Orthogonal pseudo-random frequency hopping sequence generation method combining time domain synchronization with encryption

Abstract

The invention relates to the technical field of frequency hopping communication, and discloses a method for generating an orthogonal pseudo-random frequency hopping sequence by combining time domain synchronization with encryption, which comprises the following steps of: S1, obtaining an initial value: obtaining an N-bit TOD initial value from TOD information; s2, calculating a sequence: carrying out progressive increase operation on the TOD initial value according to a frequency hopping time interval to obtain a TOD sequence value; s3, calculating a ciphertext: taking the TOD sequence value as a plaintext input of an encryptor, and encrypting with a preset key to obtain an N-bit ciphertext; and S4, frequency hopping code division: taking a group of T-bit numerical values from the N-bit ciphertext as frequency hopping codes, wherein T is a preset bit number. The method mainly adopts a method of combining time domain synchronization and AES encryption, has the characteristics of strong interception resistance, high transmission reliability and strong anti-interference capability, avoids a periodic problem or an initial value dependence weakness possibly existing in a traditional pseudo-random sequence, adopts an encryptor to carry out multi-round encryption transformation on a TOD sequence, generates a ciphertext as a basis of a frequency hopping code, and improves the frequency hopping efficiency. And the anti-cracking capability of the sequence is obviously enhanced.

Description

Technical Field

[0001] This invention relates to the field of frequency hopping communication technology. Background Technology

[0002] With the development of wireless communication technology, it plays an increasingly important role in national defense, government agencies, commerce, and civilian fields, bringing huge social and economic benefits. Frequency hopping communication (FHSS), as a key anti-jamming technology, is widely used in military, IoT, and 5G fields, but it still has the following problems: a) Anti-interception defects: Insufficient pseudo-randomness of frequency hopping sequences leads to increased predictability of frequency hopping patterns, allowing the enemy to reconstruct the frequency change pattern through limited sampling; b) Deterioration of transmission reliability: The probability of frequency collision increases exponentially with the weakening of pseudo-randomness, causing co-channel interference and inter-symbol crosstalk, ultimately causing the bit error rate to exceed the communication availability threshold; c) Lack of anti-jamming effectiveness: Degradation of orthogonality between sequences causes a sharp drop in multi-user interference tolerance. Summary of the Invention

[0003] The purpose of this invention is to provide a method for generating orthogonal pseudo-random frequency hopping sequences that combines time-domain synchronization with encryption. This method deeply integrates time-domain synchronization with encryption algorithms, enabling the generation of frequency hopping sequences with high randomness, orthogonality, and security.

[0004] To address the aforementioned technical problems, this invention provides a method for generating orthogonal pseudo-random frequency hopping sequences that combines time-domain synchronization with encryption, comprising the following steps: S1. Obtain initial values: Obtain N initial values ​​for TOD from the TOD information; S2. Calculate the sequence: Increment the initial value of TOD according to the frequency hopping time interval to obtain the TOD sequence value; S3, Calculate Ciphertext: Use the TOD sequence value as the plaintext input of the encryptor and encrypt it with a preset key to obtain N bits of ciphertext; S4, Frequency hopping code: Take a set of T bits from the N-bit ciphertext as the frequency hopping code, where T is the preset number of bits.

[0005] The value of N is 128.

[0006] The preset key is N bits.

[0007] The encryptor is an AES encryptor.

[0008] The TOD information is real-time TOD.

[0009] The AES encryptor uses the AES-128 algorithm.

[0010] The AES encryptor undergoes N rounds of transformation during encryption.

[0011] The preset key is obtained from the user's address.

[0012] Compared to existing technologies, this invention primarily employs a combination of time-domain synchronization and AES encryption, featuring strong anti-interception capabilities, high transmission reliability, and strong anti-interference capabilities. It utilizes Time-of-Demand (TOD) information as an initial value to ensure the uniqueness and unpredictability of the sequence. Leveraging the inherent high entropy and continuity of time information, it avoids the periodicity issues or initial value dependence weaknesses that may exist in traditional pseudo-random sequences. An encryptor performs multiple rounds of encryption transformations on the TOD sequence, generating ciphertext as the basis for the frequency-hopping code, significantly enhancing the sequence's anti-cracking capabilities and avoiding linear attacks or prediction vulnerabilities that may exist in traditional pseudo-random sequences. The preset key is generated based on the user address, achieving a unique key for each user and further personalizing the sequence generation process. This mechanism greatly enhances the system's anti-cooperative interference capabilities and supports multi-user orthogonal operations. The design of extracting the frequency-hopping code from the ciphertext ensures the uniform distribution and redundancy of the frequency slot index, improving the sequence's orthogonality and collision resistance.

[0013] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0014] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0015] Figure 1 This is a flowchart illustrating at least one embodiment of the present invention; Figure 2 yes Figure 1 A flowchart illustrating the AES encryption algorithm. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this invention. The embodiments can be combined with and referenced by each other without contradiction.

