A method for interference situation analysis based on terminal fusion positioning

Abstract

The present invention discloses an interference situation analysis method based on terminal fusion positioning, which belongs to the field of satellite navigation. The present invention determines the location of the interference source by the carrier-to-noise ratio information before and after the terminal receives the interference; combines the information fusion of the interference source signal monitored by the direction finding monitoring equipment to obtain the accurate location of the interference source; according to the terminal location and the received power, the power of the interference source is predicted and derived by the path loss model to obtain the situation analysis of the interference source. In a complex environment, the present invention can integrate the terminal interference information and the interference information received by the monitoring station, and adjust the prediction of the interference source location and power in real time, so that the interference source situation presentation effect is more superior.

Description

Technical Field

[0001] The invention belongs to the field of satellite navigation, and in particular refers to an interference situation analysis method based on terminal fusion positioning. Background Art

[0002] In actual production and life applications, the role of the global satellite navigation and positioning system (GNSS) is becoming increasingly important. In recent years, the development of navigation technology has shown a trend of multi-system and multi-level integration. If the navigation signal is interfered with or cannot be used, it will have a huge impact on people's lives and even cause serious losses. Therefore, it is very necessary and meaningful to study the navigation interference situation.

[0003] Navigation interference situation refers to judging whether there is an interference source within the movement area through known surrounding geographic information and each received signal, understanding the global interference situation, and providing prior knowledge for subsequent navigation signal environment inversion, which facilitates subsequent navigation. Navigation interference situation is a supplement to the traditional navigation situation based on target recognition. By learning the algorithms of each situation level, the accuracy of situation analysis is improved, so as to accurately present and express the navigation interference situation. At present, the research field of situation awareness is mostly network systems, and there are no systematic research articles in the field of navigation interference. The interference source positioning methods are mostly based on observations to locate the interference source, such as angle, arrival time, frequency, etc. These methods only focus on the location information of the interference source, without solving the interference source power information, and the positioning accuracy still has room for improvement. Summary of the invention

[0004] In view of this, the present invention proposes an interference situation analysis method based on terminal fusion positioning. The method has high accuracy and can solve the location and power information of the interference source. Combined with the signal propagation attenuation model, the situation of the interference source can be obtained.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An interference situation analysis method based on terminal fusion positioning includes the following steps:

[0007] (1) determining a first estimated position of the interference source according to changes in the carrier-to-noise ratio of received signals of multiple observation terminals before and after the interference;

[0008] (2) Obtain the interference source signal angle information through direction finding monitoring equipment, cross-locate the second estimated position of the interference source through direction finding, and fuse the first estimated position and the second estimated position to obtain the accurate position of the interference source;

[0009] (3) Based on the location and received power of the observed terminal, the power of the interference source is estimated using the path loss model;

[0010] (4) According to the accurate location of the interference source obtained in step (2) and the power of the interference source obtained in step (3), the situation of the interference source is obtained.

[0011] Furthermore, the specific method of step (1) is:

[0012] The carrier-to-noise ratio change value u of the received signal of the observation terminal i before and after the interference i for:

[0013]

[0014] in, is the carrier-to-noise ratio after interference, is the carrier-to-noise ratio before interference; according to u i The sign of the value determines the type of interference, u i >0 means interference suppression, u i <0 is deception interference;

[0015] Calculate the weight w of observation terminal i i :

[0016]

[0017] n is the total number of observation terminals;

[0018] The position of observation terminal i is q i =(x i ,y i ), according to the position and weight of each observation terminal, the first estimated position Pt of the interference source is obtained:

[0019]

[0020] Furthermore, in step (2), the specific method of fusing the first estimated position and the second estimated position is:

[0021] The first estimated position and the second estimated position are weighted and summed to obtain the accurate position of the interference source; wherein the weight of the first estimated position is α, the weight of the second estimated position is 1-α, and the value of the weight α is determined as follows:

[0022]

[0023] d is the average spacing of observation terminals, in meters.

