National Instruments Corporation

Agora Lab, Inc.

Other

Hughes Electronics Corporation

Dts, Inc.

Shie Qian

Hui Shao

Wei Qiang Jin

Nanxiong Zhang

Ruofei Chen

Siqiang Yao

Zehua Gao

Zhijun Gu

Mark E Dunham

Xiang-Gen Xia

Yi Hang Lv

Zhonghou Zheng

Qiuhong Yang

Jin Wei

Shao Hui

A method for encoding multiple descriptions for a media stream includes: determining, for a current block of the media stream, a first number of duplicate blocks, determining, for the current block, a plurality of complementary forward gain factors, and determining a first number of descriptions for the current block by applying the plurality of complementary forward gain factors to the first number of duplicate blocks. A method for decoding multiple descriptions for a media stream includes: determining, for a current block of the media stream, a first number of descriptions from the media stream, in which each description comprises a scaled block corresponding to the current block, determining backward gain factors for the first number of scaled blocks, and determining the current block by applying the backward gain factors to the first number of scaled blocks.

Gain control for multiple description coding

A method for decoding multiple descriptions for a media stream includes decoding at least one of a first description and a second description from the media bitstream, wherein the first description and the second description are associated with a current sample of the media bitstream and independently decodable; based on a determination that the second description is missing, reconstructing, by a decoder, the current sample by performing a third shifting operation on the first description, wherein the third shifting operation on the first description comprises left shifting the first description by one bit; and based on a determination that both the first description and the second description have been received, reconstructing, by the decoder, the current sample by summing the first description and the second description. An encoding method is also provided.

Integer multiple description coding system

An audio system is provided that employs time-frequency analysis and/or synthesis techniques for processing audio obtained from a microphone array. These time-frequency analysis/synthesis techniques can be more robust, provide better spatial resolution, and have less computational complexity than existing adaptive filter implementations. The time-frequency techniques can be implemented for dual microphone arrays or for microphone arrays having more than two microphones. Many different time-frequency techniques may be used in the audio system. As one example, the Gabor transform may be used to analyze time and frequency components of audio signals obtained from the microphone array.

Microphone array processing system

A system, method, and memory medium for operating on an electrocardiogram (ECG) signal. A multiscale short-time Fourier transform (STFT) is perform on a set of ECG samples {s(n)} to obtain a transform array. For each sufficiently energetic peak in the transform array, a refined window width value and a refined window displacement value is generated by: computing an inner product between the set of samples and each of a plurality of functions, where the plurality of functions are sufficiently close to a coarse approximation function given by the peak location; and solving a linear system Av=c for the unknown vector v, where the vector c is determined by the inner products, where the matrix A is determined by the center times of the plurality of functions. After appropriate selection, the refined window width and refined window displacement may be used to represent ECG waveform features.

Analyzing electrocardiogram signals with multiscale short-time fourier transforms

A system, method and memory medium for operating on an electrocardiogram (ECG) signal. A multiscale short-time Fourier transform (STFT) is performed on a set of ECG samples {s(n)} to obtain a transform array. For each sufficiently energetic peak in the transform array, a refined window width value and a refined window displacement value is generated by: computing an inner product between the set of samples and each of a plurality of functions, where the plurality of functions are sufficiently close to a coarse approximation function given by the peak location; and solving a linear system Av=c for the unknown vector v, where the vector c is determined by the inner products, where the matrix A is determined by the center times of the plurality of functions. After appropriate selection, the refined window width and refined window displacement may be used to represent ECG waveform features.

Electrocardiogram analysis and parameter estimation

System and method for performing Time Domain Reflectometry (TDR) on a Device Under Test (DUT) using Gaussian pulses. A signal is received comprising an initial Gaussian pulse and one or more reflected pulses from the DUT. Each pulse is characterized by determining a set of estimated parameters, permuting the estimated parameter set to generate one or more permuted parameter sets, generating linear equations from the parameter sets, including parameter variables for the corresponding Gaussian pulse, and determining values for the parameter variables by solving the linear equations. The determined parameters characterize the Gaussian pulse. If there are N parameters to determine and M permutations generated, where M is greater than or equal to N, M&plus;1 linear equations are solved to overdetermine the N parameters. The determined parameters of the initial pulse and the one or more reflected pulses are useable to perform TDR analysis on the DUT.

System and method for performing time domain reflectometry using Gaussian pulses

A system and method for analyzing order components present in a physical signal X acquired from a physical system. Measurement information for the physical signal X may be received, where the measurement information includes information indicating a plurality of order components of the physical signal X. Time frequency plot information visually indicating order components of the physical signal X may be displayed. User input selecting one or more of the visually indicated order components may be received. A time domain signal may be created based on the one or more selected order components and may then be presented to a user on a presentation device. Presenting the time domain signal on the presentation device may enable the user to analyze the physical signal X or the physical system. Where the physical system includes one or more rotating elements, the method may enable order components of the signal to be analyzed even when no rotation speed information (e.g., tachometer information) for the rotating element is available.

Time varying harmonic analysis including determination of order components

System and method for analyzing an input signal acquired from a physical system with a rotating element. A tachometer signal is received comprising rotation speed information for the rotating element. A time sequence is determined using the tachometer signal, comprising time values for the rotating element at substantially equal angle increments, e.g., by edge detection software or timer/counter. A software-based first digital interpolation filter, e.g., a Cascade-Integrator-Comb filter, is applied to the time sequence, generating a modified time sequence. A digitized data signal is received comprising data for the rotating element at substantially equal time increments. A second software-based digital interpolation filter is applied to the data signal, generating a modified data signal which is re-sampled using the modified time sequence to generate an angle domain data signal, comprising data signal values at substantially equal angle increments, where the angle domain data signal is usable to analyze the physical system.

