118 results about "Coherent integration" patented technology

The invention provides a motion compensation method and device for passive sonar detection. The compensation method comprises the following steps: acquiring underwater acoustic signals acquired by a passive sonar in real time within a preset period; performing segmentation processing and Fourier transform on the underwater acoustic signal to obtain an underwater acoustic frequency domain signal segment; constructing a parameterized search matrix of each water audio frequency domain signal segment, and determining a motion compensation parameter of each water audio frequency domain signal segment through similar energy spectrum search; based on the motion compensation parameter, performing phase compensation on the water audio frequency domain signal segment to obtain a compensation frequency domain signal segment; and performing inverse discrete Fourier transform on the compensation frequency domain signal segment to obtain a compensation time domain signal segment so as to determine a long-time coherent integration result corresponding to the underwater acoustic signal. Through the method, the gain of passive sonar detection processing is improved under the condition of low signal-to-noise ratio, and the accuracy and stability of passive sonar detection are improved.

The invention relates to the field of radar detection and signal processing, and particularly discloses a radar data technology system for monitoring a tiny target, and the system comprises a signal receiving and transmitting module which is used for generating and transmitting a linear frequency modulation signal based on a linear frequency modulation technology, and receiving an original echo signal reflected by the target; the pulse compression processing module is used for performing complex convolution operation on the original echo signal based on a matched filter to generate a compressed pulse signal; the multi-pulse coherent accumulation module is used for performing frequency domain energy accumulation on a plurality of compressed pulse signals of the same distance unit based on a discrete Fourier transform technology; and the Kalman filtering tracking module is used for processing the signals after multi-pulse coherent accumulation through a Kalman filtering algorithm, predicting and updating a target state in real time, and generating final trace point data. According to the invention, through key technologies of large-time wide-bandwidth pulse compression, multi-pulse coherent accumulation and the like, the detection capability of the radar on a tiny target is remarkably improved.

The present invention discloses a GNSS spoofing interference detection method based on combined SQM square, which includes the following steps: obtaining the carrier-to-noise ratio, correlator spacing, and coherent integration time of a GNSS receiver, and calculating the coherent integration values of the early path, prompt path, and late path of the tracking loop; calculating three SQM metrics, namely Delta, Ratio, and ELP, according to the coherent integration values; calculating the statistical characteristics of the SQM metrics based on the carrier-to-noise ratio, correlator spacing, and coherent integration time of the receiver; establishing a combined detection quantity; setting a false alarm rate, and determining a decision threshold according to the statistical distribution of the combined detection quantity; setting a time window length, and making a decision according to the decision threshold within the detection time to achieve spoofing interference detection. The method disclosed by the present invention does not need to change the receiver structure, has a wide range of applicable scenarios, can be applied to static and dynamic receivers, and has good detection effects on small-delay spoofing interference and complex offset spoofing interference.

The invention discloses a time-frequency cooperative multi-sub-pulse adaptive matched filtering main lobe intermittent sampling interference resisting method, which comprises the following steps of: modeling a radar multi-sub-pulse transmitting signal to obtain an echo signal, modeling a radar system total receiving signal, filtering an interference signal, recovering a target signal, and obtaining a pulse pressure result. According to the method, multi-channel pulse compression is completed, then distance gate alignment is carried out, finally, distance and speed information of a real target is further highlighted through intra-sub-pulse coherent accumulation and inter-sub-pulse coherent accumulation, and intermittent sampling interference is effectively suppressed. According to the method, a multi-sub-pulse structure is utilized, the interception length of a single sub-pulse by a jammer can be reduced, so that the interference degree of the single sub-pulse is reduced, and the intermittent sampling interference can be effectively suppressed under the condition that interference prior information does not need to be known.

