17 results about "Narrow band interference" patented technology

The invention relates to a narrow-band interference filtering method and device based on an HPLC (High Performance Liquid Chromatography) chip, and belongs to the technical field of power line carrier communication. When pulse processing is carried out on a signal, AGC / DAGC processing is paused if a narrowband interference detection starting signal is detected, a narrowband interference detection module calculates a narrowband interference frequency point by using the signal of which the AGC / DAGC processing is paused, and a filter coefficient used by a narrowband interference elimination module is determined based on the narrowband interference frequency point; and the narrowband interference elimination module carries out narrowband interference elimination processing according to the determined filter coefficient. Wherein the AGC / DAGC processed signal is paused when the signal participating in the calculation of the narrowband interference frequency point is subjected to pulse processing, so that signal fluctuation caused by AGC / DAGC processing is avoided, the calculation accuracy of the narrowband interference frequency point is improved, and the narrowband interference filtering effect is ensured.

The utility model provides a double-antenna double-diversity Beidou positioning terminal. The double-antenna double-diversity Beidou positioning terminal comprises a module box, a partition plate, a PCB, a first antenna, a second antenna and a cable, the partition plate is arranged in the module box, the partition plate is of a hollow annular structure, the first antenna and the second antenna are arranged on the two sides of the partition plate respectively, the PCB is fixed to the side, close to the second antenna, of the partition plate, and the cable penetrates through an arm of the module box to be connected with the PCB; the PCB is provided with a double-antenna double-diversity Beidou positioning module circuit, and the double-antenna double-diversity Beidou positioning module circuit is used for selecting the first antenna or the second antenna with strong signals to receive B3, B2b and S frequency band satellite navigation signals and transmitting L frequency band satellite navigation signals. The device has the advantages of high sensitivity, high precision and high dynamic performance, can display excellent narrowband interference resistance in a complex environment, meets the application requirements of industry users on high-precision positioning and speed measurement and short message requirements, can be widely applied to multiple fields, and is low in cost and small in size.

This invention provides a satellite communication anti-interference access method, system, device, medium, and program product, relating to the field of wireless communication network technology. The method includes: acquiring an access signal; the access signal is a multi-frequency radio frequency signal superimposed with Doppler frequency shift, pulse interference, and narrowband interference, where different service replica packets are transmitted by spacecraft nodes in different time slots, and the spacecraft nodes use different frequencies to transmit service replica packets in different time slots; performing Doppler compensation on the access signal based on satellite orbit information to obtain the signal to be detected; and performing time-slot-by-slot signal detection and cross-frequency parameter estimation on the signal to be detected to obtain the service data corresponding to the spacecraft node. Through the above method, the packet loss rate of service replica packets during data transmission is reduced, the reliability and accuracy of data transmission between the spacecraft and the satellite are improved, and the anti-interference performance of the spacecraft and the satellite is enhanced.

The invention discloses an anti-interference signal processing method and device of a signal receiver, equipment and a medium, and relates to the field of wireless communication, and the method comprises the steps: inputting an antenna signal into a radio frequency front end, and carrying out the down-conversion and analog-to-digital conversion operation, so as to obtain a target signal flow; determining a to-be-analyzed signal from the target signal flow, and judging whether single-frequency interference exists in the to-be-analyzed signal; if the single-frequency interference exists, reconstructing an interference time domain waveform according to the obtained frequency, amplitude and initial phase, and determining target estimated interference based on the interference time domain waveform; performing interference cancellation on the target signal flow based on the target estimated interference to generate a signal after target interference cancellation; performing timing and frequency synchronization operation on the signal after target interference cancellation to generate a synchronized signal, converting the synchronized signal to a frequency domain, and performing broadband suppression to generate a suppressed signal; and decoding the suppressed signal by using a preset decoder to obtain a modulation symbol stream, and outputting the modulation symbol stream to a user side to complete signal processing. The synchronization performance can be improved under strong single-frequency or narrow-band interference.

