Abstract: Techniques and apparatuses are described that implement a smartphone-based radar system capable of detecting user gestures using coherent multi-look radar processing. Different approaches use a multi-look interferometer or a multi-look beamformer to coherently average multiple looks of a distributed target across two or more receive channels according to a window that spans one or more dimensions in time, range, or Doppler frequency. By coherently averaging the multiple looks, a radar system generates radar data with higher gain and less noise. This enables the radar system to achieve higher accuracies and be implemented within a variety of different devices. With these accuracies, the radar system can support a variety of different applications, including gesture recognition or presence detection.

Abstract: This document describes techniques and devices for type-agnostic radio frequency (RF) signal representations. These techniques and devices enable use of multiple different types of radar systems and fields through type-agnostic RF signal representations. By so doing, recognition and application-layer analysis can be independent of various radar parameters that differ between different radar systems and fields.

Abstract: This document describes apparatuses and techniques for radar-enabled sensor fusion. In some aspects, a radar field is provided and reflection signals that correspond to a target in the radar field are received. The reflection signals are transformed to provide radar data, from which a radar feature indicating a physical characteristic of the target is extracted. Based on the radar features, a sensor is activated to provide supplemental sensor data associated with the physical characteristic. The radar feature is then augmented with the supplemental sensor data to enhance the radar feature, such as by increasing an accuracy or resolution of the radar feature. By so doing, performance of sensor-based applications, which rely on the enhanced radar features, can be improved.

Abstract: This document describes apparatuses and techniques for radar-enabled sensor fusion. In some aspects, a radar field is provided and reflection signals that correspond to a target in the radar field are received. The reflection signals are transformed to provide radar data, from which a radar feature indicating a physical characteristic of the target is extracted. Based on the radar features, a sensor is activated to provide supplemental sensor data associated with the physical characteristic. The radar feature is then augmented with the supplemental sensor data to enhance the radar feature, such as by increasing an accuracy or resolution of the radar feature. By so doing, performance of sensor-based applications, which rely on the enhanced radar features, can be improved.

Abstract: This document describes techniques and devices for type-agnostic radio frequency (RF) signal representations. These techniques and devices enable use of multiple different types of radar systems and fields through type-agnostic RF signal representations. By so doing, recognition and application-layer analysis can be independent of various radar parameters that differ between different radar systems and fields.

Abstract: Techniques and apparatuses are described that enable radar attenuation mitigation. To improve radar performance, characteristics of an attenuator and/or properties of a radar signal are determined to reduce attenuation of the radar signal due to the attenuator and enable a radar system to detect a target located on an opposite side of the attenuator. These techniques are beneficial in situations in which the attenuator is unavoidably located between the radar system and a target, either due to integration within other electronic devices or due to an operating environment. These techniques save power and cost by reducing the attenuation without increasing transmit power or changing material properties of the attenuator.

Abstract: Techniques and apparatuses are described for radar angular ambiguity resolution. These techniques enable a target's angular position to be determined from a spatial response that has multiple amplitude peaks. Instead of solely considering which peak has a highest amplitude, the techniques for radar angular ambiguity resolution select a frequency sub-spectrum, or multiple frequency sub-spectrums, that emphasize amplitude or phase differences in the spatial response and analyze an irregular shape of the spatial response across a wide field of view to determine the target's angular position. In this way, each angular position of the target has a unique signature, which the radar system can determine and use to resolve the angular ambiguities. Using these techniques, the radar can have an antenna array element spacing that is greater than half a center wavelength of a reflected radar signal that is used to detect the target.

Abstract: This document describes techniques and devices for type-agnostic radio frequency (RF) signal representations. These techniques and devices enable use of multiple different types of radar systems and fields through type-agnostic RF signal representations. By so doing, recognition and application-layer analysis can be independent of various radar parameters that differ between different radar systems and fields.

Abstract: This document describes techniques using, and devices embodying, radar gesture sensing using existing data protocols. These techniques and devices enable transmitting data according to an existing data protocol, modulating the data on a radar field to transmit to another device, and sensing user gestures by analyzing reflections of portions of transmitted data by the transmitting or receiving device. Techniques are also described to filter received signals based on addressing information in the transmitted data to limit gesture recognition at a receiving device to transmitting devices known to the receiver.

Abstract: This document describes techniques for radio frequency (RF) based micro-motion tracking. These techniques enable even millimeter-scale hand motions to be tracked. To do so, radar signals are used from radar systems that, with conventional techniques, would only permit resolutions of a centimeter or more.

Abstract: This document describes techniques for radio frequency (RF) based micro-motion tracking. These techniques enable even millimeter-scale hand motions to be tracked. To do so, radar signals are used from radar systems that, with conventional techniques, would only permit resolutions of a centimeter or more.