Analysis of rotating machines

System and method for characterizing a Gaussian pulse in a signal. The system includes a computer operable to receive the signal, determine a set of estimated parameters for the Gaussian pulse using a &ldquo;zoom-in&rdquo; approach, permute the estimated parameter set to generate one or more permuted parameter sets, where the estimated and permuted parameter sets each represent a corresponding waveform, generate closed form inner products between the received signal and each waveform, generate linear equations from the inner products, each linear equation being a function of a respective one of the parameter sets and corresponding parameter variables for the Gaussian pulse, and determine values for the parameter variables by solving the linear equations. The determined parameters characterize the Gaussian pulse. If there are N parameters to determine and M permutations generated, where M is greater than or equal to N, M&plus;1 linear equations are solved to overdetermine the N parameters.

System and method for detecting and characterizing gaussian pulses

A signal analysis system and method for analyzing an input signal acquired from a mechanical system. The mechanical system may include at least one rotating apparatus. The signal analysis system may be configured to: (a) receive samples of the input signal, (b) perform an invertible joint time-frequency transform (e.g., a Gabor transform) on the samples of the input signal to produce a first array of coefficients which depend on time and frequency, (c) construct an order mask array in response to user input designed to select coefficients from the first array which correspond to one or more order components in the input signal, (d) mask the first array of coefficients with the order mask array to generate a second array of coefficients which depend on time and frequency, wherein the second array of coefficients correspond to the one or more order components in the input signal, (e) generate a time domain signal from the second array of coefficients, and (f) present the time domain signal to a user on a presentation device. The signal analysis system may generate the time domain signal from the first coefficients by performing an inverse joint time-frequency transform on the first coefficients. The time domain signal may then be useable in analyzing the mechanical system.

Analyzing signals generated by rotating machines using an order mask to select desired order components of the signals

A signal analysis system and method for analyzing an input signal acquired from a mechanical system. The mechanical system may include at least one rotating apparatus. The signal analysis system may include an input for receiving samples of an input signal acquired from the mechanical system, wherein the input signal is sampled in time, and wherein the input signal comprises a plurality of order components. The signal analysis system may also include a processor coupled to the input and a memory medium coupled to the processor which stores analysis software. The processor may be operable to execute the analysis software to: (a) perform an invertible joint time-frequency transform on the input signal to produce a first array of coefficients which depend on time and frequency; (b) generate a modified array of coefficients from the first array of coefficients, wherein the modified array of coefficients corresponds to a desired subset of the plurality of order components; and (c) generate a time domain signal from the modified array of coefficients. The signal analysis system may also include a presentation device coupled to the processor which is operable to present the time domain signal to a user. The time domain signal is useable in analyzing operation of the rotating apparatus in the mechanical system.

System for analyzing signals generated by rotating machines

A signal analyzer, method and memory medium for generating a time varying spectrum for input signals characterized by frequency components which change in time. The signal analyzer includes a source of a sequence of digital signals representative of an input signal, a processor coupled to the source, and a memory medium coupled to the processor. The memory medium stores a software program which is executable by the processor to compute the time-varying spectrum of the input signal. When the processor executes the software program, the processor is operable to first compute a Gabor transform (that is, a sampled short-time Fourier transform) of the digital signals to produce Gabor coefficients. The processor then computes a two dimensional auto-correlation of the Gabor coefficients to produce auto-correlation results. The auto-correlation results are then applied to a 2-dimensional fast interpolation filter to produce the time-varying spectrum, wherein the time-varying spectrum is a Gabor spectrogram. The signal analyzer may repeat the above steps n&plus;1 times, based on the order determined by a user, and sum the results for an n order time-varying spectrum. The process more may then operate to process and/or display the time-varying spectrum.

Signal analyzer system and method for computing a fast Gabor spectrogram

A signal analysis system and method for analyzing an input signal acquired from a mechanical system. The mechanical system may include at least one rotating apparatus. The signal analysis system may be configured to: (a) receive samples of the input signal, (b) perform an invertible joint time-frequency transform (e.g. a Gabor transform) on the samples of the input signal to produce a first array of coefficients which depend on time and frequency, (c) compute an instantaneous rotation frequency signal, (d) select first coefficients from the first array which correspond to one or more order components in the input signal, i.e. one or more multiples of the instantaneous rotation frequency signal, (e) generate a time domain signal from the first coefficients, and (f) present the time domain signal to a user on a presentation device. The signal analysis system may generate the time domain signal from the first coefficients by performing an inverse joint time-frequency transform on the first coefficients.

System and method for analyzing signals generated by rotating machines

A signal analysis system and method for analyzing an input signal acquired from a mechanical system. The mechanical system may include at least one rotating apparatus. The signal analysis system may be configured to: (a) receive samples of the input signal, (b) perform an invertible joint time-frequency transform (e.g. a Gabor transform) on the samples of the input signal to produce a first array of coefficients which depend on time and frequency, (c) select first coefficients from the first array which correspond to a first subset of one or more order components in the input signal, (d) generate a time domain signal from the first coefficients, and (e) present the time domain signal to a user on a presentation device. The signal analysis system generate the time domain signal from the first coefficients by performing an inverse joint time-frequency transform on the first coefficients. The signal analysis system extract the one or more order components for presentation to the user by masking out all coefficients except those corresponding to the one or more components. Conversely, the signal analysis system may suppress the one or more order components, i.e. present to the user the input signal minus the one or more order components by masking out coefficients corresponding to the one or more components and keeping the remaining coefficients.

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Shie Qian