An apparatus comprising a processor configured to: receive an input dataset indicative of radar signals received at a plurality of antenna elements from a plurality of targets; define a matrix, Ã, of direction-of-arrival-angle vectors representing an expected response of the radar signals from the target and comprising a function of a direction of arrival angle relative to the antenna elements and including antenna-imperfection-factors that represent the angle dependent effect of antenna imperfections; define an objective function based on the input dataset and the matrix; search for a set of the direction 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, wherein said set is derived from one of the candidate matrices of the plurality of candidate matrices that provides a maximum or minimum evaluation of the objective function.

A direction of arrival estimation apparatus includes at least first and second sub-arrays to receive a reflected wave of a transmission waveform from a target; first and second phasing parts that perform phasing of reception signals at the first and second sub-arrays to generate first and second sub-array beams; an arrival time difference calculation part that calculates first and second correlations of the reception signals of the first and second sub-array beams at first and second time points to find an arrival time difference between times of the reflected wave arriving at the first and second sub-arrays, based on a result of a predetermined operation on the first and second correlations and a time difference between the first time point and the second time point; and a direction of arrival calculation part that finds a direction of arrival of the target based on the arrival time difference.

A direction of arrival estimation apparatus includes at least first and second sub-arrays to receive a reflected wave of a transmission waveform from a target; first and second phasing parts that perform phasing of reception signals at the first and second sub-arrays to generate first and second sub-array beams; an arrival time difference calculation part that calculates first and second correlations of the reception signals of the first and second sub-array beams at first and second time points to find an arrival time difference between times of the reflected wave arriving at the first and second sub-arrays, based on a result of a predetermined operation on the first and second correlations and a time difference between the first time point and the second time point; and a direction of arrival calculation part that finds a direction of arrival of the target based on the arrival time difference.

This document describes techniques and systems for radar-based gesture-recognition with context-sensitive gating and other context-sensitive controls. Sensor data from a proximity sensor (108) and/or a movement sensor (108) produces a context of a user equipment (102). The techniques and systems enable the user equipment (102) to recognize contexts when a radar system (104) can be unreliable and should not be used for gesture-recognition, enabling the user equipment (102) to automatically disable or “gate” the output from the radar system (104) according to context. The user equipment (102) prevents the radar system (104) from transitioning to a high-power state (1910) to perform gesture-recognition in contexts where radar data detected by the radar system (104) is likely due to unintentional input. By so doing, the techniques conserve power, improve accuracy, or reduce latency relative to many common techniques and systems for radar-based gesture-recognition.

This document describes techniques and systems for radar-based gesture-recognition with context-sensitive gating and other context-sensitive controls. Sensor data from a proximity sensor (108) and/or a movement sensor (108) produces a context of a user equipment (102). The techniques and systems enable the user equipment (102) to recognize contexts when a radar system (104) can be unreliable and should not be used for gesture-recognition, enabling the user equipment (102) to automatically disable or “gate” the output from the radar system (104) according to context. The user equipment (102) prevents the radar system (104) from transitioning to a high-power state (1910) to perform gesture-recognition in contexts where radar data detected by the radar system (104) is likely due to unintentional input. By so doing, the techniques conserve power, improve accuracy, or reduce latency relative to many common techniques and systems for radar-based gesture-recognition.

Techniques for diagnosing and disambiguating a bias in one or more axels of a bidirectional four-wheel drive vehicle. In some examples, the diagnostics system may diagnose and disambiguate the bias in the two axles by collecting data related to the movement of the vehicle while the vehicle traverses a zero curvature path in a forward direction. The diagnostics system may then determine a bias in an axle acting as the rear axle based on the collected data. The bias in the axle acting as the front axle may then be determined based on the collected data and the bias in the rear axle.

Techniques for diagnosing and disambiguating a bias in one or more axels of a bidirectional four-wheel drive vehicle. In some examples, the diagnostics system may diagnose and disambiguate the bias in the two axles by collecting data related to the movement of the vehicle while the vehicle traverses a zero curvature path in a forward direction. The diagnostics system may then determine a bias in an axle acting as the rear axle based on the collected data. The bias in the axle acting as the front axle may then be determined based on the collected data and the bias in the rear axle.

A method by which a transmission terminal transmits a signal in an optical wireless communication system can comprise: transmitting a first optical signal including a reference signal to a reception terminal having established a communication link with the transmission terminal; receiving feedback information about the first optical signal from the reception terminal; and transmitting a second optical signal to the reception terminal on the basis of the feedback information, wherein an orbital angular momentum (OAM) mode of the second optical signal can be selected on the basis of the feedback information.

A method by which a transmission terminal transmits a signal in an optical wireless communication system can comprise: transmitting a first optical signal including a reference signal to a reception terminal having established a communication link with the transmission terminal; receiving feedback information about the first optical signal from the reception terminal; and transmitting a second optical signal to the reception terminal on the basis of the feedback information, wherein an orbital angular momentum (OAM) mode of the second optical signal can be selected on the basis of the feedback information.

A self-location estimation device includes a landmark detection unit that detects a landmark from camera information, an association unit that associates the landmark detected by the landmark detection unit with a radar information group, a landmark sorting unit that performs sorting of the landmarks detected by the landmark detection unit based on the radar information groups associated with the landmarks by the association unit, and a positional relation calculation unit that calculates a positional relation between an own vehicle and the landmark employed by the landmark sorting unit, based on the radar information group associated with the landmark.