Link 16 signal identification and positioning method based on pulse template

Abstract

The invention discloses a Link 16 signal identification and positioning method based on a pulse template, which comprises the following steps: generating a pulse frame template according to the characteristics of a Link 16 signal, screening input pulses, matching according to the frame template, recording the matched pulses, carrying out time difference positioning on the pulses identified as the Link 16 signal, and using a time frequency pairing method to identify the Link 16 signal. And performing traversal matching on the pulse sequences of the main station and the auxiliary stations in sequence, and outputting a time difference value of the two stations so as to determine a target position. According to the scheme of the invention, the Link 16 data is identified and positioned on the pulse level, the hardware cost is reduced, the identification accuracy is improved, the positioning error is reduced, and the method is suitable for identifying and positioning Link 16 signals and other frequency hopping signals with a large number of pulses in a complex electromagnetic environment, and can be applied to the fields of air traffic control, situation awareness and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of passive reconnaissance, and particularly relates to a Link16 signal recognition and positioning method based on a pulse template. BACKGROUND

[0002] Link16 is a high-security, large-capacity, anti-interference and node-free data link, adopts J sequence messages and a centerless node network structure, the system is a time division multiple access system, adopts direct sequence spread spectrum, frequency hopping, RS coding and various technologies, has the capabilities of secret transmission, reconnaissance and identification, over-the-horizon combat, cooperation and command combat, etc.

[0003] A Link16 data message is composed of 258 or 444 pulses, the pulse interval and pulse width are fixed, and the difference between the frequencies of adjacent pulses is greater than 30MHz, a traditional IFF signal recognition algorithm can only process the case of a small number of pulses and fixed pulse intervals, while the Link16 signal has a large number of pulses and the pulse interval may be indefinite due to random loss of pulses in the middle, and the pulse loss conditions are different for each time difference station, therefore, for a traditional time difference positioning system, the position of the first pulse cannot be determined, which leads to the failure to match the time difference and the failure to effectively position. SUMMARY

[0004] In view of the above problems, the purpose of the application is to provide a Link16 signal recognition and positioning method based on a pulse template.

[0005] The specific technical scheme for realizing the purpose of the application is as follows:

[0006] A Link16 signal recognition and positioning method based on a pulse template, comprising the following steps:

[0007] Step 1: generating a pulse framework template according to the characteristics of the Link16 signal;

[0008] Step 2: screening input pulses and matching the pulses according to the framework template, and recording the matched pulses;

[0009] Step 3: performing time difference positioning on the pulses identified as Link16 signals, using a time-frequency pairing method, sequentially traversing and matching the pulse sequences of the main station and each secondary station, and outputting the time difference values of the two stations;

[0010] Step 4: determining the target position according to the time difference values.

[0011] Compared with the prior art, the application has the beneficial effects as follows:

[0012] The scheme of the application identifies and positions Link16 data at the pulse level, reduces the hardware cost, improves the accuracy of identification, the algorithm model is simple and easy to understand, and the use range is wide; the scheme uses the traversal pulse method to calculate all possible time differences, and selects the time difference with the most occurrences for positioning calculation, thereby improving the positioning accuracy; the scheme is suitable for identification and positioning of Link16 signals and other high-frequency frequency hopping signals in a complex electromagnetic environment, and can be applied to the fields of air traffic control, situation awareness and the like.

[0013] The application will be further described below in conjunction with the specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a flowchart of the Link16 signal identification and positioning method based on the pulse template of the application.

[0015] Figure 2 It is a Link16 pulse frame template generated in the embodiment of the application.

[0016] Figure 3 It is a schematic diagram of a positioning program receiving three-station Link16 data in the embodiment of the application.

[0017] Figure 4 It is a flowchart of the Link16 signal search based on the frame template in the embodiment of the application.

[0018] Figure 5 It is a time difference pairing flowchart based on the pulse in the embodiment of the application. DETAILED DESCRIPTION

[0019] EMBODIMENT

[0020] The technical solutions in the embodiments of the application will be described clearly and completely below in conjunction with the drawings in the embodiments of the application. The described embodiments are only some of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0021] As shown in the application and claims, unless the context clearly indicates otherwise, the words “one”, “a”, “an” and / or “the” do not specifically refer to the singular, but also include the plural. Generally, the terms “comprise” and “include” only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements.