The invention discloses a GNSS deception jamming suppression method based on inertial navigation auxiliary tracking, and the method specifically comprises the steps: carrying out the signal modeling through coherent integration after a radio frequency front end of a GNSS receiver receives a signal, and obtaining a coherent integration value of an in-phase branch and an orthogonal branch; constructing an observation equation and a state equation through coherent integration values of the orthogonal branch and the in-phase branch, and constructing a code loop phase discriminator error and a carrier loop frequency discriminator error by using coherent integration to obtain the observation equation and the state equation; obtaining deception jamming of different traction speeds by using combined detection quantity of constructed SQM and satellite and inertial information; on the basis of an NEYMAN-PEARSON detection theory framework, the optimal detection performance is sought under the constraint condition that the maximum false alarm probability PFAMAX is met, and robust Kalman filtering suitable for deception jamming suppression is designed; and inputting the state equation and the observation equation into robust Kalman filtering to obtain an interference coefficient and an anti-deception adaptive factor for deception interference suppression. According to the method, deception jamming of slow traction is effectively suppressed.

The invention discloses a maneuvering target long-time coherent accumulation method, system and device and a medium, and relates to the technical field of radar signal processing, and the method comprises the steps: enabling a plane array to achieve the complete airspace coverage in the azimuth angle range dimension through the introduction of FDA; according to the planar array, three-dimensional information of a target is utilized, so that the target can obtain information with higher dimensionality than that of coherent FDA. Then, an azimuth angle-pitch angle-distance three-dimensional matching filter is designed, and rapid waveform matching is realized. The method aims at the influence of a maneuvering target phase-coherent accumulation process. And finally, compensating range migration and Doppler frequency migration in a high-altitude maneuvering target detection process by adopting a second-order Keysone transform-LVD algorithm to realize coherent accumulation of the target. The invention not only provides a novel radar array combining PA and FDA, but also is applied to the field of target detection, especially for complex detection conditions such as high-altitude maneuvering targets.

The embodiment of the invention provides a signal tracking method and device, electronic equipment and a storage medium, and belongs to the technical field of satellite navigation. The method comprises the following steps: determining a reference parameter of a first tracking channel according to a captured to-be-processed signal; synchronizing the reference parameter to a second tracking channel; controlling the first tracking channel and the second tracking channel to perform coherent integration and non-coherent accumulation based on the reference parameters respectively to obtain a first accumulation result and a second accumulation result; and under the condition that the effective accumulation result does not exist, according to the integral result of the coherent integral of the first tracking channel, respectively updating the carrier loop and the code loop of the BPSK signal to obtain an updated reference parameter, and returning to execute the step of synchronizing the reference parameter to the second tracking channel until the effective accumulation result is detected to exist. And generating a to-be-frame-synchronized message based on the effective accumulation result. According to the invention, stable tracking requirements of BPSK and MCSK signals can be compatible.

The invention discloses a GNSS (Global Navigation Satellite System) rapid capture satellite-on method with high sensitivity and a receiver. The method comprises the following steps: determining a rapid capture parameter and a high-sensitivity capture parameter; wherein the fast capture parameters are a first coherent integration time and a first incoherent number of times; the high-sensitivity capture parameters are second coherent integration time and second incoherent times; the first coherent integration time is shorter than the second coherent integration time; the first incoherence frequency is smaller than the second incoherence frequency; determining the environment of the receiver based on the number of satellites received by the receiver and the satellite signal intensity; the proportion of rapid capture and high-sensitivity capture is determined according to the environment where the receiver is located; the capture scheduling is performed using the fast capture parameter and the high-sensitivity capture parameter according to the ratio of fast capture to high-sensitivity capture. According to the scheme provided by the invention, the capturing sensitivity can be effectively improved under the condition that the time characteristic is not influenced.

