147 results about "Finite impulse response" patented technology

A closed-loop neuromodulation system, including an electrode array that is implantable to a brain of a subject, analog front-end device (AFD) for selectively selecting and reading a plurality of channels from electrode array, a finite impulse response (FIR) filter for selectively filtering signals from the AFD, a feature extraction engine (FEE) operatively connected to the FIR filter, configured to selectively extract features from signals provided by the FIR filter, a tree-structured hierarchical neural network classifier for detecting disease symptoms, and a multi-channel stimulator having high-voltage (HV) drivers operatively connectable to the electrode array.

The invention belongs to the technical field of underwater acoustic engineering and digital signal processing, and particularly relates to a fractional delay FIR (Finite Impulse Response) phase calibration method and system of a multichannel sonar system. Comprising the steps of signal acquisition and reference channel selection; high-precision relative delay estimation; calculating a cross-correlation function of other channel signals and the reference channel signal, performing coarse estimation by searching a peak point of the amplitude of the cross-correlation function, and performing fine estimation on the peak position by using a parabola interpolation method to obtain the delay time of each channel relative to the reference channel; designing an FIR fractional delay filter; digital filtering and phase calibration; verifying a calibration effect; and calculating the phase of each channel signal at the target frequency point after calibration, and counting the standard deviation of each channel signal so as to evaluate the improvement degree of phase consistency. The method aims at overcoming the defect that traditional integral multiple sampling delay correction precision is insufficient, high-precision phase compensation of a sub-sampling point level is achieved, and therefore the performance of algorithms such as beam forming of a multi-channel sonar system is remarkably improved.

Serializer / deserializer (SerDes) modules, equalizers, and equalization techniques having robust parameter initialization may substantially reduce convergence time. One illustrative equalizer includes: a discrete-time, finite impulse response (“FIR”) filter to convert a receive signal to a filtered signal; a decision element to determine channel symbols represented by the filtered signal; and a controller. The controller is configured to, for each of multiple values in a search range, estimate a performance of the equalizer based on the channel symbols and at least one of the filtered signal or an input signal to the decision element; configured to find a centroid value based on the performance for each of the multiple parameter values in the search range; and configured to derive an initial value for the parameter from the centroid value.

A feature extraction and simulation method for sound signals of an autonomous navigation ship tunnel thruster. A digital filter is used to process measured signals to remove spike signals, and the characteristics of residual wideband floor noise signals are analyzed. A finite impulse response filter is designed, and the impulse response of the finite impulse response filter is convolved with white Gaussian noise, so that simulated noise is matched with frequency-domain characteristics of floor noise signals. A spike signal amplitude is calculated, and a group of sine wave signals having a corresponding frequency are generated as spike signals. Narrowband spike signals and wideband floor signals are superposed and synthesized into simulated tunnel thruster noise. A feasible solution is provided for research and analysis of sound signals of a tunnel thruster. The sound characteristics of the tunnel thruster are accurately extracted, a predicted sound level is improved, and a tunnel thruster sound source database is established, thus providing valuable data support for signal quality analysis of a ship autonomous navigation system, fault diagnosis and improvement of a control strategy for the tunnel thruster.

Certain disclosed embodiments pertain to suppressing interference in a wireless communication system. For example, a method of suppressing interference can include receiving one, two, or more first signals including components from a plurality of sub-channels. Each of the first signals can be processed by a Finite Impulse Response filter adapted using an LMS update algorithm,

The invention discloses a distribution network power line anti-interference communication method based on adaptive filtering, and belongs to the technical field of distribution network power line communication. According to the method, a communication signal adopting a frequency shift keying modulation mode is acquired from a power line coupler of a distribution network through a signal acquisition module, the communication signal is preprocessed by using a digital signal processing unit, spectral analysis is performed on the preprocessed signal, and characteristic parameters of interference noise are extracted; a coefficient vector of a finite impulse response adaptive filter is initialized based on the characteristic parameters, the order of the filter is in direct proportion to the reciprocal of the dominant interference frequency, fine adjustment is carried out based on noise energy distribution through a table look-up method or a linear mapping relation, and the weight coefficient of the filter is adjusted in real time in the communication process. The adjustment step length is dynamically adjusted according to the real-time estimated signal-to-noise ratio, and finally, the processed signal is output through the adaptive filter and data demodulation is carried out. The method is mainly used for improving the anti-interference capability and the communication reliability of the power private line communication of the distribution network.

