Two-dimensional DOA estimation is challenging as the computational and hardware complexity could scale as the square as compared to that of one-dimensional problem. The proposed scheme relies on designing antenna locations and also involves a mix of subarray and digital beamforming to lower the overall system performance and cost by reducing the costly transceiver chains.

This framework proposes a two-step solution which first isolates a target to a given range doppler bin and elevation angle by linear receive subarray in the elevation direction. However, the elevation estimate is relatively coarse which is further refined along with a high-resolution estimate of azimuth angle. This is achieved by processing the received data from a 2D sparse antenna array, which are systematically chosen to maximize the resolution in both directions. The compressive sensing algorithm is applied to the 2D sparse received array data which exploits the sparse representation of the underlying signal support. The propose approach successfully pairs the correct elevation and azimuth angles for multiple targets. The methodology is effective for a case of single data snapshot and algorithm performance scale well with the availability of multiple data snapshots. It is noted that the proposed methodology allows to further increase the system resolution when data is processed with MIMO virtual array processing.

Provided is an array antenna divided into a plurality of sub-arrays disposed along a first dimension, wherein each sub-array comprises: a plurality of frequency scannable elements disposed along the first dimension and a plurality of phase shifters or transmit/receive (T/R) modules disposed along a second spatial dimension, each phase shifter or T/R module connected to a plurality of frequency scannable elements disposed along the first spatial dimension; and one or more processors being configured to generate a recurring radar waveform having a transmit portion, the transmit portion having multiple successive pulses at different frequencies to generate transmit beams by the array antenna at different angles in the first dimension; control at least one of the plurality of phase shifters or T/R modules along the second dimension to cause the transmit beams to be generated by the array antenna at different angles in the second dimension; and process return signals received by the plurality of sub-arrays to estimate a target location.

Disclosed is a compact integrated apparatus of an interferometric radar altimeter (IRA) and a radar altimeter (RA) capable of performing individual missions by altitude, which includes: a plurality of antennas; a signal processing control unit selecting an RA mode at a low altitude and selecting an IRA mode at a high altitude based on a mode threshold and selecting an FMCW waveform at the low altitude and selecting an FM pulse waveform at the high altitude based on a waveform threshold; and a transceiving unit transmitting a signal by a first antenna positioned at an outermost portion among the plurality of antennas and receiving a signal by an nth antenna positioned at another outermost portion among the plurality of antennas in the RA mode and transmitting a signal through the first antenna and receiving signals through the plurality of antennas in the IRA mode.

A vehicle control system may include a controller that detects an object outside a vehicle, calculates an angle based on a ratio of a relative speed between the object and the vehicle to a speed of the vehicle, and updates a phase curve reflecting a phase distortion of an input signal based on the calculated angle.

A method for a radar sensor, in particular a radar sensor for motor vehicles. The method includes the steps: determining, for particular evaluation channels that correspond to different central antenna positions of relevant transmitting antennas and receiving antennas in one direction, and for particular individual radar targets, a respective individual radial velocity of the particular radar target associated with the particular evaluation channel, based on signals obtained in respective evaluation channels; estimating a particular velocity of the particular radar target based on the determined individual radial velocities of the radar target, the velocity including information concerning a velocity in the forward direction in relation to the radar sensor, and a tangential velocity; and associating radar targets as belonging to an extended radar object as a function of the estimated velocities of the radar targets. A radar sensor is also described.

A method of identifying item selection by a user, the method comprising: receiving signals at a receiver of a fixed terminal from a transmitter of a mobile terminal associated with the user, generating a signature at the receiver of the fixed terminal of the movement of the user based on changes in the signals received from the transmitter, matching the signature with prior stored movement information to determine the movement of the user, and identifying the item being selected by the user based on the determined movement of the user.

Aspects of the present disclosure are directed to radar and radar processing. As may be implemented in accordance with one or more embodiments involving multi-input multi-output (MIMO) co-prime radar signals transmitted by a plurality of transmitters and reflected from at least one target, the reflected radar signals are processed by resolving ambiguities associated with a range-Doppler detection based on unique pulse repetition frequencies (PRF)s associated with respective chirp groups of the reflected radar signals. Phase compensation is applied to compensate for motion-induced phased biases and, thereafter, Doppler estimates are reconstructed to provide a dealiased version of the reflected radar signals.

A mechanism is provided for determining an unambiguous direction of arrival (DoA) for radio frequency (RF) signals received by a sparse array. A DoA angle domain is split into hypothesis regions. The hypothesis regions are derived from the phase differences of the antenna element pairs used for the DoA angle estimate. In each hypothesis region, the ambiguous phase of antenna element pairs is unwrapped according to expected wrap-around. After unwrapping the phase, for each hypothesis region, a phasor is calculated by combining the individual antenna element pair phasors. The hypothesis region that obtains the phasor with a largest amplitude is selected as the most likely DoA region and the phase of the winning phasor is used as an unambiguous estimate for the DoA angle.

An angle-resolving radar sensor for motor vehicles, having an antenna system having a plurality of antennas set up for receiving, configured in various positions in a direction in which the radar sensor is angle-resolving, and having a control and evaluation device designed for an operating mode in which at least one antenna of the radar sensor that is set up for transmitting sends out a signal that is received by a plurality of the antennas of the radar sensor that are set up to receive, the control and evaluation device being designed, in the mentioned operating mode, for an individual estimation of an angle of a radar target to determine respective individual distances of the radar target for each of the evaluation channels, which correspond to different configurations of transmitting and receiving antennas, and to use the individual distances in the estimation of the angle of the radar target.

The present invention minimizes the overall area occupied by a reception antenna while preventing erroneous detections resulting from azimuth aliasing. A reception antenna includes antenna elements that are disposed along the horizontal direction, antenna elements that are disposed along the vertical direction, and an antenna element that is disposed at an angle from the antenna elements with respect to the horizontal direction and is disposed at an angle from the antenna elements with respect to the vertical direction. The distance between the centers of the antenna elements in the horizontal direction differs from the distances between the center of the antenna element and the respective centers of the antenna elements in the horizontal direction. The distance between the centers of the antenna elements in the vertical direction differs from the distances between the center of the antenna element and the respective centers of the antenna elements in the vertical direction.