21 results about "Filter bandwidth" patented technology

The invention discloses cross-scene reusable multi-modal physiological intelligent monitoring equipment and system. The equipment comprises a multi-modal physiological acquisition sensing array, an acquisition control module, a placement detection module, a self-adaptive parameter adjustment module and a signal processing module. The multi-modal physiological acquisition sensing array comprises an ambient light sensor, a photoelectric volume pulse wave sensor, a temperature sensor, a sensing electrode, a pressurizing electrode, a sound collector, an inertial measurement unit and the like; the placement detection module is used for calculating the comprehensive confidence coefficient of the current physiological electric signal belonging to each physiological signal type for each signal acquired by the multi-modal physiological acquisition sensing array, so as to judge the physiological signal type to which the physiological electric signal belongs; the adaptive parameter adjusting module is used for generating a sampling rate, an amplification factor, a filtering bandwidth and an ADC bit depth corresponding to the current physiological signal type; and the signal processing module is used for carrying out signal processing according to the parameters of the self-adaptive parameter adjusting module. Multi-modal physiological signal monitoring can be realized by adopting one set of equipment.

The application provides a terahertz wave tunable waveguide type narrow-band filter and a manufacturing method thereof. The filter comprises a cavity with a rectangular structure, the upper surface and the lower surface of the cavity are low-loss metal surfaces with a periodic groove structure, a wedge-shaped protruding area is arranged in the middle of the cavity, and the two side walls are flat. The application has the advantages of simple structure, small size, low cost, easy integration, high Q value, small insertion loss, small transmission loss, and the like. The tuning of the output center frequency of the filter can be realized by adjusting the transverse position of the filter. The filter bandwidth and the transmissivity of the filter can be changed by changing the number of waveguide periods, the distance between the upper and lower flat plates, and the groove depth.

The invention discloses a wavelength division isolation anti-interference method and system for a radio frequency optical network front return signal, and the method comprises the steps: introducing an interference monitoring system which represents the quality of a radio frequency signal and the power optical noise at the same time, and constructing a wavelength interference matrix of the normalized interference intensity between any wavelength channel pairs according to the interference monitoring system; carrying out topology analysis based on the matrix, calculating the interference degree and automatically dividing interference clusters of high-interference channels to realize global perception and quantitative description of a common-fiber link interference relationship; target wavelength configuration parameters of the central wavelength, the wavelength interval, the guard band width and the optical filter bandwidth of each channel are adaptively determined by using the interference matrix and the interference cluster result, and differential widening and frequency shift are performed on the channels in the interference cluster; and finally, by controlling the adjustable light source and the adjustable optical filter, the wavelength division configuration is dynamically reconstructed along with the interference environment. Therefore, in an ARoF + PoF common-fiber transmission scene, both the anti-interference capability of the radio frequency signal and the frequency spectrum utilization rate of the optical fiber can be considered.

The utility model provides a weft self-adaptive detection device for a weft accumulator. The weft self-adaptive detection device comprises a photoelectric transmitting and receiving module, a primary filtering module, a secondary filtering module, a weft threshold signal judging and adjusting module and an electronic control module, the photoelectric emitting and receiving module detects weft yarns and sends weft yarn detection signals to the primary filtering module and the electronic control module; the first-stage filtering module comprises a first multi-stage filtering circuit, and the first multi-stage filtering circuit is provided with a bandwidth adjusting unit; the electronic control module is connected with the bandwidth adjusting unit to adjust the filtering bandwidth of the first-stage filtering module; the secondary filtering module comprises a second multi-order filtering circuit, and the second multi-order filtering circuit is provided with a gain adjusting unit; the electronic control module is connected with the gain adjusting unit to adjust the gain of the secondary filtering module; the weft yarn threshold signal judging and adjusting module comprises a hysteresis comparison circuit, and the hysteresis comparison circuit is provided with a threshold adjusting unit; the electronic control module is connected with the threshold adjusting unit to adjust hysteresis threshold voltage.