The invention discloses a gate fault detection method and system, and relates to the technical field of fault diagnosis and health monitoring, and the method comprises the steps: collecting a gate vibration signal, extracting a main modal frequency, setting a sampling frequency and a passband range, designing a finite impulse response filter for filtering, and carrying out the optimization through a particle swarm algorithm, thereby obtaining an enhanced signal; extracting features in the enhanced signal for integration to obtain a feature vector, mapping the feature vector to a discrete state set by using a rule threshold matching method, and obtaining a gate state; the method comprises the following steps: acquiring historical data for sampling, constructing a state transition probability matrix, calculating a steady-state probability vector according to the state transition probability matrix, combining a gate state, generating a state sequence track, setting an influence factor and a weight by using an empirical rule, and calculating a fault occurrence probability for risk detection; according to the method, the gate fault detection precision, efficiency and reliability are remarkably improved.

The invention discloses a GNSS element signal interference suppression method and system based on double complex number modeling, and the method comprises the steps: firstly introducing a double complex number model, carrying out the modeling of a received multi-frequency multi-path signal, and obtaining a GNSS element signal; secondly, carrying out modular operation projection on the GNSS element signal to obtain time-frequency domain analysis of the element signal, and obtaining a ridge value through detection; and correcting the ridge value to obtain instantaneous frequency estimation and instantaneous frequency modulation slope estimation of the element signal interference carrier and subcarrier, and applying the instantaneous frequency estimation and the instantaneous frequency modulation slope estimation to a finite impulse response filter to obtain the finite impulse response filter based on double complex numbers. And finally, performing double complex Kalman filtering on the received element signal to obtain an interference estimation value, removing the interference estimation value from the received element signal, and taking a real part to obtain a GNSS expected signal. According to the method, the high-precision interference is estimated by using the high-precision interference parameter estimation value and the double-complex Kalman filtering, and interference suppression in a multi-frequency multi-path environment is efficiently realized.

The invention relates to the technical field of optical communication, and discloses a multi-dimensional and multi-phase-based 50G PON signal noise compensation method, which comprises the following steps: S1, generating a mixed signal, including superposing a multi-phase orthogonal pilot signal into a data signal time domain at a transmitting end according to a preset proportion lower than the power of a data signal; and S2, transmitting the mixed signal in a polarization multiplexing mode, wherein the polarization multiplexing adopts double-channel parallel transmission of an X polarization state and a Y polarization state. Multi-phase orthogonal pilot signals are superposed to a data signal time domain in a low-power proportion at a transmitting end, polarization multiplexing dual-channel transmission is adopted, a narrow-band filter is utilized at a receiving end to separate pilots and calculate channel damage parameters, and a finite impulse response filter is configured to perform linear equalization compensation. And the simplified Kalman filtering algorithm is combined to estimate the phase noise and correct the phase, so that collaborative suppression of the linear channel damage and the phase noise in the 50G PON signal is facilitated.

Serializer / deserializer (SerDes) modules, equalizers, and equalization techniques having robust parameter initialization may substantially reduce convergence time. One illustrative equalizer includes: a discrete-time, finite impulse response (“FIR”) filter to convert a receive signal to a filtered signal; a decision element to determine channel symbols represented by the filtered signal; and a controller. The controller is configured to, for each of multiple values in a search range, estimate a performance of the equalizer based on the channel symbols and at least one of the filtered signal or an input signal to the decision element; configured to find a centroid value based on the performance for each of the multiple parameter values in the search range; and configured to derive an initial value for the parameter from the centroid value.

Data transceivers including a transmitter configured with a digital filter, and a receiver configured with an equalizer, are equipped with logic to measure a combined pulse response to a symbol generated by the transmitter at an output of the equalizer, adjust the combined pulse response by an impulse response of the digital filter to generate an adjusted pulse response, and modify the digital filter with one or more floating taps based on the adjusted pulse response.

Aspects of the present disclosure include a biometric device configured to receive biometric signals from sensors placed on a subject, and attenuate at frequencies causing noise in the biometric signals. Aspects are directed to a finite impulse response (FIR) filter configured to attenuate noise frequencies caused by line frequencies and / or flicker frequencies. Aspects of the FIR filter may be configured based on an analog-to-digital (ADC) sampling rate.

