A radar sensing system for an autonomous driving vehicle (ADV) is disclosed. The system comprises a number of radar sensors operable to detect radio waves emitted from one or more objects in proximity of the ADV. Each of the radar sensors includes one or more antennas to receive the radio waves and to convert the radio waves into respective antenna output signals. The system further comprises a signal processor configured to determine a number of angles of arrival associated with the radio waves responsive to the antenna output signals, and to provide object location information based on the angles of arrival. The object location information includes a location of each of the one or more objects.