[0017] Example 1 like Figure 1 The method for generating orthogonal pseudo-random frequency hopping sequences by combining time-domain synchronization and encryption, as shown, includes the following steps: S1. Obtain initial values: Obtain N initial values ​​for TOD from the TOD information; S2. Calculate the sequence: Increment the initial value of TOD according to the frequency hopping time interval to obtain the TOD sequence value; S3, Calculate Ciphertext: Use the TOD sequence value as the plaintext input of the encryptor and encrypt it with a preset key to obtain N bits of ciphertext; S4, Frequency hopping code: Take a set of T bits from the N-bit ciphertext as the frequency hopping code, where T is the preset number of bits.

[0018] Example 2 Based on Example 1, N takes the value 128.

[0019] Furthermore, the default key is N bits.

[0020] Furthermore, the TOD information is real-time TOD.

[0021] Furthermore, the T-digit value.

[0022] Example 3 Based on Example 1, the encryptor is an AES encryptor.

[0023] Furthermore, the AES encryptor uses the AES-128 algorithm.

[0024] Furthermore, the AES encryptor undergoes N transformations during encryption.

[0025] Furthermore, the preset key is obtained using the user's address.

[0026] Example 4 In conjunction with the above embodiments, the AES data encryption standard is used as the encryption method. A 128-bit TOD initial value starts a 128-bit counter, which generates a 128-bit monotonically increasing TOD sequence according to the frequency hopping code time interval, serving as the plaintext input for the DES encryptor; a 128-bit input key (user address); and so on. Figure 2 The AES encryption outputs 128 bits of ciphertext. Six bits are taken from this ciphertext (representing 64 available frequency slots) to form 64 frequency hopping codes from 0 to 63. For example... Figure 1As shown, the 128-bit TOD initial value is a binary number obtained by converting the actual start time of each communication according to a certain format; the 128-bit TOD sequence is a digital sequence that starts with the 128-bit TOD initial value and monotonically increases cyclically according to the frequency hopping code hopping rate as the counting unit. The advantage of this scheme is that it allows users to maintain and adjust synchronization with a highly stable and high-precision clock. By injecting the received transmitter's TOD initial value, the receiver within the network can quickly achieve and adjust synchronization.

[0027] This embodiment was used to generate a three-channel frequency hopping sequence for a certain frequency point of 1000 and to perform communication simulation. The following performance indicators are shown in Table 1: Table 1-1000 Frequency Point Multichannel Frequency Hopping Sequence Performance Indicators Statistics Table Using this embodiment to generate a three-channel frequency hopping sequence at a frequency of 10,000 points and performing communication simulation, the following performance indicators are shown in Table 2: Table 2 - Statistical Table of Performance Indicators of Multichannel Frequency Hopping Sequences at Frequency Points 10000 Therefore, based on this embodiment, it is possible to achieve completely independent frequency points for each channel, frequency point distribution without periodic repetition, full coverage, uniformity test for all three channels, and stable curve slope.

[0028] Those skilled in the art will understand that the above embodiments can be modified in form and detail in practical applications without departing from the spirit and scope of the invention.

Claims

1. A method for generating orthogonal pseudo-random frequency hopping sequences combining time-domain synchronization and encryption, characterized in that, Includes the following steps: S1. Obtain initial values: Obtain N initial values ​​for TOD from the TOD information; S2. Calculate the sequence: Increment the initial value of TOD according to the frequency hopping time interval to obtain the TOD sequence value; S3, Calculate Ciphertext: Use the TOD sequence value as the plaintext input of the encryptor and encrypt it with a preset key to obtain N bits of ciphertext; S4, Frequency hopping code: Take a set of T bits from the N-bit ciphertext as the frequency hopping code, where T is the preset number of bits.

2. The method for generating orthogonal pseudo-random frequency hopping sequences combining time-domain synchronization and encryption as described in claim 1, characterized in that, The value of N is 128.

3. The method for generating orthogonal pseudo-random frequency hopping sequences combining time-domain synchronization and encryption as described in claim 1, characterized in that, The preset key is N bits.

4. The method for generating orthogonal pseudo-random frequency hopping sequences by combining time-domain synchronization and encryption as described in claim 1, characterized in that, The encryptor is an AES encryptor.

5. The method for generating orthogonal pseudo-random frequency hopping sequences by time-domain synchronization combined with encryption as described in claim 1, characterized in that, The TOD information is real-time TOD.

6. The method for generating orthogonal pseudo-random frequency hopping sequences combining time-domain synchronization and encryption as described in claim 4, characterized in that, The AES encryptor uses the AES-128 algorithm.

7. The method for generating orthogonal pseudo-random frequency hopping sequences combining time-domain synchronization and encryption as described in claim 1, characterized in that, The AES encryptor undergoes N rounds of transformation during encryption.

8. The method for generating orthogonal pseudo-random frequency hopping sequences combining time-domain synchronization and encryption as described in claim 1, characterized in that, The preset key is obtained from the user's address.

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