The invention relates to an analog-to-digital converter of an embedded filter, a driving chip and electronic equipment, and the analog-to-digital converter comprises a first analog-to-digital conversion module which is a successive approximation type analog-to-digital converter with a plurality of sampling capacitors and a plurality of sampling periods, the first analog-to-digital conversion module realizes a finite impulse response (FIR) filtering effect on an input sampling signal through charge sharing among sampling capacitors; and while part of the sampling capacitors still perform the process of sampling the input signals, the successive approximation quantization process of the signals on part of the sampling capacitors which have already been sampled is started. The analog-to-digital converter provided by the embodiment of the invention has a filtering characteristic and also has the characteristics of high bandwidth, low power consumption and small area.

The invention belongs to the technical field of ground penetrating radar signal processing, and relates to a ground penetrating radar signal denoising method based on optimal proportion-kurtosis joint masking, which comprises the following steps: carrying out short-time Fourier transform on a single-channel ground penetrating radar echo signal to obtain a complex time-frequency graph and a power spectrum thereof; calculating an optimal proportion masking index; calculating the frequency domain kurtosis of each frame according to the amplitude of the complex time-frequency graph in the time-frequency domain, and adaptively determining a kurtosis threshold; constructing an optimal proportion masking matrix, constructing a kurtosis masking matrix by using the kurtosis threshold, and multiplying the optimal proportion masking matrix and the kurtosis masking matrix point by point to obtain a final masking matrix; the final masking matrix is multiplied by the complex time-frequency graph, then inverse short-time Fourier transform is executed, and a preliminary denoising time-domain signal is reconstructed; and applying zero-phase finite impulse response band-pass filtering to obtain a final high-signal-to-noise-ratio ground penetrating radar signal. The method does not need to additionally collect a reference channel, is low in calculation complexity, and can remarkably improve the signal-to-noise ratio of the ground penetrating radar data and the target identifiability.

A system for beamforming and filtering. In some embodiments, the system includes an array of antenna elements; and a front-end circuit connected to the antenna elements, the front-end circuit including a plurality of delay elements. The delay elements may be configured to provide beam forming; and to operate as delay elements in a finite impulse response filter.

The invention provides a digital beam forming method and device based on multiple time delays and scale correction, and the method comprises the steps: determining a reference time delay group based on a plurality of reference positions divided from a corresponding breadth range in a distance direction; on the basis of the reference time delay group, performing finite impulse response (FIR) time delay filtering processing, scale transformation processing and pulse compression processing on an echo signal in sequence; and on the basis of an error compensation function, receiving scanning SCORE weighting is carried out on the signal after pulse compression, and a digital beam forming DBF composite signal is obtained. Therefore, the problems of inter-channel time delay and scale mismatch caused by view angle change in a large-breadth SAR system are effectively suppressed, the signal-to-noise ratio and the target positioning precision are improved, meanwhile, residual phase errors introduced by scale change are eliminated through an error compensation mechanism, and finally high-precision digital beam forming is achieved.

An equalizer circuit includes: an analog front end circuit configured to receive an analog input signal from a transmission line; an analog finite impulse response filter circuit including: a sample and hold circuit configured to sample an output of the analog front end circuit; and a weighting circuit configured to weight the output of the analog front end circuit to generate a feedforward signal; and a decision feedback equalizer circuit configured to receive an output of the analog front end circuit and the feedforward signal.

The invention relates to a road cavity detection and identification method and system based on multichannel optical fiber sensing. The method comprises the following steps: acquiring and storing Rayleigh scattering light time domain signals which are acquired by a DAS underground sensing system at different positions and different time periods of a detection road section and contain active knocking signals; determining a frequency range of the active knocking signal according to a frequency spectrum obtained after the Rayleigh scattering light time domain signal is subjected to fast Fourier transform processing; carrying out filtering processing on the Rayleigh scattering light time domain signal by adopting a finite impulse response band-pass filter to obtain a filtered signal; the filtered signal is input into a PhaseNetDAS model for seismic phase pickup, and an active source seismic phase is obtained; associating the active source seismic facies with the active source event to obtain a seismic facies report including event latitude and longitude, time and seismic facies arrival time; and inverting the velocity structure of the underground medium by using the seismic phase report by using a tomography method, and determining a road cavity detection and recognition result, thereby improving the accuracy of road cavity detection.

