Staggering identification method based on time difference of arrival of adjacent sequences

Abstract

The invention relates to a stagger identification method based on the arrival time difference of adjacent sequences, which comprises the following steps of: sequencing M pulse sequences with the same multiple cycles according to the arrival time sequence of a first pulse, marking a sequence number label i (i = 1, 2,..., M) to obtain a sequence set M, and calculating the sequence set M of all adjacent sequence numbers [i, 2,..., M]; and further calculating a variance # imgabs0 #, and further determining the sequences of other radars by judging whether the pulse sequences corresponding to all the serial numbers and the left adjacent sequence # imgabs1 # or the right adjacent sequence # imgabs2 # are greater than a threshold or not, wherein the pulse sequences correspond to all the serial numbers and the left adjacent sequence # imgabs1 # or the right adjacent sequence # imgabs2 # are greater than the threshold. Adding corresponding sequence numbers of the sequences which are all greater than the threshold into the set S and removing the sequence numbers from the set M; and finally, the pulse sequences corresponding to all the remaining elements in the set M are the staggered PRI sequences, and the pulse sequences in the set S are the pulse sequences of other radars. In a word, the complexity that time difference of arrival needs to be carried out on any two sequences when the number of periodic staggers is large is avoided, the calculated amount is smaller when the number of periodic staggers is large, and the calculation efficiency is improved. The method has the advantages of convenience in use and small calculation amount.

Description

Technical Field

[0001] The invention belongs to the technical field of radar signal processing, and in particular relates to a method for distinguishing between time differences of arrival of adjacent sequences. Background Art

[0002] With the rapid development of radar signal generation and corresponding processing technologies, the tasks that radars need to complete are becoming more and more diverse, accompanied by complex and changeable radar PRI (time difference of arrival) modulation styles, whose main purposes include resolving ambiguity, overcoming blind speed or blind range, and countering enemy reconnaissance; among them, staggered PRI is widely used in radar PRI modulation style design because of its advantage in overcoming blind speed. The so-called staggered PRI is a modulation style in which PRI appears in alternating periods, and its characterization parameters mainly include period stagger number, sub-period and frame period.

[0003] For staggered PRI pulse sequences, most of the existing sorting methods can only first obtain multiple fixed PRI pulse sequences with a frame period, and then perform staggered identification on these sequences; most of the existing staggered identification methods judge by the correlation between sequences, that is, calculate the variance of the arrival time difference of two sequences, and judge whether the variance is greater than a threshold to determine whether they come from two different radars. This method has the advantages of simplicity and easy implementation, but since the correlation and orderliness between adjacent pulses of the staggered PRI pulse sequence are not considered, when there are many periodic staggers, it is necessary to make arrival time differences and calculate variances for multiple PRI sequences, which requires a large amount of calculation, so it is not convenient to use and the resource utilization rate is not high.

[0004] Therefore, there is an urgent need for a discrepancy identification method based on the arrival time differences of adjacent sequences, which can specifically solve the problem of large computational complexity in the existing discrepancy identification method that calculates the variance of the arrival time differences of two sequences when dealing with a large number of periodic discrepancies. Summary of the invention

[0005] In view of this, the present invention proposes a discrepancy identification method based on the arrival time difference of adjacent sequences, which is applied to the field of radar signal processing and can solve the technical problems of large calculation amount and inconvenient use in the existing discrepancy identification methods.

[0006] In order to achieve the above technical objectives, the specific technical solutions adopted by the present invention are:

[0007] A method for discriminating differences based on the arrival time differences of adjacent sequences comprises the following steps:

[0008] S1, sort all M pulse sequences with the same frequency according to the arrival time of the first pulse and label them with sequence number i (i=1, 2, ..., M) to obtain a sequence set M;

[0009] S2, calculate the arrival time difference between all the pulse sequences corresponding to the adjacent sequence numbers [i, i+1] and further calculate the variance

[0010] S3, by judging the pulse sequence corresponding to all the serial numbers and its left adjacent sequence or right adjacent sequence Whether they are all greater than the threshold to further determine the sequence of other radars;

[0011] S4, the pulse sequences corresponding to all the remaining elements in the final set M are the staggered PRI sequences, and the pulse sequences in the set S are the pulse sequences of other radars;

[0012] Step S3 includes the following steps:

[0013] S301, first determine the pulse sequence corresponding to the middle sequence number i (i = 2, 3, ..., M-1) and its left adjacent sequence and right adjacent sequence Is the value greater than the threshold? If so, add the sequence number i to the set S of other radar pulse sequences and remove i from M.

