Configurable dynamic navigation anti-interference starting threshold judgment method

Abstract

According to the configurable dynamic navigation anti-interference starting threshold judgment method provided by the invention, dynamic judgment is carried out according to the time correlation and the interference intensity value, the reasonable control problem of the starting and shutting threshold of anti-interference operation is effectively solved, a configuration function is supported, and the adaptability to various interference signals is expanded. The navigation anti-interference technology is applied to a satellite navigation receiving device, and interference signals are suppressed and eliminated, so that the working performance of the receiving device in a complex electromagnetic environment is enhanced. According to the method, the problem of repeated switching due to the fact that the interference signal intensity approaches a threshold in single static judgment of a traditional method is solved, and anti-interference operation dynamic judgment supporting different intensity correlation, different time correlation and different interference types can be effectively controlled by adjusting configuration parameters; therefore, the method has good expansibility and applicability.

Description

Technical Field

[0001] The present invention relates to the field of navigation anti-interference, and in particular to a dynamic navigation anti-interference start threshold judgment method, which is used to judge whether a navigation receiving device performs anti-interference processing during operation in a complex interference scenario. Background Art

[0002] Navigation anti-interference technology suppresses and eliminates interference signals through complex calculations, making it easier for satellite navigation receivers to complete normal operations in complex electromagnetic environments. Therefore, devices that perform navigation anti-interference calculations are an important part of satellite navigation receivers, especially in electromagnetic confrontation environments. However, the amount of anti-interference calculations is large, which leads to problems such as increased power consumption and decreased stability of the equipment. At the same time, the scenarios that require navigation anti-interference calculations often deal with strong electromagnetic confrontation environments, and satellite navigation receivers are not in such scenarios most of the time. If the anti-interference calculations can be turned off, power consumption can be effectively reduced and equipment performance can be improved.

[0003] In most scenarios without strong electromagnetic confrontation, anti-interference operations do not need to be performed, and the satellite navigation receiving device can complete functions such as satellite reception and positioning. If the anti-interference operation is not turned off, this no-load operation will bring more power consumption and heat, and even a loss of the satellite reception carrier-to-noise ratio in performance. The loss of power consumption, especially in portable navigation receiving devices, will greatly reduce its battery life, which is not conducive to the use of the equipment. The loss of the satellite reception carrier-to-noise ratio will also lead to a decline in performance. It can be seen that navigation anti-interference operations are a key component of satellite navigation receiving devices on the one hand, and on the other hand, they also need to be well controlled. Obviously, if the above-mentioned shutdown control function is not available, the application scenarios of satellite navigation receiving devices will be greatly limited.

[0004] Satellite navigation receivers receive satellite information to complete satellite positioning and navigation. On the one hand, in complex electromagnetic environments, it is necessary to perform anti-interference processing on complex electromagnetic interference to ensure normal satellite positioning. On the other hand, in modern electronic countermeasure environments, the enemy often uses jammers and other jamming devices to interfere with our equipment. Therefore, in order to ensure the normal operation of our satellite navigation receivers, anti-interference processing is required.

[0005] Through navigation anti-interference technology, it is possible to suppress and eliminate interference signals by performing anti-interference operations in the presence of external interference, so that the satellite navigation receiving device can work normally and complete the satellite positioning and navigation functions. Therefore, for modern satellite navigation receiving devices, navigation anti-interference equipment is an important component.

[0006] However, navigation anti-interference calculations will result in high power consumption. Modern equipment pays more attention to miniaturization and lightweight, so power consumption is one of the key technical performances of the equipment. Satellite navigation receiving devices have a wide range of application scenarios. In some portable devices, high power consumption will seriously reduce the battery life and limit the application scenarios of the equipment. Therefore, there is a significant demand to shut down the navigation anti-interference calculations to reduce power consumption in miniaturized devices. At the same time, for miniaturized devices, high integration and high power consumption will bring more heat and reduce system performance, so it is also of great significance to improve system performance.

[0007] In summary, an effective anti-interference operation start threshold judgment method is needed to reasonably and effectively control the opening and closing of the anti-interference operation, which meets the low power consumption and high performance requirements of satellite navigation receiving devices in complex application scenarios.

[0008] Current satellite navigation receiving devices with anti-interference functions often do not have the above-mentioned function of shutting down the anti-interference operation, or use a simple method of determining a fixed threshold value, which has great limitations.