[0024] Furthermore, the specific method of step (3) is:

[0025] The sampling range of a circle is defined with the exact location of the interference source as the center. The radius r of the sampling range is selected in one of the following two ways:

[0026] 1) Take one quarter of the radius of the observation terminal distribution range;

[0027] 2) Sort the observation terminals in descending order according to the change value of the carrier-to-noise ratio, find the observation terminal at the quarter position in the sequence, and take the distance from the observation terminal to the interference source as the r value;

[0028] The received power and signal-to-interference ratio of the observed terminals within the sampling range are averaged respectively, and the two average values ​​are summed to obtain the estimated power of the interference source.

[0029] Furthermore, the specific method of step (4) is:

[0030] According to the accurate location of the interference source obtained in step (2) and the interference source power obtained in step (3), the receiving power at each step point within the area is calculated through the surrounding geographical environment and path loss model, and the situation of the interference source within the area is obtained. It is then displayed in a visual form together with the receiving power of each observation terminal.

[0031] The beneficial effects of the present invention are:

[0032] (1) The present invention uses a fusion of two positioning methods to obtain the accurate location of the interference source, which can improve the positioning accuracy and reduce the defects of a single positioning method.

[0033] (2) The present invention estimates the power of interference sources based on the actual environment and geographical conditions, can invert the interference situation and display it visually, and realizes the situation analysis function of the interference source. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described below.

[0035] An interference situation analysis method based on terminal fusion positioning includes the following steps:

[0036] (1) The terminal receives the carrier-to-noise ratio information before and after the interference, and intelligently locates the interference source;

[0037] The satellite information received by the terminal is compared before and after interference, and the carrier-to-noise ratio of the received signal changes.

[0038] Set the carrier-to-noise ratio change value of the terminal receiving signal before and after interference to u i ,

[0039]

[0040] in, is the carrier-to-noise ratio after interference, is the carrier-to-noise ratio before interference. i The positive or negative value determines the type of interference, ui >0 means interference suppression, u i <0 is deceptive interference.

[0041] Calculate the weight w of each terminal i The calculation method can be adjusted according to the specific environment. The core of the weight determination method is to use the relative distance between the interference source and the receiver to correct the weight. For example, the weight of each sample point can be calculated according to the carrier-to-noise ratio change value according to the following formula:

[0042]

[0043] Each terminal position is q i =(x i ,y i ), calculate the interference source position according to different weights, and get the interference source position as:

[0044]

[0045] (2) Combined with the interference source signal information monitored by the direction finding monitoring equipment, the accurate location of the interference source is obtained by using two positioning fusion methods. The specific methods are as follows:

[0046] The monitoring equipment measures the interference signal angle information, cross-locates the interference source through direction finding, and fuses the data with the location located in step (1). The fusion standard is determined based on the number of terminals and the accuracy of terminal positioning. The terminal positioning effect is best when the terminal interval is within a certain range. The two positioning results use different weighting coefficients to obtain the final position coordinate result. Assuming the average terminal interval is d meters and the terminal positioning weight is α, then

[0047]

[0048] The positioning weight of the direction finding monitoring equipment is 1-α.

[0049] (3) Based on the terminal location and received power, the power of the interference source is predicted and derived using the path loss model;

[0050] The interference source location information obtained from steps (1) and (2) and the signal power strength received by the terminal and monitoring equipment are combined with geographic information and the surrounding environment. The power prediction of the interference source is achieved by selecting a terminal and using its interference-to-signal ratio and power information after interference.

[0051] Terminal average power P S and average signal-to-disturbance ratio JSR S The calculation is shown in formula (1) and formula (2)

[0052]

[0053]

[0054] Among them, k is the number of terminal samples in the circle with the interference source positioning result as the center and r as the radius. There are two ways to take the value of r. One is to take a quarter of the observation range, and the other is to sort the carrier-to-noise ratio change values ​​and find the terminal at a quarter of the total number of carrier-to-noise ratio change values ​​from large to small, and take the distance from the terminal to the interference source as the r value. j is the received power of the terminal sample after interference, JSR j It is the signal-to-noise ratio after interference.

