Collision zone-free frequency hopping sequence set construction method and system in '1 + M' form

Abstract

The invention discloses a method and a system for constructing a collision-zone-free frequency hopping sequence set in a '1 + M' form, and mainly solves the problems that in the prior art, frequency point collision is generated when time delay deviation is large, and new collision is introduced in a secondary mapping or expansion process. The implementation scheme of the method comprises the following steps: generating two frequency hopping sequence set sums with different collision-free regions by adopting a collision-free region construction method; combining the two sequence sets to obtain 1 + M frequency hopping sequences; segmenting 1 + M frequency hopping sequences according to a set length to obtain sequence segments of the first sequence; setting random numbers which are uniformly distributed between 0 and 1, and constructing a zeroth dynamic frequency slot set and a first dynamic frequency slot set by utilizing the sum of the frequency slot sets, the size of the total frequency slot set and the sum of frequency slot elements in the total frequency slot set; and performing frequency slot mapping by using the sum sequence segment to obtain a collision-zone-free frequency hopping sequence set consisting of 1 + M frequency hopping sequences. According to the method, effective expansion of the collision-free area can be realized while the consistency of the sequence structure is kept, and the method can be used for orthogonal frequency hopping networking when the relative time delay difference between users is relatively large.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and specifically relates to a method for constructing a collision-free frequency hopping sequence set, which can be used for orthogonal frequency hopping networking when the relative time delay difference between users is large. Background Technology

[0002] Frequency hopping communication is a commonly used wireless communication method that improves communication reliability and security by hopping signals across multiple frequency bands. In frequency hopping communication systems, frequency hopping sequence analysis and design are the core technologies. An ideal frequency hopping sequence should have good Hamming correlation characteristics. Frequency hopping communication systems using collision-free frequency hopping sequences allow for a certain synchronization delay between users, avoiding collisions between multiple users within the delay range and eliminating the effects of multi-user multiple access interference. Therefore, they have a wide range of applications.

[0003] Patent document with application number CN202211354471.3 discloses a method for constructing a collision-free region frequency hopping sequence set, which first uses a local key to encrypt TOD information to generate a base sequence. Then expand the vector through the sequence. base sequence Expand the elements in the sequence to obtain M sequences of length . Sequence families composed of orthogonal sequences , Finally, for the frequency hopping sequence set Elements at different positions are superimposed with different values, and frequency mapping is used. This method yields M collision-free frequency hopping sequences. While it guarantees collision-free characteristics between sequences under ideal conditions, it only creates a single collision-free zone within the sequence. In practical orthogonal frequency hopping network applications, there are often significant relative latency differences between user terminals. When the latency deviation is large, this single collision-free zone cannot cover the latency differences of all users, leading to frequency collisions potentially occurring in the frequency hopping sequences of some users even with latency offsets.

[0004] Patent application CN202110063984.8 discloses a design method for a two-level NHZ / LHZ frequency hopping sequence in a power communication system. The implementation scheme is as follows: First, a collision-free zone frequency hopping sequence set R is selected. Based on R, a first frequency hopping sequence set R1 and a second frequency hopping sequence set R2 are constructed. The final NHZ / LHZ frequency hopping sequence is obtained from the constructed R1 and R2. R is... This method uses complex mathematical transformations to expand or reconstruct an existing NHZ sequence set. However, the two key operations it employs, integer division and modular arithmetic, are mathematically "many-to-one mappings," which irreversibly compress and lose information from the original sequence, thereby destroying the collision-free property of the original NHZ sequence and introducing new collisions. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and propose a method and system for constructing a collision-free zone frequency hopping sequence set in the form of "1+M" to avoid the problem of frequency point collisions for some users when the time delay deviation is large and the introduction of new collisions when constructing collision-free sequences.

[0006] The technical approach to achieving the objective of this invention is as follows: by designing a sequence with a larger collision-free zone to solve the problem of frequency collisions for some users when the time delay deviation is large; by generating a collision-free zone frequency hopping sequence set, generating a dynamic frequency slot set, and frequency slot mapping to avoid introducing new collisions when constructing a collision-free sequence.

