KR101559904B1 - A method of recognizing PRI modulation type of radar signals based on genetic algorithm - Google Patents

Abstract

The present invention relates to a method of recognizing a radar signal PRI modulation type, the method comprising: generating a sample code; Generating a solution group (P []) for performing a genetic algorithm; Calculating a fitness of the harmful group; Selecting a pair of solutions based on the fitness of the solution group; Crossing a pair of solutions selected on the basis of the fitness of the solution group on the basis of the fitness of the solution group; Generating a mutation for a solution selected based on the fitness of the harmful population; Updating the mating and the mutated sea population to a new sea population; Confirming a generation termination condition; And a final PRI modulation form. Accordingly, the present invention is robust and easy to automate the signal distortion phenomenon such as a missing pulse and an unnecessary signal.

Description

 [0001] The present invention relates to a PRI modulation type radar signal based on genetic algorithm,

The present invention relates to a radar signal PRI modulation type recognition method, and more particularly, to a radar signal PRI modulation type recognition method for identifying a radar in an electronic control system.

In order to identify the radar signal, analysis of frequency, PRI (Pulse Repetition Interval), scan, etc., which are the main factors of the radar signal, should be preceded. Among them, PRI is the most basic and essential element for identifying radar because it uses unique modulation type and value for each radar.

There are several methods for analyzing the PRI modulation pattern in the electronic warfare system, such as the histogram method and the autocorrelation method. However, these methods have some limitations.

The method using the histogram generates the histogram using the difference of TOA (Time Of Arrival) between each pulse and recognizes the PRI modulation type by using the characteristic of the histogram according to each modulation type. This method is mainly used for manual analysis of operator because it is difficult to automate due to large sensitivity to signal distortion such as histogram bin size, ambiguity such as threshold value, missing pulse, and unnecessary signal.

The autocorrelation method calculates the autocorrelation between each pulse and defines a type separator for distinguishing each PRI modulation type and applies it to each pulse train. The autocorrelation method should be preceded by filtering that acts as a preprocessor for missing and distorted phenomena. Since the periodicity is used for type classification, a sufficient number of pulses must be collected to confirm the periodicity. There is a disadvantage that the time complexity is high because the relationship is calculated.

KR 10-1075516 B

An object of the present invention is to provide a radar signal PRI modulation shape recognition method that is robust but easy to automate the signal distortion phenomenon such as a missing pulse and an unnecessary signal by using a genetic algorithm.

According to an aspect of the present invention, there is provided a radar signal PRI modulation type recognition method for identifying a radar in an electronic warfare system.

The present radar signal PRI modulation type recognition method includes: generating a sample code for an input signal; Generating a solution group (P []) for performing a genetic algorithm; (P []) and the recognition code (Rk []) between the present year's sea group (P []) and the sample code (S [ Calculating a fitness; Selecting a pair of solutions based on the fitness of the solution group; Crossing a pair of solutions selected on the basis of the fitness of the solution group on the basis of the fitness of the solution group; Generating a mutation for a solution selected based on the fitness of the harmful population; Updating the mating and the mutated sea population to a new sea population; Confirming the generation termination condition by determining whether to continue the inheritance to the new child generation using the threshold value? E equal to the maximum generation (G); And determining the final PRI modulation form by using the best fit and the goodness of fit of the recognition code, the ratio of which is the same among all groups of the solution.

In the generating of the sample code, a code string is generated by using a difference between TOAs (Time Of Arrival) of input pulses and a predetermined threshold value, and the probability of changing from each state of the code to the next state And generates the sample code by the generated sample matrix.

S [4], S [5], S [6], S [7], and S [7] }, The sample code can be expressed by Equation (2).

Equation 1:

Equation 2:

The initial population generation step generates a total of M initial solutions for genetic algorithm execution, and each solution is generated by a 7-digit code, and each 7-digit code can be generated with a random value between 0 and 1 have.

