Satellite navigation receiver pulse interference identification method, device and computer equipment

Abstract

This application relates to a method, apparatus, and computer device for identifying impulse interference in a satellite navigation receiver. The method includes: acquiring a satellite navigation signal and calculating the instantaneous envelope at each moment; determining a corresponding histogram statistical interval based on each instantaneous envelope; obtaining an original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within a statistical time window; smoothing the original histogram sequence; detecting local maxima in the smoothed histogram sequence; designating the local maxima with the largest value as the primary peak and the remaining local maxima as secondary peaks; determining impulse interference based on the relationship between the significance of each secondary peak relative to its adjacent valley and a preset decision threshold; and outputting the determination result of the presence of impulse interference as an interference flag to a baseband processor to trigger interference response operations in the satellite navigation receiver. This method can achieve accurate impulse interference identification while maintaining low power consumption and robustness.

Description

Technical Field

[0001] This application relates to the field of signal processing technology, and in particular to a method, apparatus and computer equipment for identifying pulse interference in a satellite navigation receiver. Background Technology

[0002] With the development of satellite navigation signal processing technology, global satellite navigation systems have become a core supporting technology for providing high-precision positioning, navigation, and timing services. They are widely used in various industries such as transportation, surveying and mapping, and communications, bringing great convenience to social production and life. However, satellite navigation signals have extremely low power when they reach the ground, making them highly susceptible to various intentional or unintentional interferences such as continuous wave interference and pulse interference. Among these, pulse interference, with its high duty cycle, wide instantaneous bandwidth, and burst characteristics, can instantly raise the noise floor of the receiver front end, causing carrier and code tracking loops to lose lock and directly interrupting positioning, velocity measurement, and timing services. Therefore, rapid and accurate identification of pulse interference is crucial to ensuring the robustness of the navigation system.

[0003] Current interference identification technologies mainly rely on threshold analysis, time-frequency analysis, higher-order statistical features, or machine learning algorithms. Traditional time-domain thresholding methods typically set fixed amplitude thresholds or adaptive thresholds based on automatic gain control levels. However, in the presence of strong continuous wave interference or significant changes in the signal's dynamic range, the average signal power is inflated, causing the fixed threshold to fail or generating numerous false alarms, making it difficult to distinguish between pulse interference and continuous wave interference. Transform domain processing methods, such as short-time Fourier transform and wavelet transform, can effectively identify pulses, but they involve numerous complex multiplications and Fourier transform operations, consuming huge hardware resources and making them difficult to adapt to navigation receiver chips with low power consumption and high real-time requirements. Higher-order statistical methods use kurtosis to determine the Gaussianity of the signal. While theoretically effective, fourth-order moment calculations require high data bit width and are susceptible to outliers, resulting in poor stability. Machine learning-based recognition methods, though accurate and adaptable, involve massive multiplication and accumulation operations in the forward inference process of classification models, contradicting the stringent requirements of low cost and low power consumption for navigation receivers. Furthermore, model training requires massive amounts of complete labeled interference data, leading to extremely high data acquisition and labeling costs. Generalization capabilities in unknown scenarios are also questionable. These traditional technical approaches generally suffer from a difficult-to-reconcile contradiction between performance and complexity. High-precision recognition often comes with unbearable computational overhead, while lightweight solutions tend to sacrifice recognition reliability, failing to meet the practical application needs of existing commercial receiver chips. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, and computer equipment for identifying pulse interference in a satellite navigation receiver to address the aforementioned technical problems.

[0005] A method for identifying pulse interference in a satellite navigation receiver, the method comprising:

[0006] The satellite navigation signal is acquired, and the digital complex baseband signal corresponding to the satellite navigation signal is processed point by point to calculate the instantaneous envelope at each moment;

[0007] Set the total number of statistical intervals for the histogram and a preset statistical time window. Determine the corresponding histogram statistical interval based on each instantaneous envelope. Obtain the original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within the statistical time window.

[0008] The original histogram sequence is smoothed to obtain a smoothed histogram sequence, and local maxima are detected in the smoothed histogram sequence; the local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals.

[0009] The local maximum point with the largest value is taken as the main peak, and the remaining local maximum points are taken as secondary peaks. Impulse interference is determined based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, it is determined that there is impulse interference.