[0007] Based on the above technical concept, the technical solution of the present invention includes:

[0008] 1. A method for constructing a collision-free region frequency hopping sequence set in the form of "1+M", characterized in that it includes:

[0009] (1) Two frequency hopping sequence sets with different collision-free regions are generated using the collision-free region construction method, namely:

[0010] Collision-free zone frequency hopping sequence set , Collision-free zone frequency hopping sequence set ,

[0011] in, for The size of the frequency gap, The length of the sequence in the sequence set. for The size of the collision-free zone

[0012] for Frequency gap size, for The number of sequences in the middle, for The size of the collision-free region in the sequence. ;

[0013] (2) Combine the sequences in the two sequence sets above to obtain 1+M frequency hopping sequences. : ,

[0014] in For the first The first in the sequence One element, , ,and ;

[0015] (3) The two collision-free zone frequency hopping sequences mentioned above are arranged according to a set length. Segmentation, to obtain the first Sequence segment of the sequence: , , The total number of segments into which a sequence is divided;

[0016] (4) Let A random number uniformly distributed between 0 and 1. To determine the total size of the frequency gap set for the final construction of the frequency hopping sequence set, for The frequency gap set, in which For the first One available frequency band, ; and utilize the aforementioned , , , and Construction satisfies: The zeroth dynamic frequency gap set and the first dynamic frequency slot set ;

[0017] (5) Utilizing the aforementioned frequency gap set , and sequence segments By performing frequency slot mapping, a collision-free frequency hopping sequence set consisting of 1+M frequency hopping sequences is obtained: .

[0018] Furthermore, in step (4), the method utilizes the aforementioned method. , , , and Construct satisfying The zeroth dynamic frequency gap set and the first dynamic frequency slot set Its implementation includes:

[0019] (4a) Set the zeroth dynamic frequency gap First dynamic frequency slot set The element is denoted as :

[0020] (4b) Set the zeroth dynamic frequency gap First dynamic frequency slot set and remaining frequency slot set elements in exist The initial state is set to ,in For frequency slot set Available frequency slots;

[0021] (4c) According to and , Relationship and For different ranges, different iteration methods are selected to update the elements of the three frequency gap sets, and the zeroth dynamic frequency gap set is obtained through iteration. First dynamic frequency slot set and remaining frequency slot set .

[0022] 2. A system for constructing a collision-free frequency hopping sequence set in the form of "1+M", characterized in that it comprises:

[0023] The base sequence generation module receives the local key KEY and time synchronization information TOD, encrypts the known frequency hopping sequence, and generates the base sequence. ;

[0024] The collision-free region construction module is used to construct two frequency-hopping sequence sets with different collision-free region sizes based on the base sequence. This includes expanding the base sequence, superimposing offsets, and performing frequency mapping to obtain... Collision-free zone frequency hopping sequence set and Collision-free zone frequency hopping sequence set ,in for The size of the frequency gap set, for The size of the frequency gap set, The length of the sequence in the sequence set. for The number of sequences in the middle, for The size of the collision-free zone for The size of the collision-free zone;

[0025] Sequence combination module, used to combine and The sequences from the two collision-free frequency hopping sequence sets are combined according to a preset rule to generate 1+M initial frequency hopping sequences. ;

[0026] The sequence segmentation module is used to segment sequences according to a set length. Each frequency hopping sequence is divided into sequence segments. ;

[0027] The dynamic frequency gap set generation module is used to generate frequency gap sets based on the total frequency gap set size. , The size of the frequency gap set and The size of the frequency gap set Available frequency slots in the total frequency slot set Generate the zeroth dynamic frequency gap set First dynamic frequency slot set and remaining frequency slot set initial state , and And update according to the iteration rules to obtain the zeroth dynamic frequency slot set. First dynamic frequency slot set and remaining frequency slot set ;

[0028] The frequency gap mapping module is used to map the frequency gaps according to the sequence position. Zero dynamic frequency gap set and the first dynamic frequency slot set Elements of frequency gap concentration Mapped to the corresponding frequency hopping sequence element Finally, a collision-free zone frequency hopping sequence set in the form of "1+M" is generated. .

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] Firstly, the present invention has a frequency hopping sequence with a large collision-free region in the constructed frequency hopping sequence set. This sequence has a larger collision-free region, which can cover a larger time delay deviation. It can enable the primary user and any secondary user to maintain orthogonality within a larger time delay range, thus solving the problem that existing methods still produce frequency point collisions when the time delay deviation is large.

[0031] Secondly, this invention divides the frequency gaps into different ranges and adopts a dynamic construction method of "internal iteration within the same range" and "no cross-region update" when constructing the frequency hopping sequence set. This ensures that the entire frequency gap mapping process remains consistent with the original collision-free region structure, does not destroy the Hamming correlation properties of the original sequence, and avoids the introduction of new collision problems in the secondary mapping or expansion process of existing methods.

