Showing papers on "Signal published in 2011"

Sparse and Redundant Representations: From Theory to Applications in Signal and Image Processing

Abstract: This textbook introduces sparse and redundant representations with a focus on applications in signal and image processing The theoretical and numerical foundations are tackled before the applications are discussed Mathematical modeling for signal sources is discussed along with how to use the proper model for tasks such as denoising, restoration, separation, interpolation and extrapolation, compression, sampling, analysis and synthesis, detection, recognition, and more The presentation is elegant and engaging Sparse and Redundant Representations is intended for graduate students in applied mathematics and electrical engineering, as well as applied mathematicians, engineers, and researchers who are active in the fields of signal and image processing

Magnetic resonance imaging device

Abstract: By using a multiple receiving coil composed of receiving coils, an imaging portion of a subject is subjected to a first pulse sequence to create n sensitivity images (701 to 703) fewer than the examination images. When these sensitivity images are created, an NMR signal is measured for only the low-frequency region of the k space. A second pulse sequence from which a phase encode step is removed is conducted to create m (m>n) examination images (704, 705) of the subject by using the receiving coils. When sensitivity distributions (707, 708) of the receiving coils are determined for the sensitivity images (701 to 703), and if there are no sensitivity distributions corresponding to the slice positions of the examination images (704, 705), they are determined by slice interpolation using the sensitivity distributions (701 to 703), and the aliasing artifacts of the examination images (704, 705) are removed by matrix operation by using the sensitivity distributions (707, 708).

Unveiling the biometric potential of finger-based ECG signals

Abstract: The ECG signal has been shown to contain relevant information for human identification. Even though results validate the potential of these signals, data acquisition methods and apparatus explored so far compromise user acceptability, requiring the acquisition of ECG at the chest. In this paper, we propose a finger-based ECG biometric system, that uses signals collected at the fingers, through a minimally intrusive 1-lead ECG setup recurring to Ag/AgCl electrodes without gel as interface with the skin. The collected signal is significantly more noisy than the ECG acquired at the chest, motivating the application of feature extraction and signal processing techniques to the problem. Time domain ECG signal processing is performed, which comprises the usual steps of filtering, peak detection, heartbeat waveform segmentation, and amplitude normalization, plus an additional step of time normalization. Through a simple minimum distance criterion between the test patterns and the enrollment database, results have revealed this to be a promising technique for biometric applications.

Advanced continuous analyte monitoring system

Abstract: Systems and methods for processing, transmitting, and displaying data received from a continuous analyte (e.g., glucose) sensor are provided. A sensor system can comprise a sensor electronics module that includes power saving features, e.g., a low power measurement circuit that can be switched between a measurement mode and a low power mode, wherein charging circuitry continues to apply power to electrodes of a sensor during the low power mode. The sensor electronics module can be switched between a low power storage mode and a higher power operational mode via a switch, e.g., a reed switch or optical switch. A validation routine can be implemented to ensure an interrupt signal sent from the switch is valid. The sensor can be physically connected to the sensor electronics module in direct wireless communication with a plurality of different display devices.

Method of powering a surgical instrument

Abstract: A method for powering electrically powered surgical instruments includes removably inserting a cordless battery assembly into a handle thereof, the instrument handles having a battery chamber and different types. The battery assembly comprises an energy cell powering a signal generation assembly of the instruments. A battery/handle interface has connectors mating with connectors within the chamber. A voltage-control circuit is operable to communicate with and power the signal generation assembly, detect which handle type is connected to the battery assembly, and provide different outputs in response to a detection of the handle types. As the battery assembly is inserted, connectors of the battery/handle interface are coupled with connectors within the battery chamber to communicatively couple the voltage-control circuit to the signal generation assembly and provide power thereto. The connected handle is detected and dependent upon the detected handle type a different one of the outputs are provided.

Materials, systems and methods for optoelectronic devices

Abstract: A photodetector is described along with corresponding materials, systems, and methods. The photodetector comprises an integrated circuit and at least two optically sensitive layers. A first optically sensitive layer is over at least a portion of the integrated circuit, and a second optically sensitive layer is over the first optically sensitive layer. Each optically sensitive layer is interposed between two electrodes. The two electrodes include a respective first electrode and a respective second electrode. The integrated circuit selectively applies a bias to the electrodes and reads signals from the optically sensitive layers. The signal is related to the number of photons received by the respective optically sensitive layer.

