阅读说明：本技术 一种基于cdif的抖动信号分选方法 (CDIF-based dither signal sorting method ) 是由 许敏良 向俊 王萌 孙恩元 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种基于CDIF的抖动信号分选方法,其包括：步骤S1：对指定检测的重周间隔范围进行区域划分；步骤S2：对各PDW数据的TOA进行差分,依据步骤S1中划分方法做直方图；步骤S3：使用指定的最大抖动范围进行门限确定,通过确定的门限寻找潜在可能的抖动PRI中心及其抖动范围；步骤S4：使用潜在的PRI及抖动范围进行脉冲串的起始,若起始成功,则使用此参数进行脉冲串的分选；步骤S5：分选成功,输出最终结果。本发明具有原理简单、适用范围广、分选效果好的等优点。(The invention discloses a CDIF-based dither signal sorting method, which comprises the following steps: step S1: performing region division on the range of the designated detected repeated interval; step S2: differentiating TOAs of each PDW data, and making a histogram according to the dividing method in the step S1; step S3: determining a threshold by using the specified maximum jitter range, and searching a potential jitter PRI center and a jitter range thereof through the determined threshold; step S4: using the potential PRI and the jitter range to start the pulse train, and if the start is successful, using the parameter to sort the pulse train; step S5: and (5) successfully sorting and outputting a final result. The invention has the advantages of simple principle, wide application range, good sorting effect and the like.)

1. A CDIF-based jittered signal sorting method, comprising:

step S1: performing region division on the range of the designated detected repeated interval;

step S2: differentiating TOAs of each PDW data, and making a histogram according to the dividing method in the step S1;

step S3: determining a threshold by using the specified maximum jitter range, and searching a potential jitter PRI center and a jitter range thereof through the determined threshold;

step S4: using the potential PRI and the jitter range to start the pulse train, and if the start is successful, using the parameter to sort the pulse train;

step S5: and (5) successfully sorting and outputting a final result.

2. The CDIF-based jittered signal sorting method of claim 1, wherein in step S1, different regions use different histogram resolutions.

3. The CDIF-based jittered signal sorting method according to claim 1, wherein in step S2, the TOA of the input PDW data is subjected to a pairwise I difference, where the initial I is 1, and an index of a histogram is calculated according to the difference result.

4. The CDIF-based jittered signal sorting method of claim 3, wherein the index of the histogram is calculated by:

in the above formula, reg _ base represents the lower bound of the histogram of the region where the differential value is located, TOA _ diff represents the differential value of the TOA, and time _ bound represents the lower bound of the time value of the region where the differential value is located; reg _ solution represents the histogram resolution of the area where the difference value is located.

5. The CDIF-based jittered signal sorting method according to claim 3, wherein in the step S3, all the straight squares are traversed according to the histogram divided in the step S2; supposing traversing to a square lattice with index idx _ of _ hist, calculating the corresponding repetition interval pri _ of _ judge, setting the maximum jitter range of the allowable signal and the pulse interception rate, and accordingly obtaining the judgment threshold of the square lattice.

6. The CDIF-based jittered signal sorting method according to claim 5, wherein in the step S3, if the histogram satisfies the threshold, go to step S4; if there is no dither signal satisfying the condition after traversing the straight squares, the differential stage number I is I +1, and the process returns to step S2.

7. The CDIF-based dither signal sorting method according to claim 6, wherein in step S4, upper and lower boundaries edge _ down, edge _ upper of the dither signal centered around pri _ of _ judge are searched.

8. The CDIF based jittered signal sorting method of claim 7, wherein in step S4, all the straight squares within the upper and lower boundaries should satisfy the threshold determined in step S3; after the upper and lower boundaries are determined, re-calculating the center repetition interval of the jitter signal by using the upper and lower boundaries, if the center is located in the histogram with the index of idx _ of _ hist of step S3, calculating the jitter range of the determined signal, and performing step S5; otherwise, the process returns to step S3 to determine the next square.

9. The CDIF-based jittered signal sorting method according to any one of claims 1 to 8, wherein in step S5, a pulse start search is performed on the signals using the center repetition interval and the jitter range determined in step S4; if the starting is successful, sequence searching is carried out, and a final sorting result is output; if the start fails, the process returns to step S3.

Technical Field

The invention mainly relates to the technical field of radar countermeasure, in particular to a CDIF-based dither signal sorting method.

Background

In modern electronic countermeasures, in order to effectively interfere with the radar signal of the other party, it is known that the signals received from the radar of the other party must be sorted to gain advantages in electronic warfare. The radar signal sorting is a technology for separating each radar pulse sequence under the condition that a plurality of radar pulses are mutually staggered, and estimating and identifying parameters of each radar. By sorting the radar signals, various radars and their parameters in the space are accurately identified and put into a radar library for further processing, such as positioning, tracking, interference, etc. Radar signal sorting is said to be an important link in electronic countermeasures.