[0010] The determination result of the presence of pulse interference is output as an interference flag to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

[0011] A pulse interference identification device for a satellite navigation receiver, the device comprising:

[0012] The signal acquisition module is used to acquire satellite navigation signals and process the digital complex baseband signal corresponding to the satellite navigation signals point by point to calculate the instantaneous envelope at each moment;

[0013] The quantity statistics module is used to set the total number of statistical intervals of the histogram and the preset statistical time window, determine the corresponding histogram statistical interval based on each instantaneous envelope, and obtain the original histogram sequence according to the number of instantaneous envelopes falling into each statistical interval within the statistical time window;

[0014] The smoothing module is used to smooth the original histogram sequence to obtain a smoothed histogram sequence and detect local maxima in the smoothed histogram sequence; the local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals.

[0015] The interference decision module is used to take the local maximum point with the largest value as the main peak and the remaining local maximum points as secondary peaks. The module determines the impulse interference based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, the module determines that there is impulse interference.

[0016] The result output module is used to output the determination result of the presence of pulse interference as an interference flag bit to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

[0017] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program performing the following steps:

[0018] The satellite navigation signal is acquired, and the digital complex baseband signal corresponding to the satellite navigation signal is processed point by point to calculate the instantaneous envelope at each moment;

[0019] Set the total number of statistical intervals for the histogram and a preset statistical time window. Determine the corresponding histogram statistical interval based on each instantaneous envelope. Obtain the original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within the statistical time window.

[0020] The original histogram sequence is smoothed to obtain a smoothed histogram sequence, and local maxima are detected in the smoothed histogram sequence; the local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals.

[0021] The local maximum point with the largest value is taken as the main peak, and the remaining local maximum points are taken as secondary peaks. Impulse interference is determined based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, it is determined that there is impulse interference.

[0022] The determination result of the presence of pulse interference is output as an interference flag to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

[0023] A computer-readable storage medium having a computer program stored thereon, the computer program performing the following steps when executed by a processor:

[0024] The satellite navigation signal is acquired, and the digital complex baseband signal corresponding to the satellite navigation signal is processed point by point to calculate the instantaneous envelope at each moment;

[0025] Set the total number of statistical intervals for the histogram and a preset statistical time window. Determine the corresponding histogram statistical interval based on each instantaneous envelope. Obtain the original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within the statistical time window.

[0026] The original histogram sequence is smoothed to obtain a smoothed histogram sequence, and local maxima are detected in the smoothed histogram sequence; the local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals.

[0027] The local maximum point with the largest value is taken as the main peak, and the remaining local maximum points are taken as secondary peaks. Impulse interference is determined based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, it is determined that there is impulse interference.

[0028] The determination result of the presence of pulse interference is output as an interference flag to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

[0029] The aforementioned pulse interference identification method, device, and computer equipment for satellite navigation receivers obtain the instantaneous envelope by processing the digital complex baseband signal corresponding to the satellite navigation signal point by point. By combining the total number of histogram statistical intervals and a preset time window to construct the original histogram sequence, the continuous envelope amplitude distribution can be transformed into low-complexity discrete statistical data, avoiding expensive computations such as Fourier transform and matrix decomposition, thus meeting the low-power requirements of navigation receivers. By smoothing the original histogram sequence and detecting local maxima, combined with the distinction between primary and secondary peaks and their significance determination, the multi-peak distribution characteristics of the envelope can be accurately identified, effectively reducing interference from sampling jitter and noise, significantly lowering the false alarm rate, and improving the accuracy of pulse interference identification. The entire technical solution is based on the statistical distribution shape rather than absolute amplitude for judgment, which can immunize against the total power increase caused by automatic gain control gain fluctuations or continuous wave interference, accurately distinguishing pulse interference from other interference types. Furthermore, the judgment result is output as a simple interference flag, facilitating integration with existing receiver interference mitigation modules, achieving rapid pulse interference identification and response, effectively balancing identification performance and computational complexity, and ensuring the robustness of the navigation system. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating a satellite navigation receiver pulse interference identification method in one embodiment;

[0031] Figure 2 This is a flowchart illustrating a satellite navigation receiver pulse interference identification method in a specific embodiment;

[0032] Figure 3 This is a smoothed histogram obtained without interference after processing by the method of the present invention in one embodiment.