[0032] Simulation results show that the present invention achieves effective expansion of the collision-free region while maintaining the consistency of the sequence structure, and can meet the orthogonal frequency hopping networking requirements under conditions of large relative time delay differences. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating the implementation of the "1+M" form collision-free region frequency hopping sequence set construction method of the present invention.

[0034] Figure 2 This is a block diagram of the sequence segmentation structure in the method of the present invention;

[0035] Figure 3 This is a block diagram of the dynamic frequency gap set structure in the method of the present invention;

[0036] Figure 4 This is a block diagram of the system for constructing a collision-free frequency hopping sequence set in the form of "1+M" according to the present invention;

[0037] Figure 5 This refers to the "1+M" form collision-free frequency hopping sequence set constructed in this invention. Hamming correlation distribution map;

[0038] Figure 6 The "1+M" form collision-free frequency hopping sequence constructed in this invention and frequency hopping sequence set Hamming autocorrelation distribution plot;

[0039] Figure 7 The "1+M" form collision-free frequency hopping sequence constructed in this invention and frequency hopping sequence set The distribution map of Hamming cross-correlation. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative effort should all fall within the protection scope of the present invention.

[0041] It should be noted that the step numbers in the specification and claims of this invention are only for the purpose of clearly describing the embodiments of this invention and facilitating understanding, and their order is not limited.

[0042] Example 1: A method for constructing a collision-free frequency hopping sequence set in the form of "1+M".

[0043] Reference Figure 1 The implementation steps of this example include the following:

[0044] Step 1: Use the collision-free region construction method to generate two frequency hopping sequence sets with different collision-free regions.

[0045] (1.1) Encrypt the known frequency hopping sequence using the local key KEY and time synchronization information TOD to generate the base sequence. ,in, For the first in the sequence One element, ;

[0046] (1.2) Expanding vectors through sequences base sequence Expanding the elements in the sequence yields a sequence family consisting of M orthogonal sequences of length L. :

[0047] ,

[0048] in For the extended vector, the first One element, , For the first in the sequence family The first of the sequence One element;

[0049] (1.3) For sequence families Different values ​​are superimposed on elements at different positions, and frequency mapping is used to achieve this. get The collision-free zone is The frequency hopping sequence forms Collision-free zone frequency hopping sequence set ;

[0050] (1.4) Base sequence Elements at different positions are superimposed with different values, and frequency mapping is used. The collision-free zone is obtained as The frequency hopping sequence forms Collision-free zone frequency hopping sequence set ,in for The size of the frequency gap, for Frequency gap size.

[0051] Step 2: Based on the two sequence sets mentioned above, obtain 1+M frequency hopping sequences. .

[0052] Will Collision-free zone frequency hopping sequence set The sequence and Collision-free zone frequency hopping sequence set The sequences in the given information are combined, where:

[0053] The 0th sequence is taken from Frequency hopping sequence set, the remaining sequences are taken from Frequency hopping sequence set, i.e. Arrange the sequences in these two frequency hopping sequence sets in order to obtain 1+M frequency hopping sequences. : ,

[0054] in For the first The first in the sequence One element, .

[0055] Step 3: Process 1+M frequency hopping sequences Divide into segments.

[0056] To facilitate subsequent frequency mapping, the obtained 1+M frequency hopping sequences need to be... Segment the structure and ensure that the segment boundaries are offset from the collision-free zone boundaries, so that each segment falls completely within the safe range and avoids damaging the zero-correlation structure.

[0057] Reference Figure 2 This step is implemented as follows:

[0058] Set segment length Set the length of the segment to the maximum size of the collision-free region of the two sequences plus 1, that is... ;

[0059] Based on the length of the segments , with a length of The sequence is arranged by each segment Each element is divided into: One sequence segment;

[0060] No. The first of the sequence The sequence segment is composed of the first sequence segment. To the Composed of elements, thus forming A sequence of equal length :

[0061] , .

[0062] Step 4: Construct the zeroth dynamic frequency gap set and the first dynamic frequency slot set .

[0063] To ensure that the boundary relationships of the original collision-free regions are maintained during subsequent segment-by-segment frequency slot mapping and to avoid introducing new frequency point collisions during the mapping process, it is necessary to construct a zeroth dynamic frequency slot set that can be updated with each segment and whose category structure remains consistent. and the first dynamic frequency slot set .

