60 results about "Quadrature filter" patented technology

The present invention relates to methods for providing impedance protection differentiating between in-zone and out-of-zone faults based on instantaneous, digitally derived operating and polarizing, distance comparator signals. The method uses a pair of fast orthogonal filters to derive D and Q components of the input voltages and currents. Two sets of operating and polarizing signals are derived for better speed of response under varying fault moment with respect to the peaks and zero crossings of power signals. Three stages of comparison between the operating and polarizing impedance terms are used. These comparator stages use half a cycle averaging windows, and three-quarters-of-a-cycle windows. The first stage of comparison is based on energy comparator responding to both magnitude and phase information in the signals. Stages 2 and 3 are of phase comparison type, responding mostly at the phase information and neglecting the magnitude information for better immunity to noise and signal distortions.

A method for designing QMF set includes designing original filter according to preset initial cut-off frequency, calculating system function of analysis filter according to system function of original filter, calculating system function of each analysis filter and composition error under each cut-off frequency, obtaining system function of each analysis filter and each integrated filter on confirmed QMF set according to cut-off frequency corresponding to minimum composition error.

The invention discloses an orthogonal filter-based inverter non AC voltage sensor control method. The method comprises steps: a second-order generalized integrator is firstly used for constructing an orthogonal filter according to no difference following characteristics of specific-frequency AC signals; the orthogonal filter is then used for constructing a voltage observer of a three-phase grid-connected inverter, in a two-phase stationary coordinate system, grid side current signals obtained after measurement and voltage reference signals at an inverter controller output bridge end serve as input of the voltage observer for carrying out observation on the grid voltage; and in combination with PR control of the three-phase grid-connected inverter in the two-phase stationary coordinate system, operation control on the inverter in the condition of non AC voltage sensor can be realized. Due to the method, in the condition of ensuring control stability of the inverter, integral saturation, initial value sensitivity, static error and other problems possibly appearing during the conventional non AC voltage sensor control can be avoided, and the method has the advantages of being quick, free of static errors and insensitive to the initial value.

The invention discloses a miniature dual microwave and millimeter wave self-load I/Q quadrature filter which comprises a directional coupler and two microwave and millimeter wave filters. Wherein the directional coupler is in self connection with a matched load and the two microwave and millimeter wave filters are each of a strip line structure. The directional coupler in self connection with the matched load comprises a surface-mounted input/output interface, a broadside coupling strip line of a dual spiral structure and the matched load in self connection with an isolation port. The two microwave and millimeter wave filters each comprise a surface-mounted output interface and a six-level parallel resonance unit achieved through the strip line structure, and the structures are achieved through the multi-layer low temperature co-fired ceramic process technology. The miniature dual microwave and millimeter wave self-load I/Q quadrature filter has the advantages of being free of any external load, capable of generating a quadrature phase, easy to debug, small in insertion loss, light, small in size, high in reliability, good in electrical performance, good in temperature stability, good in electrical performance batch consistency, low in cost and the like, and is suitable for communication of corresponding millimeter wave frequency bands, satellite communications, and other occasions and corresponding systems having strict requirements for sizes, electrical performance, temperature stability and reliability.

The invention discloses a switching circuit fault classifying method based on wavelet transform and ICA feature extraction. The method comprises the following steps: (1) generating a pseudo random signal as a test stimulation signal; (2) defining a fault mode; (3) acquiring the original response data of the circuit; (4) pre-treating the original response data by a Haar wavelet orthogonal filter; (5) extracting the fault feature parameters, and calculating the entropy and kurtosis as well as fuzzy sets thereof of low-frequency approximate information and high-frequency detail information for the pre-treated signal respectively; and (6) constructing a fault dictionary based on the extracted fault feature parameters so as to realize fault classification of the switching circuit. The method disclosed by the invention has the advantages of skillful concept, easiness in implementation and simulation proof and can distinguish the fault types more accurately than the existing method.

A method for processing image data includes inputting image data, determining a plurality of quadrature filter pairs based on filter parameter values to detect features of interest in the image data, applying the quadrature filter pairs to the image data to obtain a set of filter responses, and processing the filter responses to obtain the features of interest in the image data.

The invention discloses a mini active microwave and millimeter wave self-loading I/Q variable phase reversal orthogonal filter, which comprises a single-pole double-throw switch chip KD102010040, a low-noise amplifier chip WFD022036-L12, a surface mount 50-ohm impedance input/output interface, a parallel resonance unit module implemented through a strip line structure, a broadside coupled strip line of a double helix structure and a matched load connected to an isolated port, wherein the structures are implemented by adopting a multilayer low-temperature co-fired ceramic technology (LTCC technology). The mini active microwave and millimeter wave self-loading I/Q variable phase reversal orthogonal filter has the advantages of no external load, variability, phase reversal orthogonality, small insertion loss, easiness in debugging, light weight, small volume, high reliability, good electrical property, good temperature stability, low cost, mass production and the like, and is applied to communication, satellite communication and the other occasion at the corresponding millimeter wave frequency band have strict requirements on the volume, the electrical property, the temperature stability and the reliability and corresponding systems.