Battery Assembly for Battery-Powered Surgical Instruments

Abstract: A battery assembly is used in battery-powered surgical instruments with handles having a battery chamber and different handle types. The battery assembly includes a housing having an exterior shape formed to removably connect with the battery chamber of the handles and a voltage-control circuit. The housing has at least one energy storage cell operable to power a signal generation assembly of the surgical instruments and a battery/handle interface having a plurality of connectors shaped to mate with a plurality of corresponding connectors within the battery chamber of the handles. The voltage-control circuit is operable to communicatively couple with and provide power to the signal generation assembly, detect which one of the handle types is connected to the housing, provide a first output in response to a detection of a first handle type, and provide at least a second output in response to a detection of a second handle type.

Electronic device assembly

Abstract: An electronic device assembly includes an electronic device and an enclosure receiving the electronic device The electronic device includes a display and a sensor The enclosure includes a cover and a controller attached to the cover The cover is rotatable relative to the electronic device between a first position and a second position In the first position, the cover covers the electronic device, and the controller controls the sensor transmitting a first signal to the electronic device, for turning off a power supplied to the display In the second position, the electronic device is exposed, and the controller controls the sensor transmitting a second signal to the electronic device, for turning on the power of the display

Towards ultrasensitive optical links enabled by low-noise phase-sensitive amplifiers

Abstract: Optical phase-sensitive amplifiers (PSAs) are known to be capable, in principle, of realizing noiseless amplification and improving the signal-to-noise-ratio of optical links by 3 dB compared to conventional, phase-insensitively amplified links. However, current state-of-the-art PSAs are still far from being practical, lacking e.g. significant noise performance improvement, broadband gain and modulation-format transparency. Here we demonstrate experimentally, for the first time, an optical-fiber-based non-degenerate PSA link consisting of a phase-insensitive parametric copier followed by a PSA that provides broadband amplification, signal modulation-format independence, and nearly 6-dB link noise-figure (NF) improvement over conventional, erbium-doped fiber amplifier based links. The PSA has a record-low 1.1-dB NF, and can be extended to work with multiple wavelength channels with modest system complexity. This concept can also be realized in other materials with third-order nonlinearities, and is useful in any attenuation-limited optical link.

Reference signal for a coordinated multi-point network implementation

Abstract: A system and method of receiving a channel state information reference signal (CSI-RS) is presented. At a user equipment, a first CSI-RS transmitted from a base station is received. In some implementations, the first CSI-RS is transmitted at a first periodicity using a first set of antenna ports. At the user equipment, a second CSI-RS transmitted from the base station is received. In some implementations, the second CSI-RS is transmitted at a second periodicity using a second set of antenna ports. At least one of the first CSI-RS and the second CSI-RS is used to perform channel measurement.

Scale-Free Properties of the Functional Magnetic Resonance Imaging Signal during Rest and Task

Abstract: It has been shown recently that a significant portion of brain electrical field potentials consists of scale-free dynamics. These scale-free brain dynamics contain complex spatiotemporal structures and are modulated by task performance. Here we show that the fMRI signal recorded from the human brain is also scale free; its power-law exponent differentiates between brain networks and correlates with fMRI signal variance and brain glucose metabolism. Importantly, in parallel to brain electrical field potentials, the variance and power-law exponent of the fMRI signal decrease during task activation, suggesting that the signal contains more long-range memory during rest and conversely is more efficient at online information processing during task. Remarkably, similar changes also occurred in task-deactivated brain regions, revealing the presence of an optimal dynamic range in the fMRI signal. The scale-free properties of the fMRI signal and brain electrical field potentials bespeak their respective stationarity and nonstationarity. This suggests that neurovascular coupling mechanism is likely to contain a transformation from nonstationarity to stationarity. In summary, our results demonstrate the functional relevance of scale-free properties of the fMRI signal and impose constraints on future models of neurovascular coupling.

Self calibrating multi-element dipole microphone

Abstract: A self calibrating dipole microphone formed from two omni-directional acoustic sensors. The microphone includes a sound source acoustically coupled to the acoustic sensors and a processor. The sound source is excited with a test signal, exposing the acoustic sensors to acoustic calibration signals. The responses of the acoustic sensors to the calibration signals are compared by the processor, and one or more correction factors determined. Digital filter coefficients are calculated based on the one or more correction factors, and applied to the output signals of the acoustic sensors to compensate for differences in the sensitivities of the acoustic sensors. The filtered signals provide acoustic sensor outputs having matching responses, which are subtractively combined to form the dipole microphone output.

