77 results about "Cross-spectrum" patented technology

The invention discloses a direct positioning method based on cross-spectral domain subspace data fusion and Taylor expansion, which comprises the following steps of: firstly, integrating time domain receiving signals of all sensors, and segmentally calculating cross correlation of the receiving signals of every two sensors; a cross-spectrum model is obtained through cross-correlation, forward space smoothing is carried out on the cross-spectrum model, a cost function is constructed through subspace data fusion, and then the extreme value of the cost function is searched to obtain rough estimation of the position of the radiation source; and finally, obtaining a position compensation value by using Taylor expansion to obtain the precise estimation of the position of the radiation source. According to the method, the complexity of calculating the subspace can be reduced, the hardware and calculation burden of the base station is reduced, and the real-time requirement of the time difference positioning system is met; meanwhile, the positioning precision of the algorithm is effectively improved. In computer simulation, compared with other time difference positioning methods, the method provided by the invention shows better positioning precision and better anti-multipath capability.

The invention discloses a sound source localization method based on multi-frequency separation and Newton optimization deconvolution, relates to the technical field of array acoustic signal processing, and is used for solving the problem that weak sound sources and multiple sound sources are difficult to identify. According to the method, dominant frequency is extracted through multichannel frequency domain analysis, a cross-spectrum matrix is constructed in combination with a near-field propagation model and a guide vector, delay summation beam forming is executed to obtain sound source preliminary distribution, then the distribution is regarded as a convolution result, a maximum likelihood model is introduced, and a two-stage deconvolution strategy of coarse estimation and Newton method fine optimization is adopted to obtain a high-resolution sound source. According to the multi-sound-source positioning method, subgrid-level analysis of sound source positions and amplitudes is achieved, finally, all frequency results are fused, continuous sound source images are smoothly output through a two-dimensional Gaussian kernel, the resolution and real-time performance of multi-sound-source positioning are remarkably improved, and the multi-sound-source positioning method is suitable for high-precision acoustic imaging in a complex sound field.

The invention discloses a user health data monitoring method and system based on a smart watch, and relates to the technical field of smart wearable health monitoring, and the method comprises the steps: carrying out the optimization through Hilbert transform and cross-spectral density, carrying out the iteration of a sparse coefficient through employing MCMC, carrying out the dimension reduction construction of a track matrix through employing Ortho-SSA, carrying out the screening through ReliefF and VC-SSA, and initializing a GBTN model. NAS is used for adjustment, integration is carried out through federated average and incremental learning, and the health state is monitored. According to the method, through the VIB model, cross-spectral density optimization, GMM noise modeling and MCMC sparse iteration, the dynamic coupling relation between modes is accurately captured, the robustness of data representation is improved, and through fusion of causal reasoning and federated learning, the accuracy of the health monitoring state is improved.

The invention discloses a modularized hydraulic system testing system and method, and relates to the technical field of hydraulic testing, and the method comprises the following steps: S1, collecting outlet pulsating pressure signals of a high-pressure plunger pump and a low-pressure vane pump by adopting a nanosecond-level synchronous time mark system, generating a phase residual error map, and calculating a phase residual error map of the outlet pulsating pressure signals of the high-pressure plunger pump and the low-pressure vane pump; the hidden resonance risk is preliminarily judged through frequency drift and amplitude gradient calculation; and S2, on the basis of the synchronous acquisition base line, carrying out cross spectrum coherence degree calculation and phase difference time sequence analysis on the pulsating pressure sequence, identifying a frequency dislocation anchor point, generating a pump source pulsating interference fingerprint, and determining a time window of recessive resonance. According to the method, real-time identification, dynamic intervention and closed-loop control of recessive resonance in the hydraulic system are realized through nanosecond-level synchronous acquisition, phase conjugate inversion and frequency dislocation traction strategies, energy coupling caused by frequency dislocation is effectively avoided, the operation stability and safety of the system are improved, and the service life of equipment is prolonged.