[0033] Figure 4 This is a smoothed histogram under pulse interference obtained after processing by the method of the present invention in one embodiment;

[0034] Figure 5 This is a smoothed histogram under narrowband interference obtained after processing by the method of the present invention in one embodiment;

[0035] Figure 6This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0037] In one embodiment, such as Figure 1 As shown, a method for identifying pulse interference in a satellite navigation receiver is provided, comprising the following steps:

[0038] Step 102: Obtain the satellite navigation signal, and process the corresponding digital complex baseband signal point by point to calculate the instantaneous envelope at each moment.

[0039] Digital complex baseband signals are digital signals containing both real and imaginary parts, obtained by down-converting and analog-to-digital converting satellite navigation signals. They can completely preserve the phase and amplitude information of the original signal. The instantaneous envelope is a physical quantity that characterizes the instantaneous amplitude change of a signal, reflecting the intensity characteristics of the signal at each moment.

[0040] It is understandable that by processing the digital complex baseband signal point by point to calculate the instantaneous envelope, the overall process of envelope calculation can be simplified, the computational complexity can be reduced, and it is beneficial to implement it in low-power satellite navigation receiver chips. At the same time, the calculation accuracy of the instantaneous envelope is guaranteed, providing accurate and reliable basic data support for subsequent pulse interference identification.

[0041] Step 104: Set the total number of statistical intervals for the histogram and the preset statistical time window. Determine the corresponding histogram statistical interval based on each instantaneous envelope. Obtain the original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within the statistical time window.

[0042] The total number of statistical intervals is the number of equally spaced intervals that divide the amplitude range of the instantaneous envelope, used for discretizing and statistically analyzing the envelope amplitude. The statistical time window is a preset time length used to accumulate and statistically analyze the instantaneous envelope data. The original histogram sequence is an ordered set of data formed by arranging the number of times the instantaneous envelope falls within each statistical interval in the interval order within the statistical time window.

[0043] It is understandable that transforming the continuous envelope amplitude distribution into discrete statistical data can intuitively present the distribution characteristics of the signal envelope, providing a structured data carrier for subsequent multi-peak discrimination. At the same time, the statistical process only involves simple counting operations, which can further control the computational complexity of the overall technical solution and adapt to the low power consumption requirements of the receiver.

[0044] Step 106: Smooth the original histogram sequence to obtain a smoothed histogram sequence, and detect local maxima in the smoothed histogram sequence.

[0045] A smoothed histogram sequence is a sequence obtained by filtering the original histogram sequence. It is used to eliminate statistical jitter caused by sampling randomness and make the envelope distribution trend smoother.

[0046] A local maximum is a point where the value of the corresponding statistical interval is greater than the values ​​of the two adjacent statistical intervals. In a smooth histogram sequence, a point where the value of a certain statistical interval is simultaneously greater than the values ​​of the statistical intervals to its left and right is a local maximum, and it is the core element that constitutes the "peak" of the histogram.

[0047] It is understandable that smoothing the original histogram sequence can reduce the impact of noise interference on the envelope distribution characteristics and clearly present the true distribution pattern of the envelope. Accurate detection of local maxima can precisely locate the potential peaks in the histogram, providing a clear basis for distinguishing between the main peak and secondary peaks, which is conducive to improving the accuracy and reliability of subsequent impulse interference judgment.

[0048] Step 108: The local maximum point with the largest value is taken as the main peak, and the remaining local maximum points are taken as secondary peaks. Impulse interference is determined based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, it is determined that there is impulse interference.

[0049] The primary peak is the local maximum point with the largest value in the smoothed histogram sequence, corresponding to the most concentrated amplitude interval in the envelope distribution. Secondary peaks are other local maxima besides the primary peak, reflecting secondary concentrated areas in the envelope distribution. Significance is the ratio of the statistical interval value corresponding to the secondary peak to the smaller value among the adjacent valley values, used to measure the prominence of the secondary peak. The preset decision threshold is a pre-set critical value used to determine whether a secondary peak is a valid peak.

[0050] It is understandable that by distinguishing between the primary peak and secondary peaks and calculating the significance of the secondary peaks, the effective multi-peak features in the envelope distribution can be accurately identified. Combined with the preset decision threshold for pulse interference judgment, the pulse interference can be accurately distinguished from no interference and continuous wave interference, significantly improving the accuracy of pulse interference identification. At the same time, the judgment process only involves simple numerical comparison and ratio calculation, which can maintain the advantage of low computational complexity of the technical solution.