Surgical instrument with integrated wireless camera

Abstract: A surgical instrument including an integrated wireless camera includes a handle assembly housing control circuitry. An elongated shaft extends from the handle assembly and includes an end effector disposed at a distal end thereof. An image sensor assembly is disposed toward the distal end of the elongated shaft and is electrically coupled to the control circuitry. The image sensor assembly is configured to convert an optical image into an electrical signal and communicate the electrical signal to the control circuitry. The control circuitry is configured to process the signal and wirelessly transmit the processed signal to a wireless receiver positioned remote of the surgical instrument.

Wireless energy transfer and continuous radio station signal coexistence

Abstract: This disclosure provides systems, methods and apparatus for wirelessly transmitting power while avoiding interference with wireless communication devices. In one aspect a wireless power transmitter apparatus is provided. The wireless power transmitter apparatus includes a transmit circuit configured to wirelessly transmit power at a transmit frequency to a first receiver device. The wireless power transmitter apparatus further includes a controller circuit configured to reduce a level of emission of the transmit circuit at a determined frequency during a period of time based on information about an information signal transmitted to a second receiver device substantially at the determined frequency to be received within the period of time.

Wireless transmission of solar generated power

Abstract: A wireless power source station includes a solar panel generating an output DC voltage, power and control circuitry that receives the output DC voltage and generates an electronic drive signal at a frequency, f, and a source magnetic resonator that generates an oscillating magnetic near field in response to the electronic drive signal for providing power to electronic devices in a region around the solar panel.

Energy harvesting computer device in association with a communication device configured with apparatus for boosting signal reception

Abstract: Disclosed embodiments comprise an energy harvesting computer device in association with a communication device comprising interactive user interface operatively configured with CMOS multiple antennas on chip for boosting signal receptions and for providing faster data transmission speed. Disclosed embodiment encompasses three modes of communications—the Cell phone, wireless Internet applications, and Global communication and media information. Embodiments provide communication apparatus operable to enhance mobile communication efficiency with touch sensitive display comprising energy harvesting platform in communication with a charging circuit board configured with memories, processors, sensors, and modules. Embodiments further provide a gaming device, a wireless media device configured with touch pads comprising sensors being embedded in silicon substrate and fused in nano-fiber/microfiber material having excellent electrical characteristics. Certain embodiments provide communication apparatus configured for voice enabled applications comprising human voice auditory operable to convert text into voice auditory and/or voice auditory into text applications.

Compact and flexible raster scanning multiphoton endoscope capable of imaging unstained tissue.

Abstract: We present a compact and flexible endoscope (3-mm outer diameter, 4-cm rigid length) that utilizes a miniaturized resonant/nonresonant fiber raster scanner and a multielement gradient-index lens assembly for two-photon excited intrinsic fluorescence and second-harmonic generation imaging of biological tissues. The miniaturized raster scanner is fabricated by mounting a commercial double-clad optical fiber (DCF) onto two piezo bimorphs that are aligned such that their bending axes are perpendicular to each other. Fast lateral scanning of the laser illumination at 4.1 frames/s (512 lines per frame) is achieved by simultaneously driving the DCF cantilever at its resonant frequency in one dimension and nonresonantly in the orthogonal axis. The implementation of a DCF into the scanner enables simultaneous delivery of the femtosecond pulsed 800-nm excitation source and epi-collection of the signal. Our device is able to achieve a field-of-view (FOVxy) of 110 μm by 110 μm with a highly uniform pixel dwell time. The lateral and axial resolutions for two-photon imaging are 0.8 and 10 μm, respectively. The endoscope’s imaging capabilities were demonstrated by imaging ex vivo mouse tissue through the collection of intrinsic fluorescence and second-harmonic signal without the need for staining. The results presented here indicate that our device can be applied in the future to perform minimally invasive in vivo optical biopsies for medical diagnostics.

Transmission and reception of proximity detection signal for peer discovery

Abstract: Techniques for performing peer discovery to enable peer-to-peer (P2P) communication are disclosed. In an aspect, a proximity detection signal used for peer discovery may be generated based on one or more physical channels and/or signals used in a wireless network. In one design, a user equipment (UE) may generate a proximity detection signal occupying at least one resource block based on a SC-FDMA modulation technique. In another design, the UE may generate a proximity detection signal occupying at least one resource block based on an OFDMA modulation technique. The UE may generate SC-FDMA symbols or OFDMA symbols in different manners for different physical channels. In yet another design, the UE may generate a proximity detection signal including a primary synchronization signal and a secondary synchronization signal. For all designs, the UE may transmit the proximity detection signal to indicate its presence and to enable other UEs to detect the UE.

