Radio frequency motion sensors may be configured for operation in a common vicinity so as to reduce interference. In some versions, interference may be reduced by timing and/or frequency synchronization. In some versions, a master radio frequency motion sensor may transmit a first radio frequency (RF) signal. A slave radio frequency motion sensor may determine a second radio frequency signal which minimizes interference with the first RF frequency. In some versions, interference may be reduced with additional transmission adjustments such as pulse width reduction or frequency and/or timing dithering differences. In some versions, apparatus may be configured with multiple sensors in a configuration to emit the radio frequency signals in different directions to mitigate interference between emitted pulses from the radio frequency motion sensors.

This document describes techniques and systems for generating a fused object bounding box based on uncertainty. At least two bounding boxes, each associated with a different sensor, is generated. A fused center point and yaw angle as well as length, width, and velocity can be found by mixing the distributions of the parameters from each bounding box. A discrepancy between the center points of each bounding box can be used to determine whether to refine the fused bounding box (e.g., find an intersection between at least two bounding boxes) or consolidate the fused bounding box (e.g., find a union between at least two bounding boxes). This results in the fused bounding box having a confidence level of the uncertainty associated with the fused bounding box. In this manner, better estimations of the uncertainty of the fused bounding box may be achieved to improve tracking performance of a sensor fusion system.

A SIL monopulse radar includes a self-injection-locking oscillator (SILO), a transmit antenna, two receive antennas, a hybrid coupler, a first demodulator, a second demodulator and a processor. The transmit antenna transmits the oscillation signal of the SILO to object. The two receive antennas receive a reflected signal from the object as a first echo signal and a second echo signal. The hybrid coupler outputs a difference signal and a sum signal. The difference signal is injected into the SILO. The first demodulator frequency-demodulates the oscillation signal to produce a first demodulated signal. The second demodulator phase-demodulates the sum signal by using the oscillation signal as a reference signal to produce a second demodulated signal. The processor processes the first and second demodulated signals to produce a monopulse ratio signal. The SIL monopulse radar can identify the posture and motion of a human body by analyzing the monopulse ratio signal.

A method for measuring a high-accuracy and real-time heart rate based on a continuous-wave radar is provided. The method includes receiving an in-phase (I) signal and a quadrature (Q) signal for a receive signal received through the continuous-wave radar, selecting any one signal by comparing magnitudes of the received I signal and the received Q signal, performing frequency transform of each of bases respectively having predetermined phases with respect to the any one selected signal, and determining a heart rate based on a magnitude response of each of the bases by the frequency transform.

A method for real-time THz sensing using true time delay (TTD) is implemented by a base station and includes transmitting, by a transceiver that includes TDD elements and phase shifters configured in the transceiver, simultaneous frequency dependent (SFD) beams to scan an environment at a first granularity to detect a spatial cluster target. Each of the SFD beams corresponds to a different phase angle and different frequency. The method includes determining, among the SFD beams, a subset of beams that detected the spatial cluster target. The method includes beam switching, by the transceiver, using time division multiplexing (TDM) and a TDM bandwidth to scan a portion of the environment at phase angles corresponding to the subset of beams and at a second granularity finer than the first granularity. The method includes combining data received from the SFD beams, by multiple threads that concurrently process data received from the SFD beams.

An estimating method includes: measuring and receiving reception signals including a reflected signal reflected by a moving body, for a first period equivalent to a cycle of movement of the moving body; calculating first complex transfer functions indicating propagation characteristics, from the reception signals measured in the first period; calculating second complex transfer functions having reduced components corresponding to fluctuations, from the first complex transfer functions; extracting moving body information corresponding to a component related to the moving body by extracting moving body information corresponding to a predetermined frequency range of the second complex transfer functions calculated; and estimating a direction in which the moving body is present using the moving body information.

Various arrangements for performing fall detection are presented. A smart-home device (110, 201), comprising a monolithic radar integrated circuit (205), may transmit radar waves. Based on reflected radar waves, raw waveform data may be created. The raw waveform data may be processed to determine that a fall by a person (101) has occurred. Speech may then be output announcing that the fall has been detected via the speaker (217) of the smart home device (110, 201).

Various arrangements for performing ballistocardiography using a mobile device are presented. A radar integrated circuit of a mobile device may emit frequency-modulated continuous-wave (FMCW) radar. Reflected radio waves based on the FMCW radar being reflected off objects may be received and used to create a raw radar waterfall. The raw radar waterfall may be analyzed to create a ballistocardiography waveform. Data based on the ballistocardiography waveform may be output, such as to a machine-learning application installed on the mobile device.

A system for providing contactless movement of a vehicle door relative to a vehicle body including an electric-motor movement device for moving the vehicle door, a radar sensor system for detecting, in the region of the vehicle door, a gesture to be performed by a user, and a control device for controlling the movement device according to a detection by the radar sensor system. The radar sensor system is configured to detect, in a first operating mode, a movement in a detection region in an environment of the vehicle door and to detect, in a second operating mode, a gesture for moving the vehicle door, the radar sensor system being configured to switch to the second operating mode when a movement is detected in the first operating mode.

Methods and systems for remote sleep monitoring are provided. Such methods and systems provide non-contact sleep monitoring via remote sensing or radar sensors. In this regard, when processing backscattered radar signals from a sleeping subject on a normal mattress, a breathing motion magnification effect is observed from mattress surface displacement due to human respiratory activity. This undesirable motion artifact causes existing approaches for accurate heart-rate estimation to fail. Embodiments of the present disclosure use a novel active motion suppression technique to deal with this problem by intelligently selecting a slow-time series from multiple ranges and examining a corresponding phase difference. This approach facilitates improved sleep monitoring, where one or more subjects can be remotely monitored during an evaluation period (which corresponds to an expected sleep cycle).