The current main radar signal histogram sorting methods are the following two types:

first, cumulative histogram sorting (CDIF);

the steps of the CDIF method are as follows: first, a first-order difference is calculated for the input pulse stream based on the TOA to obtain a histogram. Comparing the TOA interval and the double interval corresponding to the primary difference histogram with a detection threshold, and when both of the TOA interval and the double interval exceed the detection threshold, considering that the PRI exists, and comparing and matching the PRI in the input pulse stream; if the comparison is successful, separating the corresponding sequence set from the input pulse stream. The one-level difference histogram is then recalculated for the remaining pulse stream until the number of pulses is too small to continue operation. If the comparison fails, comparing and matching the PRI which is possible and meets the condition at the minimum interval in the level, if the PRI does not meet the condition, counting the histogram of the next level, adding the statistical values of the previous level, and repeating the steps.

Second, sequence difference histogram Sorting (SDIF)

The sequence difference histogram algorithm (SDIF) is modified on the basis of CDIF algorithm, which also includes two parts: PRI estimation, pulse sequence alignment and matching. The method comprises the following steps: firstly, calculating a first-level difference of an input pulse stream based on the TOA to obtain a histogram; the potential PRI is then derived based on the detection threshold. And if and only if the primary difference exceeds only one value of the detection threshold, taking the corresponding TOA interval as a potential PRI and comparing and matching in the input pulse stream. And when the value of the one-stage difference exceeding the detection threshold is not only one, performing the next-stage difference histogram calculation. When the two differential values exceed the respective corresponding thresholds, the TOA differential of the corresponding sequence is considered as a potential PRI and is compared and matched in the input pulse stream. If the corresponding pulse sequence is successfully found, the sequence set is separated from the incoming pulse stream. Drawing the rest pulse streams from the first-stage difference histogram, setting a new detection threshold value, and repeating the steps.

However, in a practical complex electromagnetic environment, the conventional histogram sorting cannot simultaneously satisfy sorting identification of several wide-range jitter signals (such as 100us-5ms jitter +/-15%).

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the technical problems in the prior art, the invention provides the CDIF-based dither signal sorting method which is simple in principle, wide in application range and good in sorting effect.

In order to solve the technical problems, the invention adopts the following technical scheme:

a CDIF-based jittered signal sorting method, comprising:

step S1: performing region division on the range of the designated detected repeated interval;

step S2: differentiating TOAs of each PDW data, and making a histogram according to the dividing method in the step S1;

step S3: determining a threshold by using the specified maximum jitter range, and searching a potential jitter PRI center and a jitter range thereof through the determined threshold;

step S4: using the potential PRI and the jitter range to start the pulse train, and if the start is successful, using the parameter to sort the pulse train;

step S5: and (5) successfully sorting and outputting a final result.

As a further improvement of the process of the invention: in step S1, different histogram resolutions are used for different regions.

As a further improvement of the process of the invention: in step S2, a pairwise difference of the I-level is made for the TOA of the input PDW data, where initial I is 1, and an index of the histogram where the TOA is located is calculated according to the difference result.

As a further improvement of the process of the invention: the index of the histogram is calculated by:

in the above formula, reg _ base represents the lower bound of the histogram of the region where the differential value is located, TOA _ diff represents the differential value of the TOA, and time _ bound represents the lower bound of the time value of the region where the differential value is located; reg _ solution represents the histogram resolution of the area where the difference value is located.

As a further improvement of the process of the invention: in the step S3, traversing all the straight squares according to the histogram divided in the step S2; supposing traversing to a square lattice with index idx _ of _ hist, calculating the corresponding repetition interval pri _ of _ judge, setting the maximum jitter range of the allowable signal and the pulse interception rate, and accordingly obtaining the judgment threshold of the square lattice.

As a further improvement of the process of the invention: in the step S3, if the histogram satisfies the threshold, go to step S4; if there is no dither signal satisfying the condition after traversing the straight squares, the differential stage number I is I +1, and the process returns to step S2.

As a further improvement of the process of the invention: in step S4, upper and lower boundaries edge _ down and edge _ upper of the dither signal centered around pri _ of _ judge are searched.

As a further improvement of the process of the invention: in step S4, all the straight squares in the upper and lower boundaries should satisfy the threshold obtained in step S3; after the upper and lower boundaries are determined, re-calculating the center repetition interval of the jitter signal by using the upper and lower boundaries, if the center is located in the histogram with the index of idx _ of _ hist of step S3, calculating the jitter range of the determined signal, and performing step S5; otherwise, the process returns to step S3 to determine the next square.

As a further improvement of the process of the invention: in step S5, performing a pulse start search on the signal using the center repetition interval and the jitter range determined in step S4; if the starting is successful, sequence searching is carried out, and a final sorting result is output; if the start fails, the process returns to step S3.