This invention discloses a DPSK receiver for adapting to the defect of undesirable carrier frequency variation over time in the presence of a transmitter. The aim of providing an apparatus and method for adapting the receiver to transmitter defects is thus achieved. The frequency offset estimation unit includes a first phase estimation unit, a second phase estimation unit, and a clean / dirty selector, wherein a first phase error estimate e is output. dirty (k) The first phase estimation unit includes a first frequency offset estimation low-pass filter, the bandwidth of which is wider than the bandwidth of the second frequency offset estimation low-pass filter in the second phase estimation unit. The second phase estimation unit outputs a second phase error estimate e. clean (k), the dirty / clean selector is configured to compare the ratio of the second phase error estimate to the first phase error estimate with a threshold T and output a binary comparison result c(k). The demodulation reference estimation unit includes a first filter and a second filter, wherein the filter bandwidth of the first filter, which is part of the “dirty” reception path of the receiver, is wider than the filter bandwidth of the second filter, which is part of the “clean” reception path of the receiver. If the ratio of the second phase error estimate to the first phase error estimate is lower than the threshold T, the “clean” reception path is used to output the received information bits; otherwise, the “dirty” reception path is used.

The invention discloses a rolling bearing fault sound feature extraction method based on anti-noise Hough index guided optimal demodulation. The method comprises the following steps: collecting a sound signal during operation of rotating mechanical equipment through a sound sensor; determining a preset filtering bandwidth and a center frequency sequence; respectively carrying out band-pass filtering on the sound signal according to the filtering bandwidth and the center frequency sequence; calculating an anti-noise Hough index of each filtering signal to obtain a corresponding sequence; outputting the filtering signal corresponding to the maximum anti-noise Hough index as a target filtering signal; performing element-by-element adaptive sparse processing on the target filtering signal; demodulating the signal after the sparse processing by using an enhanced frequency weighted energy operator; and performing square envelope spectrum analysis on the demodulated signal to realize extraction of each fault characteristic frequency of the rolling bearing and recognition of a bearing fault mode. According to the method, the weak fault characteristic frequency of the rolling bearing can be adaptively and accurately extracted based on the non-contact acoustic measurement signal with a lower signal-to-noise ratio.

Embodiments of the present disclosure relate to systems, methods, apparatuses, and computer program products that align filter configurations between a device and a network. A method can include transmitting capability information to a network element. The method can also include receiving a radio resource configuration from the network element, the radio resource configuration including parameters for support of frequency arrangement and dynamic analog filter bandwidth switching determined from a local oscillator, and at least one parameter range. The method can further include maintaining a current local oscillator arrangement and analog filter configuration, or switching to a new local oscillator arrangement and analog filter bandwidth configuration, based on the radio resource configuration.

The embodiment of the invention discloses a signal processing method and system. The method is applied to a transmitting end, and comprises the following steps: acquiring a baseband signal to be transmitted, and determining a filter bandwidth of a channel where the baseband signal is located; determining the bandwidth of the pseudo-random sequence generated by the pseudo-random sequence generator based on the filter bandwidth; performing spread spectrum processing on the baseband signal based on the bandwidth of the pseudo-random sequence, and transmitting the radio frequency signal after the spread spectrum processing; wherein the bandwidth of the radio frequency signal after the spread spectrum processing is equal to the bandwidth of the filter. According to the technical scheme, the bandwidth of the pseudo-random sequence generated by the pseudo-random sequence generator can be determined through the bandwidth of the filter, and spectrum spreading processing is carried out on the baseband signal through the bandwidth of the pseudo-random sequence, so that the bandwidth of the baseband signal is expanded to be the same as the bandwidth of the filter; therefore, all useful signals of the baseband signals can pass through the filter, and useless out-of-band signals are just out of the band of the filter and can be filtered out, so that the signals can be better filtered.