The invention relates to a sparse Bayesian learning target orientation estimation method with robust near-field mismatch. The method comprises the following steps: forming an initialized spatial spectrum by using near-field wave velocity; reconstructing a cross-spectral density matrix; correcting the cross-spectral density matrix; constructing a to-be-optimized objective function and a constraint condition by combining a spatial spectrum expression of a sparse Bayesian learning algorithm; obtaining vector estimation under an optimization condition by solving an optimization problem; correcting the guide vector; updating the historical guide vector; substituting into an iterative formula of sparse Bayesian learning to complete spatial spectrum estimation; and iteratively repeating the previous steps until a stopping condition is met, and outputting a spatial spectrum estimation result. The method has good orientation estimation performance for the near-field target, and has good engineering practical prospects.

The invention discloses a photovoltaic panel vibration monitoring method and system based on AI and heterogeneous convergence network communication, and the method comprises the steps: enabling each sensor terminal to transmit a local relative timestamp generated by a free operation timer to a gateway base station along with an uplink data message after completing the vibration data collection and processing in the same collection period; the gateway base station calculates the relative transmission delay inequality of any node pair according to each message receiving moment and the local relative timestamp, constructs a frequency domain phase correction factor at each discrete frequency point according to the relative transmission delay inequality, and corrects the uncorrected cross-spectral density to obtain the corrected cross-spectral density; and a coherence function value is further calculated by combining the self-spectral density of each node, and a vibration abnormal area is positioned according to the spatial distribution of the coherence function value on the photovoltaic array topology. The method can improve the accuracy of multi-node vibration joint analysis and the reliability of abnormal positioning, and is suitable for online monitoring of a photovoltaic power station.

Embodiments of the present application disclose a river bed load transport characteristic determination method and device, electronic equipment and a computer readable medium, relating to the field of engineering technology. The method performs fast Fourier transform on the sound pressure signals of the microphone array to obtain a sound pressure matrix in the frequency domain; based on the sound pressure matrix, cross-spectrum operation is performed to obtain a cross-spectrum matrix; based on each scanning grid point j on the surface of the monitoring sensor plate as an imaginary sound source point, a sound propagation model is selected according to the aerodynamics theory to determine the sound signal monitored by any microphone; each grid point is scanned, the auto-spectrum of the simulated sound signal is calculated, and the sound source holographic image of the bed load shock wave is determined; the sound source intensity is simulated, the bed load spatial position is obtained, and the bed load particle size component information is obtained through the calibration function relationship. That is, in the present application, the bed load spatial position and the bed load particle size component information are obtained, this method can accurately determine the transport characteristics of the bed load, and becomes an important support for quantifying the disaster prevention and reduction work of mountainous rivers.

The application discloses a kind of arbitrary pulsating wind field active control wind tunnel physical simulation method and system, comprising: establishing generalized pulsating wind field spectrum model, it has 6 controllable pulsating wind spectrum in the energy distribution model parameter of frequency domain;Based on generalized pulsating wind field spectrum model, inter-spectrum matrix is calculated using coherence function;Based on harmonic superposition method, inter-spectrum matrix is converted into pulsating wind field space-time information;Pulsating wind field space-time information is introduced into the control program of active control wind tunnel, through real-time monitoring and iterative adjustment model parameter, until the target wind field generated reaches expectation.The application can simulate wind field with arbitrary frequency energy distribution by generalized pulsating wind field spectrum model with 6 model parameters, combined with iterative closed-loop control, significantly improve the simulation accuracy and adaptability of complex wind field such as mountain valley wind, typhoon.