Compared with the prior art, the invention has the advantages that:

the CDIF-based dither signal sorting method is simple in principle and wide in application range, and refers to an SDIF-based optimization scheme for sorting wider-range dither signals; accurately measuring the jitter range of the jitter signal in a positive feedback mode; and the measured jitter range is used for carrying out sequence search on the pulse sequence so as to achieve the purposes of adapting to the wider range of jitter signal sorting and more accurate jitter range measurement and pulse search. Therefore, the invention can adapt to the sorting of jitter signals in a wider range, and can measure the jitter range and carry out pulse de-interlacing more accurately.

Drawings

FIG. 1 is a schematic flow diagram of the process of the present invention.

FIG. 2 is a flow chart of the present invention in a specific application example.

Detailed Description

The invention will be described in further detail below with reference to the drawings and specific examples.

As shown in fig. 1, the CDIF-based jittered signal sorting method of the present invention includes the steps of:

step S1: carrying out region division on the range of the designated detected repeating interval, wherein different regions use different histogram resolutions;

step S2: differentiating TOAs of each PDW data, and making a histogram according to the dividing method in the step S1;

step S3: determining a threshold by using the specified maximum jitter range, and searching a potential jitter PRI center and a jitter range thereof through the determined threshold;

step S4: using the potential PRI and the jitter range to start the pulse train, and if the start is successful, using the parameter to sort the pulse train;

step S5: and (5) successfully sorting and outputting a final result.

The invention is illustrated by a specific application example. In this example, the detected signal cycle is in the range of 100us-6ms, and the jitter is + -15%. Referring to fig. 2, the detailed steps are as follows:

step S1: dividing the detection range of signal repetition into 5 regions, wherein the upper bound of each region is 300us, 700us, 1.5ms, 3ms and 6 ms;

of the above 5 regions, different regions use different histogram resolutions, such as 5, 10, 25, 50, 100us histogram resolutions, respectively;

step S2: performing I-level pairwise difference on TOA of input PDW data (initial I is 1), and calculating an index of a histogram of the TOA according to a difference result, wherein the specific calculation method comprises the following steps:

in the above formula, reg _ base represents the lower bound of the histogram of the region where the differential value is located, TOA _ diff represents the differential value of the TOA, and time _ bound represents the lower bound of the time value of the region where the differential value is located; reg _ solution represents the histogram resolution of the area where the difference value is located.

Here, taking the difference value as 750us as an example, the histogram index where it is located is further calculated:

that is, when the difference value is 750us, the index of the histogram where the difference value is located is 102;

step S3: traversing all the straight squares according to the histogram divided in the step S2;

assuming that the square grid with index idx _ of _ hist is traversed, the corresponding repetition interval pri _ of _ judge is calculated, the maximum jitter range of the allowed signal is set to be +/-20%, and the pulse interception rate is 0.8, then the judgment threshold of the square grid is set as:

in the above formula, time _ len is the duration of the intercepted pulse;

if the histogram satisfies the threshold, go to step S4;

if no dither signal meeting the condition is found after the straight square is traversed, the differential stage number I is equal to I +1, and the process returns to step S2;

step S4: find the upper and lower boundaries edge _ down, edge _ upper of the dither signal centered at pri _ of _ judge.

All the straight squares in the upper and lower boundaries should satisfy the threshold Th obtained in step S3, but in the process of finding the boundary, the repetition interval of the jitter signal inevitably crosses the region, so the threshold should be changed accordingly;

after the upper and lower boundaries are determined, re-calculating the center repetition interval of the jitter signal by using the upper and lower boundaries, if the center is located in the histogram with the index of idx _ of _ hist of step S3, calculating the jitter range of the determined signal, and performing step S5; otherwise, the process returns to step S3 to determine the next square.

Step S5: the signal is subjected to a pulse start search using the center repetition interval and the jitter range determined in step S4. If the starting is successful, sequence searching is carried out, and a final sorting result is output; if the start fails, the process returns to step S3.

In particular, it is obvious to a person skilled in the art that the resolution of the histogram can also be modified for different application scenarios without departing from the inventive concept.

Through the above description, it can be seen that the above scheme of the present invention can simultaneously adapt to a wider range of radar repetition frequency jitter signals, and simultaneously compare with a histogram with fixed resolution, so that the initial jitter range measurement and the center interval are more accurate and controllable.

To further demonstrate the advantage of this scheme over fixed precision histograms, the following is illustrated with actual simulations.

Simulation conditions are as follows:

simulation data duration: 1 s;

probability of pulse loss: 0.05;

the repetition parameters are as follows: the repeated interval is respectively 100, 300, 700, 1500, 3000 and 5000, the unit us is us, and the shaking range is +/-15 percent;

pulse arrival time measurement error: 0.1+ 1% PRI, unit us.

The 6 signals were sorted using a fixed histogram resolution of 10us, with the following results:

the 6 signals were sorted using the gradient histogram resolution, which was the same as the example above, and the sorting results were as follows:

the comparison of simulation results shows that the gradually-changed histogram lattice can complete the identification of the jitter signal in a wider range, and the overall accuracy and accuracy of the histogram lattice are higher than those of the histogram lattice with fixed resolution.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.