[0022] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples herein are not meant to limit the scope of the present application unless otherwise specifically stated. Also, it is to be understood that the dimensions of the various parts shown in the drawings are not drawn to scale. Techniques, methods, and equipment known to those of ordinary skill are not discussed in detail because such techniques, methods, and equipment are considered standard options available to those with ordinary skill in the art. In all examples shown and discussed herein, any specific values are to be interpreted as merely exemplary and not limiting. Thus, other examples of the exemplary embodiments can have different values. It is to be noted that like numbers and letters refer to like elements throughout the several views of the drawings and, as such, no further discussion with regard thereto is deemed necessary.

[0023] In conjunction Figure 1 , a Link16 signal recognition and positioning method based on pulse template, comprising the following steps:

[0024] Step 1, generate a pulse framework template according to the characteristics of Link16 signal, as Figure 2 shown;

[0025] The pulse framework template includes the generation settings of pulse number, pulse width and pulse interval.

[0026] In this embodiment, there are several packaging formats for Link16 signal, the one with the most pulses contains 444, the pulse width is 6.4us, and the pulse interval is 13us.

[0027] Step 2, in conjunction Figure 4 , screen the input pulses and match them according to the framework template, and record the matched pulses:

[0028] Step 2-1, screen the input pulses for frequency and pulse width to meet:

[0029] |P i -P b |<P Min

[0030] |F i -F b |<F min

[0031] Where, P i is the pulse width of the i-th pulse (unit: us), P b is the pulse width of Link16 signal (fixed at 6.4us), P min is the allowable pulse width error (usually set to 0.8us), F i is the frequency of the i-th pulse (unit: MHz), Fb It is one of the 51 frequency points of the Link16 signal, F min This is the allowable frequency error (generally set to 1MHz);

[0032] Step 2-2: Take the first pulse P0 that meets the filtering conditions as the starting pulse, and search for subsequent pulses in sequence. If the arrival time of a subsequent pulse and the interval between pulse P0 meet the set frame template (i.e., the difference between the arrival time of the subsequent pulse and P0 is an integer multiple of 13us), then the counter cnt is incremented by 1, and the pulse information is recorded.

[0033] Steps 2-3: If the arrival time difference between the current pulse and the starting pulse exceeds the set duration T of the Link16 signal... max For example, 5772µs, and the arrival time difference with the previous pulse exceeds TDOA. max For example, if the response time is 1800µs, then the search for this Link16 signal ends.

[0034] Step 3: Perform time difference localization on the pulses identified as Link16 signals. Using the time-frequency pairing method, sequentially traverse and match the pulse sequences of the main station and each slave station, and output the time difference value between the two stations:

[0035] Specifically, when the value of the counter cnt for this message in step 2 is greater than the set value, generally greater than 30, then the search is considered valid and this message is considered a Link16 signal.

[0036] Combination Figure 5 The time difference positioning process includes:

[0037] Step 3-1: First, connect the main station and each auxiliary station (referred to as S) of the time difference positioning system. A S B S C And intermediate stations are generally set as the main station S. B The reconnaissance results from the three stations are aggregated into the time difference positioning software, which simplifies the pulses of the same frame searched by each reconnaissance station into a sequence of encapsulation format, frequency, and arrival time, such as... Figure 3 As shown;

[0038] Step 3-2: Using the time-frequency pairing method, sequentially traverse and match the pulse sequences of the main station and each slave station, and output the time difference between the two stations:

[0039] Step 3-2-1: Select sequence B1 from the main station and each sequence A from the secondary station 1. 1，2，3...N First, select sequence A from the sequences in substation 1 whose time difference with sequence B1 is less than or equal to the duration of the Link16 signal. j (The duration of a single signal in Link16 is 7.8ms, therefore the time difference T here is...) win(It can be set to ±7.8ms), and then select sequence C from the sequences of substation 2 whose time difference with sequence B1 is less than or equal to the duration of the Link16 signal. k ;

[0040] Step 3-2-2: If the m-th pulse A of substation 1... j a m And the nth pulse B1b of the main station n If the pulses are within a time window and have the same mode and frequency, they are considered to have successfully paired. Record the arrival time difference ΔT1 and the frequency value within that time difference. If the current frequency appears for the first time within that time difference, record the number of frequencies Cnt. f If the frequency value is 1, and it has not appeared before, then a new frequency value is recorded, and the number of frequencies is Cnt. f +1, after each pairing time difference ΔT1, the number of pairings C mat +1;

