10 results about "Wideband signal processing" patented technology

The application discloses a kind of uniform circular array wideband beam forming method and target distance, azimuth detection method, and uniform circular array wideband beam forming includes: first, establish uniform circular array wideband signal processing model, then combine empirical mode decomposition timescale filter with uniform circular array, introduce empirical mode decomposition into uniform circular array, carry out empirical mode decomposition to each subband signal, obtain multiple groups of solid eigenfunctions, then construct new modal field data matrix, carry out array beam forming in modal field, improve weak target detection effect in interference environment.The application utilizes the characteristics that empirical mode decomposition can strengthen signal local instantaneous characteristics and effectively decompose different signal characteristic scales, which helps to improve the performance of traditional adaptive beam forming method in signal direction vector mismatch environment and the problem that conventional beam forming resolution is limited by "Rayleigh limit".

The invention discloses a broadband signal sorting and identifying method and system based on time-frequency image target detection, and relates to the technical field of broadband signal processing. The method comprises the following specific steps: acquiring a broadband IQ signal and converting the broadband IQ signal into a time-frequency image; inputting the time-frequency image into a trained YOLO target detection model, and outputting a bounding box of each target signal; analyzing the position and size information of the bounding box of each target signal to obtain a frequency domain parameter of each target signal; adaptively designing a digital band-pass filter according to the frequency domain parameter, and extracting IQ data corresponding to the current target signal; and processing the IQ data through a CNN classification model, and finally outputting a category label of a modulation mode, thereby completing automatic sorting and identification of each target signal in the broadband signal. According to the method, an end-to-end intelligent processing framework is constructed, the broadband signals are automatically and efficiently recognized and separated by combining the time-frequency image and the target detection technology, and the accuracy and the real-time performance of signal sorting and recognition are improved.

The invention relates to a low-altitude radar, in particular to an all-digital array low-altitude early warning radar, which comprises a digital beam forming module, realizes rapid pointing adjustment of beams and simultaneous formation of multiple beams by digitally controlling the amplitude and phase of each array element in an antenna array, and supports omni-directional scanning of a low-altitude airspace and residence in a key area; the broadband signal processing module is used for generating a high-resolution linear frequency modulation LFM signal, completing pulse compression and Doppler processing of an echo signal, realizing distance-speed joint resolution and meeting a low-speed low-altitude target detection requirement; the self-adaptive interference suppression module is used for dynamically suppressing interference in a low-altitude environment and improving the signal-to-noise ratio of a target; the multi-target tracking and decision-making module is used for realizing multi-target state estimation and trajectory prediction and supporting threat level evaluation and alarm decision-making; according to the technical scheme provided by the invention, the defects that the low-speed low-altitude target is difficult to accurately monitor and the low-altitude safety prevention and control capability is insufficient in the prior art can be effectively overcome.

A microwave photon radar ultra-wideband signal processing method based on Keystone conversion comprises the following steps: S1, carrying out digital down-conversion on an intermediate frequency sampling signal to respectively obtain baseband signals of an I path and a Q path; s2, performing inter-channel phase calibration on the baseband signals of the I path and the Q path; s3, performing beam forming on the signal after phase calibration to obtain a sum-path beam signal; s4, performing pulse compression processing on the sum path beam signal, wherein the pulse compression processing comprises the steps of performing fast Fourier transform, matched filtering, Keystone transform-based range migration correction and inverse fast Fourier transform on the sum path beam signal in sequence; and S5, performing coherent accumulation on the signal after pulse compression processing, and generating a two-dimensional spectrogram containing target distance and radial speed information. According to the invention, an efficient solution is provided for the problem of range migration under the ultra-wideband signal, and the advantages are obvious.

Embodiments here broadly relate to a system which allows for flexibly, and adaptively, accommodating for various analog and digital streams. In one example case, the system can accommodate for the use of both legacy modems as well as newer digital modems. The system may not require the use of complex and expensive, very high data rate and / or very high throughput wideband digital switches in some architectures, as well as potentially eliminating the need for some additional processing equipment found in traditional architectures (i.e., wideband signal processors (WSP), legacy modem data converts (LDMCs), etc.).

The invention discloses a transformer substation high-voltage chamber power equipment insulation fault early warning and positioning method based on supercomputing, and relates to the technical field of transformer substation early warning and positioning, and the method comprises the following steps: S1, collecting partial discharge signals in real time; s2, classifying signal types; s3, narrowband and broadband signal processing; s4, positioning a partial discharge source space; and S5, triggering graded early warning. According to the method, adaptive algorithms are adopted for wide-band and narrow-band partial discharge signal characteristics, the accuracy of direction-of-arrival estimation is improved through sub-array optimization and focusing matrix improvement, and a complex signal environment is effectively adapted; the positioning algorithm is fused with population initialization so as to avoid a local optimal solution and realize accurate spatial positioning of a partial discharge source; according to the overall scheme, early accurate recognition, real-time positioning and reliable early warning of faults are achieved, scientific support is provided for equipment operation and maintenance, major accidents of a power grid are effectively prevented, and safe and stable operation of a power system is guaranteed.

