15104 results about "Signal-to-noise ratio (imaging)" patented technology

Apparatus and methods are disclosed for simultaneously tracking multiple finger and palm contacts as hands approach, touch, and slide across a proximity-sensing. compliant, and flexible multi-touch surface. The surface consists of compressible cushion, dielectric, electrode, and circuitry layers. A simple proximity transduction circuit is placed under each electrode to maximize signal-to-noise ratio and to reduce wiring complexity. Such distributed transduction circuitry is economical for large surfaces when implemented with thin-film transistor techniques. Scanning and signal offset removal on an electrode array produces low-noise proximity images. Segmentation processing of each proximity image constructs a group of electrodes corresponding to each distinguishable contact and extracts shape, position and surface proximity features for each group. Groups in successive images which correspond to the same hand contact are linked by a persistent path tracker which also detects individual contact touchdown and liftoff. Combinatorial optimization modules associate each contact's path with a particular fingertip, thumb, or palm of either hand on the basis of biomechanical constraints and contact features. Classification of intuitive hand configurations and motions enables unprecedented integration of typing, resting, pointing, scrolling, 3D manipulation, and handwriting into a versatile, ergonomic computer input device.

The invention is directed to apparatus and methods for delivering multiple reagents to, and monitoring, a plurality of analytical reactions carried out on a large-scale array of electronic sensors underminimal noise conditions. In one aspect, the invention provides method of improving signal-to-noise ratios of output signals from the electronic sensors sensing analytes or reaction byproducts by subtracting an average of output signals measured from neighboring sensors where analyte or reaction byproducts are absent. In other aspects, the invention provides an array of electronic sensors integrated with a microwell array for confining analytes and/or particles for analytical reactions and a method for identifying microwells containing analytes and/or particles by passing a sensor-active reagent over the array and correlating sensor response times to the presence or absence of analytes or particles. Such detection of analyte- or particle-containing microwells may be used as a step in additional noise reduction methods.

Apparatus, method, logic arrangement and storage medium are provided for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source can be split into N spectral bands. The N spectral bands can be individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band may be detected by a separate photo detector and amplified. For each spectral band, the signal can be band p3 filtered around the signal band by analog electronics and digitized, or, alternatively, the signal may be digitized and band pass filtered in software. As a consequence, the shot noise contribution to the signal is likely reduced by a factor equal to the number of spectral bands, while the signal amplitude can remain the same. The reduction of the shot noise increases the dynamic range and sensitivity of the system.

Audio frames are classified as either speech, non-transient background noise, or transient noise events. Probabilities of speech or transient noise event, or other metrics may be calculated to indicate confidence in classification. Frames classified as speech or noise events are not used in updating models (e.g., spectral subtraction noise estimates, silence model, background energy estimates, signal-to-noise ratio) of non-transient background noise. Frame classification affects acceptance/rejection of recognition hypothesis. Classifications and other audio related information may be determined by circuitry in a headset, and sent (e.g., wirelessly) to a separate processor-based recognition device.

The present invention relates to a method and device for improving concealment of frame erasure caused by frames of an encoded sound signal erased during transmission from an encoder (106) to a decoder (110), and for accelerating recovery of the decoder after non erased frames of the encoded sound signal have been received. For that purpose, concealment/recovery parameters are determined in the encoder or decoder. When determined in the encoder (106), the concealment/recovery parameters are transmitted to the decoder (110). In the decoder, erasure frame concealment and decoder recovery is conducted in response to the concealment/recovery parameters. The concealment/recovery parameters may be selected from the group consisting of: a signal classification parameter, an energy information parameter and a phase information parameter. The determination of the concealment/recovery parameters comprises classifying the successive frames of the encoded sound signal as unvoiced, unvoiced transition, voiced transition, voiced, or onset, and this classification is determined on the basis of at least a part of the following parameters: a normalized correlation parameter, a spectral tilt parameter, a signal-to-noise ratio parameter, a pitch stability parameter, a relative frame energy parameter, and a zero crossing parameter.

A multi-user MIMO downlink beamforming system with limited feedback (200) is provided to enable preceding for multi-stream transmission, where a channel codeword (u_i) and one or more channel quality indicator values (CQI_A, CQI_B) are computed at the user equipment (201.i) on the basis of maximizing a predetermined SINR performance metric (ρ_i) which estimates the receive signal-to-noise-ratio (SINR) at the user equipment (201.i). The computed codeword (u_i) and CQI values (or differential values related thereto) are quantized and fed back to help the base station (210) which applies a correction to the appropriate CQI value in the course of designing the transmit beamforming vectors w and determining the appropriate modulation and coding level to be used for downlink data transmission.

An Ultra-Tightly Coupled GPS-inertial navigation system for use in a moving agile platform includes a range residual extractor that uses best curve fitting of a third order polynomial for estimating range residual. The curve-fitted residual is used to update an error Kalman filter. The error Kalman filter includes correction for navigation solution, and IMU and GPS parameters. The navigation solution together with GPS parameter corrections are used in a Tracking Predictor to generate high-sampling-rate carrier and code replicas. The curve-fitting error covariance indicates signal to noise ratio for the tracked GPS signal and may be used for early indication of interference or jamming.