The invention discloses a multi-channel signal receiving calibration method and device based on a cross-spectrum method, and relates to the field of signal processing, and the method comprises the following steps: S1, configuring system parameters, and generating a test signal; s2, performing frequency domain transformation on the test signal; s3, performing cross spectrum analysis on the test signal; s4, performing time delay extraction on the test signal; s5, performing compensation calibration; and S6, experimental verification. According to the multi-channel signal receiving calibration method and device based on the cross-spectrum method, by optimizing a cross-spectrum calculation process, introducing high-resolution time delay estimation and improving a phase compensation mechanism, the problems existing in the prior art are effectively solved, time delay and amplitude inconsistency between channels are accurately estimated and corrected, and the accuracy of calibration is improved. The problems that the calibration precision is limited due to high calculation complexity and poor real-time performance of a traditional method, the time delay estimation performance is reduced in a low signal-to-noise ratio environment, and the requirements of a modern multi-channel system for high synchronism and low delay cannot be met are solved.

Interference removal device (100), comprising: a Fourier transform unit (3) to divide an input signal into frames which are divided into segments by a fixed time, wherein the input signal contains a component other than a target signal, and to transform the input signal into a frequency spectrum to generate a plurality of pairs of frequency spectra by using a delay amount, wherein the pairs of frequency spectra have a fixed time difference; a cross-spectra unit (4) to generate a plurality of cross-spectra or a plurality of coherences from the plurality of pairs of frequency spectra with the fixed time difference; and a disturbance removal unit (5) to average the multitude of cross-spectra or the multitude of coherences in order to extract a power spectrum of the target signal.

A wave spectrum calculation method based on GNSS wave measuring buoy is provided, which includes: placing GNSS drift buoys in the sea, collecting buoy position data; then obtaining three-dimensional velocity data of ocean waves; performing high pass filtering on velocity data of a sliding window to remove noise signals and trend terms, retaining wave motion data; calculating a cross spectrum and wave direction spectrum. The present disclosure solves limitations of traditional GNSS measurement methods applied to ocean buoy wave measurement, such as limited observation distance, high cost, tedious measurement and average calculation accuracy, and a need for correction services. The measurement accuracy is high and no additional correction services are required, which is more suitable for wave measurement, the wave spectrum algorithm in this method can adapt to more complex observation environments and incorporate results of a velocity measurement algorithm into a matched wave spectrum algorithm.

This invention relates to a method and system for locating coaxial counter-rotating sound sources in rotorcraft, belonging to the technical field of sound source identification methods. It includes: processing the sound pressure signal of the moving sound source using continuous wavelet transform to obtain time-frequency domain variation results; performing Doppler effect correction based on experimental conditions; estimating the spatial location and relative intensity of the noise source using a cross-spectral matrix and weight vector; and performing phase-locked analysis of the rotor noise source intensity using a phase-locked averaging method. This invention differs from traditional time-domain delay superposition algorithms and frequency-domain cross-correlation spectrum methods. It can image unsteady sound sources using time-frequency domain characteristics, solving the acoustic imaging problem of counter-rotating propeller noise and possessing potential applications in the rotorcraft industry.

The invention discloses a weak sound source sound pressure level calibration method based on an improved DAS beam, relates to the technical field of sound source positioning, and is used for solving the problem of repeated weak sound source positioning. According to the method, a distance matrix is constructed based on array geometric parameters, and a cross spectrum matrix and a steering vector are respectively calculated for a plurality of target frequencies in combination with a near-field propagation model to obtain a multi-frequency acoustic image; and performing normalization and relative threshold side lobe suppression on each frequency sound image result, superposing and highlighting a real sound source area on a scanning grid, suppressing a side lobe irrelevant to a position, and utilizing a sound pressure level calibration model obtained by training reference data to convert a sound image output quantity into a real sound pressure level, so as to realize spatial positioning and quantitative sound pressure evaluation of multiple sound sources. The weak sound source can still be clearly distinguished under the background that the sound pressure level difference of the strong and weak sound sources is large and the noise is complex, and the sound source positioning precision and the engineering detection reliability are improved.