[0014] S302, determine the pulse sequence with sequence number 1 and its right adjacent sequence The pulse sequence with sequence number 2 and its right adjacent sequence is greater than the threshold. If it is less than the threshold, the pulse sequence with sequence number 1 is added to the set S of other radar sequences, and 1 is removed from M;

[0015] S303, determine the pulse sequence with sequence number M and its left adjacent sequence Greater than the threshold, and the sequence number is M-1 and its left adjacent sequence If the value is less than the threshold, the pulse sequence with sequence number M is added to the set S of other radar sequences, and M is removed from M.

[0016] Furthermore, the threshold in step S3 is determined by the following formula:

[0017] γ thre =Δ 2 / 4

[0018] Wherein, Δ represents the maximum jitter of all pulse sequences with the same frequency.

[0019] Furthermore, in step S4, it is determined whether the number of elements of the obtained set S is greater than 1. If the number of elements of the set S in step S4 is greater than 1, all pulse sequences of the set S are re-identified according to the above steps.

[0020] By adopting the above technical solution, the present invention can also bring the following beneficial effects:

[0021] The present invention mentions a method for discriminating between arrival times of adjacent sequences, which makes use of the correlation and orderliness between adjacent pulses of a discriminating PRI pulse sequence to make discriminating between results more reliable. All fixed PRI sequences of the same period are arranged in TOA order, and the variance of the arrival times of adjacent sequences is calculated to further determine whether there are other radar pulse sequences. This avoids the tediousness of calculating the arrival times of any two sequences when the number of period discrepancies is large. When the number of period discrepancies is large, the amount of calculation is smaller. The method is also applied to discriminating between PRI sequences in radar signal sorting and identification, and has the advantages of being easy to use and having a small amount of calculation in the discriminating between PRI sequences. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A flowchart of a specific implementation of the present invention;

[0024] Figure 2 It is a comparison diagram of adjacent sequence arrival time difference sequences when one 4-staggered radar and one fixed radar are overlapped in a specific embodiment of the present invention;

[0025] Figure 3 It is a comparison diagram of the arrival time difference sequence of adjacent sequences of staggered radars obtained after staggered identification in a specific implementation mode of the present invention;

[0026] Figure 4 It is a comparison chart of the calculation amount of the specific implementation of the present invention and the existing staggered identification method as the periodic staggered number changes. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0029] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present invention, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0030] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0031] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0032] Example 1

[0033] The present invention provides a method for distinguishing between differences in arrival time of adjacent sequences, comprising the following steps:

[0034] S1, sort all M pulse sequences with the same frequency according to the arrival time of the first pulse and label them with sequence number i (i=1, 2, ..., M) to obtain a sequence set M;

[0035] S2, calculate the arrival time difference between all the pulse sequences corresponding to the adjacent sequence numbers [i, i+1] and further calculate the variance

[0036] S3, by judging the pulse sequence corresponding to all the serial numbers and its left adjacent sequence or right adjacent sequence Whether they are all greater than the threshold is used to further determine the sequence of other radars. The threshold in step S3 is determined by the following formula:

[0037] γ thre =Δ 2 / 4

[0038] Wherein, Δ represents the maximum jitter of all pulse sequences with the same frequency.

[0039] Step S3 specifically includes the following steps:

[0040] S301, first determine the pulse sequence corresponding to the middle sequence number i (i = 2, 3, ..., M-1) and its left adjacent sequence and right adjacent sequence Is the value greater than the threshold? If so, add the sequence number i to the set S of other radar pulse sequences and remove i from M.

[0041] S302, determine the pulse sequence with sequence number 1 and its right adjacent sequence The pulse sequence with sequence number 2 and its right adjacent sequence is greater than the threshold. If it is less than the threshold, the pulse sequence with sequence number 1 is added to the set S of other radar sequences, and 1 is removed from M;

[0042] S303, determine the pulse sequence with sequence number M and its left adjacent sequence Greater than the threshold, and the sequence number is M-1 and its left adjacent sequence If the value is less than the threshold, the pulse sequence with sequence number M is added to the set S of other radar sequences, and M is removed from M.

[0043] S4. The pulse sequences corresponding to all the remaining elements in the final set M are the staggered PRI sequences, and the pulse sequences in the set S are the pulse sequences of other radars. In step S4, it is determined whether the number of elements of the obtained set S is greater than 1. If the number of elements of the set S in step S4 is greater than 1, the staggered identification is performed again for all the pulse sequences of the set S according to the above steps.

[0044] In this embodiment, a situation where one fixed pulse sequence is mixed with one four-staggered pulse sequence is set, wherein the PRI of the fixed pulse sequence is 3169μs, the number of pulses is 100, the sub-periods of the four-staggered pulse sequences are 680μs, 1008μs, 893μs and 588μs respectively, and the total number of pulses is 400.

