Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Techniques for synchronizing a receiver and transmitter in a wireless communication system address synchronization within the context of a detection formulation and provide synchronization statistics used to declare a synchronization detection. A signal is received from a channel at multiple receiving antennas. The receiver and transmitter are synchronized based on the received signal and a channel model incorporating the multiple receiving antennas. The channel model may also incorporate a resolvable delay spread of the received signal with respect to each receiving antenna. Synchronization may be based on a known component of a received signal and further on a channel model incorporating multiple receiving antennas and an interference signal. The known component may be a cyclic prefix or a pilot sequence as in orthogonal frequency division multiplexing (OFDM).

Abstract: Techniques for synchronizing a receiver and transmitter in a wireless communication system address synchronization within the context of a detection formulation and provide synchronization statistics used to declare a synchronization detection. A signal is received from a channel at multiple receiving antennas. The receiver and transmitter are synchronized based on the received signal and a channel model incorporating the multiple receiving antennas. The channel model may also incorporate a resolvable delay spread of the received signal with respect to each receiving antenna. Synchronization may be based on a known component of a received signal and further on a channel model incorporating multiple receiving antennas and an interference signal. The known component may be a cyclic prefix or a pilot sequence as in orthogonal frequency division multiplexing (OFDM).

Abstract: For multichannel multiuser detection in a wireless communication system such as a CDMA system, for a set of user spreading codes, coefficients to delay lines are adjusted and the delay line output processed to estimate a symbol. The symbol is estimated based on a space-time correlation for an antenna space delay time correlation. The estimated symbol is then remodulated and subtracted from the received antenna signal corresponding to other users of the wireless communication system. The adjusting and processing are iterated until the estimated symbols converge such that they correspond to a predetermined symbol decision criteria.