[0051] Step 110: The determination result of the presence of pulse interference is output as an interference flag to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

[0052] The interference flag is a Boolean signal used to characterize whether impulse interference has been detected, conveying the interference identification result in the form of a specific level or value. The baseband processor is a key component in a satellite navigation receiver responsible for core tasks such as signal baseband processing and navigation calculation. Interference mitigation operations are adaptive suppression measures initiated by the receiver after detecting impulse interference, including impulse blanking, interference event recording, and reducing the weight of observations.

[0053] It is understandable that outputting the pulse interference determination result to the baseband processor in the form of an interference flag can enable the rapid transmission of the interference identification result, ensure that the baseband processor triggers the corresponding interference response operation in a timely manner, effectively reduce the impact of pulse interference on the receiver carrier and code tracking loop, and help ensure the stability of the navigation system's positioning, velocity measurement and timing services. At the same time, the simple Boolean flag design facilitates seamless integration with the interference mitigation module of the existing receiver, improving the engineering practicality of the technical solution.

[0054] In the aforementioned pulse interference identification method for satellite navigation receivers, the instantaneous envelope is obtained by processing the digital complex baseband signal corresponding to the satellite navigation signal point by point. The original histogram sequence is constructed by combining the total number of histogram statistical intervals and a preset time window. This transforms the continuous envelope amplitude distribution into low-complexity discrete statistical data, avoiding expensive computations such as Fourier transform and matrix decomposition, thus meeting the low-power requirements of navigation receivers. By smoothing the original histogram sequence and detecting local maxima, and combining the distinction between primary and secondary peaks and their significance determination, the multi-peak distribution characteristics of the envelope can be accurately identified, effectively reducing interference from sampling jitter and noise, significantly lowering the false alarm rate, and improving the accuracy of pulse interference identification. The entire technical solution is based on the statistical distribution shape rather than absolute amplitude for judgment, which can immunize against the total power increase caused by automatic gain control gain fluctuations or continuous wave interference. It accurately distinguishes pulse interference from other types of interference, and the judgment result is output as a simple interference flag, facilitating integration with existing receiver interference mitigation modules. This enables rapid identification and response to pulse interference, effectively balancing identification performance and computational complexity, and ensuring the robustness of the navigation system.

[0055] In one embodiment, the method further includes: if the significance of all minor peaks is less than or equal to a preset decision threshold, or if there are no minor peaks, then it is determined that there is no pulse interference; and the determination result of no pulse interference is output as an interference flag bit to the baseband processor.

[0056] This invention utilizes the physical characteristic that impulse interference causes the probability density function (PDF) of the received signal envelope to exhibit a bimodal or multimodal distribution. By constructing low-complexity histogram statistics and peak detection logic, it achieves accurate identification of impulse interference. In this embodiment, based on the single-peak distribution characteristic of the histogram, it clearly distinguishes between interference-free, continuous wave interference, and impulse interference scenarios. It comprehensively covers various interference and interference-free operating conditions, improving the completeness of the judgment results and providing a clear basis for the receiver to subsequently activate interference suppression measures, thus helping to ensure the normal operation efficiency of the navigation system in an environment without impulse interference.

[0057] In one embodiment, the instantaneous envelope of each moment is calculated by processing the digital complex baseband signal corresponding to the satellite navigation signal point by point, including: taking the absolute value of the real part and the absolute value of the imaginary part of the digital complex baseband signal respectively; obtaining the maximum and minimum values ​​of the absolute values ​​of the real part and the imaginary part; and performing a weighted summation of the maximum and minimum values ​​using a linear approximation algorithm to obtain the instantaneous envelope of each moment.

[0058] Specifically, the receiver's radio frequency front-end performs down-conversion and analog-to-digital conversion on the satellite navigation signals (such as GPSL1 and BDSB3 signals) received by the antenna to obtain a digital intermediate frequency (IF) signal. This IF signal is then down-converted to baseband to obtain a digital complex baseband signal. The digital complex baseband signal of the satellite navigation receiver... Point-by-point processing is performed. To reduce computational complexity while maintaining recognition performance, a linear approximation algorithm is used to calculate the instantaneous envelope of the signal. The calculation formula for the linear approximation algorithm is as follows:

[0059] ;

[0060] in, and These are preset linear fitting coefficients. Preferably, they are taken as follows: , To minimize the approximation error, or to take , This is so that it can be implemented through bit shift operations.