[0064] Reference Figure 3 This step is implemented as follows:

[0065] (4.1) Settings Individual and total frequency gap set The frequency gap set with the same number of elements Each frequency gap set There are in China elements, represented as ,in Indicates the first The first frequency gap set One element;

[0066] (4.2) According to and The size of the frequency gap set Divided into three segments, the zeroth dynamic frequency gap set before the element update. The first dynamic frequency slot set before element update The remaining frequency slot set before element update The segmentation method is as follows:

[0067] Pick From the 0th to the 1st The elements that make up the zeroth dynamic frequency gap set before the element update. ,

[0068] Pick The Middle To the The elements constitute the first dynamic frequency gap set before the element update. ,

[0069] Pick The Middle To the Each element constitutes the remaining frequency gap set before the element is updated. ,

[0070] To facilitate symbol representation during subsequent slot set updates, all three slot sets will use the elements in the slot set. The representation is as follows:

[0071] ;

[0072] The above method of constructing the frequency slot set is as follows: At that time, for each frequency gap set Both select frequency slot sets Center front The elements constitute the zeroth dynamic frequency gap set before the element update. After taking After taking the first element, continue taking... The elements constitute the first dynamic frequency gap set before the element update. Then, the remaining elements are used to form the remaining frequency slot set before the element update. Since the elements in each group do not overlap and can cover the entire frequency band during the construction process, therefore... When the above frequency slot sets all satisfy , ;

[0073] (4.3) Set the zeroth dynamic frequency gap set First dynamic frequency slot set and remaining frequency slot set exist initial state at time , and Conditions to be met: , This ensures that the three frequency slot sets do not overlap when the frequency slot sets are updated subsequently.

[0074] (4.4) Based on the above frequency band concentrations, This attribute only represents elements within a frequency slot set and has no actual frequency slot meaning; it is used to satisfy... , Conditions, frequency slot set exist Initial state elements at time Set as ,in For frequency slot set Available frequency slots in, at this time ;

[0075] Because the above construction process is to The elements in the array are divided into the following order: , and Therefore, the above frequency gap set must satisfy... , And because Then the initial state can be determined. , and satisfy , ,at this time , and It can be represented as:

[0076] ;

[0077] ;

[0078] ;

[0079] To facilitate subsequent updates and symbolic representation of the frequency slot set, the elements of the frequency slot set in the initial state are uniformly denoted as... After adopting this unified representation, the three frequency slot sets can be written as:

[0080] ;

[0081] ;

[0082] ;

[0083] Here are the initial state elements Only need to meet , The value is not unique;

[0084] (4.5) Based on a random number uniformly distributed between 0 and 1 Element position and the size of the frequency gap set , Set the internal elements of the frequency gap set Update mode:

[0085] if ,and Then the next state element Compared to the previous state, the first element correspond;

[0086] if ,exist When, the next state element Compared to the previous state, the first element Correspondingly, in When, the next state element Compared to the previous state, the first element correspond;

[0087] if ,exist When, the next state element Compared to the previous state, the first element Correspondingly, in When, the next state element Compared to the previous state, the first element correspond;

[0088] if ,and Then the next state element Compared to the previous state, the first element correspond;

[0089] if ,and Then the next state element Compared to the previous state, the first element correspond;

[0090] if ,and Then the next state element Compared to the previous state, the first element correspond;

[0091] The above element update modes can be represented as follows:

[0092] ;

[0093] (4.6) According to When the above frequency slots are concentrated, This attribute only represents elements within a slot set and has no actual slot meaning; it is obtained through a slot set. , and Initial state elements with frequency gap significance Update using the above element update mode Time-frequency slot set elements in , making Time-frequency slot set elements in Each can represent the corresponding frequency slot;

[0094] (4.7) Based on the updated slot set elements ,Pick The elements of time constitute the zeroth dynamic frequency gap set ,Pick The elements of time constitute the first dynamic frequency gap set .

[0095] Step 5, based on the frequency slot set , and sequence segments Frequency slot mapping is performed to obtain a set of collision-free frequency hopping sequences in the form of "1+M".