The invention discloses a wide-narrow band joint interference identification method based on bidirectional and multipath attention. The method comprises the following steps: firstly, respectively converting data of a narrow-band detection channel and a wide-band reconnaissance channel into time-frequency diagrams through short-time Fourier transform; secondly, constructing a bidirectional attention interference pattern recognition network, inputting a narrowband time-frequency graph, and outputting an interference pattern type and confidence; meanwhile, constructing a multi-path attention interference area detection network, and inputting a broadband time-frequency diagram to output an interference pattern type, confidence and area coordinates; and finally, combining the identification results of the two channels, judging narrowband interference, broadband interference or unknown types through preset conditions, carrying out clustering labeling on unknown samples, and updating the model. According to the invention, cooperative identification of wide-band interference and narrow-band interference and accurate detection of the interference area are realized, and the robustness of interference identification in a complex electromagnetic environment is significantly improved.

The embodiment of the present specification provides a narrow-band interference filtering method, device and equipment of a partial discharge signal, and a storage medium. The method comprises: performing frequency slice wavelet transform on the partial discharge signal to obtain a frequency slice wavelet time-frequency spectrum; dividing the time-frequency spectrum according to frequency to obtain a sub-region containing narrow-band interference signals but not containing partial discharge pulses; calculating the narrow-band interference frequency of each sub-region; performing fast Fourier transform to obtain a partial discharge signal spectrum; filtering the narrow-band interference signals in the spectrum according to the narrow-band interference frequency; and performing inverse fast Fourier transform on the spectrum filtered of the narrow-band interference signals to reconstruct the partial discharge signal filtered of the narrow-band interference signals. The embodiment of the present specification achieves the purpose of effectively filtering the narrow-band interference in the partial discharge signal.

The application discloses a kind of receiving end multi-interference signal fast detection and nonlinear suppression circuit, including interference frequency point fast positioning module, receive baseband signal, and interference frequency point position is positioned fast using two-step method, the two-step method includes power threshold preliminary frequency point positioning and high-precision frequency point positioning;Nonlinear reference signal generation module receives baseband signal and interference frequency point position information, and generates each nonlinear reference signal;Adaptive elimination module receives nonlinear reference signal, and receives baseband signal through delay module, after alignment data, corresponding nonlinear term is filtered out, and the elimination of interference signal is completed.The application is used to fast detect the frequency point of in-band narrowband interference signal, and filter out nonlinear signal such as common quadratic or cubic nonlinearity generated by interference signal through normalization adaptive (GNGA) algorithm.

The present application is to solve the problems of spectrum leakage, large loss of useful signal and insufficient interference locking precision in the existing narrow-band interference suppression technology; a narrow-band interference suppression method for Beidou navigation is provided, comprising the following steps: S101: discrete signal sequence sampling and segmented caching; S102: constructing an adaptive signal covariance matrix; S103: performing fast eigenvalue decomposition on the covariance matrix; S104: determining the number of interference components based on the eigenvalue distribution; S105: constructing an interference subspace projection matrix; S106: performing orthogonal projection to suppress narrow-band interference; S107: signal gain compensation and output reconstruction; S108: detecting whether the interference environment has changed dramatically; all components pointing to the interference in the signal space are filtered through the orthogonal projection matrix, avoiding the convergence problem of time-domain adaptive filtering, and effectively dealing with the strong narrow-band interference scene with high power density.

