Arizona State University

The University of Texas System

Carnegie Mellon University

The University of Arizona

Daniel W Bliss

Yu Rong

Andrew Herschfelt

Sharanya Srinivas

Jacob Holtom

Joshua Mack

Owen C Ma

Chaitali Chakrabarti

Radu Marculescu

Samet Egemen Arda

Umit Ogras

Anderson Sartor

Owen Ma

Sumit Mandal

Ali Akoglu

Anish Krishnakumar

Arindam Dutta

Nirmal Kumbhare

Ahmet Goksoy

Alex Chiriyath

Adarsh Venkataramani

Multi-stage distributed beamforming for distributed mosaic wireless networks is provided. Embodiments described herein present systems, devices, and methods that provide increased range, data rate, and robustness to interference and jamming. A distributed mosaic wireless network includes a transmitter, a receiver, and one or more distributed clusters of radios referred to herein as mosaics or relay mosaics. Each mosaic consists of several distributed, cooperative radio transceivers (e.g., mosaic nodes) that relay a signal sent by the transmitter towards the receiver. In some embodiments, a single-stage beamforming technique is implemented whereby the transmitter sends a signal to a first mosaic, which then relays this signal by beamforming to the receiver. In some embodiments, a multi-stage beamforming technique is implemented whereby the transmitter sends a signal to a first mosaic, which then relays this signal by beamforming to a second mosaic, which then relays this signal by beamforming to the receiver.

Multi-stage distributed beamforming for distributed mosaic wireless networks

Hierarchical and lightweight imitation learning (IL) for power management of embedded systems-on-chip (SoCs), also referred to herein as HiLITE, is provided. Modern SoCs use dynamic power management (DPM) techniques to improve energy efficiency. However, existing techniques are unable to efficiently adapt the runtime decisions considering multiple objectives (e.g., energy and real-time requirements) simultaneously on heterogeneous platforms. To address this need, embodiments described herein propose HiLITE, a hierarchical IL framework that maximizes energy efficiency while satisfying soft real-time constraints on embedded SoCs. This approach first trains DPM policies using IL; then, it applies a regression policy at runtime to minimize deadline misses. HiLITE improves the energy-delay product by 40% on average, and reduces deadline misses by up to 76%, compared to state-of-the-art approaches. In addition, the trained policies not only achieve high accuracy, but also have negligible prediction time overhead and small memory footprint.

HiLITE: hierarchical and lightweight imitation learning for power management of embedded SoCs

A precise cardiac data reconstruction method is provided, which may also be referred to herein as radar cardiography (RCG). RCG can reconstruct cardiac data, such as heart rate and/or electrocardiogram (ECG)-like heartbeat waveform signals wirelessly by using advanced radar signal processing techniques. For example, heartbeat and related characteristics can be monitored by isolating cardiovascular activity from strong respiratory interference in spatial spaces: azimuth and elevation. This results in significant improvements to pulse signal-to-noise-ratio (SNR) compared to conventional approaches, facilitating heart-rate variability (HRV) analysis.

Radar cardiography: a precise cardiac data reconstruction method

Hybrid in-situ and signal of opportunity (SoOP) calibration for antenna arrays is provided. Deployment of aircraft antennae is redesigned to support multiple services with shared physical elements that conform to the exterior of an aircraft to mitigate drag. Conformal arrays are, however, susceptible to structural changes in the fuselage that manifest as pointing errors and side lobe degradation. Embodiments provide an online calibration algorithm that leverages cooperative satellites in direct line-of-sight of a radio frequency (RF) device with an antenna array (e.g., an aircraft with a conformal antenna array) to optimally steer beams. These external calibration sources supplement an in-situ source mounted on a common platform with the antenna array (e.g., placed on the aircraft's tail). Models are established for potential sources of mismatch and the hybrid calibration method is demonstrated via simulations.

Hybrid in-situ and signal of opportunity calibration for antenna arrays

Methods, systems, and devices for direct radio frequency (RF) signal processing for heart rate (HR) monitoring using ultra-wide band (UWB) impulse radar are presented. A radar sensor is able to directly sample a received signal at RF which satisfies the Nyquist sampling rate, preserving a subject's vital sign information in the received signal. The vital sign information can be extracted directly from a raw RF signal and thus down conversion to a complex baseband is not required. The HR monitoring performance from the proposed direct RF signal processing technique provides an improvement in continuous HR monitoring as compared against existing methods using a complex baseband signal and/or other measurement techniques.

Direct RF signal processing for heart-rate monitoring using UWB impulse radar

Position information estimation in a distributed radio frequency (RF) communications system is provided. Embodiments disclosed herein facilitate high-precision estimations of positions, orientations, velocities, and acceleration of network nodes in a distributed RF network. The distributed RF communications system incorporates a series of estimation processes which makes it susceptible to propagation of errors. To ensure robustness of the distributed RF communications system, relative positions of network nodes are tracked by iteratively tracking parameters used for estimating position information. Some embodiments take advantage of Kalman filtering algorithms by leveraging principles directed by physics. At every network node, several filtering algorithms can be employed to synchronize clocks, track delay between multiple-input multiple-output (MIMO) antennas and estimate position and orientation of other network nodes. Information from other sensors like global positioning system (GPS) and inertial navigation system (INS) can also be employed to further improve estimation processes.