[0061] In this embodiment, the linear approximation algorithm can significantly reduce the computational complexity of the instantaneous envelope, avoid the complex square root operation in traditional envelope calculation, and reduce hardware resource consumption while ensuring the accuracy of envelope calculation, which is beneficial for integration into low-power, low-cost navigation receiver chips.

[0062] In one embodiment, determining the corresponding histogram statistical interval based on each instantaneous envelope includes: obtaining the maximum value of all instantaneous envelopes within the statistical time window; calculating the interval index corresponding to each instantaneous envelope based on the ratio of each instantaneous envelope to the maximum value and the preset total number of histogram statistical intervals; and determining the histogram statistical interval corresponding to each instantaneous envelope based on the interval index.

[0063] Specifically, the total number of statistical intervals (Bin) in the histogram is set to... For each instantaneous envelope Calculate the corresponding histogram interval index. :

[0064] ;

[0065] in, This indicates rounding down to the nearest integer. If Then let Within the preset statistical time window Within, the statistics fall into each interval. The instantaneous envelope count is used to obtain the original histogram sequence. .

[0066] In this embodiment, the interval index is calculated by multiplying the ratio by the total number of statistical intervals and then rounding down, ensuring that the instantaneous envelope is evenly distributed across each statistical interval according to its amplitude proportion. This enables precise discretization and statistical analysis of the envelope amplitude, visually presenting the distribution characteristics of the signal envelope, and providing a structured and analyzable data carrier for subsequent multi-peak discrimination, which is beneficial to improving the accuracy of subsequent peak detection.

[0067] In one embodiment, if the interval index is greater than or equal to the total number of statistical intervals, the interval index is corrected to the total number of statistical intervals minus one.

[0068] In this embodiment, the correction logic addresses the extreme case where the instantaneous envelope is close to or equal to the maximum value, ensuring that such envelopes can be assigned to the last statistical interval. This avoids statistical errors caused by index overflow, ensures that all instantaneous envelopes can be reasonably assigned to their corresponding statistical intervals, maintains the integrity and statistical accuracy of the original histogram sequence, and lays a reliable foundation for subsequent smoothing and peak detection.

[0069] In one embodiment, smoothing the original histogram sequence to obtain a smoothed histogram sequence includes: obtaining the values ​​of each statistical interval and its adjacent intervals before and after each sliding window radius in the original histogram sequence according to a preset sliding window radius; averaging the obtained values ​​to obtain the smoothed value corresponding to each statistical interval; and obtaining the smoothed histogram sequence based on the smoothed values ​​of all statistical intervals.

[0070] Specifically, a moving average filter is used to process the original histogram sequence. Smoothing is performed to eliminate statistical jitter caused by sampling randomness, resulting in a smoothed histogram sequence. The smoothing formula is as follows:

[0071] ;

[0072] in Let be the radius of the sliding window.

[0073] Next, the smoothed histogram sequence is detected. All local maxima in the . A local maximum is defined as: for the ... Each histogram interval satisfies and Record all interval indices that meet the conditions. .

[0074] In this embodiment, the sliding window radius L can be set according to actual needs. For example, when L=1 is selected, a 3-point moving average filter is used for smoothing, so that the smoothed value of each statistical interval is the average of its own value and the values ​​of the one adjacent interval before and after it. This can effectively eliminate statistical jitter caused by sampling randomness, make the histogram curve smoother, highlight the true trend of the envelope distribution, facilitate accurate detection of local maxima, and improve the reliability of subsequent multi-peak discrimination.

[0075] In one embodiment, the step of calculating the significance of a secondary peak relative to its adjacent valleys includes: obtaining the significance based on the ratio of the statistical interval value corresponding to the secondary peak to the smaller value among the values ​​of the adjacent valleys to the left and right of the secondary peak; the adjacent valleys are the statistical intervals to the left and right of the statistical interval corresponding to the secondary peak that have values ​​smaller than the secondary peak.

[0076] Specifically, not all local maxima represent meaningful "peaks". This invention proposes a low-complexity saliency filtering criterion:

[0077] (1) Main peak identification: Find the peak with the largest count value in the histogram as the main peak, and record its height as . .