The present invention discloses a multi-channel coherent accumulation method of an FDA-MIMO radar based on range-frequency offset compensation, which belongs to the technical field of radar moving target detection. The present invention comprises: obtaining the echo signal of the target by using a two-dimensional planar array FDA-MIMO radar; performing multi-channel matched filtering on the echo signal, and performing FFT transformation in slow time to realize pulse accumulation; then performing covariance matrix calculation to obtain the noise subspace and signal subspace; then performing azimuth and elevation angle search of the target, and obtaining the range-frequency offset coupling compensation vector based on eigendecomposition; multi-channel beamforming, coherently synthesizing the multi-channel signal energy and using a constant false alarm rate to detect the target. The present invention can significantly improve the output signal-to-noise ratio and reduce the computational complexity of coherent accumulation. Moreover, when there is an error in the target distance estimation or the Doppler effect is generated by the frequency offset, the present invention can obtain a higher coherent accumulation gain than the MUSIC algorithm.

The present application provides a dual-satellite GNSS deceptive interference tracking method and system, which includes: when the deceptive interference emitted by the same deceptive interference source is propagated to two satellites respectively, performing correlation operations on the deceptive interference received by the two satellites; performing short-time coherent integration operations; performing fast Fourier transforms; taking multiple consecutive fast Fourier transform results as a group, performing incoherent integration operations; finding the maximum value; using a set threshold to distinguish the maximum value; when the tracking channel is configurable, configuring the tracking channel based on the delay time corresponding to the maximum value and the spectral line sequence of the fast Fourier transform; repeating the above steps to obtain a sequence of delay time and fast Fourier transform number combinations, which is the interference tracking result. The advantages of the present application are: it is applicable to a dual-satellite monitoring and positioning system, and provides a solution to the current problem of dual-satellite GNSS deceptive interference tracking.

The invention discloses a distributed radar target detection method and device based on space-time unified compensation, and the method comprises the steps: determining a slope distance process expression between each radar in a distributed radar and a target object for each echo signal group; based on the slant range process expression, respectively constructing an envelope range walking correction function and a frequency domain phase compensation function between radars; according to the to-be-solved parameters of the target object and the parameters of the target radar corresponding to the echo signal group, respectively constructing a range walk correction function and a time domain phase compensation function in each radar; constructing a space-time two-dimensional compensation function according to the envelope range walk correction function, the frequency domain phase compensation function, the range walk correction function and the time domain phase compensation function; the phase-coherent accumulation echo signal expression constructed according to the space-time two-dimensional compensation function and the to-be-solved parameters of the target object is solved, the parameter target value of the target object can be obtained, and the target detection accuracy of the distributed radar is improved.

The invention belongs to the technical field of navigation receivers, and relates to a CP-OFDM signal navigation receiving method and a navigation receiver. The method comprises the following steps: performing down-conversion on a received CP-OFDM signal to obtain an intermediate frequency signal; sending the intermediate frequency signal into an incoherent delay tracking loop, wherein the incoherent delay tracking loop comprises a leading branch, an instant branch and a lagging branch; the leading branch and the lagging branch process the intermediate frequency signal to obtain coherent integral amplitudes respectively; when the two branches process the intermediate frequency signal, local copy signals are generated firstly, and the protection interval of the local copy signals is filled to be zero; calculating according to the amplitude of the coherent integration of the two branches to obtain signal propagation time delay; eliminating noise to obtain a filtered time delay value; and estimating the time delay experienced by the received signal based on the filtered time delay value, and estimating the position information of the receiver. The problem that the cyclic prefix and the adjacent frequency points in the CP-OFDM signal influence the navigation tracking precision is solved.

A signal acquisition method includes: establishing a sub-integration length of a prime code signal to be a half of a symbol duration of navigation data, where the prime code signal is received by a signal receiver and includes a plurality of sub-integration pairs, and each sub-integration pair includes a first sub-integration and a second sub-integration; for each sub-integration, generating a first local replica and a second local replica based on the prime code signal; and executing FFT based convolution on the prime code signal, the first local replica and the second local replica to yield two convolution results; comparing two convolution maximum peak values and selecting convolution maximum peak values with higher magnitude in the sub-integration pair as first and second convolution peak values; and comparing the first convolution peak value and the second convolution peak value to obtain a corresponding IFFT convolution result to be outputted.