[0045] Based on step S1, set and sort to obtain 5 pulse sequences with a period of 3169 μs, sort them according to the arrival time of the first pulse, and obtain a sequence number set M{1,2,3,4,5};

[0046] Based on step S2, the arrival time difference between the pulse sequences corresponding to all adjacent sequence numbers [i, i+1] in the set M{1,2,3,4,5} is calculated and the variance is further calculated;

[0047] Based on step S3, first determine the pulse sequence corresponding to the middle sequence number 3 and its left adjacent sequence. and right adjacent sequence Is the value greater than the threshold? If so, add sequence number 3 to the set of other radar pulse sequences S and remove 3 from M. Then determine the value of the pulse sequence with sequence number 1 and its right adjacent sequence. The pulse sequence with sequence number 2 and its right adjacent sequence is greater than the threshold. If the number of elements in set S is greater than 1, the pulse sequence with serial number 1 is added to the set S of pulse sequences of other radars, and 1 is removed from M. Finally, the pulse sequences corresponding to all the remaining elements in set M are the staggered PRI sequences, and the pulse sequences in set S are the pulse sequences of other radars. If the number of elements in set S is greater than 1, the pulse sequences in set S are further identified according to the above steps.

[0048] like Figure 2 As shown in the figure, since the fixed pulse sequence with pulse number 3 is aliased in the 4 staggered pulse sequences, the jitter of its arrival time difference sequence with the left and right adjacent sequences is more obvious than that of other sequences. Therefore, it can be determined that the pulse sequence with pulse number 3 is another radar pulse sequence. After removing it, the arrival time difference sequences of the 2nd and 4th sequences are calculated. The results are as follows Figure 3 As shown, it can be determined that the pulse sequences numbered 1, 2, 4 and 5 together constitute a 4-staggered pulse sequence.

[0049] The calculation amount of the method of the present invention and the existing discrepancy identification method as the number of pulse sequences changes is compared by counting the number of subtractions.

[0050] If the number of pulse sequences is M, and the number of pulses in each pulse sequence is N, when only one fixed pulse sequence of another radar is aliased, the existing error identification method needs to calculate the variance of the arrival time difference between any two pulse sequences, so MN (M-1) subtractions are required; while the method of the present invention only needs to calculate the variance of the arrival time difference of adjacent pulse sequences, and the number of subtractions is 2MN. The trend of the number of subtractions with the number of pulse sequences is as follows: Figure 4 As shown, the values ​​of the pulse sequence number M are 5, 6, 7, 8, 9, 10 and 11 respectively, and the number of pulses in each pulse sequence is N=200. The correlation and order between adjacent pulses are used to make the difference identification result more reliable. The present invention avoids the tediousness of calculating the arrival time difference between any two sequences when the number of period differences is large. When the number of period differences is large, the amount of calculation is smaller, and it has the advantages of easy use and small amount of calculation.

[0051] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for discriminating between arrival times of adjacent sequences, characterized in that: The following steps are involved: S1, sort all M pulse sequences with the same frequency according to the arrival time of the first pulse and label them with sequence number i (i=1, 2, ..., M) to obtain a sequence set M; S2, calculate the arrival time difference between all the pulse sequences corresponding to the adjacent sequence numbers [i, i+1] and further calculate the variance S3, by judging the pulse sequence corresponding to all the serial numbers and its left adjacent sequence or right adjacent sequence Whether they are all greater than the threshold to further determine the sequence of other radars; S4, the pulse sequences corresponding to all the remaining elements in the final set M are the staggered PRI sequences, and the pulse sequences in the set S are the pulse sequences of other radars; The step S3 comprises the following steps: S301, first determine the pulse sequence corresponding to the middle sequence number i (i = 2, 3, ..., M-1) and its left adjacent sequence and right adjacent sequence Is the value greater than the threshold? If so, add the sequence number i to the set S of other radar pulse sequences and remove i from M. S302, determine the pulse sequence with sequence number 1 and its right adjacent sequence The pulse sequence with sequence number 2 and its right adjacent sequence is greater than the threshold. If it is less than the threshold, the pulse sequence with sequence number 1 is added to the set S of other radar sequences, and 1 is removed from M; S303, determine the pulse sequence with sequence number M and its left adjacent sequence Greater than the threshold, and the sequence number is M-1 and its left adjacent sequence If the value is less than the threshold, the pulse sequence with sequence number M is added to the set S of other radar sequences, and M is removed from M.

2. A method for identifying differences based on arrival time differences of adjacent sequences as claimed in claim 1, characterized in that: The threshold in step S3 is determined by the following formula: c thre =D 2 / 4 Wherein, Δ represents the maximum jitter of all pulse sequences with the same frequency.

3. A method for identifying differences based on arrival time differences of adjacent sequences as claimed in claim 2, characterized in that: In step S4, it is determined whether the number of elements of the obtained set S is greater than 1. If the number of elements of the set S in step S4 is greater than 1, all pulse sequences of the set S are re-identified according to steps S1, S2 and S3.

Images