[0078] (2) Screening of secondary peaks: For each other local maximum point Calculate its significance. :

[0079] ;

[0080] This ratio reflects the prominence of the point relative to its adjacent valley floor.

[0081] (3) Decision: If there is at least one minor peak and its significance is Greater than a preset threshold (usually taken) If the histogram shows a multi-peak distribution, then pulse interference is identified. Otherwise, it is identified as a single-peak distribution, meaning there is no pulse interference or only continuous wave interference.

[0082] In this embodiment, a decision threshold is used to filter out secondary peaks with practical significance, excluding minor spikes caused by noise. This accurately distinguishes between valid secondary peaks and spurious peaks, preventing meaningless local fluctuations from being misjudged as secondary peaks, improving the accuracy of multi-peak distribution discrimination, and thus enhancing the accuracy of impulse interference identification.

[0083] In one embodiment, the interference response operation of the satellite navigation receiver includes: initiating a pulse blanking operation based on the interference flag bit to shut down the receiver correlator during the duration of the pulse interference; or recording pulse interference event information based on the interference flag bit for subsequent spectrum monitoring; or reducing the weight of satellite navigation observations in the integrated navigation system based on the interference flag bit.

[0084] In this embodiment, the multi-peak discrimination result is output as an interference flag. When pulse interference is detected, this flag can trigger the interference response module inside the receiver, for example: 1) initiating pulse blanking (disabling the correlator during the interference duration); 2) recording the interference event for spectrum monitoring; 3) reducing the weight of GNSS observations in the integrated navigation system. The interference flag is a simple Boolean signal that can be directly interfaced with the interference response module inside the receiver. It can quickly respond to pulse interference, promptly initiate targeted suppression measures, reduce the impact of pulse interference on the receiver carrier and code tracking loop, and help ensure the stability of the navigation system's positioning, velocity measurement, and timing services. At the same time, it enriches the interference handling methods and adapts to different navigation application scenarios.

[0085] In one specific embodiment, such as Figure 2 The diagram illustrates a method for identifying pulse interference in a satellite navigation receiver. Taking a B3I frequency (1268.52MHz) satellite navigation receiver as an example, the specific application and effects of the invention are explained.

[0086] Signal system: Beidou B3I signal, QPSK modulation, code rate 10.23MHz;

[0087] Receiver parameters: sampling rate 21MHz (satisfies the Nyquist sampling theorem and is easy to implement in engineering), quantization bits: 16 bits (data range -2048 to +2047), statistical time window. T 1ms (corresponding to one pseudocode period).

[0088] Interference parameters: (1) Pulse interference parameters: periodic pulse interference, pulse width 15us, pulse repetition period 100us, duty cycle 15%, interference-to-signal ratio 40dB. (2) Narrowband continuous wave interference: interference bandwidth is 2MHz, interference center frequency is 1268.52MHz, interference interference-to-signal ratio is 40dB.

[0089] S1: The receiver's RF front-end performs down-conversion and analog-to-digital conversion on the satellite navigation signal received by the antenna to obtain a digital intermediate frequency (IF) signal. This IF signal is then down-converted to baseband to obtain a digital complex baseband signal. (The last sentence appears to be incomplete and possibly refers to a separate process: "The digital complex baseband signal of the satellite navigation receiver...") Point-by-point processing is performed, and the instantaneous envelope of the signal is calculated using a linear approximation algorithm. :

[0090] ;

[0091] use , This algorithm requires only comparison and two multiplication-addition operations, greatly reducing the computational burden.

[0092] S2: Set the total number of histogram intervals (Bin) to M=32. For each instantaneous envelope, calculate its corresponding histogram interval index. :

[0093] ;

[0094] in, This indicates rounding down to the nearest integer. If Then let Within the preset statistical time window Within 1ms (a total of 21,000 instantaneous envelope values), the values ​​falling into each interval are counted. The instantaneous envelope count is used to obtain the original histogram sequence. .

[0095] S3: Apply a moving average filter to the original histogram Smoothing is performed to eliminate statistical jitter caused by sampling randomness, resulting in a smoothed histogram. Using a 3-point moving average filter ( Smoothing:

[0096] ;

[0097] After smoothing, the histogram curve becomes smoother, making it easier to find the peak.