[0096] To effectively convert symbolic sequence segments into frequency-hopping sequences with frequency slot meaning while maintaining the collision-free region structure, and to achieve dynamic and ordered allocation of frequency slots, a frequency slot mapping method based on dynamic frequency slot sets is required, which is implemented as follows:

[0097] (5.1) Based on the frequency slot set , and sequence segments Set the frequency slot mapping mode:

[0098] (5.1.1) Generate the 0th sequence:

[0099] when First, based on the position of the generated sequence element. Size determines segment position Value: This allows for the determination of the frequency slot set of the mapped frequency. and :

[0100] Then divide the element values ​​in the segmented sequence As selected frequency slot set element In Select the element Corresponding to the 0th sequence element In the process, we obtain the 0th sequence: ;

[0101] (5.1.2) Generate the remaining M sequences:

[0102] when At that time, firstly, based on the position of the generated sequence element... Size determines segment position Value: This allows for the determination of the frequency slot set of the mapped frequency. and ;

[0103] Then divide the element values ​​of the segmented sequence Plus As selected frequency slot set element In Select the element Corresponding to the first of the remaining M sequences element From this, we obtain the remaining M sequences: ;

[0104] The first two cases generated above element Its formula is expressed as:

[0105] ;

[0106] (5.2) Based on the obtained 1+M frequency hopping sequences , sort the sequence Arranged sequentially, we obtain a set of collision-free zone frequency hopping sequences in the form of "1+M": .

[0107] Example 2: Construction System of Collision-Free Frequency Hopping Sequence Set in "1+M" Form

[0108] Reference Figure 4 This embodiment includes: a base sequence generation module 1, a collision-free region construction module 2, a sequence combination module 3, a sequence segmentation module 4, a dynamic frequency gap set generation module 5, and a frequency gap mapping module 6. The collision-free region construction module 2 includes a sequence extension submodule 21 and a collision-free region construction submodule 22; the dynamic frequency gap set generation module 5 includes an initial dynamic frequency gap set generation submodule 51 and a dynamic frequency gap set iteration submodule 52; and the frequency gap mapping module 6 includes a zeroth sequence mapping submodule 61 and an Mth sequence mapping submodule 62.

[0109] The working principle of the entire system is as follows:

[0110] The base sequence generation module 1 is used to receive the local key KEY and time synchronization information TOD, encrypt the known frequency hopping sequence, and generate the base sequence. and the base sequence The collision-free region construction module 2 is used to construct the collision-free region frequency hopping sequence set.

[0111] The collision-free region construction module 2 is used to construct based on the base sequence. Construct two sets of frequency-hopping sequences with different collision-free region sizes. The sequence expansion submodule 21 is based on the sequence expansion vector. base sequence Expand into M orthogonal sequences of length L, forming a sequence family. The collision-free region construction submodule consists of 22 pairs of sequence families. Elements and base sequences The elements in the array are superimposed with different offsets and frequency-mapped to obtain... Collision-free zone frequency hopping sequence set and Collision-free zone frequency hopping sequence set In the formula for The size of the frequency gap set, for The size of the frequency gap set, The length of the sequence in the sequence set. for The number of sequences in the middle, for The size of the collision-free zone for The size of the collision-free zone and the obtained Collision-free zone frequency hopping sequence set and Collision-free zone frequency hopping sequence set The sequence is fed into sequence combination module 3 for sequence combination.

[0112] The sequence combination module 3 is used to combine the sequences into a single sequence. and The sequences from the two collision-free frequency hopping sequence sets are combined according to a preset rule to generate 1+M initial frequency hopping sequences. The sequence is then sent to sequence segmentation module 4 for sequence segmentation.

[0113] The sequence segmentation module 4 is used to segment according to a set segment length. Each frequency hopping sequence is divided into sequence segments. The obtained sequence segment is then sent to the frequency slot mapping module 6 for frequency slot mapping to select mapping elements;

[0114] The dynamic frequency gap set generation module 5 is used to generate frequency gap sets based on the total frequency gap set size. , The size of the frequency gap set , The size of the frequency gap set Available frequency slots in the total frequency slot set Construct the zeroth dynamic frequency gap set and the first dynamic frequency slot set The initial dynamic frequency slot set generation submodule 51 generates the initial state of the frequency slot set, and sets the zeroth dynamic frequency slot set... First dynamic frequency slot set and remaining frequency slot set initial state , and The middle element is set to The dynamic frequency slot set iteration submodule 52 provides iteration rules, according to... and , By selecting different iteration methods to update the slot set elements, the zeroth dynamic slot set can be obtained. First dynamic frequency slot set and remaining frequency slot set and the generated zeroth dynamic frequency gap set and the first dynamic frequency slot set The frequency slot mapping module 6 provides frequency slot mapping elements;

[0115] The frequency gap mapping module 6 is used to map according to the sequence position. Zero dynamic frequency gap set and the first dynamic frequency slot set Generate a collision-free zone frequency hopping sequence set in the form of "1+M". The zeroth sequence mapping submodule 61 is used to construct the 0th sequence, and the M-sequence mapping submodule 62 is used to construct the remaining M sequences, which are elements of the frequency slot set. Mapped to the corresponding frequency hopping sequence element Finally, a collision-free zone frequency hopping sequence set in the form of "1+M" is generated. .

