A TCM code parameter blind identification method and device and a storage medium

Abstract

The application discloses a TCM code parameter blind identification method and device and a storage medium, and belongs to the field of electronic signal reconnaissance and countermeasure. The method comprises the following steps: S1, acquiring binary code stream data of TCM coding, an initial code length and an initial constraint length; S2, constructing a binary linear equation group to obtain a mapping vector; S3, segmenting the mapping vector and then constructing a Hadamard matrix; S4, performing Walsh-Hadamard transformation on the segmented vector to obtain the value of a Walsh spectrum; S5, searching for a Walsh spectrum peak value outside the 0 point position, if the Walsh spectrum peak value is found, the correct code length and the correct constraint length are obtained according to the position of the Walsh spectrum peak, and S6 is performed; if the Walsh spectrum peak value is not found, the initial code length is increased by 1, and the subsequent steps are continued to be performed from S2; S6, constructing a new binary linear equation group, performing Walsh-Hadamard transformation according to the correct code length and the correct constraint length, obtaining a correct starting position and a check matrix, and outputting an identification result. The application has low calculation complexity, is easy to implement in engineering, and has high operation speed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic signal reconnaissance and countermeasure, and in particular to a TCM code parameter blind identification method and device and storage medium. BACKGROUND

[0002] In a digital communication system, various interference and noise exist in the channel, resulting in errors in the information during transmission. In order to ensure the reliability of the transmission process and reduce the influence of the error code on the correct information, channel coding technology is usually used. In the field of non-cooperative electronic reconnaissance and electronic countermeasure, how to correctly identify the type of channel coding and its coding parameters from the intercepted information code stream, so as to realize correct decoding is the first step for electronic reconnaissance to cross from the signal layer to the information layer, and has extremely important significance. In the above field, in order to ensure the security of the system, non-standard coding parameters are usually used, so that the information acquisition party cannot recover the information beyond the intercepted information. However, as an information acquisition party, in order to recover the original information from the intercepted signal, the coding parameters of the signal must be identified without prior coding information.

[0003] Trellis Coded Modulation (TCM) is a signal set space coding, which is a high-efficiency communication technology combining error correction coding and modulation technology. TCM coding improves the anti-noise capability by increasing the Euclidean distance between symbols, while maintaining bandwidth and power efficiency, so it is widely used in telephone modulation and demodulation, WIFI, cellular communication, satellite communication, broadcast television and other fields. How to correctly identify the coding parameters of TCM codes in various fields, especially to realize the blind identification of TCM coding parameters, and then recover the original information from the intercepted signal, has important significance in the fields of electronic countermeasure, electronic reconnaissance, radio signal detection and the like. The existing TCM code parameter blind identification method has high computational complexity, slow operation speed and is not easy to implement in engineering. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provide a TCM code parameter blind identification method, device and storage medium.

[0005] The purpose of the present application is achieved by the following technical solutions: the present application provides a TCM code parameter blind identification method, comprising the following steps:

[0006] S1: obtaining the binary code stream data of TCM coding, the initial code length and the initial constraint length;

[0007] S2: constructing a binary linear equation system to obtain a mapping vector;

[0008] S3: segmenting the mapping vector, and then constructing a Hadamard matrix;

[0009] S4: Walsh-Hadamard transform is performed on the segmented vector to obtain Walsh spectrum values;

[0010] S5: Walsh spectrum peak values are searched for outside the 0 point position, if a Walsh spectrum peak value is found, correct code length and correct constraint length are obtained according to the position of the Walsh spectrum peak value, and S6 is performed, if no Walsh spectrum peak value is found, the initial code length is increased by 1, and the subsequent steps are continued to be performed from S2;

[0011] S6: a new binary linear equation set is constructed, Walsh-Hadamard transform is performed according to the correct code length and the correct constraint length, correct starting position and check matrix are obtained, and the identification result is output.

[0012] Preferably, S1 further comprises the following steps:

[0013] The TCM encoded binary code stream data is segmented according to 2^n, and is traversed in the code length range to form a truncated sequence C2, wherein n = 1, 2…12; the code length range is 3, 4, 5.

[0014] Preferably, S2 further comprises the following steps:

[0015] According to the length of the truncated sequence C2, a binary linear equation set is constructed, and the row coefficients of the binary linear equation set are mapped to decimal data to obtain a mapping vector V.

