8 results about "Narrow band interference" patented technology

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.

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 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.