The invention discloses a bearing fault diagnosis method based on feature mode decomposition and heterogeneous model fusion, and belongs to the technical field of mechanical fault diagnosis. An original vibration signal of the rolling bearing is collected; independent of any bearing geometric parameter or fault characteristic frequency information, a finite impulse response (FIR) filter is iteratively optimized to maximize a correlation kurtosis (CK) value, and a plurality of intrinsic mode functions (IMF) are adaptively decomposed; selecting first M IMFs with the highest CK value, extracting time domain, frequency domain and nonlinear complexity features of the IMFs, generating high-order derivative features by adopting depth feature synthesis DFS, and constructing an enhanced fusion feature vector; and finally, inputting a stacked integrated classifier consisting of six types of heterogeneous basic learners and an XGBoost element learner, and outputting a fault diagnosis result. According to the method, high-precision and high-robustness diagnosis can still be realized under the working conditions of speed change, strong noise and weak faults.

The invention relates to the technical field of wireless communication, and discloses a novel channel estimation method based on residual frequency offset elimination, which comprises the following steps of: despreading descrambled pilot frequency data to obtain a channel estimation value after noise smoothing, and transmitting the channel estimation value to an FIR (Finite Impulse Response) filter to generate a noise suppression channel estimation signal; phase-frequency response of the noise suppression channel estimation signal is obtained through calculation, conjugate multiplication and smoothing are conducted on the phase-frequency response of the noise suppression channel estimation signal and the phase-frequency response of the FIR filter, a residual frequency offset estimation signal for suppressing the noise influence is obtained and compensated to the noise suppression channel estimation signal output by the FIR filter, and a noise suppression channel estimation value for eliminating the residual frequency offset influence is obtained. And balancing with the service de-spreading signal compensated by the residual frequency offset estimation signal to obtain a final output signal. According to the method, the phase-frequency response characteristics of the filter are deeply analyzed, the FIR filter is used for improving the signal-to-noise ratio, meanwhile, the residual frequency offset is estimated through the phase-frequency characteristics of the FIR filter, finally, the phase error is compensated for, an accurate channel estimation value is obtained, and the signal detection precision is improved.

An integrated circuit includes a continuous time delta sigma analog-to-digital converter (CTDS ADC) and a test circuit for testing the CTDS ADC. The test circuit converts multibit digital reference data to a single-bit digital stream. The test circuit then passes the single-bit digital stream to a finite impulse response digital-to-analog converter (FIR DAC). The FIR DAC converts the single-bit digital stream to an analog test signal. The analog test signal is then passed to the CTDS ADC. The CTDS ADC converts the analog test signal to digital test data. The test circuit analyzes the digital test data to determine the accuracy of the CTDS ADC.

The application relates to the field of photonic device modeling, and discloses a parameterized optoelectronic joint simulation platform construction method for optoelectronic chip design, which is characterized in that, in an electronic design automation platform, a unified model framework of a photonic device is constructed based on a hardware description language, and conversion between frequency domain response and time domain response is realized in the model, including the following steps: a general VerilogA model framework is constructed based on the frequency domain response of the photonic device; a frequency-time domain numerical conversion mechanism is realized in the model; and for the photonic device with dispersion characteristics, a parameterized time domain model is constructed based on a finite impulse response. The application can directly embed the photonic device model into an electronic circuit simulation environment, co-simulate the electronic device, support time-frequency domain analysis of the cascade structure and the loop structure, thereby avoiding the complicated steps of separate simulation by relying on external simulation tools in the process of optoelectronic chip design, and further improving the design efficiency and iteration speed of the chip.

The present invention provides a method and device for increasing the beam duty cycle by using colored noise, and relates to the field of particle accelerators and signal processing technology. The method comprises: generating a digital noise signal through a finite impulse response filter; converting the digital noise signal into two branch signals of equal magnitude and opposite sign through a phase shifter; and loading the two branch signals onto a transverse electrode plate after each of the two branch signals passes through an attenuator, an amplitude modulator, an impedance converter, and an all-pass network in sequence, thereby obtaining an extracted beam subjected to transverse excitation. The present invention can effectively improve the impact of the current traditional RF-KO sweep mode on beam extraction, making the time structure of the slow extraction beam more uniform, promoting the widespread application of precise point scanning, and improving treatment efficiency.

This invention relates to the field of track detection technology, and discloses a method, system, device, and medium for track elevation detection. The method includes: acquiring vehicle body state data and corresponding track elevation information when a vehicle is running on different tracks; constructing an inverse filter based on a finite impulse response (FIR) compensation filter, obtaining the mapping relationship between the corresponding vehicle body state data and track elevation information through the inverse filter, and optimizing the delay of the inverse filter using a recursive least squares method based on the mapping relationship; optimizing the order of the inverse filter using power spectral density analysis; reconstructing the acquired vehicle body response data based on the optimized delay and order of the inverse filter; training a convolutional neural network using all reconstructed vehicle body response data and corresponding track elevation information to obtain a track detection model, which is then used to detect the elevation of a target track, thereby improving the accuracy of track elevation detection.