[0098] Next, the smoothed histogram is detected. All local maxima in the . A local maximum is defined as: for the ... Each histogram interval satisfies and Record all interval indices that meet the conditions. .

[0099] Figures 3-5 This is the smoothed histogram obtained after processing by the method of this invention. Figure 3 This is the histogram without interference. Figure 4 It is a histogram under impulse interference. Figure 5 This is a histogram under narrowband interference. As can be seen from the figure, the histogram has obvious bimodal peaks under impulse interference, while it shows a single peak under no interference and narrowband interference.

[0100] S4: Under both interference-free and narrowband interference conditions, only one local maximum was detected, thus indicating no impulse interference. However, under impulse interference, two local maxima were detected, with interval indices of 2 and 24, and count values ​​of 4763 and 580 respectively. 4763 is the dominant peak. For the secondary peak 580, its significance was calculated: its left and right neighboring valleys were 476 and 559, respectively. Therefore, the significance criteria are met, and the decision is multi-peaked, indicating the presence of impulse interference.

[0101] S5: Set the interference flag to 1 and send it to the baseband processor. The baseband processor can immediately apply pulse blanking to the data within the current time window, or mark the batch of observations as unreliable.

[0102] This specific embodiment fully verifies the outstanding advantages and significant effects of the present invention. Its core operations involve only amplitude comparison, counting, addition and subtraction, and a small number of multiplications and divisions, completely avoiding expensive operations such as Fourier transform and matrix decomposition. Its complexity is extremely low, making it suitable for implementation on FPGAs or low-end DSPs, meeting the low-cost, low-power application requirements of satellite navigation receivers. Furthermore, this method identifies pulse interference based on the statistical distribution shape rather than absolute amplitude, effectively resisting the impact of automatic gain control gain fluctuations or continuous wave interference on total power increase, accurately distinguishing between single-peak continuous wave interference and multi-peak pulse interference, exhibiting extremely strong robustness. In addition, the algorithm adopts a streaming processing mode, with an overall delay of only one statistical time window, typically down to the millisecond level, meeting the practical application requirements of real-time interference alarms and ensuring timely response of the navigation system to interference. Moreover, by flexibly adjusting the total number of histogram statistical intervals and the decision threshold, this method can adapt to pulse interference environments with different duty cycles and interference-to-signal ratios, with adjustable sensitivity and a wide range of applicable scenarios. In addition, the judgment result is output in a simple Boolean flag form, which does not require complex data format conversion and is easy to integrate seamlessly with the interference mitigation module of existing receivers, greatly reducing the integration cost and difficulty in engineering applications.

[0103] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0104] In one embodiment, a satellite navigation receiver pulse interference identification device is provided, comprising:

[0105] The signal acquisition module is used to acquire satellite navigation signals and process the corresponding digital complex baseband signals point by point to calculate the instantaneous envelope at each moment.

[0106] The quantity statistics module is used to set the total number of statistical intervals of the histogram and the preset statistical time window. It determines the corresponding histogram statistical interval based on each instantaneous envelope and obtains the original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within the statistical time window.

[0107] The smoothing module is used to smooth the original histogram sequence to obtain a smoothed histogram sequence and detect local maxima in the smoothed histogram sequence; local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals.

[0108] The interference decision module is used to take the local maximum point with the largest value as the main peak and the remaining local maximum points as secondary peaks. The module determines the impulse interference based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, the module determines that there is impulse interference.

[0109] The result output module is used to output the determination result of the presence of pulse interference as an interference flag bit to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

[0110] Specific limitations regarding the pulse interference identification device for satellite navigation receivers can be found in the limitations of the pulse interference identification method for satellite navigation receivers mentioned above, and will not be repeated here. Each module in the aforementioned pulse interference identification device for satellite navigation receivers can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0111] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6 As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a pulse interference identification method for a satellite navigation receiver. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0112] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0113] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the method described above.

