Radar system to jointly detect direction-of-arrival and direction-of-departure angles in multipath scenarios

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 transmitter array being a sparse uniform linear array, the receiver array being a sparse array without angle ambiguity within a field-of-view of the second array, and the receiver array being different than the transmitter array;
• generate, using the EM energy received at the receiver array, a two-dimensional (2D) data matrix, the 2D data matrix having the first quantity of rows and the second quantity of columns, a horizontal dimension of the 2D data matrix corresponding to a direction of arrival (DoA) angular phase for the one or more objects and a vertical dimension of the 2D data matrix corresponding to a direction-of-departure (DoD) angular phase for the one or more objects;
• determine, by performing one-dimensional (1D) angular phase estimation on the vertical dimension of the 2D data matrix, a DoD angular phase estimate and a DoD angle estimate corresponding to each object of the one or more objects;
• beamform, for each object of the one or more objects, the transmitter array to a corresponding DoD angular phase estimate of the DoD angular phase estimates and estimate a corresponding receiver-array vector by extracting a DoA measurement associated with a corresponding DoD angular phase estimate in one radar wave propagation path;
• determine, by performing 1 D angular phase estimation on the horizontal dimension of the 2D data matrix using the corresponding receiver-array vector, a DoA angular phase estimate and a DoA angle estimate corresponding to each object of the one or more objects;
• determine, for each object of the one or more objects, a matching error between the corresponding DoD angular phase estimate and the corresponding DoA angular phase estimate;
• for each object of the one or more objects and in response to the matching error being larger than a tolerance value, determine that a bistatic reflection condition exists and output the DoA angle estimate as a DoA angle for the corresponding object, the bistatic reflection condition corresponding to the DoA angular phase estimate not being approximately equal to the DoD angular phase estimate;
• and
• for each object of the one or more objects and in response to the matching error not being larger than the tolerance value, determine that a monostatic reflection condition exists and output the DoA angle estimate as the DoA angle for the corresponding object, the monostatic reflection condition corresponding to the DoD angular phase estimate being approximately equal to the DoA angular phase estimate.

A method comprising:

• transmitting, through a transmitter array of a 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 transmitter array being a sparse uniform linear array, the receiver array being a sparse array without angle ambiguity within a field-of-view of the receiver array, and the receiver array being different than the transmitter array;
• generating, using the EM energy received at the receiver array, a two-dimensional (2D) data matrix, the 2D data matrix having the first quantity of rows and the second quantity of columns, a horizontal dimension of the 2D data matrix corresponding to a direction of arrival (DoA) angular phase for the one or more objects, and a vertical dimension of the 2D data matrix corresponding to a direction-of-departure (DoD) angular phase for the one or more objects;
• determining, by performing one-dimensional (1D) angular phase estimation on the vertical dimension of the 2D data matrix, a DoD angular phase estimate and a DoD angle estimate corresponding to each object of the one or more objects;
• beamforming, for each object of the one or more objects, the transmitter array to a corresponding DoD angular phase estimate of the DoD angular phase estimates and estimate a corresponding receiver-array vector by extracting a DoA measurement associated with a corresponding DoD angular phase estimate in one radar wave propagation path;
• determining, by performing 1D angular phase estimation on the horizontal dimension of the 2D data matrix, using the corresponding receiver-array vector, a DoA angular phase estimate and a DoA angle estimate corresponding to each object of the one or more objects;
• determining, for each object of the one or more objects, a matching error between the corresponding DoD angular phase estimate and the corresponding DoA angular phase estimate;
• for each object of the one or more objects and in response to the matching error being larger than a tolerance value, determining that a bistatic reflection condition exists and outputting the DoA angle estimate as a DoA angle for the corresponding object, the bistatic reflection condition corresponding to the DoA angular phase estimate not being approximately equal to the DoD angular phase estimate;
• and
• for each object of the one or more objects and in response to the matching error not being larger than the tolerance value, determining that a monostatic reflection condition exists and outputting the DoA angle estimate as the DoA angle for the corresponding object, the monostatic reflection condition corresponding to the DoD angular phase estimate being approximately equal to the DoA angular phase estimate.