)를 계산하고, 그 계산된 적합도 중 최소값(

)과 해 집단과 상기 표본코드와의 적합도의 합의 역수(

)를 계산하는 것에 의해 수행될 수 있다.The calculation of the harmonic group fitness is based on the fitness of the harmonic group and the recognition code

), And calculates a minimum value (

) And the reciprocal of the sum of the fitness of the sea population and the sample code

). ≪ / RTI >

), 상기 최소값(

) 및 상기 해 집단과 상기 표본코드와의 적합도의 합의 역수(

)는 수식 3에 의해 계산될 수 있다.Specifically, the fitness (

), The minimum value (

) And a reciprocal of the sum of the fitness of the harm group and the sample code

) Can be calculated by Equation (3).

Equation 3:

The pair selection step of the solution of the present radar signal PRI modulation shape recognition method can be performed by selecting one pair in the roulette wheel method based on the fitness of the solution group.

The step of crossing the pair of solutions of the present radar signal PRI modulation shape recognition method comprises: a step of generating a new solution (* Pv) by crossing the selected one pair {Pj, Pk} And the like.

Equation 4:

The step of generating the mutation of the present radar signal PRI modulation shape recognition method may be performed by Equation 5, reflecting only the predefined mutation occurrence rate in the solution group.

Equation 5:

As described above, the present invention uses a genetic algorithm in which a mating and a mutation are present to thereby provide a modulation shape recognition method with low sensitivity to missing pulses and distortion pulses. The algorithm is simple and easy to automate and has a high modulation type recognition rate.

Further, according to the present invention, the present invention can be directly applied to an electronic warfare support (ES) system and an electronic intelligence (ELINT) system that require signal analysis.

1 is a flowchart of a radar signal PRI modulation type recognition method according to an embodiment of the present invention.
2 is a conceptual view of a code string of a radar signal PRI modulation type recognition method according to an embodiment of the present invention.
3 is a conceptual diagram of a sample matrix of a radar signal PRI modulation type recognition method according to an embodiment of the present invention.

The present invention will now be described with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Thus, the shape and size of the elements in the figures may be exaggerated for clarity.

FIG. 1 is a flowchart of a radar signal PRI modulation type recognition method according to an embodiment of the present invention. FIG. 2 is a conceptual view of a code column of a radar signal PRI modulation type recognition method according to an embodiment of the present invention. FIG. 2 is a conceptual diagram of a sample matrix of a radar signal PRI modulation type recognition method according to an embodiment of the present invention. FIG.

A radar signal PRI modulation type recognition method according to the present embodiment includes generating a sample code for an input signal (S100), generating an initial solution group for a genetic algorithm (S200), calculating a fitness for a solution group (S300), selecting two solutions in the solution group according to the selection algorithm (S400), generating a new solution by crossing the two selected solutions by the mating algorithm (S500), adding the mutation property (S600), a step of updating the existing solution group to a new solution (S700), a step of confirming a condition for terminating the genetic generation (S800), and a step of determining a PRI modulation type from the optimal solution (S900).

The input signal sample code generation step S100 generates a code string using threshold values θi, θd and θs as shown in FIG. 2 by using the difference between the TOAs of the input pulses (DTOA) (SM, Sampling Matrix) as shown in FIG. 3, which shows the probability of changing from the state (-2 to +2) of the code to the next state by using the column. (S []) from the generated sample matrix in the same manner as in Table 1 and Equation 1 below.

S [1] S [2] S [3] S [4] S [5] S [6] S [7]

[Equation 1]

The initial population generation (S200) is a step of generating a solution group (P []) for genetic algorithm execution, generating a total of M initial solutions, and each solution is generated by a 7-digit code. Each code is generated with a random value between 0 and 1 as shown in Table 2.

0 to 1 0 to 1 0 to 1 0 to 1 0 to 1 0 to 1 0 to 1

The calculation of the population fitness (S300) is calculated by the sum of the fitness between the current group of the sea (P []) and the sample code (S []) and the fitness between the current group and the recognition code. The recognition code is a recognition solution generated by a 7-digit code (Rk []), as shown in Table 3 below.