The invention discloses a satellite-borne SAR narrow-band interference suppression method, and relates to the technical field of satellite-borne SAR, and the method comprises the steps: carrying out the feature decomposition of an original echo signal, constructing a feature beam, and judging whether the maximum value of the feature beam is located in an antenna main lobe range or not, and accurately recognizing the feature vector and feature value of a narrow-band interference signal; constructing a whitening matrix to perform whitening processing on the original echo signal, and removing signal correlation; an approximation function is constructed based on the ultra-Gaussian distribution characteristics of narrow-band interference, and narrow-band interference signal samples are analyzed, processed and separated by using independent components; and finally, constructing an orthogonal projection matrix according to the sample, and carrying out orthogonal projection processing on an original echo signal to effectively suppress narrowband interference. The method has better interference identification accuracy and suppression performance, the SAR imaging quality can be remarkably improved, and image artifacts caused by interference are eliminated.

The application discloses a Ku-band satellite chain downlink signal interference suppression method, system, device and medium, and relates to the technical field of wireless communication signal processing. First, an OFDM signal from a satellite chain system is received, the OFDM signal is segmented, and fast Fourier transform is performed on the segmented signal to convert the segmented signal into a frequency domain to obtain a frequency domain signal. Then, an FCME algorithm is used to preliminarily locate a narrow-band interference frequency of the frequency domain signal to obtain an interference range. Further, a frequency offset value is calculated by using an interference frequency determined by DTFT, and then, spectrum shifting is performed on the frequency domain signal according to the frequency offset value, and interference alignment is completed through the spectrum shifting, so that interference suppression of the Ku-band satellite chain downlink signal is realized while spectrum leakage is avoided.

An example frequency hopping transceiver includes one or more antennas, a transmitter digital oscillator, transmitter correlation circuitry, a receiver digital oscillator, and receiver correlation circuitry. The transmitter correlation circuitry is communicatively coupled to the transmitter digital oscillator and to the antennas, and is configured to spread, based on transmitter oscillation signals, transmit signals over transmit channels to create frequency-hopped transmit signals that are provided to the antennas. The receiver correlation circuitry is communicatively coupled to the receiver digital oscillator and to the antennas, and is configured to: de-spread the frequency-hopped data signals; spread, based on the receiver oscillation signals, one or more narrow-band interference signals included in received signals over a group of receive channels to create frequency-hopped interference signals, where the receive channels are orthogonal to the transmit channels; and filter out the frequency-hopped interference signals from the de-spread data signals.

The invention provides a molten pool temperature coaxial monitoring system and method based on optical filter angle optimization, the system comprises a laser processing module, a coaxial monitoring module and an image processing module, the laser processing module is used for processing a substrate located below the laser processing module, the coaxial monitoring module is integrally placed above the laser processing module, and the image processing module is used for processing the substrate located below the laser processing module. The image processing module is connected with the coaxial monitoring module; in order to solve the problems of blue shift of a transmission center wavelength of a narrow-band interference filter and field-of-view related spectrum distortion caused by galvanometer scanning, the coaxial monitoring module adopts a prism-filter cascade light splitting architecture. The corresponding method comprises the following steps: establishing a double-variable angle response model and a full-view-field objective function, and obtaining and configuring an optimal asymmetric pretilt angle of a narrow-band filter through a global numerical optimization algorithm to align a channel attenuation derivative so as to suppress disturbance induced by scanning; and adjusting narrow-band filters corresponding to the two light incidence channels based on the optimal geometric working angle, collecting an original dual-wavelength molten pool image, and eliminating translation and rotation errors between the two light incidence channels by adopting a dual-wavelength image affine registration algorithm based on an image moment to obtain a high-uniformity molten pool temperature distribution diagram.

The application discloses a sparse frequency waveform design method and equipment based on high-bit rate and low distance resolution, and the method comprises the following steps: obtaining a phase encoding signal to be processed; calculating the spectrum of N p frequency components of the phase encoding signal to be processed, obtaining N p spectra; respectively performing pulse compression on the N p spectra, and respectively obtaining N p pulse compression values; performing pulse compression processing on a reference signal, and obtaining a pulse compression value of the reference signal; the encoding length of the reference signal is less than the encoding length of the phase encoding signal to be processed; determining an expected pulse compression main lobe value based on the encoding length relationship between the reference signal and the phase encoding signal to be processed and the pulse compression value of the reference signal; constructing an optimization objective function according to the N p pulse compression values, the expected pulse compression main lobe value, the N p spectra and a preset weight; and solving the optimization objective function to obtain a sparse frequency signal. The application can overcome the defects of easy generation of same-frequency narrowband interference and low degree of freedom of a full-band radar.