[0055] The interference source power prediction result PN is shown in formula (3):

[0056] P N =P S +JSR S (3)

[0057] (4) Based on the predicted location and power of the interference source, the situation analysis of the interference source is obtained.

[0058] Through the first three steps, the location and power information of the interference source are obtained. Through the surrounding geographical environment and path loss model, the power value of each reference point within a certain area is calculated, that is, the received signal strength of each step point within the area. Combined with the terminal power value after the previous interference, the interface is displayed to achieve the inversion and visualization of the navigation interference situation.

[0059] In the actual navigation environment, the signal observation range is not an ideal environment, and there is a certain probability that interference sources exist, causing the signal received by the terminal to be interfered with and the navigation effect to be unsatisfactory. In order to better determine the degree of interference and navigation positioning accuracy, the present invention studies and analyzes the interference situation awareness technology.

[0060] The interference situation analysis method based on terminal fusion positioning proposed in the present invention makes full use of the information obtained by the terminal and the monitoring equipment and the properties of the signal itself, and uses intelligent positioning algorithm, fusion positioning and power prediction to obtain a more accurate interference situation inversion effect.

[0061] In summary, the present invention can integrate the terminal interference information and the interference information received by the monitoring station in a complex environment, and adjust the prediction of the interference source position and power in real time, so that the interference source situation presentation effect is more superior.

Claims

1. A method for analyzing interference situation based on terminal fusion positioning, characterized in that: The steps include: (1) Determine the first estimated position of the interference source according to the change of the carrier-to-noise ratio of the received signals of the multiple observation terminals before and after the interference; the specific method is as follows: The carrier-to-noise ratio change value u of the received signal of the observation terminal i before and after the interference i for: in, is the carrier-to-noise ratio after interference, is the carrier-to-noise ratio before interference; according to u i The sign of the value determines the type of interference, u i >0 means interference suppression, u i <0 is deceptive interference; Calculate the weight w of observation terminal i i : n is the total number of observation terminals; The position of observation terminal i is q i =(x i ,y i ), according to the position and weight of each observation terminal, the first estimated position P of the interference source is obtained t : (2) Obtain the signal angle information of the interference source by monitoring the direction finding monitoring equipment, obtain the second estimated position of the interference source by cross-locating the direction finding, and fuse the first estimated position and the second estimated position to obtain the accurate position of the interference source; wherein the specific method of fusing the first estimated position and the second estimated position is: The first estimated position and the second estimated position are weighted and summed to obtain the accurate position of the interference source; wherein the weight of the first estimated position is α, the weight of the second estimated position is 1-α, and the value of the weight α is determined as follows: d is the average interval between observation terminals, in meters; (3) The power of the interference source is estimated by the path loss model based on the location and received power of the observed terminal. The specific method is as follows: the interference source location information obtained in steps (1) and (2) and the signal power strength received by the terminal and the monitoring device are combined with the geographic information and the surrounding environment. The power prediction of the interference source is achieved by selecting a terminal and using its interference signal ratio and power information after interference. The average power P of the terminal is S and average signal-to-disturbance ratio JSR S The calculation is shown in formula (1) and formula (2): Among them, k is the number of terminal samples in the circle with the interference source positioning result as the center and r as the radius. There are two ways to take the value of r. One is to take a quarter of the observation range, and the other is to sort the carrier-to-noise ratio change values ​​and find the terminal at a quarter of the total number of carrier-to-noise ratio change values ​​from large to small, and take the distance from the terminal to the interference source as the r value; P j is the received power of the terminal sample after interference, JSR j is the interference signal ratio after interference; Interference source power prediction result P N As shown in formula (3): P N =P S +JSR S (3) (4) According to the accurate location of the interference source obtained in step (2) and the power of the interference source obtained in step (3), the situation of the interference source is obtained, specifically in the following manner: According to the accurate location of the interference source obtained in step (2) and the interference source power obtained in step (3), the receiving power at each step point within the area is calculated through the surrounding geographical environment and path loss model, and the situation of the interference source within the area is obtained. It is then displayed in a visual form together with the receiving power of each observation terminal.

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