Abstract: A receiver for cancelling strong signals from combined weak and strong signals includes: a first circuitry for inputting a weak and strong signal as an input; a parametric cancellation circuit for inputting a representation of the strong signal and an output of the first circuitry to produce a cancellation signal; a second circuitry electrically coupled to the parametric cancellation circuit for inputting the cancellation signal to produce a modulated output; a demodulator electronically coupled to the second circuitry for demodulating the modulated output to produce a demodulated output and an error signal, where the demodulated output is the data contained in the weak signal; and an adaptation logic circuit for inputting the representation of the strong signal, the demodulated output and the error signal to adaptively produce parameters for the parametric cancellation circuit. The parametric cancellation circuit further inputs the error signal and the parameters to produce the cancellation signal.

Abstract: A receiver for cancelling strong signals from combined weak and strong signals includes: a first circuitry for inputting a weak and strong signal as an input; a parametric cancellation circuit for inputting a representation of the strong signal and an output of the first circuitry to produce a cancellation signal; a second circuitry electrically coupled to the parametric cancellation circuit for inputting the cancellation signal to produce a modulated output; a demodulator electronically coupled to the second circuitry for demodulating the modulated output to produce a demodulated output and an error signal, where the demodulated output is the data contained in the weak signal; and an adaptation logic circuit for inputting the representation of the strong signal, the demodulated output and the error signal to adaptively produce parameters for the parametric cancellation circuit. The parametric cancellation circuit further inputs the error signal and the parameters to produce the cancellation signal.

Abstract: A receiver for cancelling strong signals from combined weak and strong signals includes: a first circuitry for inputting a weak and strong signal as an input; a parametric cancellation circuit for inputting a representation of the strong signal and an output of the first circuitry to produce a cancellation signal; a second circuitry electrically coupled to the parametric cancellation circuit for inputting the cancellation signal to produce a modulated output; a demodulator electronically coupled to the second circuitry for demodulating the modulated output to produce a demodulated output and an error signal, where the demodulated output is the data contained in the weak signal; and an adaptation logic circuit for inputting the representation of the strong signal, the demodulated output and the error signal to adaptively produce parameters for the parametric cancellation circuit. The parametric cancellation circuit further inputs the error signal and the parameters to produce the cancellation signal.

Abstract: Aspects of the present disclosure include cancellation systems, techniques, apparatuses, and software for acoustic or electromagnetic measurement or communication systems. In some embodiments, cancellation techniques can be enhanced by providing one or both of a transmit transducer and a receiving transducer with a directional null and locating the other of the transmit transducer and the receiving transducer so that it is in the respective directional null. Cancellation techniques including iteratively solving one or more Wiener filter problems as a function of various signals and a delay imparted into the signal being transmitted by the local transmit transducer to create various cancellation signals that cancel self-interference of the locally transmitted signal.

Abstract: A receiver for cancelling strong signals from combined weak and strong signals includes: a first circuitry for inputting a weak and strong signal as an input; a parametric cancellation circuit for inputting a representation of the strong signal and an output of the first circuitry to produce a cancellation signal; a second circuitry electrically coupled to the parametric cancellation circuit for inputting the cancellation signal to produce a modulated output; a demodulator electronically coupled to the second circuitry for demodulating the modulated output to produce a demodulated output and an error signal, where the demodulated output is the data contained in the weak signal; and an adaptation logic circuit for inputting the representation of the strong signal, the demodulated output and the error signal to adaptively produce parameters for the parametric cancellation circuit. The parametric cancellation circuit further inputs the error signal and the parameters to produce the cancellation signal.

Abstract: A code division multiaccess (CDMA) communications system with low probability of intercept, low probability of detect (LPI/LPD) includes at least one data dictionary stored on a storage device of a sender subsystem and a recipient subsystem. The at least one data dictionary includes at least one data predetermined start time and date, at least one data predetermined end time and date based on a mission length or a predetermined wrap time and date, a CDMA chip rate, and a complex zero-mean independent and identically distributed (iid) sequence where each complex number in the complex zero-mean iid sequence represents a CDMA chip stored on the storage device of the sender subsystem and the recipient subsystem.

