Method and apparatus for determination of direction of arrival angle

A method for determining the directions of arrival angles for each of a plurality of targets K in radar signals comprising:

• receiving, by way of a processor of a frequency-modulated-continuous-wave (FMCW) radar system, an input dataset, x, indicative of radar signals received at a plurality of antenna elements wherein the radar signals have reflected from a plurality of targets;
• defining, by way of the processor, a matrix, A, formed of direction-of-arrival-angle vectors, an, comprising one for each one of the plurality of targets, each direction-of-arrival-angle vector representing an expected response at the antenna elements of radar signals from the target with a predetermined amplitude and comprising a function of the direction of arrival angle relative to the plurality of antenna elements;
• defining, by way of the processor, a signal amplitude vector s to represent expected complex amplitudes of each of the plurality of targets as received in the radar signals;
• defining, by way of the processor, an objective function based on x, A and s;
• searching, by way of the processor, for a set of directions of arrival angles for each of the plurality of targets by the repeated evaluation of the objective function for a plurality of candidate matrices based on matrix A that each include different direction-of-arrival-angle vectors over a search space, wherein said set of directions of arrival angles are derived from one of the candidate matrices of the plurality of candidate matrices that provides one of a maximum and minimum evaluation of the objective function over the search space;
• and
• wherein said search space comprises a plurality of discrete points associated with the direction of arrival angles by a function comprising sin(θk), wherein θk represents the direction of arrival angle and wherein the distribution of the direction of arrival angles in the search space is non-uniform.