A base transceiver station operating a sectorized cell of a cellular radio system operates a plurality of narrow uplink main receive beams, and one or a plurality of uplink diversity received beams. A scanning means scans each of the uplink main receive beams to locate a communications channel on the main uplink beams. A diversity receiver receives a diverse beam signal from the diverse beam(s), which is compared with a beam signal received from a main uplink beam, and the main beam signal from the main beam, or a diverse beam signal from the diversity antenna is selected, depending on the comparative signal to noise ratio and signal strength of the main beam signal and diversity beam signal.

In the systems and methods of the present invention a multifocal multiphoton imaging system has a signal to noise ratio (SNR) that is reduced by over an order of magnitude at imaging depth equal to twice the mean free path scattering length of the specimen. An MMM system based on an area detector such as a multianode photomultiplier tube (MAPMT) that is optimized for high-speed tissue imaging. The specimen is raster-scanned with an array of excitation light beams. The emission photons from the array of excitation foci are collected simultaneously by a MAPMT and the signals from each anode are detected using high sensitivity, low noise single photon counting circuits. An image is formed by the temporal encoding of the integrated signal with a raster scanning pattern. A deconvolution procedure taking account of the spatial distribution and the raster temporal encoding of collected photons can be used to improve decay coefficient. We demonstrate MAPMT-based MMM can provide significantly better contrast than CCD-based existing systems.

A signal detector employs a coherent accumulation system that coherently combines the correlation results derived from segments of samples of a received signal. The segments may have non-uniform lengths and may have been obtained over different and non-overlapping time periods. The segments are obtained during sampling windows of arbitrary length and at arbitrary times, and the results of processing the segments are successively combined in a coherent manner (separate magnitude and phase accumulation) until a threshold signal-to-noise ratio (SNR) has been achieved. Coherent integration is enabled by introducing a carrier phase offset as well as a code phase offset, so that different segments are aligned in carrier phase as well as code phase. Although not limited to this application, in one implementation example, the signal detector is used in connection with and as part of a global positioning system (GPS) receiver.

A system for providing an accurate prediction of a signal-to-interference noise ratio is described. The system includes a first circuit for receiving a signal transmitted across a channel via an external transmitter. A second circuit generates a sequence of estimates of signal-to-interference noise ratio based on the received signal. A third circuit determines a relationship between elements of the sequence of estimates. A fourth circuit employs the relationship to provide a signal-to-interference noise ratio prediction for a subsequently received signal. In the illustrative embodiment, the inventive system further includes a circuit for generating a data rate request message based on the signal-to-noise ratio prediction. A special transmitter transmits the data rate request message to the external transmitter. In the specific embodiment, the relationship between elements of the sequence of estimates is based on an average of the elements of the sequence of estimates. The third circuit includes a bank of filters for computing the average. The bank of filters includes finite impulse response filters. Coefficients of the transfer functions associated with each filter in the bank of filters are tailored for different fading environments. The different fading environments include different Rayleigh fading environments, one environment associated with a rapidly moving system, a second environment associated with a slow moving system, and a third system associated with a system moving at a medium velocity. A selection circuit is connected to each of the filter banks and selects an output from one of the filters in the filter bank. The selected output is associated with a filter having a transfer function most suitable to a current fading environment.

By utilizing parameters derivable from a compressed bit-stream, measures are obtained of the subjective quality of a decoded picture, without the necessity for reference to source material. A blockiness measure is derived both locally and globally and used to control a de-blocking filter. An estimate of signal-to-noise ratio is derived from quantization values.

Disclosed is a method for enabling a subscriber station to shift from a sleep mode to an awake mode in a broadband wireless access communication system including the sleep mode in which there exists no data to be transmitted between the subscriber station and a base station, and the awake mode in which there exists data to be exchanged between the subscriber station and the base station. The method includes measuring a Carrier-to-Interference and Noise Ratio(CINR) with respect to the base station in a time interval for monitoring a received signal during the sleep mode; and shifting from the sleep mode to the awake mode when the measured signal-to-noise ratio is less than a first threshold value set in advance.

Embodiments of the present invention are directed to acoustic data transmission using a spreading code. A system for acoustic data transmission includes an ingestible capsule and an acoustic receiver. The ingestible capsule includes a modulator, a spreader, and an acoustic transmitter. The modulator modulates data according to a modulation scheme. The spreader spreads the modulated data according to a spreading code. The acoustic transmitter acoustically transmits the modulated and spread data through a body of an animal. The acoustic receiver includes an acoustic transducer a de-spreader and a demodulator. The acoustic transducer receives the acoustically transmitted signal and forms an electrical signal therefrom. The de-spreader de-spreads the received signal in accordance with the spreading code. The demodulator demodulates the received and de-spread signal in accordance with the modulation scheme, wherein a phase of the spreading code is synchronized with the received signal whereby a signal-to-noise ratio of the received signal is increased.

Apparatus and method of communicating data employing current pulses transmitted by an implanted device through living biological tissue to an external device. The method also contemplates transmission of current pulses from the external device through living biological tissue to an implanted device. Uniquely configured antenna electrodes are preferably employed in the implanted device. Increase in signal-to-noise ratio is achieved through synchronization. The method may be employed in diagnostic, therapeutic and general monitoring activities in connection with human beings.

Signal detection and recognition employees coordinated illumination and capture of images under to facilitate extraction of a signal of interest. Pulsed illumination of different colors facilitates extraction of signals from color channels, as well as improved signal to noise ratio by combining signals of different color channels. The successive pulsing of different color illumination appears white to the user, yet facilitates signal detection, even for lower cost monochrome sensors, as in barcode scanning and other automatic identification equipment.