The invention discloses a terminal general processing resource allocation architecture suitable for multi-system satellite communication waveforms. The architecture comprises intermediate frequency preprocessing resource evaluation, baseband processing resource evaluation, protocol processing resource evaluation and internal and external interface resource evaluation. And allocating a filtering bandwidth, a receiving level, an analog transceiving channel, a baseband processing resource, a protocol processing resource and an internal and external interface resource. Through intermediate frequency preprocessing resource evaluation, baseband processing resource evaluation, protocol processing resource evaluation and internal and external interface resource evaluation, a terminal product developed based on the method can support switching operation of various satellite communication system waveforms, the number of terminals is reduced, and the development and maintenance cost of the terminal product in the whole life cycle is reduced; and hardware resource configuration and maintenance support equipment are reduced, and the use and maintenance support pressure is reduced.

This application discloses a wavelength division multiplexing (WDM) isolation anti-interference method and system for front-back signals in radio frequency (RF) optical networks. The method includes: introducing an interference monitoring system that simultaneously characterizes RF signal quality and power optical noise, and constructing a wavelength interference matrix based on this matrix to represent the normalized interference intensity between arbitrary wavelength channel pairs; performing topology analysis based on this matrix to calculate the interference degree and automatically classify high-interference channel interference clusters, achieving global perception and quantitative characterization of interference relationships in co-fiber links; using the interference matrix and interference cluster results, adaptively determining the target wavelength configuration parameters for the center wavelength, wavelength spacing, guard band width, and optical filter bandwidth of each channel, and implementing differentiated widening and frequency shifting of channels within the interference clusters; finally, by controlling tunable light sources and tunable optical filters, the WDM configuration is dynamically reconstructed according to the interference environment. Therefore, in ARoF+PoF co-fiber transmission scenarios, both RF signal anti-interference capability and fiber optic spectrum utilization can be balanced.

The application provides a filter bandwidth selection method and device for a Raman-fluorescence laser radar. The method provided by the application comprises the following steps: using a biological optical model to solve the attenuation contribution of pure water and chlorophyll components in a water body to a laser signal, and obtaining water optical parameters; constructing a laser radar signal simulation model based on the water optical parameters; including background light noise into the laser radar signal simulation model to form a complete received signal model; taking the ratio of a target channel exclusive signal to the complete received signal as the target signal ratio of filter bandwidth selection; determining a signal intensity rule; determining a target signal ratio rule; setting a signal intensity lower limit and a target signal ratio lower limit based on the signal intensity rule and the target signal ratio rule, screening out a filter bandwidth range that meets the requirements of both lower limits, and determining the maximum bandwidth in the filter bandwidth range as the optimal filter bandwidth.

The invention discloses an angular spectrum diffraction method based on dynamic acquisition of effective information of an object field spectrum, and the method comprises the steps: dynamically extracting the effective information in the object field spectrum through a multistage threshold image segmentation algorithm, adaptively adjusting the filtering bandwidth, optimizing a sampling strategy of a transfer function, and obtaining the effective information of the object field spectrum. Therefore, the calculation complexity and the memory occupation are remarkably reduced while the calculation precision is ensured. The method solves the problems of undersampling and computing resource waste in far-field diffraction calculation of a traditional angular spectrum method, is particularly suitable for diffraction calculation of a complex light field containing a high-frequency component, and has a wide application prospect in the fields of digital holography, light beam quality analysis and the like.

The invention relates to an intelligent dynamic response phase-locked loop filtering method and system, and belongs to the technical field of phase-locked loops, and the method comprises the steps: carrying out the fragmentation cooperative processing of a phase-locked loop output signal, so as to detect the noise characteristics of the output signal in real time, and the noise characteristics at least comprise the frequency domain noise distribution information of the output signal; dynamically matching the optimal filter bandwidth in the current noise environment according to the noise characteristics; and adjusting the actual bandwidth of the filter in the phase-locked loop according to the optimal filter bandwidth. According to the invention, the bandwidth can be dynamically adjusted according to the real-time signal noise environment, so that the optimal filtering effect can be obtained under different noise conditions.