[0114] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0115] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0116] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for identifying pulse interference in a satellite navigation receiver, characterized in that, The method includes: The satellite navigation signal is acquired, and the digital complex baseband signal corresponding to the satellite navigation signal is processed point by point to calculate the instantaneous envelope at each moment; Set the total number of statistical intervals for the histogram and a preset statistical time window. Determine the corresponding histogram statistical interval based on each instantaneous envelope. Obtain the original histogram sequence based on the number of instantaneous envelopes falling into each statistical interval within the statistical time window. The original histogram sequence is smoothed to obtain a smoothed histogram sequence, and local maxima are detected in the smoothed histogram sequence; the local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals. The local maximum point with the largest value is taken as the main peak, and the remaining local maximum points are taken as secondary peaks. Impulse interference is determined based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, it is determined that there is impulse interference. The determination result of the presence of pulse interference is output as an interference flag to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

2. The method according to claim 1, characterized in that, The method further includes: If the significance of all minor peaks is less than or equal to the preset decision threshold, or if there are no minor peaks, then it is determined that there is no impulse interference. The determination result that there is no pulse interference is output as an interference flag to the baseband processor.

3. The method according to claim 1, characterized in that, The instantaneous envelope at each moment is calculated by processing the digital complex baseband signal corresponding to the satellite navigation signal point by point, including: Take the absolute values ​​of the real part and the absolute values ​​of the imaginary part of the real part and the imaginary part of the digital complex baseband signal, respectively; The maximum and minimum values ​​of the absolute values ​​of the real and imaginary parts are obtained. The maximum and minimum values ​​are then weighted and summed using a linear approximation algorithm to obtain the instantaneous envelope at each time step.

4. The method according to claim 1, characterized in that, The corresponding histogram statistical intervals determined based on each instantaneous envelope include: Get the maximum value of all instantaneous envelopes within the statistical time window; Based on the ratio of each instantaneous envelope to the maximum value, and using the ratio and a preset histogram statistical interval total, the interval index corresponding to each instantaneous envelope is calculated. Based on the interval index, determine the histogram statistical interval corresponding to each instantaneous envelope.

5. The method according to claim 4, characterized in that, If the interval index is greater than or equal to the total number of statistical intervals, then the interval index is corrected to the total number of statistical intervals minus one.

6. The method according to claim 1, characterized in that, The original histogram sequence is smoothed to obtain a smoothed histogram sequence, which includes: Based on the preset sliding window radius, the values ​​of each statistical interval and its adjacent intervals before and after the sliding window radius in the original histogram sequence are obtained. The obtained values ​​are averaged to obtain the smoothed value corresponding to each statistical interval. Based on the smoothed values ​​of all statistical intervals, a smoothed histogram sequence is obtained.

7. The method according to claim 1, characterized in that, The steps for calculating the significance of the secondary peak relative to the adjacent valley include: The significance is obtained by the ratio of the statistical interval value corresponding to the secondary peak to the smaller value among the adjacent valley values ​​to the left and right of the secondary peak; the adjacent valleys are the statistical intervals on the left and right sides of the statistical interval corresponding to the secondary peak whose values ​​are smaller than those of the secondary peak.

8. The method according to claim 1, characterized in that, The interference handling operations of the satellite navigation receiver include: Based on the interference flag, initiate pulse blanking operation and turn off the receiver correlator for the duration of the pulse interference; Alternatively, based on the interference flag, pulse interference event information can be recorded for subsequent spectrum monitoring; Alternatively, based on interference flags, the weight of satellite navigation observations in the integrated navigation system can be reduced.

9. A pulse interference identification device for a satellite navigation receiver, characterized in that, The device includes: The signal acquisition module is used to acquire satellite navigation signals and process the digital complex baseband signal corresponding to the satellite navigation signals point by point to calculate the instantaneous envelope at each moment; The quantity statistics module is used to set the total number of statistical intervals of the histogram and the preset statistical time window, determine the corresponding histogram statistical interval based on each instantaneous envelope, and obtain the original histogram sequence according to the number of instantaneous envelopes falling into each statistical interval within the statistical time window; The smoothing module is used to smooth the original histogram sequence to obtain a smoothed histogram sequence and detect local maxima in the smoothed histogram sequence; the local maxima are points where the value of the corresponding statistical interval is greater than the values ​​of two adjacent statistical intervals. The interference decision module is used to take the local maximum point with the largest value as the main peak and the remaining local maximum points as secondary peaks. The module determines the impulse interference based on the relationship between the significance of each secondary peak relative to the adjacent valley and the preset decision threshold. If the significance of at least one secondary peak is greater than the decision threshold, the module determines that there is impulse interference. The result output module is used to output the determination result of the presence of pulse interference as an interference flag bit to the baseband processor to trigger the interference response operation of the satellite navigation receiver.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 8.

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