The invention relates to a decision-guided frequency compensation type carrier tracking method and system, and belongs to the field of satellite navigation. According to the method, aiming at the tracking lock losing problem caused by overlarge capture frequency deviation and navigation signal bit hopping in a capture-to-tracking link of a traditional frequency-locked loop, after receiving initial frequency deviation and code phase for delay alignment, down-conversion and coherent integration are carried out on intermediate frequency data based on the initial frequency deviation to obtain two groups of values; a frequency discriminator is used for calculating a first frequency difference, reverse frequency compensation is carried out on the first frequency difference to obtain a second frequency difference, frequency offset is synthesized to form two frequency assumptions, subsequent signals are processed in parallel, and correct frequency offset is output by comparing absolute values of coherent integration results, so that the frequency tracking range is effectively expanded, and the bit hopping interference resistance is enhanced. And the stability and the reliability of the navigation receiver in a high dynamic environment are improved.

The invention discloses a method and system for improving low signal-to-noise ratio direct sequence spread spectrum signal code tracking performance, and the method comprises the steps: generating an I-path bipolar code information source, and obtaining a baseband signal; performing convolution operation with the matched filter coefficient to obtain a matched filtering result; time lag and time lead are respectively carried out according to a specified length, so that a lag branch signal and a lead branch signal are respectively obtained; coherent integration is carried out on the local pseudo code sequence at a PL end, and an envelope value is solved; setting an incoherent accumulation length at a PS end, performing incoherent accumulation operation on the envelope value, and selecting a code phase discrimination mode to obtain a code phase discrimination value; and a phase change value is obtained through the linear filter and a loop filter of the code loop, and the phase change value is used for correcting the NCO of the local pseudo code sequence to realize closed-loop feedback. Code tracking performance is improved, signals can be accurately transmitted in a complex interference environment, error codes are reduced, inter-symbol crosstalk is effectively reduced, signal decoding accuracy is improved, and communication quality is guaranteed.

The present invention relates to a low-complexity, high-precision GNSS high-dynamic signal frequency estimation method and system. The method comprises: modeling a post-correlation signal to obtain a post-correlation signal; performing adjacent differential processing on the post-correlation signal and then integrating it to obtain a nearest-neighbor differential coherent signal; performing multi-dimensional differential accumulation on the nearest-neighbor differential coherent signal and estimating the Doppler change rate of the signal obtained by the multi-dimensional differential accumulation; calculating a differential signal based on the post-correlation signal and integrating it, then performing addition / subtraction processing to obtain a data bit symbol and an accumulated amount corresponding to each flip position; performing maximum position determination on the accumulated amount to obtain the actual data flip position; removing bits from the post-correlation signal to obtain a signal to be processed, performing coherent integration processing on the signal to be processed, and then performing Doppler frequency estimation on the signal after the coherent integration processing. The present invention realizes low-complexity and high-precision frequency parameter estimation in a high-dynamic environment.

The invention relates to a method for a radar system and to a radar system for detecting surroundings, comprising: transmission means having a plurality of transmitting antennas operating in parallel for emitting transmission signals which contain one or more sequences of K individual signals; means for changing the phase position of the transmitted individual signals, via which a different phase progression for the transmitting antennas is realized via the K individual signals; receiving means having a plurality of receiving antennas for receiving transmission signals reflected at objects; and signal processing means for processing the received signal; wherein not all transmitting antennas emit the same average transmission level, a non-coherent integration is carried out via certain signal components (TX integration); and wherein this non-coherent TX integration is carried out multiple times under the assumption of different radial relative velocities of an object and, optionally, distances away at which an object is located, and in the non-coherent TX integration, signal components are weighted more heavily the higher the emitted transmission level of the associated transmitting antenna is, and the result of the non-coherent TX integration is used in order to identify the phase progression resulting from the object relative speed and, optionally, object distance, and / or to identify a variable derived therefrom.