This invention discloses a method for calculating and calibrating the cumulative radiance matrix within the effective bandwidth of a narrowband filter. The method first acquires the transmittance curve of the narrowband filter and determines the effective bandwidth integration interval. It then collects the response value matrix and dark background response matrix of a blackbody at multiple temperature points. Dark background correction and exposure normalization are performed on the response value matrix to obtain the blackbody bandwidth cumulative response matrix. Discrete integration is then performed on the blackbody spectral radiance and filter transmittance within the effective bandwidth integration interval to obtain the bandwidth cumulative radiance matrix corresponding to each temperature point. A polynomial mapping relationship between the bandwidth cumulative response matrix and the bandwidth cumulative radiance matrix is ​​established based on multi-temperature point samples. The global calibration coefficient set is obtained through least squares solution. After calibration, the original response value matrix and dark background response matrix of the object under test are acquired and subjected to consistent correction and normalization. These are then substituted into the mapping relationship to calculate and output the cumulative radiance matrix including the object under test. This method enables quantitative calculation of the cumulative radiance matrix within the effective bandwidth at the pixel level, avoiding errors caused by center wavelength approximation or single-point correction. It has the advantages of strong applicability, high computational efficiency, and simple engineering implementation.

The application provides a frequency shift control method, device and system of a repeater master-slave system, and belongs to the field of communication technology. The method applied to a master device comprises the following steps: performing bandwidth segmentation and interference signal energy scanning on a signal bandwidth corresponding to a current configuration frequency point according to a first bandwidth segmentation number to obtain a first scanning result; the scanning point for interference signal energy scanning corresponds to the bandwidth after signal bandwidth segmentation; determining a target frequency shift frequency point and a corresponding target bandwidth according to the first scanning result; configuring a master filter bandwidth and a master local oscillator frequency according to the frequency shift frequency point and the corresponding target bandwidth, and sending the frequency shift frequency point and the corresponding target bandwidth to a slave device of the repeater master-slave system; performing frequency shift processing on a received working signal according to the master filter bandwidth and the master local oscillator frequency, and sending a frequency-shifted signal after frequency shift processing to the slave device. The signal interference is reduced through the bandwidth segmentation and frequency shift mode, and the transmission effect is ensured.

A filter and a forming method thereof and an electronic device, the forming method comprising: after providing a piezoelectric laminated structure, a first thinning treatment is performed on a passivation layer in a target resonant region, so that the thickness of the passivation layer in the target resonant region is less than that in other resonant regions, and the vibration frequency of the passivation layer in the target resonant region is faster than that in other resonant regions, the frequency of the resonator in the target resonant region is right-shifted, which is beneficial to making the target resonant region used to form the resonator with the highest vibration frequency, and the performance of the filter bandwidth corresponding to the filter bandwidth is increased, because the first thinning treatment further reduces the surface roughness of the passivation layer in the target resonant region, which means that the thickness uniformity of the passivation layer in the target resonant region is improved, so that the right side frequency of the filter bandwidth is modulated, and the uniformity of the right side frequency of the filter bandwidth is improved, and more frequency points will fall within the range required by the specification during measurement, which is beneficial to improve the yield of the filter.

The present application belongs to the technical field of signal acquisition and processing, and discloses a low-noise bioelectric potential signal acquisition system and processing method. The original bioelectric signal of a human body is acquired through an electrode array, and is processed by a multi-stage adaptive filter amplification circuit and then subjected to analog-digital conversion. The digital signal is subjected to adaptive wavelet transform denoising and empirical mode decomposition to obtain a multi-level intrinsic mode function set, from which an intrinsic mode function of a characteristic frequency band is extracted and a signal is reconstructed. A double denoising mechanism combining adaptive wavelet transform and empirical mode decomposition is introduced. A signal quality real-time evaluation system is established, and system parameters, including a variable gain amplifier gain and a dynamic band-pass filter bandwidth, are dynamically adjusted through closed-loop feedback. The adaptive optimization of the whole bioelectric potential signal acquisition process is realized, various types of interference are effectively suppressed, signal characteristics are retained, and the signal-to-noise ratio is significantly improved.