Finfet device and method of manufacturing same

Abstract: A semiconductor device and method for fabricating a semiconductor device is disclosed. An exemplary semiconductor device includes a substrate including a fin structure including one or more fins disposed on the substrate. The semiconductor device further includes a dielectric layer disposed on a central portion of the fin structure and traversing each of the one or more fins. The semiconductor device further includes a work function metal disposed on the dielectric layer and traversing each of the one or more fins. The semiconductor device further includes a strained material disposed on the work function metal and interposed between each of the one or more fins. The semiconductor device further includes a signal metal disposed on the work function metal and on the strained material and traversing each of the one or more fins.

Wireless power transfer within a circuit breaker

Abstract: A wireless power service panel source includes power and control circuitry that receives power from a wired power connection at a position in a service panel, and generates an electronic drive signal at a frequency, f, and a source magnetic resonator configured to generate an oscillating magnetic field in response to the electronic drive signal, wherein the source magnetic resonator is configured to wirelessly transmit power to sensors in other positions within the service panel.

Methods and systems for in-device interference mitigation

Abstract: Methods and apparatus for mitigating in-device interference are described. The methods may include an in-device interference event (e.g. an interference situation), and the processing of events may depend on the priority of the technologies. A handover to another frequency or radio access technology (RAT) may occur in case a co-existing technology may be activated. The network may signal to the device a list of frequencies or RATs that it may be allowed to measure and handoff to. A network may provide a scaling value that the device may use to speed up reaction to the interference. The device may apply a scaling factor to an "out of synch' counter and/or the radio link failure (RLF) timer used for the RLF procedure. The device may apply different scaling factors for the measurements and time to trigger events. The device may trigger a report to the network requesting gaps for an alternate RAT.

Statistical physics-based reconstruction in compressed sensing

Abstract: Compressed sensing is triggering a major evolution in signal acquisition. It consists in sampling a sparse signal at low rate and later using computational power for its exact reconstruction, so that only the necessary information is measured. Currently used reconstruction techniques are, however, limited to acquisition rates larger than the true density of the signal. We design a new procedure which is able to reconstruct exactly the signal with a number of measurements that approaches the theoretical limit in the limit of large systems. It is based on the joint use of three essential ingredients: a probabilistic approach to signal reconstruction, a message-passing algorithm adapted from belief propagation, and a careful design of the measurement matrix inspired from the theory of crystal nucleation. The performance of this new algorithm is analyzed by statistical physics methods. The obtained improvement is confirmed by numerical studies of several cases.

Organic light emitting diode display and driving method thereof

Abstract: An organic light emitting diode display is disclosed. A signal from the pixels in the display is transmitted to a circuit which compensates the image data according to the signal, which is indicative of one or more of ageing of the organic light emitting diodes, the threshold voltages of the driving transistors, and current mobility of the driving transistors.

Microwave amplification with nanomechanical resonators

Abstract: Use of nanomechanical resonators has the potential to offer microwave amplification with the minimum possible added noise, namely that due to quantum fluctuations In order to compensate for energy losses, the radio signals used in telecommunications and detection technologies require occasional electrical amplification For specific applications, sensitive amplifiers have been demonstrated that operate near the quantum limit — where the only noise added is due to fundamental quantum fluctuations This paper describes a new concept for amplifying weak electrical signals close to this fundamental limit, using a nanomechanical resonator The system uses a resonator irradiated with microwave light of a frequency tuned so that it sets the resonator in motion with tiny vibrations; these amplify the signal In this proof-of-principle study, signal amplification of 25 decibels is demonstrated, with only 20 fundamental noise quanta added This mechanical amplification approach has the attraction that it is conceptually simple and could feasibly be used in integrated electrical circuits The sensitive measurement of electrical signals is at the heart of modern technology According to the principles of quantum mechanics, any detector or amplifier necessarily adds a certain amount of noise to the signal, equal to at least the noise added by quantum fluctuations1,2 This quantum limit of added noise has nearly been reached in superconducting devices that take advantage of nonlinearities in Josephson junctions3,4 Here we introduce the concept of the amplification of microwave signals using mechanical oscillation, which seems likely to enable quantum-limited operation We drive a nanomechanical resonator with a radiation pressure force5,6,7, and provide an experimental demonstration and an analytical description of how a signal input to a microwave cavity induces coherent stimulated emission and, consequently, signal amplification This generic scheme, which is based on two linear oscillators, has the advantage of being conceptually and practically simpler than the Josephson junction devices In our device, we achieve signal amplification of 25 decibels with the addition of 20 quanta of noise, which is consistent with the expected amount of added noise The generality of the model allows for realization in other physical systems as well, and we anticipate that near-quantum-limited mechanical microwave amplification will soon be feasible in various applications involving integrated electrical circuits