The device for designing dual orthogonal filter (DOF) includes following parts and operations: transmission filter (TF) design device in use for designing TF by using traditional method; FFT device in use to calculate FFT to calculate frequency response; device for selecting target correlation function in use for selecting target cross power spectrum function (TCPSF), and aliasing the function sampled in 1/Ts interval to obtain a constant; device for designing receiving filter carries out dividing TCPSF by frequency response of transmission filter in frequency domain (FD), or equivalent deconvolution operation in time domain (TD); adding window for the result, or equivalent convolution operation of window function in TD; inverse Fourier transforming the signal with window being added to TD, conjugated backout for the signal in TD so as to obtain impulse response in TD of DOF. Dual orthogonal nature between receiving filter and TF guarantees no loss on comm. system.

The invention discloses a fruit-form multiple-dimensioned energy measuring method and device, which will get 256 edge points by interpolating cubic spline to the fruit edge curve, compute the normalization distances from the points to the center and ascertain the corresponding random radius function, then compute the maximum value of the F(k)'s mathematical expectation and assure the origin of the curve. Using coiflets quadrature filtering device to process the F(k) and get the energy distribution vector E={Ed(1), Ed(2), Ed(3), Ed(4), Ed(5), Ed(6), Ea}, detecting the vector E's input sheet, implicit sheet and the nerval net of the output sheet whose number is 7, 8, and 3. The measuring device comprises an approach switch, two carrier wheels, chain conveying appliances, a frenquency divider, an illuminating bag, a camera, an image collecting card, a computer and a fruit-form detecting software.

The invention discloses a digital multichannel correlated processing system which comprises at least one acquisition processing module, at least one data sending module, at least one data receiving module and at least one correlated processing module. The acquisition processing module is used for carrying out digital sampling and quadrature filtering processing on input multichannel intermediate frequency analog signals, packing the input multichannel intermediate frequency analog signals into frames and sending the frames to the data sending module; the data sending module is used for outputting the received data frames to the data receiving module according to sampling moments in time slots; the data receiving module is used for packing the received data frames according to the sampling moments and outputting data packets to the correlated processing module; and the correlated processing module is used for carrying out unpacking on the received data packets, carrying out correlated operation and packing the data packets into frames to be output. The invention also discloses an output method for a buffer module in the system. The digital multichannel correlated processing system and the output method for the buffer module, which are disclosed by the invention, have the advantages of low hardware complexity, high system expandability, strong processing structure universality, low system resource consumption and high application flexibility.

The invention provides a multiple access method (F-BFDM) and a system thereof applicable to multiple application scene signals in wireless communication. The method comprises the following steps of: firstly performing a fast Fourier transform (FFT) change to each path of signals at a transmitting end to configure the signals to the allocated frequency bands, then pre-filtering to reduce the peak-to-average power ratio (PAPR) of a modulated signal, modulating the filtered signal onto a subcarrier by a cyclic Fourier transform (CCIDFT), combining the modulated signals of each path, and transmitting the combined signals to a channel together with a cyclic prefix (CP). The signal of each path in the invention corresponds to an application scenario, the complete reconstruction of the system iscompleted by the CCDFT at the receiving end, and the CCDFT is implemented by a bi-orthogonal filter bank. By freely designing a prototype filter, the interference of multiple application scene signalsfor multiple accessing can be minimized, so that the signal of each path can be accessed without interference under the situation that no isolation band exists, and the spectral efficiency can be maximized.

A system and method for measuring optical characteristics of an optical device under test (DUT) is provided. The system includes a light source for generating an optical signal applied to the optical DUT. A reference interferometer and a test interferometer are optically coupled to the light source. A computing unit is coupled to the interferometers, and utilizes amplitude and phase computing components, such as orthogonal filters, in determining optical characteristics of the optical DUT.

The invention discloses a converter control method without an AC voltage sensor during the asymmetric network voltage. The method comprises the steps: firstly building a quadrature filter for the no-difference following characteristics of an AC signal with the specific frequency through employing a second-order generalized integrator, and building a voltage observer of a three-phase grid-connected inverter under the condition of the asymmetric network voltage through employing the quadrature filter; firstly taking a measured power grid side current signal and an output bridge end reference signal of an inverter controller as the input of the voltage observer in a two-phase static coordinate system, and carrying out the observation of the network voltage; thirdly carrying out the positive and negative separation based on the output quantity of the quadrature filter, thereby enabling the positive and negative separation and the network voltage observation to be carried out synchronously; finally combining with the PR control of the three-phase grid-connected inverter in the two-phase static coordinate system and employing a negative compensation algorithm, thereby achieving the control of the inverter without the AC voltage sensor under the condition of the asymmetric network voltage.

