance of the array is improved, and distance-speed-angle joint positioning of targets can be achieved. Themethod is high in angle
measurement precision, good in anti-
noise performance, suitable for various array structures, simple, easy to operate and convenient for
engineering practical application.