An electronic device includes a transmission antenna, a plurality of reception antenna arrays, and a signal processor. The transmission antenna transmits a transmission wave. Each of the plurality of reception antenna arrays includes a plurality of reception antennas each configured to receive a reflected wave. The reflected wave is the transmission wave having been reflected. The signal processor detects, based on a transmission signal transmitted as the transmission wave and a reception signal received as the reflected wave, displacement of a subject reflecting the transmission wave. The plurality of reception antenna arrays is arranged in different orientations from one another. The signal processor synthesizes the displacement of the subject detected by each of the plurality of reception antenna arrays.

A radar system includes a set of transmitters and a processor coupled to the set of transmitters, which includes first, second, third and fourth transmitters. In operation, the processor generates a first chirp of a set of chirps, in which outputs of the first and second transmitters are modulated by a first phase and outputs of the third and fourth transmitters are modulated by a second phase; and generate a second chirp of the set of chirps, in which outputs of the first and fourth transmitters are modulated by the first phase and outputs of the second and third transmitters are modulated by the second phase.

Techniques and apparatuses are described that implement a smart-device-based radar system capable of performing location tagging. The radar system has sufficient spatial resolution to recognize different external environments associated with different locations (e.g., recognize different rooms or different locations within a same room). Using the radar system, the smart device can achieve spatial awareness and automatically activate user-programmed applications or settings associated with the different locations. In this way, the radar system enables the smart device to provide a location-specific shortcut for various applications or settings. With the location-specific shortcut, the smart device can improve the user's experience and reduce the need to repeatedly navigate cumbersome interfaces.

A method in an illustrative embodiment includes determining that a first object authenticated by an electronic device is accessing the electronic device. The method further includes, in response to a second object being detected within a detection range using a radar of the electronic device, determining, based on a detected signal, that the second object is a person. The method further includes determining a distance and an angle between the second object and the electronic device based on an azimuth signal in the detected signal. The method further includes in response to determining that the distance is less than a distance threshold and the angle is less than an angle threshold, determining, based on the biological feature signal, whether the second object is trustworthy. The method further includes deauthenticating the first object in response to determining that the second object is untrustworthy.

A method for detecting an object, comprising the steps of defining expected characteristics of scattered electromagnetic radiation to be received at a receiver; attenuating at least a portion of electromagnetic radiation received at the receiver by a presence of an object within a path of electromagnetic information; and detecting the attenuation to indicate a presence of the object. The object may be a low radar profile object, such as a stealth aircraft. The electromagnetic radiation is preferably microwave, but may also be radio frequency or infrared. By using triangulation and other geometric techniques, distance and position of the object may be computed.

A target object detecting device including first and second transmission signal generators, a wave transmitting array, first and second switches, and a controller is disclosed. The first and second transmission signal generators generate first and second transmission signals, respectively. The wave transmitting array has a plurality of wave transmitting elements which convert the first and second transmission signals into transmission waves. The first switch supplies the first transmission signal to one of the wave transmitting elements. The second switch supplies the second transmission signal to one of the wave transmitting elements. The controller performs a control in which the first switch switches the wave transmitting element to which the first transmission signal is supplied, from an element n to an element n+1, and the second switch switches the wave transmitting element to which the second transmission signal is supplied, from an element m to an element m+1.

In an embodiment, a method includes: receiving a range-Doppler image (RDI) based on raw data from a radar sensor; performing moving target indication (MTI) filtering on the RDI to generate a first filtered radar image; performing constant false alarm rate (CFAR) detection on the first filtered radar image to generate a second filtered radar image; performing minimum variance distortionless response (MVDR) beamforming on the second filtered radar image to generate a range-angle image (RAI); performing CFAR detection on the RAI to generate a third filtered radar image; generating a point set based on the third filtered radar image; clustering targets of the point set; and tracking at least one of the clustered targets using a Kalman filter.

A system is disclosed. The system may include a receiver or transmitter node. The receiver or transmitter node may include a communications interface with an antenna element and a controller. The controller may include one or more processors and have information of own node velocity and own node orientation relative to a common reference frame. The receiver or transmitter node may be time synchronized to apply Doppler corrections to signals, the Doppler corrections associated with the receiver or transmitter node's own motions relative to the common reference frame, the Doppler corrections applied using Doppler null steering along Null directions. The receiver node is configured to determine a bearing angle based on the signals based on Doppler null steering; and to determine a range based on two-way time-of-flight based ranging signals.

A radar system comprises a plurality of transmit antennas that transmit a radar signal toward a target, wherein each transmit antenna transmits its signal using a different space-time block code in a given transmission time slot. In one embodiment, no two transmit antennas transmit using the same space-time block code in the same transmission time slot.

A method for target detection in a DDM radar sensor having a number N.sub.TX of transmission antennas Tx and a number N.sub.Slots>N.sub.TX of DDM slots, the assignment of which to transmission antennas is determined by a DDM code. The method includes: calculating a range-Doppler matrix, which is divided in the Doppler dimension into N.sub.Slots ambiguity zones; converting the range-Doppler matrix into a three-dimensional range-Doppler ambiguity matrix by converting the range-Doppler matrix into a three-dimensional range-Doppler ambiguity matrix by non-coherent cyclic discrete convolution with the DDM code; and target detection by cell-by-cell comparison of the range-Doppler ambiguity matrix (34) with a threshold matrix.