The embodiment of the present application provides a signal decoding method, device and electronic equipment, when signal decoding is performed, a first coherent integration corresponding to a first branch of a pilot component in a to-be-tracked signal and a second coherent integration corresponding to a second branch of the to-be-tracked signal, and a third coherent integration corresponding to the first branch of a data component in the to-be-tracked signal and a fourth coherent integration corresponding to the second branch of the to-be-tracked signal can be acquired respectively; and according to the first coherent integration, the second coherent integration, the third coherent integration and the fourth coherent integration, a navigation message is determined from the data component to decode the data component, avoiding the dependence on a previous coherent accumulation result and a previous decoding result, so that even if a previous decoding error of the navigation message, the whole bit stream will not be reversed, thereby effectively improving the accuracy of the decoding result.

The invention provides a space-based GPS M code signal power monitoring method and system, and the method comprises the steps: receiving a GPS signal, and outputting a digital signal; adopting a band-pass filtering mode to extract a GPS M code digital signal; reading dynamic information data of a low-orbit satellite platform and dynamic information data of a GPS satellite; estimating GPS M code signal delay and Doppler; estimating the carrier phase of the GPS M code signal; generating a GPS M code signal local carrier; multiplying the generated GPS M code signal local carrier by the GPS M code digital signal extracted by filtering to complete GPS M code signal carrier demodulation; carrying out pseudo code elimination on the GPS M code signal; the signal-to-noise ratio of the signal component is improved through coherent integration; and estimating the power of the GPS M code signal. The method has the advantages that the defect that a traditional foundation monitoring GPS M code signal power means cannot monitor GPS M code signal spot beam power enhancement is overcome.

The application relates to the technical field of satellite navigation, and discloses a satellite navigation system receiver signal tracking method and system. The method comprises the following steps: obtaining a local carrier signal according to a carrier phase residual at a previous moment, performing coherent integration processing on an intermediate frequency carrier signal to obtain a coherent integration value; establishing a carrier signal state model and a carrier signal observation model of an extended Kalman filter of the intermediate frequency carrier signal according to the coherent integration value, performing extended Kalman filter iterative calculation on the coherent integration value to obtain a state vector estimation value of the intermediate frequency carrier signal; performing multi-channel carrier signal joint tracking on the coherent integration values corresponding to the intermediate frequency carrier signals of each antenna element, and obtaining a carrier phase residual at a current moment according to the obtained dynamic phase weight value, correcting the phase of the corresponding state vector estimation value to obtain a carrier signal phase estimation value. The method improves the signal tracking precision of the satellite navigation system receiver.

The invention relates to a method for a radar system and to a radar system for environment detection, comprising: a transmitting device having MTX > = 2 transmitting antennas operating in parallel for transmitting a transmission signal, said transmission signal comprising one or more sequences of K individual signals; means for changing the phase of the transmitted single signal; a receiving device having an MRX > = 1 receiving antenna for receiving a transmission signal reflected on an object; and signal processing means for processing the received signals, in which coherent integration or incoherent integration (TXRX integration) is performed on the basis of the MRX received signals arriving at the receiving antenna or on the basis of the signals derived from the received signals and on the basis of the MTX signal components, i.e. On the basis of the MTX MRX values, respectively, and the signal processing means for processing the received signals, in which coherent integration or incoherent integration (TXRX integration) is performed on the basis of the MRX received signals arriving at the receiving antenna. A value is given at a time and performed multiple times assuming different radial relative speeds and optionally distances of the object, and the phase step resulting from the object relative speeds and optionally object distances and / or a quantity derived therefrom is identified using the results of the multiple TXRX integration.