[0041] Step 3-2-3: Traverse sequence B1 and sequence A j For all pulses, proceed to step 3-2-2;

[0042] Step 3-2-4: Select the number of frequencies Cnt f If the frequency and number of pairings of the largest time difference ΔT are greater than a set value, then the sequence A of this pairing is... j The time difference ΔT between sequence B1 and sequence B1 AB =ΔT;

[0043] Step 3-2-5, if A j If there is no pairing result with B1 (step 3-2-2 is not satisfied), or the pairing result does not meet the setting (step 3-2-4 is not satisfied), then the pairing of B1 ends and the pairing of B2 begins, repeating steps 3-2-1 to 3-2-4.

[0044] Step 3-2-6: If there is a pairing time difference between the primary station and secondary station 1, then select the primary station and secondary station 2, and repeat steps 3-2-2 to 3-2-5 until sequence A is obtained. j and sequence C k The time difference is ΔT CB .

[0045] Step 4: Based on the time difference value ΔT AB and ΔT CB Determine the target location.

[0046] The application generates a pulse template of the Link16 signal locally, then performs template matching on the input pulses, considers that the search is successful when the number of matched pulses reaches a set threshold, records the corresponding pulses and then outputs, the time difference positioning software extracts the time difference value by matching the main station and each secondary station, and calculates the target position.

[0047] The application is suitable for the identification and positioning of the Link16 signal and other frequency hopping signals with a large number of pulses in a complex electromagnetic environment, and can be applied in the fields of air traffic control and situation awareness.

[0048] The application further provides a Link16 signal identification and positioning system based on a pulse template, comprising the following modules:

[0049] The matching module generates a pulse frame template according to the characteristics of the Link16 signal, filters the input pulses, and performs matching according to the frame template and records the matched pulses;

[0050] The time difference determination module is used for time difference positioning of the pulses identified as the Link16 signal, converts the data of each station into an internal format sequence, uses the time-frequency pairing method, and sequentially performs traversal matching of the pulse sequences of the main station and each secondary station, and outputs the time difference values of two stations.

[0051] The target positioning module is used for calculating the target position according to the two sets of time difference values.

[0052] The application further provides a computer device comprising a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the following steps when executing the computer program:

[0053] Step 1, generating a pulse frame template according to the characteristics of the Link16 signal;

[0054] Step 2, filtering the input pulses, performing matching according to the frame template, and recording the matched pulses;

[0055] Step 3, performing time difference positioning on the pulses identified as the Link16 signal, using the time-frequency pairing method, sequentially performing traversal matching of the pulse sequences of the main station and each secondary station, and outputting the time difference values of two stations.

[0056] Step 4, determining the target position according to the time difference values.

[0057] The application further provides a computer storage medium having a computer program stored thereon, and the computer program is executed by the processor to implement the following steps:

[0058] Step 1, generating a pulse frame template according to the characteristics of the Link16 signal;

[0059] Step 2, screen the input pulse and match according to the frame template, record the matched pulse;

[0060] Step 3, time difference positioning is performed on the pulse identified as Link16 signal, time-frequency pairing method is used, and the pulse sequence of the main station and each secondary station is matched in turn to output the time difference value of two stations;

[0061] Step 4, the target position is determined according to the time difference value.

[0062] The above embodiment only expresses one embodiment of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A Link16 signal identification and localization method based on pulse templates, characterized in that, Includes the following steps: Step 1: Generate a pulse frame template based on the characteristics of the Link16 signal; Step 2: Filter the input pulses and match them according to the framework template, and record the matched pulses; Step 3: Perform time difference positioning on the pulses identified as Link16 signals. Using the time-frequency pairing method, sequentially traverse and match the pulse sequences of the main station and each sub-station, and output the time difference value between the two stations. Step 4: Determine the target location based on the time difference.

2. The Link16 signal identification and localization method based on pulse template according to claim 1, characterized in that, The pulse frame template in step 1 includes the generation settings for the number of pulses, pulse width, and pulse interval.