The invention discloses a radar ranging precision improvement method based on high-frequency narrow pulses, and relates to the technical field of radar ranging and ultra-wideband signal processing, and the method comprises the steps: carrying out the gating interception of a radar receiving sequence, and obtaining an intra-gate sequence; performing cepstrum analysis to determine comb tooth intervals and ripple intensity; constructing a reverse comb ripple frequency domain weight sequence based on the ripple intensity, and performing weighted matched filtering on the intra-gate sequence to extract candidate peaks; calculating sidelobe cluster energy corresponding to the candidate peak according to the comb tooth interval; and calculating a group peak suppression score value based on the ripple intensity and the sidelobe cluster energy, and selecting the candidate peak with the maximum score value as a final peak position to calculate the distance. According to the method, side lobe group peak lifting caused by the wet radome can be inhibited, and the distance measurement precision and stability under the complex meteorological condition are improved.

In order to solve the problems of wideband signal processing complexity, transient signal difficult to capture and low precision of time-frequency overlapping signal sorting in electronic reconnaissance, a wideband high-resolution time-frequency analysis and signal sorting method based on photonic processor is provided. The method uses optical pulse and cascade modulator to reduce the speed of time sequence decomposition, and completes the delay extraction operation on the optical processor. By matching the bandwidth of the photoelectric detector and the subchannel bandwidth, the filtering operation is realized on the optical processor. In the digital domain, only fractional delay and inverse discrete Fourier transform need to be completed to realize time-frequency decomposition and obtain multiple narrowband reduced speed signals. Parallel short-time Fourier transform is performed on each signal, and due to the reduction of single signal bandwidth, higher time-frequency resolution is obtained under the same processing point number, and finer time-frequency features help to improve the signal sorting and parameter identification precision. The application has low computational complexity and high analysis precision, and is suitable for dense transient signal processing in complex electromagnetic environment.

A signal modification unit configured for processing high-bandwidth signals includes at least one signal input configured to receive a high-bandwidth signal. The signal modification unit includes a tunable control component configured to adjust one or more parameters for modifying the high-bandwidth signal, wherein the one or more parameters are associated with nonlinear modification of the high-bandwidth signal. The signal modification unit includes one or more waveguide components configured to modify the high-bandwidth signal to generate a modified signal based in part upon the one or more parameters. The signal modification unit includes at least one signal output configured to provide the modified signal as an output of the signal modification unit. The signal modification unit allows for feature extraction of spectral bands and may be used to replace parts of digital neural networks.

The invention discloses a broadband echo predistortion compensation method applied to a high-resolution airborne synthetic aperture radar (SAR), which comprises the following steps of: respectively fixing a radar array plane and a corner reflector at two ends of a darkroom, generating M broadband intermediate frequency dot frequency signals at intervals of S megahertz through a radar board card DAC (Digital-to-Analog Converter), performing up-conversion on the signals through a radio frequency link, and transmitting the signals, the reflected signal is reduced into an intermediate-frequency signal through link down-conversion, and interference-free intermediate-frequency AD data are acquired synchronously by an ADC; performing down-conversion on the acquired AD data to a baseband, extracting amplitude and phase values of frequency signals of each point through N-point FFT (Fast Fourier Transform), and fitting a broadband baseband echo frequency spectrum curve through Hermite interpolation; constructing a standard baseband linear frequency modulation signal, performing N-point FFT (Fast Fourier Transform), comparing with a fitting spectrum after normalization, calculating amplitude-phase difference and compensation coefficient of each frequency point, and setting the compensation coefficient of the frequency point lower than a noise threshold value to 1 to form a broadband frequency domain compensation coefficient; multiplying the frequency domain of the standard baseband signal by the compensation coefficient point by point, and obtaining a compensated baseband transmitting signal through IFFT (Inverse Fast Fourier Transform); the signal is subjected to up-conversion to a system working intermediate frequency, and a real part is quantized and then stored in an ROM to serve as a board card DA emission data source. According to the method, distortion of an intermediate frequency link and an antenna end is covered at the same time, the compensation precision is high, ideal echoes can be effectively recovered, the SAR imaging quality is remarkably improved, and the method is suitable for broadband signal processing scenes of various high-resolution airborne SAR systems.