The invention discloses a wavelet base construction method for a ground penetrating radar signal based on a lifting scheme. A method for constructing a matched wavelet according to a biorthogonal wavelet theory and target signal waveform characteristics is provided for a problem of extraction of the characteristics of a hole detection signal at the back of a tunnel lining. The method is based on aperfect reconstruction filter condition and a lifting scheme wavelet, different lifting operators and dual lifting operators are acquired by carrying out lifting and dual lifting on an initial biorthogonal filter, and the actual characteristics of the ground penetrating radar signal is combined to construct a new biorthogonal wavelet base which not only meets the linear phase and the tight support but also has the advantages of being high in signal matching degree with the ground penetrating radar signal and the like. According to the wavelet base construction method for the ground penetrating radar signal based on the lifting scheme, the wavelet base is applied to quantitative analysis of hole defects of an indoor hole detection test, and compared with other types of wavelets, the wavelet constructed by the lifting scheme can more accurately identify the time and the position of a mutation point of the hole defect signal, and quantitative analysis of the position and the vertical dimension of the hole defect in the tunnel engineering can be realized more accurately, so that the reliability and accuracy of the ground penetrating radar on the defect detection are greatly improved.

The invention provides a method and device for processing signals, which is used for solving the problems of low spectrum utilization rate, high resource overhead and complex design caused by the adoption of the existing FIR (Finite Impulse Response) filter in a system with a very low proportion of a transition band relative to the whole bandwidth in the prior art. The embodiment of the inventioncarries out filter design, orthogonal decomposition is performed on a required original signal, an FIR filter is generated according to the layer number of orthogonal decomposition and the edge high frequency bandwidth of the original signal after orthogonal decomposition, an edge high frequency signal of the original signal is filtered by adopting the FIR filter, and the filtered signal and a low-frequency signal are enabled to pass through an orthogonal filter bank for signal synthesis processing. The method adopts step-by-step decomposition on the signal, and the bandwidth of the decomposedhigh-frequency signal is narrowed relative to the whole original signal, so that the order of the generated FIR filter is reduced because the bandwidth of the transition band is constant. In addition, the calculation amount is greatly reduced, the resource overhead is small, and the design process is simpler and more convenient.

A signal processing device includes a biorthogonal filter bank that processes a finite length signal including a left boundary and a right boundary. The biorthogonal filter bank includes an analysis filter bank. The analysis filter bank includes one or more left boundary filters, one or more right boundary filters, and one or more steady-state analysis filters. Each left boundary filter and each right boundary filter includes a row vector. The left and right boundary filters have been designed by generating, from the steady-state analysis filters, an analysis matrix representing the analysis filter bank, multiplying the analysis matrix by a permutation matrix to generate a permutated analysis matrix, truncating the permutated analysis matrix to a degree to generate a rectangular truncated analysis matrix, and selecting a number of left boundary filters and a number of right boundary filters such that, when the row vectors corresponding to the number of left boundary filters and the number of right boundary filters are added to the truncated analysis matrix, the truncated analysis matrix becomes square. Each row vector added to the truncated analysis matrix lies outside a row space of the truncated analysis matrix such that a row vector specifies a permissible design for a boundary filter. The biorthogonal filter bank also includes a synthesis filter bank corresponding to the analysis filter bank. The synthesis filter bank includes a number of left boundary filters, a number of right boundary filters, and a number of steady-state synthesis filters. A synthesis matrix specifies the left boundary filters, right boundary filters, and steady-state synthesis filters of the synthesis filter bank. The synthesis matrix has been created by calculating the dual, or inverse, of the square analysis matrix.

The invention discloses a control word and I/Q waveform synchronous transmission method and device oriented to efficient mobile forward transmission, and the method comprises the steps: carrying out the quadrature amplitude modulation (QAM) constellation diagram mapping of control word data at a transmitting end, converting the control word data into a control word QAM symbol, carrying out the time domain up-sampling and digital orthogonal filtering of an I/Q component of the control word QAM symbol and a mobile signal I/Q waveform, and carrying out the time domain up-sampling and digital orthogonal filtering of the I/Q component of the control word QAM symbol; adding the filtered control word QAM symbol and the mobile signal I/Q waveform in a digital domain to realize channel aggregation; and at a receiving end, digitalizing the light current by an analog-to-digital converter and inputting into a plurality of parallel digital orthogonal filters to realize channel separation, and finally, recovering a control word QAM symbol and a mobile signal I/Q waveform through time domain down-sampling. According to the method, time domain up-sampling, digital orthogonal filtering and digital domain addition are used for replacing complex FFT/IFFT operation, the operation complexity, signal time delay and optical transceiver hardware development difficulty are remarkably reduced, good back compatibility is achieved for traditional mobile forward transmission, a communication system is easy to construct, and hardware is easy to achieve.

Embodiments provide a method for processing an audio signal, including: performing a cascaded lapped critically sampled transform on two partially overlapping blocks of samples of the audio signal, to obtain sets of subband samples; identifying one or more sets of subband samples that in combination represent the same region of the time-frequency plane; performing time-frequency transforms on the identified one or more sets of subband samples, to obtain one or more time-frequency transformed subband samples, each of which represents the same region in the time-frequency plane; performing a weighted combination of two corresponding sets of subband samples or time-frequency transformed versions thereof, to obtain aliasing reduced subband representations of the audio signal.