[0009] A common method for shutting down anti-interference operation in existing applications is to use a method of comparing and determining a threshold value to determine whether the interference intensity is lower than the threshold value. If it is lower than the threshold value, the anti-interference operation is shut down; if it is higher than the threshold, the anti-interference operation is turned on.

[0010] Although the above method is relatively simple in design and only requires comparison of interference intensity, it also has many shortcomings. On the one hand, the interference intensity varies greatly in a complex electromagnetic environment. Judging only by the interference intensity increases the instability of the system. If the enemy interference intensity is close to the threshold value, repeated fluctuations above and below the threshold will cause the anti-interference operation to be repeatedly turned on and off, resulting in greater power loss or even the device being out of working condition. For example, the enemy jammer hovers in a certain area. When the interference to us is close to the threshold value, the above phenomenon will occur due to the hovering distance and angle.

[0011] On the other hand, this method is applicable to limited types of interference signals, and is only effective for long-term suppression interference. For pulse interference signals, the interference pulse time is short, and the delay of anti-interference operation will cause the anti-interference operation to be started in time, and the interference suppression and elimination cannot be performed correctly. Therefore, in a complex electromagnetic confrontation environment, the existing application methods are not enough to meet the application needs. Summary of the invention

[0012] In order to overcome the shortcomings of the prior art, the present invention provides a configurable dynamic navigation anti-interference start threshold judgment method. Dynamic judgment is made according to time correlation and interference intensity value, effectively solving the reasonable control problem of the start and stop threshold of the anti-interference operation, and supporting configuration functions to expand the adaptability to various interference signals.

[0013] Navigation anti-interference technology is applied to satellite navigation receiving devices to enhance the working performance of receiving devices in complex electromagnetic environments by suppressing and eliminating interference signals. The specific performance is as follows:

[0014] (1) Dynamic navigation anti-interference start threshold judgment method can make dynamic judgments based on time correlation and interference intensity values, effectively solving the problem that the start and stop thresholds of anti-interference calculations are repeatedly turned on and off in the application, resulting in greater power consumption loss and even the device being out of working condition.

[0015] The present invention designs the time correlation weight according to the large volatility of the interference source signal, and dynamically determines the interference source signal according to its strength, thereby effectively avoiding the problem of repeated on and off of the anti-interference operation.

[0016] (2) Designing a configurable parameter function can effectively adjust the weight determination coefficients of both time and intensity through configuration, thereby expanding the ability of the method to adapt to different types of interference sources and expanding the application scenarios.

[0017] The specific steps of the technical solution adopted by the present invention to solve its technical problem are:

[0018] Step 1: Receive the interference intensity value, take the interference intensity value once every time interval t1, and segment the obtained interference intensity value so as to process each segment of data; because the amount of information contained in each segment of data is greater than the amount of information contained in the interference intensity value obtained at a single time, the purpose of making the anti-interference threshold switching more accurate can be achieved;

[0019] The segmented interference intensity values ​​are combined into an interference intensity matrix A.

[0020] Step 2: Perform a 3×3 convolution operation on the interference intensity matrix A to complete the weighted operation;

[0021] Step 3: Weighted interference matrix The time correlation weight is calculated and normalized according to the following formula:

[0022]

[0023] where i and j and σ t Support configuration;

[0024] Step 4: For the matrix elements of the corrected interference intensity matrix C, if more than half of them are greater than the anti-interference start judgment value K, anti-interference is started; if the number of matrix elements of the corrected interference intensity matrix C that are greater than the anti-interference start judgment value K is less than or equal to half, anti-interference is not started.

[0025] During the segmented processing, in each selected segment, the segments are continuous, that is, interference intensity values ​​are obtained sequentially within a period of time; the number of interference intensity values ​​is the square of a natural number n, and is greater than or equal to 16 and less than 144.

[0026] The interval time t1 is a configurable time parameter. The interval time t1 is greater than 0.1 seconds and less than 10 seconds.

[0027] The weighted operation in step 2 is to perform Gaussian weighting on the interference intensity value according to the following formula and perform normalization processing:

[0028]

[0029] where σ b is a configurable parameter used to adjust the weight of the center point, σ b The larger the value is, the greater the interference strength weight of the center point is; x, y represent the row and column identifiers in the convolution operation of the 3x3 range; x, y represent the distance from the center point of the 3x3 range;

[0030] The x and y are identified by

[0031] In step 3, σ t Represents the weight ratio of each edge point, σ t The larger it is, the greater the weight of the edge point is, and the weaker the correlation between the interference intensity and time is.