Synchrosqueezing-Based Recovery of Instantaneous Frequency from Nonuniform Samples

Abstract: We propose a new approach for studying the notion of the instantaneous frequency of a signal. We build on ideas from the Synchrosqueezing theory of Daubechies, Lu, and Wu [Appl. Comput. Harmonic Anal., 30 (2010), pp. 243–261] and consider a variant of Synchrosqueezing, based on the short-time Fourier transform, to precisely define the instantaneous frequencies of a multicomponent AM-FM signal. We describe an algorithm to recover these instantaneous frequencies from the uniform or nonuniform samples of the signal and show that our method is robust to noise. We also consider an alternative approach based on the conventional, Hilbert transform-based notion of instantaneous frequency to compare to our new method. We use these methods on several test cases and apply our results to a signal analysis problem in electrocardiography.

Wireless charging and communication with power source devices and power charge devices in a communication system

Abstract: A power source device and a power charge device interoperate according to a wireless charging protocol. The power source device inductively wirelessly transmits charging energy signal via an inductive wireless power transmitting circuit. The power charge device wirelessly receives the inductively wirelessly transmitted charging energy signal via an inductive wireless power receiving circuit. The power charge device transfers wirelessly received charging energy signal to a re-chargeable battery of the power charge device. In response to determining that the power source device and the power charge device are in a charging arrangement, the power source device controls user access to a lockable user interface based on receiving information from the power charge device and can display messages received by the power charge device from a wireless communication network. The power source device can include a personal computing system and the power charge device can include a mobile phone.

Apparatus and method for controlling inter-cell interference

Abstract: An apparatus and method for controlling inter-cell interference is disclosed. The user equipment for controlling inter-cell interference in a wireless communication system includes an interference level measuring module configured to measure interference levels of neighboring cells using at least one of information about the number of antennas among antennas deployed in the neighboring cells, information about indexes of the effective antennas, and information about reference signal of the neighboring cells, an interference restriction request determination module configured to compare the interference levels of the neighboring cells with a predetermined threshold and to determine whether or not UE requests an interference restriction to the neighboring cells, and a transmitter configured to transmit information about one or more neighboring cells, to which the interference restriction request will be transmitted, to a serving base station.

On the Performance of Different OFDM Based Optical Wireless Communication Systems

Abstract: This paper analyzes the performance of indoor orthogonal frequency division multiplexing (OFDM) optical wireless communication systems in the presence of light emitting diode (LED) nonlinear distortions. There are several forms of optical OFDM using intensity modulation [7th Int. Symp. on Communication Systems Networks and Digital Signal Processing (CSNDSP), 2010, pp. 566-570]. In this paper, DC-biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM) are considered. ACO-OFDM produces a half-wave symmetry time signal at the output of the OFDM modulator by special assignment of subcarriers, thus allowing signal clipping at the zero level and avoiding the need for DC bias at the expense of data rate reduction. DCO-OFDM assigns data to all possible subcarriers to increase the data rate. However, half-wave symmetry signals cannot be achieved and a high DC bias is needed to convert the bipolar signal to a unipolar signal before modulating the LED intensity. This paper considers a practical LED model and studies the performance of both systems in terms of average electrical OFDM signal power versus bit error ratio in the presence of an additive white Gaussian noise (AWGN) channel. In addition, DC power consumption and the transmitted optical power for the two systems are compared. The analytical results are validated through Monte Carlo simulations and the obtained results demonstrate close match. It is shown that LED clipping has significant impact on the performance of both systems and an optimum system design should take into account the OFDM signal power, DC-bias point, and LED dynamic range.

Method and apparatus for reducing coupling between signals in a measurement system

Abstract: A method and an apparatus for separating a composite signal into a plurality of signals is described. A signal processor receives a composite signal and separates a composite signal in to separate output signals. Pre-demodulation signal values are used to adjust the demodulation scheme.