The application discloses a kind of cable branch box electromechanical collaborative test method, its steps are: using random mechanical excitation force in external environment as passive test source, three-dimensional acceleration mechanical vibration wave and metal shielding ground line wideband weak current of box shell are synchronously collected, and double-mode time sequence is generated;Based on coherent integration algorithm, filter out power frequency induction component, extract induced displacement current and calculate electromechanical conversion coupling coefficient matrix;Using Fourier transform fitting dielectric relaxation response rate, output frequency-dependent dielectric relaxation characteristic vector;Response rate is mapped to different physical depth of insulating layer by combining radial propagation sound path difference model, and radial space charge concentration gradient parameter is output;Based on Poisson equation, reconstruct micro electric field stress distortion curve by reverse integration;Extract maximum stress peak value and compare with dendritic breakdown threshold value, and automatically output adaptive adjustment instruction.The application does not need to apply electrical excitation additionally, and can passively perceive internal space charge distribution and electric field stress distortion of insulating medium.

The invention relates to an ultra-wideband navigation signal tracking method and device based on linear frequency modulation spreading codes, and belongs to the technical field of satellite navigation. The method comprises the following steps: receiving an ultra-wideband navigation signal and multiplying the ultra-wideband navigation signal by a local in-phase carrier and a local orthogonal carrier respectively to obtain an in-phase component and an orthogonal component; acquiring a local linear frequency modulation spreading code output after phase calculation, phase quantization, code generation and signal transmission delay binding; acquiring a local pseudo-random spreading code output after signal transmission delay binding; combining the two types of spread spectrum codes to generate delayed, instant and advanced spread spectrum codes, and performing coherent integration on the spread spectrum codes, an in-phase component and an orthogonal component which are divided into three paths; calculating a phase error and a time delay error between the current receiving signal and a local carrier according to a coherent integration result; and finally, generating repeated carrier waves and two types of spreading codes based on error feedback so as to circularly realize ultra-wideband navigation signal tracking. According to the method, the complexity of ultra-wideband navigation signal tracking can be reduced.

The invention discloses a spread spectrum signal tracking method and system, and belongs to the field of signal processing. According to the invention, the spread spectrum digital signal is generated by performing oversampling on the acquired spread spectrum modulation signal. In-phase and quadrature components are generated by performing mixing, de-spreading and coherent integration on the digital signal, and frequency and phase error information is calculated based on the components at continuous moments for correcting local carriers. The corrected local carrier is then utilized to mix the signal to a baseband, and a target fractional delay is determined by applying an adjustable fractional delay and searching for an instant correlation energy peak to obtain code phase error information. After the code phase error information is utilized to correct the local pseudo code, the corrected local carrier and local pseudo code are utilized to initialize a narrow-bandwidth frequency-locked loop, a phase-locked loop and a delay-locked loop so as to start accurate tracking, and high-precision stable locking of spread spectrum signals can be realized in a short time.

A multi-frame coherent detection and tracking method for weak target line spectra is disclosed, based on multi-frame coherent integration. Step 1: Perform multi-frame coherent integration on the passive sonar received data to obtain measured values; Step 2: Establish a state equation including a target presence indicator variable; Step 3: Establish a multi-frame coherent integration measurement equation based on the coherence of the signal phase in the multi-frame data; Step 4: Derive the likelihood ratio function based on multi-frame coherent integration that matches the measurement equation; Step 5: Combine the measured values ​​from Step 1 and the multi-frame coherent detection and tracking model established in Steps 2 to 4, and use a particle filter iterative algorithm to obtain a more robust target line spectrum detection and tracking result. This invention addresses the problem of numerous missed detections in single-frame detection and tracking methods caused by amplitude fluctuations in the received signal in dynamically time-varying marine acoustic channels. It can be applied to most sonar equipment.

The invention provides a method and device for capturing a GNSS signal in real time, and relates to the technical field of GNSS satellite signal processing, and the method comprises the steps: caching the GNSS signal after baseband front-end digital signal processing to an AEFIFO in real time; when the length of the data cached in the AEFIFO reaches the data caching threshold value, reading a target data segment from the AEFIFO, and locally generating a pseudo code-carrier signal corresponding to a preset Doppler-code phase search range at the same time; coherent integration processing is carried out on the target data segment and the pseudo code-carrier signal, and after the amplitude of a coherent integration result is obtained, the coherent integration result and a historical incoherent accumulation result are superposed and temporarily stored; under the condition that the number of times of incoherent integration reaches a preset value, peak value searching is carried out, and the Doppler frequency and the code phase corresponding to the maximum value are determined as GNSS signal capturing results. According to the invention, high-sensitivity GNSS signal capture under limited storage resources can be realized.