The application belongs to the technical field of electromagnetic compatibility test, and discloses an electromagnetic compatibility test system, method, medium, equipment and terminal, wherein a narrow-band signal extraction module is used to extract a narrow-band resident interference signal, a wide-band signal extraction module is used to extract a wide-band signal in a test result through threshold comparison, a narrow-band signal elimination module is used to eliminate the resident narrow-band interference signal in a test environment, a wide-band signal elimination module is used to eliminate the wide-band interference signal, wavelet analysis multi-resolution characteristics are used, a wavelet decomposition and reconstruction module is used to decompose and reconstruct the signal processed by the difference method, and secondary noise reduction is realized. The application uses the filtering method to reduce noise, can save the spikes and mutations in the useful signal, and retains the original signal; the difference noise reduction method and the wavelet noise reduction method are combined to reduce the environmental noise, the effectiveness of eliminating the noise in the environment is improved, and the accuracy of the electromagnetic compatibility test is improved.

The application provides the application of transparent medium with thickness compensation in continuous tunable laser, wherein the cross section shape of the transparent medium with thickness compensation is right trapezoid, or the front surface of the transparent medium is curved surface and the back surface is flat surface. The application applies two different transparent mediums with thickness compensation to external cavity semiconductor laser. The laser emitted from the laser passes through narrow band interference piece, and realizes laser output under the light feedback of partial mirror. The application changes the cavity length by using the transparent medium with thickness compensation, and makes the cavity mode frequency different from the transmission frequency f IF of the interference piece, so as to observe the change of the maximum tunable range of the laser.

The invention discloses a forest trunk borer audio frequency identification method and system based on edge calculation, and relates to the technical field of audio frequency identification, and the method comprises the following steps: building a simultaneous model between a temperature and humidity coupling parameter and an electroacoustic response, collecting a mutation sample through an extreme environment condition, and generating an audio frequency fingerprint database of a self-oscillation risk; and distributing the audio frequency fingerprint database to an edge computing node, extracting field acoustic data through a dual-channel synchronous sampling mode of a reference microphone channel and a reference cavity channel, and computing the center frequency of narrow-band interference. According to the method, the audio frequency fingerprints are generated by constructing the temperature and humidity-electroacoustic simultaneous model, the interference frequency is accurately positioned by combining edge sampling and phase-locked tracking, the insect sound envelope is extracted through time-frequency decomposition, the adjustment instruction is generated through environment prediction, disturbance-induced frequency hopping is injected, residual interference is filtered out, the insect sound recognition closed loop is constructed, and the recognition stability and accuracy are improved.

The application provides a common mode noise elimination double laser frequency measurement ultra-high precision small angle measurement reference device, comprising a first light path mechanism and a second light path mechanism arranged in parallel and a beat frequency measurement module, the light path mechanism comprises a laser generating device, a narrow band interference sheet, a micro prism array and a first ring piezoelectric module, which are fixed on a high precision horizontal rotating table (7). The common mode noise elimination double laser frequency measurement ultra-high precision small angle measurement reference device changes the cavity length by rotating the cavity mirror to cause the frequency change, converts the angle change into the change of the frequency difference of the output laser of the two sets of devices, selects the mode by using the narrow band interference sheet for auxiliary adjustment, makes the cavity mode change highly synchronized with the interference frequency selection, realizes the non-mode jumping of the laser output frequency, guarantees the continuous tunability of the output frequency with the rotation angle, solves the continuous measurement problem, and further realizes the ultra-high precision measurement of the small angle.