Radar system to universally detect direction-of-arrival or direction-of-departure angles in direct-path and multipath reflection conditions

A Non-transitory computer-readable storage media comprising computer-executable instructions that, when executed, cause a processor of a radar system to:

• transmit, through a transmitter array of the radar system, electromagnetic (EM) energy, the transmitter array having a first quantity of antenna elements;
• receive, from a receiver array of the radar system, EM energy reflected by one or more objects, the receiver array having a second quantity of antenna elements, the first quantity being equal to or different than the second quantity, a first array of the transmitter array or the receiver array being a sparse array without angle ambiguity within a field-of-view of the first array, a second array of the transmitter array or the receiver array being a sparse uniform linear array;
• generate, using data samples of the EM energy received at the receiver array, a two-dimensional (2D) data matrix having a quantity of rows equal to a quantity of antenna elements for the first array and a quantity of columns equal to a quantity of antenna elements for the second array;
• determine, using data in the 2D data matrix associated with the second array, estimated angles associated with radar detections of the one or more objects, the estimated angles including one or more aliased angles and one or more actual angles associated with the radar detections, the radar detections corresponding to direct-path or multipath reflections of the EM energy by the one or more objects;
• determine a third quantity of the actual angles associated with the radar detections, the third quantity being smaller than or equal to a fourth quantity of the estimated angles;
• identify, among the estimated angles, multiple potential sets of actual angles, each respective potential set of actual angles having the third quantity of estimated angles and being different from each other potential set of actual angles;
• determine utility function values associated with the multiple potential sets of actual angles by testing, using the data in the 2D data matrix associated with the first array, each respective potential set of actual angles under a maximum likelihood criterion;
• and
• determine the actual angles associated with the radar detections as a respective set of actual angles with a maximum utility function value among the utility function values.

A method comprising:

• transmitting, through a transmitter array of the radar system, electromagnetic (EM) energy, the transmitter array having a first quantity of antenna elements;
• receiving, from a receiver array of the radar system, EM energy reflected by one or more objects, the receiver array having a second quantity of antenna elements, the first quantity being equal to or different than the second quantity, a first array of the transmitter array or the receiver array being a sparse array without angle ambiguity within a field-of-view of the first array, a second array of the transmitter array or the receiver array being a sparse uniform linear array;
• generating, using data samples of the EM energy received at the receiver array, a two-dimensional (2D) data matrix having a quantity of rows equal to a quantity of antenna elements for the first array and a quantity of columns equal to a quantity of antenna elements for the second array;
• determining, using data in the 2D data matrix associated with the second array, estimated angles associated with radar detections of the one or more objects, the estimated angles including one or more aliased angles and one or more actual angles associated with the radar detections, the radar detections corresponding to direct-path or multipath reflections of the EM energy by the one or more objects;
• determining a third quantity of the actual angles associated with the radar detections, the third quantity being smaller than or equal to a fourth quantity of the estimated angles;
• identifying, among the estimated angles, multiple potential sets of actual angles, each respective potential set of actual angles having the third quantity of estimated angles and being different from each other potential set of actual angles;
• determining utility function values associated with the multiple potential sets of actual angles by testing, using the data in the 2D data matrix associated with the first array, each respective potential set of actual angles under a maximum likelihood criterion;
• and
• determining the actual angles associated with the radar detections as a respective set of actual angles with a maximum utility function value among the utility function values.