[0032] Where k and l represent the row and column coordinates of the matrix, k and l represent the distance from the center point of the matrix, and k and l are identified by

[0033] The calculated normalized time correlation weighted matrix is:

[0034]

[0035] Multiply each element of the weighted interference matrix B by the time correlation weight W t , the corrected interference intensity matrix C is obtained as:

[0036]

[0037] The parameter σ b The value range is [0.5,10].

[0038] The parameter σ t The value range is [0.5,100].

[0039] The values ​​of i and j are determined by configuring the selection of the time base point in the time correlation weight. For a weighted interference matrix B with n-2 rows and n-2 columns, the number of matrix elements is (n-2) 2 If i=0, j=0, then the element B0 in the first row and the first column of the matrix is ​​selected as the time base point of the matrix. If i=0, j=1, then the element B1 in the first row and the second column of the matrix is ​​selected as the time base point of the matrix. And so on. The selection principle conforms to the row and column arrangement of the matrix.

[0040] The beneficial effects of the present invention are:

[0041] (1) Taking full account of the characteristics of the interference signal, a corresponding dynamic anti-interference threshold start-up judgment method is designed. It can take into account the time correlation and intensity characteristics of the interference signal and perform dynamic configuration, thereby solving the problem of repeated switching caused by the interference signal intensity approaching the threshold in the traditional single static judgment method;

[0042] (2) A plurality of configuration parameters are designed. By adjusting the configuration parameters, the dynamic judgment of anti-interference operation supporting different intensity correlations, different time correlations, and different interference types can be effectively controlled, so that the present invention has good scalability and applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flow chart of the dynamic navigation anti-interference start threshold judgment method of the present invention. DETAILED DESCRIPTION

[0044] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0045] The specific process of a configurable dynamic navigation anti-interference start threshold decision method of the present invention is as follows:

[0046] Step 1: Receive the interference intensity value, take the interference intensity value once every time interval t1, and segment the obtained interference intensity value so as to process each segment of data; because the amount of information contained in each segment of data is greater than the amount of information contained in the interference intensity value obtained at a single time, the purpose of making the anti-interference threshold switching more accurate can be achieved;

[0047] In the segmented processing, in each selected segment, the segments are continuous, that is, the interference intensity values ​​are obtained in sequence within a period of time; the number of interference intensity values ​​is the square of the natural number n, and cannot be less than 4 2That is, 16, that is, the number is 16, 25, 36...; at the same time, it should not be too large in actual application, because too large matrix operations will reduce real-time performance, which depends on the performance of specific hardware, computers, etc. during application. The method of the present invention recommends that it is less than 12 2 =144; for the number of interference intensities, the method of the present invention recommends a value of 25, that is, n=5, and will be used as an example for explanation.

[0048] The segmented interference intensity values ​​are combined into an interference intensity matrix A.

[0049] The interval time t1 is a configurable time parameter, wherein the larger t1 is, the longer the time interval for obtaining the interference intensity value is. The time is adjusted according to the actual hardware performance during the application process. However, according to the actual application in the field of navigation anti-interference, the time interval t1 applicable to the method of the present invention is greater than 0.1 seconds and less than 10 seconds. If it is too small or too large, although it can have a certain effect in the navigation anti-interference application, the effect is actually reduced.

[0050] The interference intensity value is received. The present invention takes the interference intensity value once every 1s, takes it 25 times in a row, and records it as A0-A24 respectively, and forms an interference intensity matrix

[0051] Step 2: Perform a 3×3 convolution operation on the interference intensity matrix A to complete the weighted operation. The weighted operation is to perform Gaussian weighting on the interference intensity value according to the following formula and perform normalization:

[0052]

[0053] where σ b is a configurable parameter used to adjust the weight of the center point, σ b The larger the value, the greater the interference strength weight of the center point; x, y represent the row and column identifiers in the 3x3 range convolution operation; x, y represent the distance from the center point of the 3x3 range. The invention adopts the identifier of x, y when weighting

[0054] After Gaussian weighting, for the interference strength matrix A with n rows and n columns, a weighted interference matrix with n-2 rows and n-2 columns is obtained:

[0055] Take the 5X5 interference strength matrix A as an example to illustrate this step:

[0056] Take σ b =1.5;

[0057] Given x and y, we can use

[0058] The weighting formula used is:

[0059]

[0060] σ b =1.5Substitute into:

[0061]

[0062] for Perform convolution on the first 3x3 range, and we get B0; perform convolution on the second 3x3 range, and we get B1; perform convolution on the third 3x3 range, and we get B2; and so on;

[0063] For the calculation of B0, the corresponding interference strength value within the first 3x3 range is To facilitate the description of the calculation process, an example is given below:

[0064] Bundle Substitute it into formula (3) and normalize it;

[0065] get:

[0066] B0=14*0.0947+15*0.1183+16*0.0947+24*0.1183+25*0.1477+26*0.1183+34*0.0974+35*0.1183+36*0.0947;

[0068] According to the matrix convolution operation, we can get B1, B2…B8 one by one. For example, B1 is The result of the operation;

[0069] Composition of weighted interference intensity matrix

[0070] Step 3: Weighted interference matrix The time correlation weight is calculated and normalized according to the following formula:

[0071]

[0072] where i and j and σ t Support configuration;

[0073] where σ t Represents the weight ratio of each edge point, σ t The larger it is, the greater the weight of the edge point is, and the weaker the correlation between the interference intensity and time is.

[0074] Where k and l represent the row and column coordinates of the matrix, and k and l represent the distance from the center point of the matrix. In the present invention, k and l are identified by

[0075] The values ​​of i and j are determined by configuring the selection of the time base point in the time correlation weight. For the weighted interference matrix B with n-2 rows and n-2 columns, the number of matrix elements is (n-2) 2 If i=0, j=0, then the element B0 in the first row and the first column of the matrix is ​​selected as the time base point of the matrix. If i=0, j=1, then the element B1 in the first row and the second column of the matrix is ​​selected as the time base point of the matrix. And so on. The selection principle conforms to the row and column arrangement of the matrix.

[0076] The time base point mentioned in the present invention means that the time correlation weight of the weighted interference matrix value closer to the base point is greater;

[0077] For the calculated normalized time correlation weighted matrix

[0078]

[0079] Multiply each element of the weighted interference matrix B by the time correlation weight W t , the corrected interference intensity matrix is ​​obtained as:

[0080]

[0081] Step 4: For the matrix elements of the corrected interference intensity matrix C, if more than half of them are greater than the anti-interference start judgment value K, anti-interference is started; if the number of matrix elements of the corrected interference intensity matrix C that are greater than the anti-interference start judgment value K is less than or equal to half, anti-interference is not started.

[0082] The anti-interference start judgment value K needs to be configured by the user. K is a threshold value obtained from test experience. In actual application scenarios, users need to determine a suitable judgment value based on their own navigation receiving device and hardware characteristics of anti-interference components, and test them to obtain an anti-interference start judgment value that meets their own needs, so as to achieve the purpose of adjusting the shutdown according to the anti-interference scenario without being too sensitive to cause frequent startup and shutdown effects;

[0083] Step 5: User adjusts:

[0084] (a) Interval time t1, where the larger t1 is, the longer the time interval for obtaining the interference strength value is;

[0085] The interval time t1 is a configurable time parameter, wherein the larger t1 is, the longer the time interval for obtaining the interference intensity value is. It is adjusted according to the actual hardware performance during the application process. However, according to the actual application in the field of navigation anti-interference, the time interval t1 applicable to the method of the present invention is greater than 0.1 seconds and less than 10 seconds. If it is too small or too large, although it can have a certain effect in the navigation anti-interference application, the effect is actually reduced.

[0086] (b) Parameter σ b Used to adjust the weight of the Gaussian weighted center point, σ b The larger it is, the greater the interference intensity weight of the center point is;

[0087] σ b Although the value of the parameter can be any real number in mathematical sense, according to the actual application in the field of navigation anti-interference, the method of the present invention is applicable to σ b It should be within the range of [0.5,10]. If it exceeds the range, the effect in navigation anti-interference application will be greatly reduced.

