A method for enhancing satellite communication physical layer symbol security based on spatiotemporal chaos

Abstract

The invention discloses a satellite communication physical layer codeword security enhancement method based on spatiotemporal chaos. First, the information transmitting end generates a spatiotemporal chaotic two-dimensional signal matrix, and uses a part of the information group to generate a chaotic keying index value of the spatiotemporal chaotic space dimension, and the other part of the information group and the spatiotemporal chaotic time dimension signal determined by the index value are quantized and sent by direct sequence spread spectrum; the information receiving end generates a spatiotemporal chaotic two-dimensional signal matrix based on the same initial parameters, quantizes the matrix and processes it with the received signal, determines the index value of spatial dimension information demodulation, and performs integral cleaning processing of despreading the corresponding time dimension chaotic sequence and the received signal based on the index value, and performs spatiotemporal dimension information demodulation, thereby obtaining demodulated information after security enhancement. The invention uses the same spatiotemporal chaotic mechanism to achieve the security enhancement of the expanded-dimensional codewords while reducing the complexity of implementation and improving the frequency band utilization.

Description

Technical Field

[0001] The present invention belongs to the field of physical layer communication security, and in particular relates to a satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos. Background Art

[0002] With the development of 5G and 6G mobile communications, information transmission has profoundly affected all aspects of national interests and people's livelihood. In particular, satellite communications, which can provide seamless global coverage, have become an indispensable and important role. However, since satellite communications are open wireless channels, their security faces severe challenges, and physical layer security technologies that can provide inherent security have received widespread attention.

[0003] Spread spectrum communication can provide anti-interference and covert communication capabilities, but its single symbol dimension symbol security cannot cope with the increasingly serious security threats, and the frequency band utilization rate of spread spectrum communication is not high, which is a problem that satellite communication systems with limited frequency bands need to face. On the other hand, chaotic keying can greatly improve the security of information transmission, but its implementation complexity limits its wide application in communications, especially wireless communications.

[0004] Therefore, it is necessary to study the security enhancement method of chaotic expansion code elements by utilizing the spatiotemporal two-dimensional chaotic characteristics of spatiotemporal chaos to meet the requirements of intrinsic security of satellite communications and overcome the problem of frequency band utilization. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a satellite communication physical layer codeword security enhancement method based on spatiotemporal chaos.

[0006] The specific technical solution for achieving the purpose of the present invention is:

[0007] A satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos comprises the following steps:

[0008] Step 1: The spatiotemporal chaos generator at the information sending end generates a spatiotemporal chaotic two-dimensional signal matrix according to initial parameters;

[0009] Step 2: Group the information to be sent, use part of the information group to generate the chaotic keying index value of the space-time chaotic space dimension, and use the other part of the information group and the quantized sequence of the space-time chaotic time dimension signal determined by the index value to perform direct sequence spread spectrum transmission;

[0010] Step 3: The spatiotemporal chaos generator at the information receiving end generates a spatiotemporal chaotic two-dimensional signal matrix according to the same initial parameters as those at the transmitting end;

[0011] Step 4, after quantizing the spatiotemporal chaotic two-dimensional signal matrix in step 3, the matrix is ​​processed with the received signal to determine the index value of the spatial dimension information demodulation;

[0012] Step 5: Based on the index value determined in step 4, the corresponding time-dimensional chaotic sequence and the received signal are subjected to integral cleaning processing for despreading, and the space-time dimension information is demodulated.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The solution of the present invention combines space-time chaos with spread spectrum and chaotic keying, uses the spatial dimension of space-time chaos to perform chaotic keying of information, and uses the time dimension to perform direct sequence spread spectrum of information. The same space-time chaos mechanism is used to achieve the security enhancement of the code elements of the spread dimension while reducing the complexity of implementation. On the other hand, in this method, not only the time dimension signal of the space-time chaos carries information, but also the space dimension signal carries information. Therefore, on the basis of providing anti-interference and concealment capabilities, a higher frequency band utilization rate is obtained than that of spread spectrum.

[0015] The present invention is further described below in conjunction with specific implementation modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a schematic flow chart of a satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos.

[0017] Figure 2 The present invention is a block diagram of the principle of the transmitting end of the satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos.

[0018] Figure 3 It is a schematic diagram of the two-dimensional matrix of spatiotemporal chaotic signals of the present invention.

[0019] Figure 4 The present invention is a schematic diagram of the receiving end principle of the satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos. DETAILED DESCRIPTION

[0020] Example

[0021] The technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. The described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an kind" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0024] Combination Figure 1 , a satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos, comprising the following steps:

[0025] Step 1: The spatiotemporal chaos generator at the information sending end generates a spatiotemporal chaotic two-dimensional signal matrix according to the initial parameters:

[0026] In this scheme, the spatiotemporal chaos generator in step 1 and step 3 adopts a one-way coupled image lattice model, and its expression is:

[0027] ;

[0028] Its boundary conditions are:

[0029] ;

[0030] in, represents the coupling coefficient, n represents the discrete time number, i represents the grid number, L is a positive integer representing the number of spatial grids, represents the spatiotemporal chaos value of the ith grid at time n, Represents Logistic mapping, when the parameter When , the Logistic map is a one-dimensional chaotic map:

[0031] , ;

[0032] The spatiotemporal chaotic two-dimensional signal matrix is ​​specifically:

[0033] The spatiotemporal chaos generator is based on the initial value , , Generate a sequence: , quantize it and generate a spatiotemporal chaotic sequence: ;

[0034] Among them, k is the time dimension serial number, j is the space dimension grid number, and L is , is the number of elements in the spatial dimension information group after the bit information is grouped.