[0016] Preferably, S3 further comprises the following steps:

[0017] The mapping vector V is segmented to construct a new vector V2, the column width of the vector V2 is col2, the row width of the vector V2 is row2, and a Hadamard matrix is constructed according to the column width col2.

[0018] Preferably, the Walsh spectrum peak value is searched according to a threshold value.

[0019] Preferably, S6 further comprises the following steps:

[0020] The starting position function is traversed according to the correct code length and the correct constraint length, and then the binary code stream data is truncated to form a new truncated sequence C3;

[0021] A new binary linear equation set is constructed according to the truncated sequence C3, then Walsh-Hadamard transform is performed, and the correct starting position and check matrix are determined according to the Walsh spectrum peak value;

[0022] Finally, according to the property of the TCM code, a corresponding generation matrix is obtained, and the correct code length, constraint length, starting position and check matrix are output as the identification result.

[0023] Preferably, the code stream sequence of the binary code stream data is y (j), wherein j is in the range of j=1, 2, 3…M; M is the cache length of the code stream sequence, and is an integer multiple of 2^n.

[0024] The second aspect of the application provides a TCM code parameter blind identification device for implementing any of the above TCM code parameter blind identification methods, comprising:

[0025] A data acquisition module is configured to acquire binary code stream data of TCM coding, initial code length and initial constraint length.

[0026] A binary equation set construction module is configured to construct a required binary linear equation set according to the binary code stream data, the initial code length and the initial constraint length, and transform the binary linear equation set to obtain a mapping vector.

[0027] A Walsh-Hadamard transformation module is configured to utilize Walsh-Hadamard transformation to complete identification of the correct code length and the constraint length according to the mapping vector.

[0028] A TCM code parameter identification module is configured to traverse in the starting position according to the correct code length and the constraint length, construct a new binary linear equation set, utilize Walsh spectrum peak value to determine the correct starting position and check matrix, and finally complete identification of the correct code length, the constraint length, the starting position and the check matrix of the TCM code.

[0029] The third aspect of the application provides a computer readable storage medium, wherein the computer readable storage medium stores computer executable instructions, and when the computer executable instructions are loaded and executed by a processor, any of the above TCM code parameter blind identification methods is implemented.

[0030] The application has the following advantages:

[0031] 1) The Walsh-Hadamard transformation is used to solve the problem of solving high-dimensional equation set, which is decomposed into solving two lower-dimensional equation sets, and the computational complexity is reduced from an exponential complexity to a complexity The reduction of complexity also makes the method easy to implement and fast in operation.

[0032] 2) can be in the case of unknown any parameter, for TCM code parameter blind identification problem, by constructing a binary domain linear equations, using a piece-based Walsh-Hadamard transform to solve the equation set of solution, obtain the code length and constraint length of TCM encoding; Then according to the correct parameters, construct a new binary domain linear equations, solve to obtain the code length, starting position, constraint length, check matrix. In non-cooperative communication, according to the identification parameters can realize the decoding of information, and then restore the original information. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 TCM code parameter blind identification method flow chart;

[0034] Fig. 2 TCM code parameter blind identification device principle block diagram;

[0035] Fig. 3 The equation set coefficient corresponding to the vector of the present application is segmented and shown in the figure. DETAILED DESCRIPTION

[0036] The technical solutions of the present application will be described in detail below with reference to the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] Reference Figs. 1-3 , the first aspect of the present application provides: a TCM code parameter blind identification method, comprising the following steps:

[0038] S1: obtaining the binary code stream data of TCM encoding, initial code length and initial constraint length;

[0039] S2: construct a binary linear equation set to obtain a mapping vector;

[0040] S3: segment the mapping vector, and then build a Hadamard matrix;

[0041] S4: Walsh-Hadamard transform is carried out on the segmented vector, and the value of Walsh spectrum is obtained;

[0042] S5: find the Walsh spectrum peak value outside the 0 point position, if the Walsh spectrum peak value is found, then according to the position of Walsh spectrum peak value, the correct code length and the correct constraint length are obtained, and S6 is executed; If no Walsh spectrum peak value is found, the initial code length + 1, and return to S2 and continue to execute the subsequent steps;

[0043] S6: Construct a new binary linear equation set, perform Walsh-Hadamard transform according to the correct code length and the correct constraint length, obtain the correct starting position and the check matrix, and output the identification result.

[0044] In some embodiments, S1 further includes the following steps:

[0045] The TCM encoded binary code stream data is segmented according to 2^n, and traversed in the code length range to form a truncated sequence C2, where n = 1, 2…12; the code length range is 3, 4, 5.