Abstract: This document describes apparatuses and techniques for radar-based contextual sensing. In some aspects, a radar sensor of a device is activated to obtain radar data for a space of interest. Three-dimensional (3D) radar features are extracted from the radar data and positional data is received from sensors. Based on the positional data, spatial relation of the 3D radar features is determined to generate a set of 3D landmarks for the space. This set of 3D landmarks is then compared with known 3D context models to identify a 3D context model that matches the 3D landmarks. Based on a matching 3D context model, a context for the space is retrieved and used to configure contextual settings of the device. By so doing, contextual settings of the device be dynamically configured to address changes in context or for different device environments.

Abstract: Techniques and apparatuses are described that enable digital beamforming for radar sensing using a wireless communication chipset. A controller initializes or causes the wireless communication chipset to use multiple receiver chains to receive a radar signal that is reflected by a target. A digital beamformer obtains baseband data from the wireless communication chipset and generates a spatial response, which may be used to determine an angular position of the target. The controller can further select which antennas are used for receiving the radar signal. In this way, the controller can further optimize the wireless communication chipset for digital beamforming. By utilizing these techniques, the wireless communication chipset can be used for wireless communication or radar sensing.

Abstract: Techniques and apparatuses are described that enable radar modulations for radar sensing using a wireless communication chipset. A controller initializes or controls modulations performed by the wireless communication chipset. In this way, the controller can enable the wireless communication chipset to perform modulations for wireless communication or radar sensing. In some cases, the controller can further select a wireless communication channel for setting a frequency and a bandwidth of a radar signal, thereby avoiding interference between multiple radar signals or between the radar signal and a communication signal. In other cases, the controller can cause the wireless communication chipset to modulate a signal containing communication data using a radar modulation. This enables another device that receives the signal to perform wireless communication or radar sensing. By utilizing these techniques, the wireless communication chipset can be used for wireless communication or radar sensing.

Abstract: Techniques and apparatuses are described that enable full-duplex operation for radar sensing using a wireless communication chipset. A controller initializes or controls connections between one or more transceivers and antennas in the wireless communication chipset. This enables the wireless communication chipset to be used as a continuous-wave radar or a pulse-Doppler radar. By utilizing these techniques, the wireless communication chipset can be re-purposed or used for wireless communication or radar sensing.

Abstract: Techniques and apparatuses are described that enable power management using a low-power radar. The described techniques enable a radar system to reduce overall power consumption, thereby facilitating incorporation and utilization of the radar system within power-limited devices. In one aspect, the radar system can replace other power-hungry sensors and provide improved performance in the presence of different environmental conditions, such as low lighting, motion, or overlapping targets. In another aspect, the radar system can cause other components within the electronic device to switch to an off-state based on detected activity in an external environment. By actively switching the components between an on-state or the off-state, the radar system enables the computing device to respond to changes in the external environment without the use of an automatic shut-off timer or a physical touch or verbal command from a user.

Abstract: Techniques and apparatuses are described that enable low-power radar. The described techniques enable a radar system to reduce overall power consumption, thereby facilitating incorporation and utilization of the radar system within power-limited devices. Power consumption is reduced through customization of the transmission or processing of radar signals within the radar system. During transmission, different duty cycles, transmit powers, or framing structures can be utilized to collect appropriate data based on detected activity in an external environment. During processing, different hardware or different radar pipelines can be utilized to appropriately analyze the radar data. Instead of disabling the radar system, the described techniques enable the radar system to continuously monitor a dynamic environment and maintain responsiveness while conserving power.

Abstract: A gesture detection system uses two radar tones to concurrently detect absolute distance and relative movement of a target object. A radar-based detection device alternates transmitting a first radar tone and a second radar tone via a radar-emitting device, and then captures a first return signal and a second return signal that are generated by the first radar tone and second radar tone reflecting off the target object. The radar-based detection device demodulates the return signals into a first set of quadrature signals and a second set of quadrature signals and, in some cases, generates a first set of digital samples and second set of digital samples from the respective quadrature signals. Various aspects process the first set of digital samples and second set of digital samples to concurrently identify absolute distance and relative movement and, at times, determine an in-the-air gesture performed by the target object.

Abstract: This document describes apparatuses and techniques for radar-enabled sensor fusion. In some aspects, a radar field is provided and reflection signals that correspond to a target in the radar field are received. The reflection signals are transformed to provide radar data, from which a radar feature indicating a physical characteristic of the target is extracted. Based on the radar features, a sensor is activated to provide supplemental sensor data associated with the physical characteristic. The radar feature is then augmented with the supplemental sensor data to enhance the radar feature, such as by increasing an accuracy or resolution of the radar feature. By so doing, performance of sensor-based applications, which rely on the enhanced radar features, can be improved.

Abstract: This document describes techniques using, and devices embodying, radar-based gesture recognition using compressed sensing. These techniques and devices can enable a great breadth of gestures and uses for those gestures, such as gestures to use, control, and interact with computing and non-computing devices, from software applications to refrigerators. The techniques and devices are capable of providing a radar field that can sense gestures from multiple actors at one time and through obstructions using compressed sensing, thereby improving gesture breadth and accuracy over many conventional techniques using less complex components.