Abstract: A method of performing cancellation for acoustic or electromagnetic measurement or communications includes receiving an output signal to be applied to a transmit transducer, introducing a delay to the output signal to produce a delayed output signal, applying the delayed output signal to the transmit transducer, receiving an input signal from a receiving transducer, wherein the input signal comprises at least a portion of the delayed output signal, and iteratively solving a Kalman filter problem as a function of the input signal, the output signal, and the delay to produce a first filtered input signal.

Abstract: In a full duplex data transfer method system, a first transceiver and a second transceiver are configured to transmit and receive data packets. At the first transceiver, a status indicator is added to each data packet in a set of data packets and the status indicator of each data packet is initially set to not transmitted. A list of all data packets having a status indicator set to not transmitted is maintained. All data packets of the set are transmitted from the first transceiver to the second transceiver while the first transceiver receives transmissions from the second transceiver. At the second transceiver, all data packets received are saved and an indication regarding the data packets received are transmitted back to the first transceiver. At the first transceiver, the status indicator of all data packets in the list received by the second transceiver are set to received.

Abstract: Aspects of the present disclosure include cancellation systems, methods, apparatuses, and software for acoustic or electromagnetic measurement or communications. In some embodiments, full-duplex measurement and/or communications systems can be implemented that permit simultaneous transmission and reception of signals. A cancellation signal generated in accordance with teachings herein may be produced by iteratively solving a Wiener filter problem and provided to a cancellation transducer to cancel unwanted signals in an analog fashion and/or adaptive cancellation module to cancel unwanted signals in a digital fashion. A number of new techniques for reducing or eliminating unwanted signals are described herein that can be used alone or in combination in order to tailor a signal cancelling system, method, apparatus, or software product to particular uses and environments.

Abstract: A code division multiaccess (CDMA) communications system with low probability of intercept, low probability of detect (LPI/LPD) includes at least one data dictionary stored on a storage device of a sender subsystem and a recipient subsystem. The at least one data dictionary includes at least one data predetermined start time and date, at least one data predetermined end time and date based on a mission length or a predetermined wrap time and date, a CDMA chip rate, and a complex zero-mean independent and identically distributed (iid) sequence where each complex number in the complex zero-mean iid sequence represents a CDMA chip stored on the storage device of the sender subsystem and the recipient subsystem.

Abstract: In a full duplex data transfer method system, a first transceiver and a second transceiver are configured to transmit and receive data packets. At the first transceiver, a status indicator is added to each data packet in a set of data packets and the status indicator of each data packet is initially set to not transmitted. A list of all data packets having a status indicator set to not transmitted is maintained. All data packets of the set are transmitted from the first transceiver to the second transceiver while the first transceiver receives transmissions from the second transceiver. At the second transceiver, all data packets received are saved and an indication regarding the data packets received are transmitted back to the first transceiver. At the first transceiver, the status indicator of all data packets in the list received by the second transceiver are set to received.

Abstract: A method of performing cancellation for acoustic or electromagnetic measurement or communications includes receiving an output signal to be applied to a transmit transducer, introducing a delay to the output signal to produce a delayed output signal, applying the delayed output signal to the transmit transducer, receiving an input signal from a receiving transducer, wherein the input signal comprises at least a portion of the delayed output signal, and iteratively solving a Kalman filter problem as a function of the input signal, the output signal, and the delay to produce a first filtered input signal.

Abstract: A surface inspection system, as well as related components and methods, are provided. The surface inspection system includes a beam source subsystem, a beam scanning subsystem, a workpiece movement subsystem, an optical collection and detection subsystem, and a processing subsystem. The optical collection and detection system features, in the front quartersphere, a light channel assembly for collecting light reflected from the surface of the workpiece, and a front collector and wing collectors for collecting light scattered from the surface, to greatly improve the measurement capabilities of the system. The light channel assembly has a switchable edge exclusion mask and a reflected light detection system for improved detection of the reflected light.