PRI modulation type code Jitter (R1) One 0 0 0 0 0 0 D & S (R2) 0 One 0 0 0 0 0 The wobble (R3) 0 0 One 0 0 0 0 Linear sliding + (R4) 0 0 0 One 0 0 0 Linear sliding - (R5) 0 0 0 0 One 0 0 Nonlinear sliding + (R6) 0 0 0 0 0 One 0 Nonlinear sliding - (R7) 0 0 0 0 0 0 One

 (F) calculation is shown in Equation (2). First, FR, which is a goodness of fit between a harmonic group and a recognition code, is obtained for each modulation type, and F is calculated as a reciprocal of the sum of the minimum value and the fitness of the harm group and the sample code.

&Quot; (2) "

The solution pair selection (S400) arbitrarily selects two pairs of solutions in the solution group by the solution size M of the solutions. When choosing one pair (two solutions) arbitrarily, the probability of choosing a solution with high fitness is high with the roulette wheel method considering fitness.

The solution pairing (S500) generates a new solution (* Pv) by mating the selected one pair {Pj, Pk} in consideration of the fitness.

&Quot; (3) "

The mutation generation (S600) is reflected only in the population of harmfulness by a pre-defined mutation incidence rate (U). In the formula, rand () is a random function that randomly generates a value between 0 and 1.

&Quot; (4) "

Year group update (S700) replaces the existing sea group with a new sea group that has been transformed into mating and mutation.

The generation termination condition check (S800) judges whether or not the inheritance to the new child generation is continued. The condition is the same as the maximum generation (G) and uses the threshold value? E. That is, if the hereditary generation is more than the maximum generation (for example, 20), or if the ratio of the same year among the whole population of the year is larger than θe, the generation is terminated.

In the determination of PRI modulation type (S900), the fitness of the recognition solution with the greatest ratio of the same solution is used, and the type of recognition code having the greatest fitness value is determined as the final PRI modulation type.

As described above, the radar signal PRI modulation pattern recognition method according to the present embodiment is a modulation pattern recognition method having low sensitivity to missing pulses and distortion pulses by using a genetic algorithm in which mating and mutation exist. The algorithm is simple and easy to automate, It can be directly applied to ES (Electronic Warfare Support) system and ELINT (Electronic Intelligence) system which require signal analysis because of high recognition rate.

The method of recognizing a radar signal PRI modulation type according to an embodiment of the present invention is not limited to the configuration and method of the embodiments described above and all or a part of the embodiments may be selectively combined according to the needs of the user.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Claims (4)

Generating a sample code for an input signal;
Generating a solution group for genetic algorithm execution;
Calculating a fitness of the harmful group by calculating the fitness between the current harmonic group and the sample code and the fitness between the current harmonic group and the recognition code;
Selecting a pair of solutions based on the fitness of the solution group;
Crossing a pair of solutions selected on the basis of the fitness of the solution group on the basis of the fitness of the solution group;
Generating a mutation for a solution selected based on the fitness of the harmful population;
Updating the mating and the mutated sea population to a new sea population;
Confirming the generation termination condition by determining whether to continue the inheritance to the new child generation using the same threshold as the maximum generation; And
And determining the final PRI modulation type using the best fit and the goodness of fit of the recognition code, the ratio of which is the largest among all the groups in the same year. The method according to claim 1,
In the generating of the sample code, a code string is generated by using a difference between TOAs (Time Of Arrival) of input pulses and a predetermined threshold value, and the probability of changing from each state of the code to the next state And generating the sample code based on the generated sample matrix. The method of claim 1, The method according to claim 1,
In order to perform the genetic algorithm, a step of generating a solution group generates a total of M initial solutions for genetic algorithm execution, and each solution is generated by a 7-digit code, and each 7-digit code includes 0 to 1 Generated with a random value,
The calculation of the harmonic group fitness is based on the fitness of the harmonic group and the recognition code

), And calculates a minimum value (

) And the reciprocal of the sum of the fitness of the sea population and the sample code

), ≪ / RTI >
The fitness (

), The minimum value (

) And a reciprocal of the sum of the fitness of the harm group and the sample code

) Is calculated by the equation (3).
Equation 3:

The method according to claim 1,
Wherein the pair selection step of the solution is performed by selecting one pair in the roulette wheel method based on the fitness of the solution group.

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