[0088] (c) Parameter σ t , used to adjust the weight ratio of each edge point, σ t The larger the value, the greater the weight of the edge point, and the weaker the correlation between the interference intensity and time. t The parameter applies to all real numbers, but if σ t Setting the parameter too large will not substantially change the performance except for increasing the amount of computation. The σ t The parameter range is [0.5,100]. If σ t If σ is greater than or equal to 100, it can be considered to be independent of time, that is, no time weighting is performed; t If it is less than or equal to 0.5, it can be considered that only the value of the above time base point is considered.

[0089] (d) The values ​​of i and j are used to adjust the time base point in the time correlation weight. The closer the weighted interference matrix value is to the base point, the greater the time correlation weight is.

[0090] The values ​​of i and j are determined by configuring the selection of the time base point in the time correlation weight. For the weighted interference matrix B with n-2 rows and n-2 columns, the number of matrix elements is (n-2) 2 If i=0, j=0, then the element B0 in the first row and the first column of the matrix is ​​selected as the time base point of the matrix. If i=0, j=1, then the element B1 in the first row and the second column of the matrix is ​​selected as the time base point of the matrix. And so on. The selection principle conforms to the row and column arrangement of the matrix.

[0091] (e) Anti-interference start judgment value K;

[0092] Interference judgment can be further adjusted according to the implemented hardware and usage scenarios, expanding the application scenarios and scope.

[0093] The parameters (a), (b), (c), and (d) mentioned above are independent of each other during adjustment, only affect the functions mentioned above, and have no correlation with each other. (e) is adjusted based on the actual measured results after configuration of (a), (b), (c), and (d) and application requirements.

Claims

1. A configurable dynamic navigation anti-interference start threshold decision method, characterized in that The steps include: Step 1: Receive the interference intensity value, take the interference intensity value once every time interval t1, and segment the obtained interference intensity value so as to process each segment of data; because the amount of information contained in each segment of data is greater than the amount of information contained in the interference intensity value obtained at a single time, the purpose of making the anti-interference threshold switching more accurate can be achieved; The segmented interference intensity values ​​are combined into an interference intensity matrix A. Step 2: Perform a 3×3 convolution operation on the interference intensity matrix A to complete the weighted operation; Step 3: Weighted interference matrix The time correlation weight is calculated and normalized according to the following formula: where i and j and σ t Support configuration; Step 4: For the matrix elements of the corrected interference intensity matrix C, if more than half of them are greater than the anti-interference start judgment value K, anti-interference is started; if the number of matrix elements of the corrected interference intensity matrix C that are greater than the anti-interference start judgment value K is less than or equal to half, anti-interference is not started.

2. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: During the segmented processing, in each selected segment, the segments are continuous, that is, interference intensity values ​​are obtained sequentially within a period of time; the number of interference intensity values ​​is the square of a natural number n, and is greater than or equal to 16 and less than 144.

3. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The interval time t1 is a configurable time parameter. The interval time t1 is greater than 0.1 seconds and less than 10 seconds.

4. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The weighted operation in step 2 is to perform Gaussian weighting on the interference intensity value according to the following formula and perform normalization processing: where σ b is a configurable parameter used to adjust the weight of the center point, σ b The larger the value is, the greater the interference strength weight of the center point is; x, y represent the row and column identifiers in the convolution operation of the 3x3 range; x, y represent the distance from the center point of the 3x3 range.

5. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The x and y are identified by 6. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: In step 3, σ t Represents the weight ratio of each edge point, σ t The larger it is, the greater the weight of the edge point is, and the weaker the correlation between the interference intensity and time is. Where k and l represent the row and column coordinates of the matrix, k and l represent the distance from the center point of the matrix, and k and l are identified by 7. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The calculated normalized time correlation weighted matrix is: Multiply each element of the weighted interference matrix B by the time correlation weight W t , the corrected interference intensity matrix C is obtained as:

8. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The parameter σ b The value range is [0.5,10].

9. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The parameter σ t The value range is [0.5,100].

10. The configurable dynamic navigation anti-interference start threshold decision method according to claim 1, characterized in that: The values ​​of i and j are determined by configuring the selection of the time base point in the time correlation weight. For a weighted interference matrix B with n-2 rows and n-2 columns, the number of matrix elements is (n-2) 2 If i=0, j=0, then the element B0 in the first row and the first column of the matrix is ​​selected as the time base point of the matrix. If i=0, j=1, then the element B1 in the first row and the second column of the matrix is ​​selected as the time base point of the matrix. And so on. The selection principle conforms to the row and column arrangement of the matrix.

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