Estimation and tracking of position information in a distributed radio frequency (RF) communications system

Position information estimation in a distributed radio frequency (RF) communications system is provided. Embodiments disclosed herein facilitate high-precision estimations of positions, orientations, velocities, and acceleration of network nodes in a distributed RF network (e.g., including base stations and vehicles, such as aircraft or unmanned aerial systems (UASs)). Modern radio systems must adapt to limited spectral access by reducing spectrum demand and increasing operational efficiency. In this regard, an RF system is provided which simultaneously performs positioning and communications tasks. This system specifically addresses the issue of spectral congestion by employing an extremely efficient positioning strategy and using a joint waveform that simultaneously enables both tasks. This efficiency in turn supports more users in a given frequency allocation.

Position information estimation in a distributed radio frequency (RF) communications system

Remote recovery of acoustic signals from passive sources is provided. Wideband radars, such as ultra-wideband (UWB) radars can detect minute surface displacements for vibrometry applications. Embodiments described herein remotely sense sound and recover acoustic signals from vibrating sources using radars. Early research in this domain only demonstrated single sound source recovery using narrowband millimeter wave radars in direct line-of-sight scenarios. Instead, by using wideband radars (e.g., X band UWB radars), multiple sources separated in ranges are observed and their signals isolated and recovered. Additionally, the see-through ability of microwave signals is leveraged to extend this technology to surveillance of targets obstructed by barriers. Blind surveillance is achieved by reconstructing audio from a passive object which is merely in proximity of the sound source using clever radar and audio processing techniques.

Remote recovery of acoustic signals from passive sources

A hyper-precise positioning and communications (HPPC) system and network are provided. The HPPC system is a next-generation positioning technology that promises a low-cost, high-performance solution to the need for more sophisticated positioning technologies in increasingly cluttered environments. The HPPC system is a joint positioning-communications radio technology that simultaneously performs relative positioning and secure communications. Both of these tasks are performed with a single, co-use waveform, which efficiently utilizes limited resources and supports higher user densities. Aspects of this disclosure include an HPPC system for a network which includes an arbitrary number of network nodes (e.g., radio frequency (RF) devices communicating over a joint positions-communications waveform). As such, networking protocols and design of data link and physical layers are described herein. An exemplary embodiment extends the HPPC system for use with existing cellular networks, such as third generation partnership project (3GPP) long term evolution (LTE) and fifth generation (5G) networks.

Hyper-precise positioning and communications system and network

Detecting abnormalities in vital signs of subjects of videos is provided. Aspects of the present disclosure include methods, apparatuses, and systems to detect and measure vital sign information of one or more human subjects of a video and detect abnormalities in the vital sign information. In some examples, such abnormalities can be used to indicate video data is likely altered or fraudulent. In this regard, imaging photophlethysmography (IPPG) and advanced signal processing techniques, including adaptive color beamforming, can be used to extract the vital signs of the video subjects.

Detecting abnormalities in vital signs of subjects of videos

A vital sign monitoring system using an optical sensor is provided. The vital sign monitoring system, and related methods and devices described herein, is equipped with a camera or other optical sensor to remotely detect and measure one or more physiological parameters (e.g., vital signs) of a subject. For example, the vital sign monitoring system can detect, measure, and/or monitor heart rates and respiration rates from one or multiple subjects simultaneously using advanced signal processing techniques, including adaptive color beamforming to more accurately detect and measure the vital sign(s) of interest.

Vital sign monitoring system using an optical sensor

Systems and devices for phase-accurate vehicle positioning are disclosed. These systems and devices facilitate high-precision estimations of positions, orientations, velocities, and accelerations of signal nodes in a distributed network (e.g., including base stations and vehicles, such as aircraft or unmanned aerial systems (UASs)). The positioning estimations are based on time-of-arrival estimations of low-bandwidth signals and a phase-accurate distributed coherence algorithm. In some cases, the low-bandwidth signals may further facilitate joint communications and positioning estimations between the signal nodes.

Phase-accurate vehicle positioning systems and devices

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).

Methods and systems for remote sleep monitoring

The present disclosure relates to a heart rate monitoring method based on heartbeat harmonics. First, mixed data of a subject, which includes a fundamental respiration signal, respiration harmonics, a fundamental heartbeat signal, and heartbeat harmonics, is acquired by scanning a set of range bins. Range Doppler processing of the mixed data is performed to determine a range bin of interest. Data spectrum is then extracted based on a portion of the mixed data acquired at the range bin of interest. Next, the data spectrum is adaptively filtered to at least remove a spectrum peak of the fundamental respiration signal and a spectrum peak of the fundamental heartbeat signal mixed with a portion of respiration harmonics that are spectrally close to the fundamental heartbeat signal. Finally, the fundamental heartbeat signal is recovered based on a strongest heartbeat harmonic in the filtered data spectrum.

Growing community of inventors

Phoenix, AZ, United States of America

Daniel W Bliss