[0046] In some embodiments, S2 further includes the following steps:

[0047] According to the length of the truncated sequence C2, a binary linear equation set is constructed, and the row coefficients of the binary linear equation set are mapped to decimal data to obtain a mapping vector V.

[0048] In this embodiment, the mapping process of the row coefficients of the binary linear equation set to decimal data is as follows: first, assume that the binary linear equation set is constructed by using The vector V of length is constructed , and the construction method is to set the position in the vector corresponding to the decimal number to m (the number of times this decimal number appears is also the number of times this code word appears), and the rest is set to 0. For example m = 10, set 1 at , and the rest is set to 0.

[0049] ;

[0050] Assume that there are N binary linear equations in the equation set, then the vector V corresponding to the equation set coefficient matrix is:

[0051] ;

[0052] In some embodiments, S3 further includes the following steps:

[0053] The mapping vector V is segmented to construct a new vector V2, the column width of the vector V2 is col2, the row width is row2, and a Hadamard matrix is constructed according to the column width col2.

[0054] In this embodiment, as shown in Fig. 3 , the mapping vector V is a × dimensional matrix, and after segmentation, the vector V2 formed is a​ The row vector of the dimension. The Hadamard matrix refers to the mapping vector V corresponding to the equation coefficient segment V2, and then the m-dimensional Hadamard matrix is constructed according to the column width of V2, where m = col2 + 1, then the Hadamard matrix can be expressed as:

[0055] ; The construction is .

[0056] In step S4, it is assumed that The Walsh-Hadamard transform can be expressed as: Further, by segmenting the vector V, the problem of solving high-dimensional equation set by Walsh-Hadamard transform is decomposed into the problem of solving two lower-dimensional equation sets. Since N The Walsh transform of order n is essentially a matrix multiplication, and its direct calculation complexity is , which is an exponential complexity. If direct calculation is performed, it will often exceed the computer memory when N is large. Considering that the form of Walsh transform is similar to Fourier transform, a fast Walsh transform algorithm can be used to reduce the calculation complexity to .

[0057] Let , then , so:

[0058] ;

[0059] The above formula is rearranged into two rows:

[0060] ;

[0061] Further:

[0062] ;

[0063] In this way, the Walsh transform can be completed after segmenting the data in V, thereby avoiding a large amount of calculation caused by the Hadamard matrix. The calculation complexity of the fast Walsh-Hadamard transform is greatly reduced, which can save storage space and register usage, and is conducive to practical application.

[0064] In step S5, after the correct code length and the correct constraint length are identified according to the peak search method, a peak value appears in the Walsh spectrum of V2 except the 0 point position, and the value of the peak position is converted into a binary vector , is a check vector. If neither the code length nor the constraint length is correct, only the 0 point position has a peak value in the Walsh spectrum, and other positions have no peak value, then the initial code length is increased by 1, and steps S2 and subsequent steps are continued. If the code length exceeds 5, the loop is directly exited and an error is reported.

[0065] In some embodiments, the Walsh spectrum peak value is searched according to a threshold value.

[0066] In some embodiments, S6 further includes the following steps:

[0067] The starting position function is traversed according to the correct code length and the correct constraint length, and then the binary code stream data is truncated to form a new truncated sequence C3.

[0068] A new binary linear equation set is constructed according to the truncated sequence C3, then a Walsh-Hadamard transform is performed, and the correct starting position and the check matrix are determined according to the Walsh spectrum peak value.

[0069] Finally, according to the properties of TCM encoding, the corresponding generating matrix is obtained, and the correct code length, constraint length, starting position and check matrix are output as the identification result.

[0070] In this embodiment, C3 is constructed as follows:

[0071]

[0072] where one row in the coefficient matrix is denoted as a vector with a length of . y i , y i is a certain segment of data of the truncated sequence C2.

[0073] In some embodiments, the code stream sequence of the binary code stream data is y (j), where the value range of j is j=1, 2, 3…M; M is the cache length of the code stream sequence, and its value is an integer multiple of 2^n.

