Techniques and apparatuses are described that implement a smart-device-based radar system capable of detecting a frame-of-reference change. In particular, a radar system includes a frame-of-reference machine-learned module trained to recognize whether or not the radar system's frame of reference changes. The frame-of-reference machine-learned module analyzes complex radar data generated from at least one chirp of a reflected radar signal to analyze a relative motion of at least one object over time. By analyzing the complex radar data directly using machine learning, the radar system can operate as a motion sensor without relying on non-radar-based sensors, such as gyroscopes, inertial sensors, or accelerometers. With knowledge of whether the frame-of-reference is stationary or moving, the radar system can determine whether or not a gesture is likely to occur and, in some cases, compensate for the relative motion of the radar system itself.

This disclosure introduces a mapping for creating good Doppler detection capable radar codes. The mapping transfers an existing digital radar code to the warped frequency domain by expressing the code elements as magnitudes and phases of selected frequencies. These frequencies are equispaced in the warped frequency domain to preserve the code's sidelobes after mapping. The frequency warping function may convert the multiplicative Doppler shift into an additive shift of the code pattern in the warped frequency domain, which allows Doppler shift detection.

This disclosure introduces a mapping for creating good Doppler detection capable radar codes. The mapping transfers an existing digital radar code to the warped frequency domain by expressing the code elements as magnitudes and phases of selected frequencies. These frequencies are equispaced in the warped frequency domain to preserve the code's sidelobes after mapping. The frequency warping function may convert the multiplicative Doppler shift into an additive shift of the code pattern in the warped frequency domain, which allows Doppler shift detection.

Disclosed are methods and systems for detecting vital signs of occupants in vehicles, for example, the vehicle cabin. A signal unit transmits a radar signal to the occupant and receiving the radar signal reflected from the occupant. The reflected radar signal is analyzed with respect to vibration data of the vehicle, to produce a modified signal. The modified signal is analyzed to determine the vital signs of the occupant.

Disclosed are methods and systems for detecting vital signs of occupants in vehicles, for example, the vehicle cabin. A signal unit transmits a radar signal to the occupant and receiving the radar signal reflected from the occupant. The reflected radar signal is analyzed with respect to vibration data of the vehicle, to produce a modified signal. The modified signal is analyzed to determine the vital signs of the occupant.

Methods and systems for monitoring blood pressure in a person are disclosed. A method for monitoring a blood pressure in a person involves transmitting millimeter range radio waves over a three-dimensional (3D) space below the skin surface of a person, receiving radio waves on multiple receive antennas, the received radio waves including a reflected portion of the transmitted radio waves that is reflected by blood in a blood vessel in the 3D space, isolating a signal that corresponds to the portion of the transmitted radio waves that is reflected by blood in the blood vessel in response to receiving the radio waves on the multiple receive antennas, and outputting a signal that corresponds to a blood pressure level in the person in response to the isolated signal.

Methods and systems for monitoring blood pressure in a person are disclosed. A method for monitoring a blood pressure in a person involves transmitting millimeter range radio waves over a three-dimensional (3D) space below the skin surface of a person, receiving radio waves on multiple receive antennas, the received radio waves including a reflected portion of the transmitted radio waves that is reflected by blood in a blood vessel in the 3D space, isolating a signal that corresponds to the portion of the transmitted radio waves that is reflected by blood in the blood vessel in response to receiving the radio waves on the multiple receive antennas, and outputting a signal that corresponds to a blood pressure level in the person in response to the isolated signal.

Methods and systems for monitoring blood pressure in a person are disclosed. A method for monitoring a blood pressure in a person involves transmitting millimeter range radio waves over a three-dimensional (3D) space below the skin surface of a person, receiving radio waves on multiple receive antennas, the received radio waves including a reflected portion of the transmitted radio waves that is reflected by blood in a blood vessel in the 3D space, isolating a signal that corresponds to the portion of the transmitted radio waves that is reflected by blood in the blood vessel in response to receiving the radio waves on the multiple receive antennas, and outputting a signal that corresponds to a blood pressure level in the person in response to the isolated signal.

Methods and systems for monitoring blood pressure in a person are disclosed. A method for monitoring a blood pressure in a person involves transmitting millimeter range radio waves over a three-dimensional (3D) space below the skin surface of a person, receiving radio waves on multiple receive antennas, the received radio waves including a reflected portion of the transmitted radio waves that is reflected by blood in a blood vessel in the 3D space, isolating a signal that corresponds to the portion of the transmitted radio waves that is reflected by blood in the blood vessel in response to receiving the radio waves on the multiple receive antennas, and outputting a signal that corresponds to a blood pressure level in the person in response to the isolated signal.

A method is disclosed for suppressing sidelobes due to artifacts introduced by FFT operations during automotive radar signal processing. Sidelobes of a stronger target from the FFT operations may bury the response from a weaker target when there are multiple targets. The method estimates the sidelobes of an identified target from a measured FFT response and subtracts the estimated sidelobes from the measured FFT response. The identified target may be the strongest target from the measured FFT response. The method estimates the sidelobes to suppress the sidelobes with respect to the peak signal of the identified target. After the estimated sidelobes of the identified target are removed, the updated FFT response may reveal other targets that had been buried. The method may identify additional targets to estimate their sidelobes and may iteratively remove the estimated sidelobes of additional targets from the FFT until a desired sidelobe residual level is achieved.