The present application belongs to the technical field of acoustic measurement, and particularly relates to an acoustic flow tube test platform and a test method thereof, wherein the transfer loss measurement of an acoustic metasurface under a flow field working condition is performed through the acoustic flow tube test platform, the test piece installation tube of the acoustic flow tube test platform can install most of the test pieces of the acoustic metasurface, and is beneficial to the acoustic metasurface related technology research; meanwhile, the test platform creates a flow acoustic measurement environment, based on the scattering matrix theory, the reference signal, the self-spectrum and the cross-spectrum signal processing method are used to weaken the influence of the turbulent flow pressure disturbance, the double load method is used to solve the parameters of the scattering matrix and calculate the acoustic characteristics of the acoustic metasurface to be measured, and the transfer loss measurement problem of the acoustic metasurface under the low Mach number (<0.3 Mach) tangential flow and in the low-middle frequency range (300-2000 Hz) is solved, and the technology will be widely used in the fields requiring noise reduction such as unmanned aerial vehicles, eVTOL, household appliances, automobiles and the like.

The invention belongs to the technical field of ship and ocean engineering, and discloses a method and a system for inverting a three-dimensional sea wave spectrum along with ship motion based on a deep learning model. According to the method, cross spectrum calculation is carried out among different ship motion time sequences to obtain a ship motion cross spectrum; carrying out data shuffling processing on the ship motion cross spectrums obtained in different time periods, and constructing a training set and a test set; and according to the constructed training set, inputting the training set into a CNN-ED-DE model, and carrying out CNN-ED-DE model training. And inputting the obtained input test data set into the trained CNN-ED-DE model, and solving to obtain a test data set inversion result. The method provided by the invention is completely based on motion sensor data such as a shipborne inertial measurement unit (IMU), does not need external remote sensing equipment or communication support, can estimate sea wave spectrum information in real time in any sailing state, and is suitable for online deployment in scenes such as complex course and unsteady sea conditions.

The invention discloses a rotating sound source recognition and positioning method based on a deep convolutional attention neural network, and belongs to the field of rotating sound source recognition, and the method comprises the steps: firstly carrying out the motion compensation and modal expansion of a sound pressure cross-spectrum matrix through a modal decomposition rotating beam forming algorithm, and generating a sound source distribution diagram in a rotating scene; then the sound source distribution map is input into a deep convolution attention neural network model, the model adopts an encoder-decoder structure, a channel and a space attention mechanism are fused, key sound source features are dynamically focused, noise interference is suppressed, and high-precision reconstruction of the sound source distribution map is achieved; and finally, carrying out local maximum value detection on a prediction map output by the network, and extracting a sound source space position. According to the method, the Doppler effect and phase distortion problems in rotating sound source positioning are effectively overcome, and the positioning precision, the anti-noise performance and the calculation efficiency in a complex rotating field are remarkably improved.

The invention relates to a high dynamic range sound source imaging method based on a double attention mechanism, and the method comprises the steps: receiving a space sound field signal through a microphone array, and processing the space sound field signal into a frequency domain signal; performing cross-spectrum matrix characteristic filtering processing on the frequency domain signal to obtain a complex frequency domain signal vector; performing adaptive enhancement on a real part and an imaginary part of the complex frequency domain signal vector by using a double attention mechanism; fusing the enhanced real part with the enhanced imaginary part to obtain an enhanced signal vector; and performing beam forming calculation by using the enhanced signal vector to generate an acoustic image. According to the invention, the real part attention module and the imaginary part attention module are introduced in parallel at the front end of beam imaging, and the amplitude and phase characteristics of the acoustic signal are subjected to adaptive weighted enhancement, so that the spatial information in the array signal is fully mined, the dynamic range of acoustic imaging and the robustness in a noise environment are significantly improved, and the method is suitable for wide application. And a better solution is provided for precise fault diagnosis and acoustic monitoring.