[0035] Step 2: Group the information to be sent, use part of the information group to generate the chaotic keying index value of the space-time chaotic space dimension, and use the other part of the information group and the quantized sequence of the space-time chaotic time dimension signal determined by the index value to perform direct sequence spread spectrum transmission:

[0036] The i-th message to be sent Group them into:

[0037] include bits of information space-dimensional information group element , , and the corresponding relationship with the original information grouping is: , space dimension information group ;

[0038] include bit information of the time dimension , , and the corresponding relationship with the original information grouping is: , time dimension information group .

[0039] Afterwards, based on the spatial dimension information group Determining the index value of the space dimension of spatiotemporal chaos :

[0040]

[0041] Finally, according to the index value The corresponding spatiotemporal chaotic time dimension sequence and time dimension information group are sent by direct sequence spread spectrum:

[0042] ;

[0043] ;

[0044] Among them, mod() represents the modular operation, Indicates floor operation.

[0045] like Figure 2 As shown, the present invention designs the sending end to generate the initial parameters through the space-time chaos generator as shown in Figure 3 The two-dimensional space-time chaotic signal matrix is ​​shown, where the rows correspond to the time dimension chaos and the columns correspond to the space dimension chaos.

[0046] The information to be sent is grouped, wherein the space dimension information group is used to generate the chaotic keying index value of the spatiotemporal chaotic space dimension, and the other part of the time dimension information group is directly sequence spread spectrum sent with the quantized sequence of the spatiotemporal chaotic time dimension signal determined by the index value.

[0047] Step 3: The spatiotemporal chaos generator at the information receiving end generates a spatiotemporal chaotic two-dimensional signal matrix according to the same initial parameters as those at the transmitting end:

[0048] The receiving end uses the same initial parameters as the sending end to generate the spatiotemporal chaotic sequence:

[0049] , .

[0050] Step 4: After the spatiotemporal chaotic two-dimensional signal matrix in step 3 is quantized, it is processed with the received signal to determine the index value of the spatial dimension information demodulation, such as Figure 4 As shown:

[0051] Step 4-1: quantize the spatiotemporal chaotic sequence generated by the receiving end and compare it with the received signal The cycle is Correlation square accumulation operation:

[0052] ;

[0053] Step 4-2: Compare the results of the cumulative operation and determine the maximum value as the index value of the sending space-time chaos space dimension. , and demodulate it to get the spatial dimension information group .

[0054] Step 5: Based on the index value determined in step 4, the corresponding time-dimensional chaotic sequence and the received signal are subjected to integral cleaning and despreading, and the space-time dimension information is demodulated:

[0055] Using index values The corresponding spatiotemporal chaotic time dimension sequence For receiving signal After despreading, the time dimension information group can be demodulated. .

[0056] In summary, the receiving end uses a chaotic signal generator with the same initial parameters as the transmitting end to generate a two-dimensional chaotic signal in space and time. The quantized sequence of all time-dimensional chaotic signals is correlated with the received signal by square accumulation operation. Then, the comparator is used to determine the spatial dimension index value corresponding to the maximum value to achieve spatial dimension information demodulation. Finally, the time-dimensional chaotic sequence corresponding to the index value is despread and integrated and cleaned with the received signal to achieve space-time information demodulation.

[0057] The present invention also provides a satellite communication physical layer symbol security enhancement system based on spatiotemporal chaos, comprising the following modules:

[0058] Transmitting module: used to generate a spatiotemporal chaotic two-dimensional signal matrix according to the initial parameters of the spatiotemporal chaotic generator at the information transmitting end; group the information to be transmitted, use part of the information groups to generate the chaotic keying index value of the spatiotemporal chaotic space dimension, and use the other part of the information groups and the quantized sequence of the spatiotemporal chaotic time dimension signal determined by the index value to perform direct sequence spread spectrum transmission;

[0059] Receiving module: It is used to generate a spatiotemporal chaotic two-dimensional signal matrix based on the same initial parameters as the transmitting end by the spatiotemporal chaotic generator at the information receiving end, and quantize the spatiotemporal chaotic two-dimensional signal matrix and process it with the received signal to determine the index value of spatial dimension information demodulation, perform integral cleaning processing on the corresponding time dimension chaotic sequence and the received signal to demodulate the spatiotemporal dimension information.