The present invention discloses a dynamic monitoring system for underground heavy metal pollution based on geophysical methods, which relates to the field of environmental monitoring technology. The system comprises: a terahertz detection module, comprising a terahertz transmitting and receiving device, wherein the transmitting device can emit 0.5-5THz terahertz waves; and a receiving device using a superconducting detector with shielding and filtering components, which can record signal intensity and phase. The present invention uses the terahertz detection module, with its high-power, narrow-pulse terahertz source and high-precision superconducting tunnel junction detector, to accurately transmit and receive terahertz waves in a specific frequency range, thereby obtaining detailed signals of underground heavy metal pollution. The data processing and analysis module performs preprocessing through wavelet threshold denoising and finite impulse response filtering, and then uses an iterative terahertz spectrum inversion algorithm to convert the signal data into information on the concentration, type and distribution of underground heavy metal pollutants, providing an extremely detailed and accurate data basis for environmental governance.

Embodiments of the present disclosure relate to low power finite impulse response filters. A finite impulse response (FIR) filter includes a plurality of registers. A data input terminal of each register is directly coupled to an input of the FIR filter. On each clock cycle of a filter clock signal, a new data value is transferred to each register. On each clock cycle, only one register processes the data value. A ring counter is coupled to the registers and determines which register processes the data value on each clock cycle.

A noise reduction (NR) system includes a finite impulse response (FIR) filter and a filter manager circuit. The FIR filter is used to perform NR upon a filter input derived from an input signal. The filter manager circuit is used to determine a configuration of a minimum phase filter according to the input signal, and update the FIR filter by the configuration of the minimum phase filter.

The application belongs to the technical field of optical fiber communication, and particularly relates to a low-complexity real-time nonlinear compensation method for a short-distance optical fiber link system. The application adopts Volterra algorithm to realize nonlinear damage compensation. The algorithm is regarded as an adaptive updating tap filter, and is divided into a linear term finite impulse response filter calculation module, a nonlinear term finite impulse response filter calculation module, an error calculation module and a tap coefficient updating module. Further, the low-complexity processing of the nonlinear compensation is realized through pruning and non-uniform quantization. The application solves the nonlinear distortion problem caused by devices and transmission in the intensity modulation direct detection system, and is simpler to realize and has greatly reduced complexity, thereby saving power consumption more. The application has been verified on an FPGA development board, and provides a basis for the hardware implementation of the nonlinear compensation and lays a foundation for the further development of future optical fiber communication systems.

The invention provides a WiFi network digital down-conversion system which comprises a multi-phase mixer and a resampling filter. The multi-phase mixer is used for converting a high-speed digital band-pass signal into a low-speed mode so as to realize digital down-conversion (DDC) on an FPGA (Field Programmable Gate Array) platform; and the resampling filter is used for reducing the sampling rate and removing unwanted frequency spectrum components to generate a complex baseband frequency spectrum. The multi-phase mixer PM of the present invention employs a parallel coordinate rotation digital computer (CORDIC) processor and a low pass filter array to reduce high speed data rates while minimizing resource utilization. The resampling filter comprises a cascade integral combination (CIC) filter and a multi-channel pulse finite impulse response (FIR) filter, optimal hardware cost is achieved, a floating point data type is converted into a fixed point data type, and resources are remarkably saved.

The application relates to the field of ultra-wideband radar imaging and optical computing technology, in particular to a light computing real-time processing method for ultra-wideband radar imaging. The method comprises core steps of signal receiving and electro-optical modulation, optical pulse compression, initial phase compensation based on Kalman filtering, envelope alignment, coherence recovery and two-dimensional grid projection. Based on the ultrafast linear processing advantage and algorithm optimization principle of light computing, the application utilizes optical finite impulse response filters and adjustable delay line technology to disassemble and reconstruct the traditional imaging method, and reduces the end-to-end processing delay to the sub-millisecond level. The application breaks through the real-time processing bottleneck of ultra-wideband radar imaging, provides effective theoretical support and method basis for developing a full real-time ultra-wideband two-dimensional fine imaging system, and is widely applicable to application fields with high real-time requirements such as military reconnaissance and geological exploration.