The invention provides a rotating sound source beam forming method based on improved wavelet transform, which comprises the following steps of: firstly, executing Morse wavelet transform on data received by each microphone, and converting a time domain signal into a time-frequency domain signal; then, parameters related to the Doppler effect are calculated, and a Doppler effect correction Green function is introduced; then, calculating a weight vector and a cross-spectrum matrix formed by an array beam; and finally, grid division is performed on a plane where a target signal is located, and beam forming is performed on each grid point by using the time-frequency array signal model on each wavelet domain so that sound imaging of a target sound source can be realized. Compared with a traditional beam forming method based on Fourier transform, the beam forming method based on improved wavelet transform has the advantage that the real-time imaging quality and background noise suppression are remarkably improved.

The application discloses a sparse Bayesian learning vector acoustic direction finding method based on orthogonal acoustic intensity flow, and belongs to the technical field of array signal processing. First, an orthogonal acoustic intensity flow data model is constructed, an acoustic intensity flow is obtained by cross spectrum of sound pressure and vibration velocity channels, and acoustic energy flow density is obtained by acoustic pressure autospectrum. Then, a joint probability density distribution function is established by means of a sparse Bayesian learning model. Finally, according to maximum log-Bayes evidence estimation of signal power, spectral peak search is performed on the signal power estimation value, and the direction estimation of the target is realized. The method uses acoustic intensity and acoustic intensity flow as input, has the effect of suppressing isotropic noise and reduces the calculation amount. When the hyperparameters are updated for the first time, a deconvolution algorithm is introduced to avoid the judgment error of the number of signal sources and the direction of arrival caused by the proximity of two targets. Moreover, the method has good direction estimation accuracy and direction resolution capability, and can maintain good performance under the condition of low signal-to-noise ratio.

The invention discloses a fast deconvolution sound source localization method based on array sparsity and broadband comprehensive processing, which comprises the following steps of: selecting microphones to form a sparse array, and converting a regular focusing plane into an irregular plane to obtain grid coordinates; calculating a sparse array cross-spectrum matrix based on coordinates, obtaining a function beam through eigenvalue decomposition and power exponent operation, and outputting the function beam; constructing a frequency domain deconvolution model according to the convolution relationship between the frequency domain and sound source distribution and the convolution relationship between the frequency domain and a rising power point spread function, and solving a sound source intensity distribution matrix by using fast Fourier transform and iterative optimization; estimating a noise floor-to-signal-to-noise ratio matrix, traversing frequency points, taking the maximum signal-to-noise ratio, and fusing the frequency points into a broadband imaging matrix; a time smoothing factor is introduced to carry out weighted fusion on the inter-frame imaging matrix, and positioning is completed; according to the method, low-consumption, high-precision and strong-robustness sound source localization is realized through array rarefaction and fast deconvolution load reduction, precision protection by means of function beam forming and Gaussian filtering, multi-frequency point fusion adaptive imaging, inter-frame smooth flicker suppression and adaptation to complex scenes.

The invention discloses a pulsating pressure wave number-frequency spectrum two-dimensional surface array data processing method, which is based on concepts such as a cross-spectrum matrix and a position difference vector, obtains a corresponding discrete area by defining a plurality of key sets related to a two-dimensional surface array and applying a Worronoi diagram method, and finally obtains the pulsating pressure wave number-frequency spectrum two-dimensional surface array data. And a two-dimensional wave number-frequency spectrum is obtained through a multiplication method. On one hand, the method can adapt to all types of two-dimensional surface array forms, the problem of applicability limitation of a traditional method is thoroughly solved, meanwhile, an analysis result directly corresponds to a TBL pulse pressure wave number-frequency spectrum, and effective measurement of real physical quantities is achieved; and on the other hand, by introducing a parallel computing architecture, the data computing time consumption can be remarkably shortened, the processing efficiency is greatly improved, the universality and high efficiency of two-dimensional pulsating pressure wave number-frequency spectrum data processing are considered, and a better support is provided for engineering landing of related technologies.