Techniques for wireless communication are disclosed. In an aspect, a user equipment (UE) receives, from a server, a request to obtain one or more positioning measurements in accordance with one or more hypotheses for measuring downlink signals transmitted by one or more transmit receive points (TRPs), wherein each of the one or more hypotheses indicates an integration type of the downlink signal, a time window during which integration of the downlink signal is performed, or both, and wherein the integration type of the downlink signal is one of: a coherent integration, an incoherent integration, or both a coherent integration and an incoherent integration of the downlink signal; and using the one or more hypotheses to obtain one or more positioning measurements of the downlink signal for each of the one or more TRP.

The present invention belongs to the research field of radar weak target detection and is applicable to solving the problem of long-time accumulation detection of targets by hypersonic missile-borne radars. Aiming at the problem of difficult detection of low-observable targets by hypersonic missile-borne terminal guidance radars, a target detection method based on micro-motion sliding window and agile long-time coherent accumulation is provided. The computational complexity of long-time coherent accumulation is improved through a hybrid accumulation method of short-time coherent accumulation within a frame and long-time compensation coherent accumulation between frames. Data is updated through the mode of sliding window micro-motion, solving the problem of high data rate output in long-time coherent accumulation and ensuring the real-time performance of target detection. By iteratively using the stationary data within the sliding window, the computational amount is reduced. This method extends the long-time coherent accumulation of early warning radars to missile-borne radars, solving the contradiction between long-time accumulation and high data rate requirements for weak target detection by missile-borne radars. The algorithm has strong real-time performance and is convenient for engineering implementation.

This application discloses a method and system for tracking spread spectrum signals, belonging to the field of signal processing. This application generates a spread spectrum digital signal by oversampling the acquired spread spectrum modulated signal. In-phase and quadrature components are generated by mixing, despreading, and coherent integration of this digital signal. Frequency and phase error information are calculated based on the components at continuous time intervals to correct the local carrier. The corrected local carrier is then used to mix the signal to baseband. An adjustable fractional delay is applied, and the instantaneous correlation energy peak is searched to determine the target fractional delay, thereby obtaining code phase error information. After correcting the local pseudocode using this code phase error information, the corrected local carrier and local pseudocode are used to initialize a narrow-bandwidth frequency-locked loop, phase-locked loop, and delay-locked loop, thus initiating precise tracking. This enables high-precision and stable locking of the spread spectrum signal in a short time.

The invention discloses a half-bit matching differential coherent integral capturing method capable of overcoming NH code hopping. The method comprises the following steps: acquiring an intermediate frequency signal and a local carrier; the method comprises the following steps: respectively modeling an intermediate frequency signal and a local carrier to obtain an intermediate frequency signal model and a local carrier model, mixing the intermediate frequency signal model and the local carrier waveform to obtain a frequency mixing result, calculating an integral accumulation term to be accumulated based on the frequency mixing result, and calculating a differential coherent integral accumulation model based on the integral accumulation term; establishing a zero-padding FFT model, supplementing a 1ms zero value behind a 1ms local carrier by the zero-padding FFT model, and performing FFT operation to obtain a 1ms coherent integration result; the delay time of differential coherent integration is set to be 20ms, and four differential coherent integration results of 10ms are obtained through accumulation; and 4 continuous 10ms differential coherent integration results are paired in pairs, and the influence of data bit hopping is eliminated through symbol discussion and addition operation. According to the invention, the Beidou NH code jump can be overcome, and the capturing effect of the Beidou satellite signal is improved.