Abstract: Aspects of the present disclosure include cancellation systems, methods, apparatuses, and software for acoustic or electromagnetic measurement or communications. In some embodiments, full-duplex measurement and/or communications systems can be implemented that permit simultaneous transmission and reception of signals. A cancellation signal generated in accordance with teachings herein may be produced by iteratively solving a Wiener filter problem and provided to a cancellation transducer to cancel unwanted signals in an analog fashion and/or adaptive cancellation module to cancel unwanted signals in a digital fashion. A number of new techniques for reducing or eliminating unwanted signals are described herein that can be used alone or in combination in order to tailor a signal cancelling system, method, apparatus, or software product to particular uses and environments.

Abstract: A surface inspection system, as well as related components and methods, are provided. The surface inspection system includes a beam source subsystem, a beam scanning subsystem, a workpiece movement subsystem, an optical collection and detection subsystem, and a processing subsystem. The optical collection and detection system features, in the front quartersphere, a light channel assembly for collecting light reflected from the surface of the workpiece, and a front collector and wing collectors for collecting light scattered from the surface, to greatly improve the measurement capabilities of the system. The light channel assembly has a switchable edge exclusion mask and a reflected light detection system for improved detection of the reflected light.

Abstract: In one aspect, the invention relates to a computer-implemented method of triggering optical coherence tomography data collection. The method includes collecting optical coherence tomography data with respect to a vessel using an optical coherence tomography probe disposed in the vessel; determining a clearing radius and a quality value for each frame of optical coherence tomography data collected for the vessel using a computer; determining if a blood clearing state has occurred using at least one clearing radius and at least one quality value; and generating a trigger signal in response to the blood clearing state.

Abstract: A surface inspection system, as well as related components and methods, are provided. The surface inspection system includes a beam source subsystem, a beam scanning subsystem, a workpiece movement subsystem, an optical collection and detection subsystem, and a processing subsystem. The optical collection and detection system features, in the front quartersphere, a light channel assembly for collecting light reflected from the surface of the workpiece, and a front collector and wing collectors for collecting light scattered from the surface, to greatly improve the measurement capabilities of the system. The light channel assembly has a switchable edge exclusion mask and a reflected light detection system for improved detection of the reflected light.

Abstract: An optical collection and detection system for use in a surface inspection system for inspecting a surface of a workpiece. The surface inspection system has an incident beam projected through a back quartersphere and toward a desired location on the surface, which is a scanned spot having a known scanned spot size. The incident beam impinges on the surface to create scattered light that is collected by a collector module. The collector module includes collection optics for collecting and focusing the scattered light to form focused scattered light. A collector output slit is positioned at an output of the collector module, through which the collection optics focus the scattered light. The scattered light that is associated with the scanned spot forms an imaged spot at the collector output slit.

Abstract: A surface inspection system, as well as related components and methods, are provided. The surface inspection system includes a beam source subsystem, a beam scanning subsystem, a workpiece movement subsystem, an optical collection and detection subsystem, and a processing subsystem. The optical collection and detection system features, in the front quartersphere, a light channel assembly for collecting light reflected from the surface of the workpiece, and a front collector and wing collectors for collecting light scattered from the surface, to greatly improve the measurement capabilities of the system. The light channel assembly has a switchable edge exclusion mask and a reflected light detection system for improved detection of the reflected light.

Abstract: A system suitable for use in classifying radio signals includes a plurality of feature extractors configured to extract a plurality of features from an object and a plurality of classification layers. Each of the plurality of classification layers includes one or more reduced enhanced Gaussian classifiers selected from a plurality of Gaussian classifiers based on a classification error rate of each of the plurality of Gaussian classifiers and configured to classify the object as belonging to an object class in a subgroup of correctly classified object classes or in a disjoint error subgroup that needs further classification, using at least one of the extracted plurality of features. If the object is classified as belonging to an object class in a disjoint error subgroup at a layer, the object is passed on to a different reduced enhanced Gaussian classifier in a next layer for further classification.