The present application provides a method and system for detecting phase synchronization between signals, the method comprising acquiring a first signal and a second signal; performing a discrete Fourier transform on the first signal to obtain a first Fourier spectrum, and performing a discrete Fourier transform on the second signal to obtain a second Fourier spectrum; calculating the cross-spectrum of the first signal and the second signal based on the first Fourier spectrum and the second Fourier spectrum; calculating the full complex plane mean ratio and the half complex plane distribution ratio based on the cross-spectrum; determining a target measurement value based on the full complex plane mean ratio and the half complex plane distribution ratio, so as to determine the degree of phase synchronization between the first signal and the second signal based on the target measurement value. The method can comprehensively consider the full complex plane mean ratio and the half complex plane distribution ratio based on the imaginary part of the cross spectrum, thereby more accurately detecting the degree of phase synchronization between the signals. At the same time, different calculation methods can be matched according to different polarity types of the imaginary part of the cross spectrum to improve the efficiency of phase synchronization detection between signals.

The invention discloses an ocean surface wave monitoring system based on a synthetic aperture radar, which relates to the technical field of ocean surface wave monitoring, and comprises the following steps: carrying out azimuth split view on single-view complex data, and generating a split view cross spectrum and an azimuth self spectrum; determining a frequency domain selection area according to the cross spectrum energy, and calculating azimuth antisymmetric phase skewness in the area; determining azimuth cut-off by the azimuth auto-spectrum, constructing an odd phase compensation operator, and performing phase correction on the split-view cross-spectrum; performing direction projection on the correction spectrum to obtain a dominant propagation direction, and determining a peak wave number according to a direction correlation weight; and the peak wavelength and the peak period are obtained by using linear dispersion relation conversion. According to the invention, the monitoring reliability and consistency under complex sea conditions can be improved.

This invention relates to the field of engineering machinery safety technology, specifically disclosing a load stability prediction system for telescopic boom forklifts based on the force exerted by the boom. The system collects motion sensing data and stress wave sensing data at the boom hinge; calculates a cross-spectral coherence function based on the motion data to generate a hinge coherence disorder index; performs time-frequency transformation on the stress wave data and automatically identifies energy impact patches, extracting their peak energy, center frequency, and duration; and generates a transient collision intensity spectrum index based on sensitive frequency band mapping and aggregation; constructs a time-series comprehensive feature vector from the two indices, inputs it into a pre-trained multi-layer gated recurrent unit structure for nonlinear dynamic system identification, and outputs a fused stability assessment state quantity; maps this state quantity to a virtual potential energy surface for multi-step forward extrapolation, calculates the dynamic stability margin value, and issues an early warning when the margin is lower than an adaptive threshold; this invention achieves early and accurate prediction of nonlinear jump instability.

The invention relates to the technical field of electronic test and measurement, and discloses a cross-spectrum correlation-based semiconductor low-frequency noise measurement system, which comprises an electromagnetic shielding unit, and an adaptive bias unit, a calibration switching unit and a dual-channel signal amplification unit which are arranged in the electromagnetic shielding unit, the external power supply unit, the data acquisition unit and the main control processing unit are arranged. The adaptive bias unit is integrated with a floating drive shielding circuit to eliminate a cable parasitic capacitance effect; and the calibration switching unit is internally provided with a standard noise source to realize full-link in-situ gain calibration. The system adopts a physically isolated dual-channel amplification architecture, signals to be detected are injected into two channels at the same time, and rigid synchronous sampling is carried out through a data acquisition unit. And the main control processing unit performs cross-power spectral density calculation and statistical averaging on the two digital sequences. According to the method, the background noise in the amplifier can be effectively suppressed, the sensitivity limit of single-channel measurement is broken through, and the ultralow-frequency weak noise of the semiconductor device is accurately extracted.