[0074] The second aspect of the present application provides a TCM code parameter blind identification device for implementing any of the above TCM code parameter blind identification methods, comprising:

[0075] A data acquisition module is configured to acquire binary code stream data of TCM encoding, an initial code length and an initial constraint length. ​

[0076] A binary equation set construction module is configured to construct a required binary linear equation set according to the binary code stream data, the initial code length and the initial constraint length, and transform the binary linear equation set to obtain a mapping vector;

[0077] A Walsh-Hadamard transform module is configured to utilize the Walsh-Hadamard transform to complete the identification of the correct code length and the constraint length according to the mapping vector;

[0078] A TCM code parameter identification module is configured to traverse in the starting position, construct a new binary linear equation set, and utilize the Walsh spectrum peak value to determine the correct starting position and the check matrix according to the correct code length and the constraint length, so as to finally complete the identification of the correct code length, the constraint length, the starting position and the check matrix of the TCM code.

[0079] The third aspect of the present application provides a computer readable storage medium, wherein the computer readable storage medium stores computer executable instructions, and the computer executable instructions are loaded and executed by a processor to implement any of the above TCM code parameter blind identification methods.

[0080] The above description is only preferred embodiments of the present application, and it should be understood that the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein by the above teachings or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

Claims

1. A TCM code parameter blind identification method, characterized by: The following steps are involved: S1: Obtain TCM-coded binary code stream data, initial code length, and initial constraint length; S2: Construct a set of two-variable linear equations and obtain the mapping vector; S3: Segment the mapping vector and then construct the Hadamard matrix; S4: Perform Walsh-Hadamard transformation on the segmented vector to obtain the value of the Walsh spectrum; S5: Search for a Walsh spectrum peak outside the zero point position. If a Walsh spectrum peak is found, the correct code length and constraint length are obtained based on the position of the Walsh spectrum peak, and S6 is executed. If no Walsh spectrum peak is found, the initial code length is increased by 1, and the process returns to S2 and continues with the subsequent steps. S6: Construct a new binary linear equation system, perform Walsh-Hadamard transform based on the correct code length and correct constraint length, obtain the correct starting position and check matrix, and output the recognition result.

2. The TCM code parameter blind identification method according to claim 1, wherein: The S1 further comprises the following steps: The TCM-encoded binary code stream data is segmented according to 2^n and traversed within the code length range to form a truncated sequence C2, where n=1, 2...12; the code length range is 3, 4, 5.

3. The TCM code parameter blind recognition method according to claim 2, wherein: The S2 further comprises the following steps: According to the length of the truncated sequence C2, a binary linear equation system is constructed, and the row coefficients of the binary linear equation system are mapped to decimal data to obtain a mapping vector V.

4. The TCM code parameter blind recognition method according to claim 3, wherein: The S3 further comprises the following steps: The mapping vector V is segmented to construct a new vector V2 with a column width of col2 and a row width of row2. The Hadamard matrix is ​​constructed based on the column width col2.

5. The TCM code parameter blind recognition method according to claim 1, wherein: Find the Walsh spectrum peak according to the threshold value.

6. The TCM code parameter blind identification method according to claim 1, wherein: The S6 further comprises the following steps: The starting position function is traversed according to the correct code length and the correct constraint length, and then the binary code stream data is truncated to form a new truncation sequence C3; A new binary linear equation system is constructed based on the truncated sequence C3, and then a Walsh-Hadamard transform is performed. The correct starting position and check matrix are determined based on the Walsh spectrum peak. Finally, according to the properties of TCM coding, the corresponding generator matrix is ​​obtained, and the correct code length, constraint length, starting position and check matrix are output as the recognition result.

7. The TCM code parameter blind recognition method according to claim 2, wherein: The code stream sequence of the binary code stream data is y (j), where the value range of j is j=1,2,3…M; M is the buffer length of the code stream sequence, and its value is an integer multiple of 2^n.

8. A TCM code parameter blind recognition device, characterized by: The method for blindly identifying TCM code parameters according to any one of claims 1 to 7 comprises: A data acquisition module is used to obtain TCM-coded binary code stream data, initial code length, and initial constraint length; A binary equation group construction module is used to construct the required binary linear equation group according to the binary code stream data, the initial code length and the initial constraint length, and transform the binary linear equation group to obtain a mapping vector; Walsh-Hadamard transform module, used to identify the correct code length and constraint length based on the mapping vector using Walsh-Hadamard transform; The TCM code parameter identification module is used to traverse the starting position based on the correct code length and constraint length, construct a new set of binary linear equations, and use the Walsh spectrum peak to determine the correct starting position and check matrix. Ultimately, it completes the identification of the correct code length, constraint length, starting position, and check matrix of the TCM code.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions. When the computer-executable instructions are loaded and executed by the processor, the TCM code parameter blind recognition method according to any one of claims 1 to 7 is implemented.

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