3. The Link16 signal identification and localization method based on pulse template according to claim 1, characterized in that, The matching according to the framework template in step 2 is specifically as follows: Step 2-1: Filter the input pulses by frequency and pulse width to meet the following requirements: |P i -P b |<P Min |F i -F b |<F min Among them, P i Let P be the pulse width of the i-th pulse. b P is the pulse width of the Link16 signal. min For the allowable pulse width error, F i Let F be the frequency of the i-th pulse. b It is one of the 51 frequency points of the Link16 signal, F min This is the permissible frequency error; Step 2-2: Using the first pulse P0 that meets the filtering criteria as the starting pulse, search for subsequent pulses in sequence. If the arrival time of a subsequent pulse matches the interval between the arrival time of pulse P0 and the set frame template, then increment the counter cnt by 1 and record the pulse information. Steps 2-3: If the arrival time difference between the current pulse and the starting pulse exceeds the set duration of the Link16 signal, and the arrival time difference with the previous pulse exceeds TDOA... max Then the search for this Link16 signal ends.

4. The Link16 signal identification and localization method based on pulse template according to claim 3, characterized in that, The pulse identified as a Link16 signal in step 3 is: If the value of the counter cnt for this message in step 2 is greater than the set value, then the search is considered valid and this message is considered a Link16 signal.

5. The Link16 signal identification and localization method based on pulse template according to claim 1, characterized in that, The time difference positioning in step 4 specifically involves: Step 3-1: First, simplify the pulses of the same frame of the main station and each auxiliary station in the time difference positioning system into a sequence of encapsulation format, frequency and arrival time; Step 3-2: Iterate and match the pulse sequences of the main station and each sub-station in sequence, and output the time difference between the two stations.

6. The Link16 signal identification and localization method based on pulse template according to claim 5, characterized in that, The traversal matching in step 3-2 specifically involves: Step 3-2-1: Select sequence B1 from the main station and each sequence A from the secondary station 1. 1，2，3...N First, select sequence A from the sequences in substation 1 whose time difference with sequence B1 is less than or equal to the duration of the Link16 signal. j Then select sequence C from the sequences of substation 2 whose time difference with sequence B1 is less than or equal to the duration of the Link16 signal. k ; Step 3-2-2: If the m-th pulse A of substation 1... j a m And the nth pulse B1b of the main station n If the pulses are within a time window and have the same mode and frequency, they are considered to have successfully paired. Record the arrival time difference ΔT1 and the frequency value within that time difference. If the current frequency appears for the first time within that time difference, record the number of frequencies Cnt. f If the frequency value is 1, and it has not appeared before, then a new frequency value is recorded, and the number of frequencies is Cnt. f +1, After each pairing time difference ΔT1, the number of pairings C mat +1; Step 3-2-3: Traverse sequence B1 and sequence A j For all pulses, proceed to step 3-2-2; Step 3-2-4: Select the number of frequencies Cnt f If the frequency and number of pairings of the largest time difference ΔT are greater than a set value, then the sequence A of this pairing is... j The time difference ΔT between sequence B1 and sequence B1 AB =ΔT; Step 3-2-5, if A j If there is no pairing result with B1, or the pairing result does not meet the settings, then end the pairing of B1 and start pairing with B2, repeating steps 3-2-1 to 3-2-4. Step 3-2-6: If there is a pairing time difference between the primary station and secondary station 1, then select the primary station and secondary station 2, and repeat steps 3-2-2 to 3-2-5 until sequence A is obtained. j and sequence C k The time difference is ΔT CB .

7. The Link16 signal identification and localization method based on pulse template according to claim 6, characterized in that, The calculation of the target location in step 4 is specifically as follows: Based on the position and time difference ΔT between the main station and each auxiliary station in the time difference positioning system AB ΔT CB Calculate the target location.

8. A Link16 signal recognition and positioning system based on pulse templates, characterized in that, Includes the following modules: Matching module: Generates a pulse frame template based on the characteristics of the Link16 signal, filters the input pulses, matches them according to the frame template, and records the matched pulses; Time difference determination module: used to locate the time difference of pulses identified as Link16 signals. The data of each station is converted into a sequence in an internal format. Using the time-frequency pairing method, the pulse sequences of the main station and each sub-station are traversed and matched in turn, and the time difference value between the two stations is output. Target positioning module: used to calculate the target position based on two sets of time difference values.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1-7.

10. A computer-storable medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-7.

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