The application discloses a kind of based on array passive source multi-mode surface wave dispersion's artifact removal method, it is related to the field of seismic imaging, including the following steps: the relative distance and azimuth between stations in array are calculated;The noise cross-correlation function between stations is calculated;According to the noise cross-correlation function between stations, causal inter-spectral density matrix is constructed;The relative distance and azimuth between stations and causal inter-spectral density matrix are brought into the expression of modified weighted cross-correlation beamforming analysis or modified correction beamforming analysis, to remove the artifact in beam pattern and dispersion chart.The application effectively reduces the appearance of artifact in dispersion chart, significantly improves the accuracy of multi-mode dispersion curve extraction and mode recognition, and then makes the result of subsequent earth velocity structure inversion more accurate and reliable.

Enabling generation of comfort noise in an encoder using an estimated coherence parameter in a network using a discontinuous transmission, DTX, includes receiving time domain audio input comprising audio input signals; and processing the input signals on a frame-by-frame basis by: encoding active content of each input signal at a first bit rate until an inactive period is detected in the input signals; switching the encoding from the active encoding to inactive encoding to encode background noise at a second bit rate during the inactive period; estimating coherence parameters during the inactive period based on a low-pass filtering or averaging of cross-spectra including reinitializing a low pass filter state of the cross-spectra based on a coherence parameter from a previous inactive period; encoding the coherence parameters estimated; and initiating transmitting of the encoded active content, background noise, and coherence parameters towards a decoder.

The invention discloses a cross-spectrum-based SAR (synthetic aperture radar) azimuth cutoff wavelength estimation method, and relates to a synthetic aperture radar. Firstly, an SAR image is obtained, screened and preprocessed, and preprocessing comprises radiometric calibration, detrending, low-pass filtering and bright target removal so as to eliminate noise and interference information; secondly, performing cross-spectrum calculation to cut the image into sub-images, and performing Fourier transform, sub-view extraction and cross-spectrum calculation on the sub-images to obtain a smooth cross-spectrum; carrying out inverse Fourier transform on the smooth cross spectrum to obtain an azimuth cross covariance function, and carrying out normalization processing and Gaussian fitting estimation to obtain an optimal azimuth cutoff wavelength value. SAR image speckle noise is suppressed by using a multi-view technology, 180-degree direction ambiguity is eliminated in combination with cross spectrum imaginary part characteristics, cross covariance function Gaussian fitting improves truncation wavelength estimation precision, the problems of noise sensitivity and direction ambiguity of a traditional method are solved, and SAR azimuth truncation wavelength estimation is efficiently and accurately realized.

Embodiments of the present disclosure describe systems and methods for dynamic spectrum management and interference mitigation in mobile communications through a network of satellite base stations. Embodiments herein monitor communication traffic across a geographic area served by one or more satellite base stations. The monitoring of the traffic includes determining spectrum assignments for the terrestrial network within the geographic area. In response, the system dynamically adjusts a spectrum assignment to the one or more satellite base stations so the assigned spectrum reduces cross spectrum interference.

A phase unwrapping algorithm and device based on periodic extension, the method comprising: step 1, calculating the cross-spectral phase, finding the cross-spectral phase of two array element signals, the value being the phase difference wrapped between π and π; step 2, periodic extension, adding or subtracting integer multiples of 2π from the phase spectrum of one period obtained in step 1 to obtain different periods, forming a periodic extension phase matrix; step 3, selecting phase points, starting from the middle row of the first column, using the difference between the current position and the next column as the quality basis; if the difference is less than a threshold value, the phase point is directly selected; otherwise, the phase value predicted by linear fitting of the selected phase point and the difference between the next column are used as the quality basis, a secondary judgment is performed, and a straight line, namely the unwrapped phase, is obtained by traversing the entire matrix; step 4, linear fitting, using the least squares method to perform linear fitting on the selected phase points to obtain the linear slope, which is divided by 2π and the frequency resolution to obtain the estimated delay value. The present invention can fully utilize the phase information of the entire bandwidth of the signal, thereby improving the accuracy of delay estimation.