[0060] The present invention combines space-time chaos with spread spectrum and chaotic keying, uses the space dimension of space-time chaos to perform chaotic keying of information, uses the time dimension to perform direct sequence spread spectrum of information, and uses the same space-time chaos mechanism to reduce the complexity of implementation while achieving the security enhancement of the codewords of the spread dimension. On the other hand, in this method, not only the time dimension signal of the space-time chaos carries information, but also the space dimension signal carries information. Therefore, on the basis of providing anti-interference and concealment capabilities, a higher frequency band utilization rate than spread spectrum is obtained. Based on the satellite communication physical layer codeword security enhancement method based on space-time chaos of the present invention, the frequency band utilization rate can be improved while improving the communication security.

[0061] The above-described embodiment only expresses one implementation method of the present application, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present application, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of this application shall be based on the attached claims.

Claims

1. A satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos, characterized in that: The following steps are involved: Step 1: The spatiotemporal chaos generator at the information sending end generates a spatiotemporal chaotic two-dimensional signal matrix according to initial parameters; Step 2: Group the information to be sent, use part of the information group to generate the chaotic keying index value of the space-time chaotic space dimension, and use the other part of the information group and the quantized sequence of the space-time chaotic time dimension signal determined by the index value to perform direct sequence spread spectrum transmission: The i-th message to be sent Group them into: include bits of information space-dimensional information group element , , and the corresponding relationship with the original information grouping is: , space dimension information group ; include bit information of the time dimension , , and the corresponding relationship with the original information grouping is: , time dimension information group ; The chaotic keying index value in step 2 is specifically: Based on spatial dimension information group Determining the index value of the space dimension of spatiotemporal chaos : ； The other part of the information group and the quantized sequence of the spatiotemporal chaotic time dimension signal determined by the index value are subjected to direct sequence spread spectrum, specifically: According to the index value The corresponding spatiotemporal chaotic time dimension sequence and time dimension information group are sent by direct sequence spread spectrum: ； ； Among them, mod() represents the modular operation, Indicates floor operation; Step 3: The spatiotemporal chaos generator at the information receiving end generates a spatiotemporal chaotic two-dimensional signal matrix according to the same initial parameters as those at the transmitting end; The spatiotemporal chaos generator in step 1 and step 3 adopts a one-way coupled image lattice model, and its expression is: ； Its boundary conditions are: ； in, represents the coupling coefficient, n represents the discrete time sequence number, i represents the grid number, L is a positive integer, representing the number of spatial grids, represents the spatiotemporal chaos value of the ith grid at time n, Represents Logistic mapping, when the parameter When , the Logistic map is a one-dimensional chaotic map: ， ； The receiving end uses the same initial parameters as the sending end to generate a spatiotemporal chaotic sequence: ， ； Step 4: After the spatiotemporal chaotic two-dimensional signal matrix in step 3 is quantized, it is processed with the received signal to determine the index value of the spatial dimension information demodulation, which is specifically: Step 4-1: quantize the spatiotemporal chaotic sequence generated by the receiving end and compare it with the received signal The cycle is Correlation square accumulation operation: ； Step 4-2: Compare the results of the cumulative operation and determine the maximum value as the index value of the sending space-time chaos space dimension. , and demodulate it to get the spatial dimension information group ; Step 5: Based on the index value determined in step 4, the corresponding time-dimensional chaotic sequence and the received signal are subjected to integral cleaning processing for despreading, and the space-time dimension information is demodulated.

2. The satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos according to claim 1 is characterized in that: The spatiotemporal chaotic two-dimensional signal matrix in step 1 is specifically: The spatiotemporal chaos generator is based on the initial value , , Generate a sequence: , quantize it and generate a spatiotemporal chaotic sequence: ; Among them, k is the time dimension serial number, j is the space dimension grid number, and L is , is the number of elements in the spatial dimension information group after the bit information is grouped.

3. The satellite communication physical layer symbol security enhancement method based on spatiotemporal chaos according to claim 1 is characterized in that: The step 5 of performing the time-space dimension information demodulation is specifically as follows: Using index values The corresponding spatiotemporal chaotic time dimension sequence For receiving signal After despreading, the time dimension information group can be demodulated. .

4. A satellite communication physical layer symbol security enhancement system based on spatiotemporal chaos, executing the method described in claim 1, characterized in that: Includes the following modules: Transmitting module: used to generate a spatiotemporal chaotic two-dimensional signal matrix according to the initial parameters of the spatiotemporal chaotic generator at the information transmitting end; group the information to be transmitted, use part of the information groups to generate the chaotic keying index value of the spatiotemporal chaotic space dimension, and use the other part of the information groups and the quantized sequence of the spatiotemporal chaotic time dimension signal determined by the index value to perform direct sequence spread spectrum transmission; Receiving module: It is used to generate a spatiotemporal chaotic two-dimensional signal matrix based on the same initial parameters as the transmitting end by the spatiotemporal chaotic generator at the information receiving end, and quantize the spatiotemporal chaotic two-dimensional signal matrix and process it with the received signal to determine the index value of spatial dimension information demodulation, perform integral cleaning processing on the corresponding time dimension chaotic sequence and the received signal to demodulate the spatiotemporal dimension information.

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