The invention discloses a bandwidth-tunable time-varying optical filtering device and method based on a stimulated Brillouin scattering effect. A double-parallel Mach-Zehnder modulator is driven by a sweep-frequency electric signal to modulate an optical carrier, so that sweep-frequency pump light is generated; sweep frequency pump light is input into a nonlinear medium to excite frequency time-varying stimulated Brillouin gain, so that frequency time-varying optical filtering of a probe light signal can be realized; by changing the chirp rate, the bandwidth and the matching relation between the duration and the nonlinear medium of the sweep frequency pump light, the center frequency change rate, the change range and the filtering bandwidth of the time-varying optical filtering response can be changed; the unevenness of the time-varying optical filtering response can be compensated through amplitude pre-distortion of the sweep frequency pump light. The bandwidth-tunable time-varying optical filtering device and the bandwidth-tunable time-varying optical filtering method provided by the invention can process non-stationary optical signals, and have good application prospects in application scenes requiring time-varying narrow-band optical filtering, such as laser radar, optical fiber sensing, microwave photon filtering and the like.

The application relates to the technical field of data processing, and discloses a signal intra-pulse modulation pattern identification method and system, which comprises the following steps: receiving a radar pulse signal; performing short-time Fourier transform on the radar pulse signal; in a time-frequency matrix, calculating the energy distribution gradient of each time point along the frequency axis; identifying a gradient mutation point according to the energy distribution gradient of each time point; determining the filter bandwidth boundary based on the gradient mutation point by adopting a negative feedback adjustment mechanism of bandwidth and signal-to-noise ratio; performing bandwidth filtering on the radar pulse signal based on the filter bandwidth boundary; calculating the instantaneous frequency, the first-order differential frequency and the second-order differential frequency of the filtered signal through Hilbert transform, and forming a feature vector; predicting the clustering number range through a long short-term memory neural network according to the feature vector; performing clustering analysis within the clustering number range through a K-Means clustering algorithm according to the feature vector; and outputting a modulation pattern label according to the clustering analysis result.

An adaptive signal conditioning and noise reduction system in a multi-channel electronics processing environment, comprising: a plurality of input terminals configured to receive electrical signals from corresponding channels; a programmable analog conditioning circuit connected to each of the plurality of input terminals, each programmable analog conditioning circuit comprising a variable-gain amplifier, a tunable filter network, and an impedance matching arrangement; a multi-channel analog-to-digital converter circuit configured to simultaneously digitize conditioned signals from the programmable analog conditioning circuits;a digital signal processing circuit electrically coupled to the multi-channel analog-to-digital conversion circuit, wherein the digital signal processing circuit comprises a plurality of parallel processing paths, each having a reconfigurable filter structure and coefficient memory; a cross-channel interaction circuit configured to compute cross-channel correlation parameters and generate compensation signals based on the computed cross-channel correlation parameters; an adaptive control circuit operationally coupled to the programmable analog conditioning circuits and the digital signal processing circuit, wherein the adaptive control circuit is configured to generate control signals for dynamically adjusting gain, filter bandwidth, and filter coefficients based on evaluated signal quality parameters;a memory circuit configured to store historical signal data and adjustment parameters; a time synchronization circuit configured to ensure phase-in-phase operation across multiple channels; and an output interface circuit configured to transmit conditioned and noise-suppressed signals to an external device.

The millimeter wave broadband tunable filter comprises an orthogonal coupler I, two paths of core circuits, an orthogonal coupler II and an LO matching circuit, wherein each core circuit comprises a double-balanced mixer I, a baseband amplifier and a double-balanced mixer II; the quadrature coupler is based on a transformer structure, and adopts differential input and output to realize a phase quadrature distribution function, so that a single-phase 50% duty ratio clock signal is alternatively used, and the generation difficulty of a non-overlapping high-frequency local oscillator signal is reduced; the baseband amplifier adopts a two-stage structure, the first stage is a differential amplifier structure and provides high gain, the second stage adopts a source follower structure and ensures good frequency response (wide bandwidth), and the baseband amplifier adjusts the cut-off frequency of the amplifier by controlling the size of injection current Iss and realizes filtering bandwidth control. The gain of the baseband amplifier effectively compensates the insertion loss of the filter.