[0116] It should be noted that the above functional modules can be implemented, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, they can be implemented, in whole or in part, as a program instruction product. A program instruction product includes one or a set of program instructions. When the program instructions are loaded and executed on a computer, the described process or function is generated, in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The program instructions can be stored in a computer-readable and writable storage medium or transferred from one computer's readable and writable storage medium to another.

[0117] In this embodiment, the direct coupling or communication connection between the modules can be achieved through indirect coupling or communication connection via interfaces, devices, or modules. The functional modules and sub-modules in this embodiment can dynamically reside within a single processing unit, or each module can exist physically independently, or two or more modules can dynamically reside within a single processing unit. When these dynamic components are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable and writable storage medium. This storage medium can be a memory, disk, or optical disc, etc.

[0118] The effects of this invention can be further illustrated by the following simulation results:

[0119] I. Simulation Conditions

[0120] This example uses Matlab to build the system.

[0121] Simulation parameter settings:

[0122] Sequence length Number of sequences The total number of sequences is 4, and the size of the frequency gap set is... Collision-free zone size , Segment length Total frequency gap set 9,2,1,6,11,10,8,3,5,4,12,7 ,

[0123] sequence set There is a sequence: ,in:

[0124] 2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5,1 .

[0125] The size of the frequency gap set ;

[0126] sequence set There are three sequences: ,in:

[0127] 5,3,5,3,6,2,4,2,4,1,6,1,4,1,5,2,6,3,5,1,6,1,6,1,6,1,4,3,6,3 ;

[0128] 4,2,6,2,5,1,5,3,5,2,4,3,5,3,4,1,4,1,4,2,5,3,5,2,5,2,6,2,5,1 ;

[0129] 6,1,4,1,4,3,6,1,6,3,5,2,6,2,6,3,5,2,6,3,4,2,4,3,4,3,5,1,4,2 .

[0130] The size of the frequency gap set ;

[0131] II. Simulation Content and Results

[0132] Under the above simulation conditions, the method of this invention is used to generate a frequency hopping sequence set consisting of four frequency hopping sequences. ,in:

[0133] 2,1,6,11,9,2,1,6,11,9,2,1,6,11,9,2,1,7,11,9,2,1,7,11,9,2,1,7,11,9

[0134] 4,3,4,3,12,8,7,8,7,10,12,10,5,10,4,8,12,3,4,10,12,6,12,6,12,6,5,3,10,3

[0135] 5,8,12,8,4,10,4,3,4,8,5,3,4,3,5,10,5,10,5,8,4,3,4,8,4,8,10,8,4,6

[0136] 12,10,5,10,5,3,12,10,12,3,4,8,12,8,12,3,4,8,12,3,5,8,5,3,5,3,4,6,5,8 ,

[0137] The above sequence set The distribution of the maximum value of aperiodic Hamming correlation under different relative time delay conditions, such as Figure 5 As shown.

[0138] from Figure 5 It can be seen from this that when the relative time delay When the collision-free zone size does not exceed 1, the maximum value of the non-periodic Hamming correlation of the sequence set is always 0, indicating that there is no frequency slot collision within the sequence set within this time delay range, thus verifying the collision-free zone characteristics of the frequency hopping sequence set constructed in this invention.

[0139] For ease of representation, Let it be denoted as sequence set For the sequence and sequence set exist Under the given conditions, the aperiodic Hamming autocorrelation performance analysis was performed, and the maximum value distribution is as follows: Figure 6 As shown.

[0140] from Figure 6 It can be seen that when the relative time delay When the number of sequences does not exceed 1, the sequence set The maximum value of the aperiodic Hamming autocorrelation is 0; when the relative time delay does not exceed 4, the sequence The maximum value of the non-periodic Hamming autocorrelation is 0, indicating that the sequence It exhibits good autocorrelation-free characteristics over a longer time delay range.

[0141] For sequence With sequence set Between and sequence sets The aperiodic Hamming cross-correlation performance between internal sequences was analyzed under different relative time delays. The maximum value distribution is as follows Figure 7 As shown. From Figure 7 As can be seen from this, when the relative time delay does not exceed the collision-free region size of 4, the sequence With sequence set Between the sequences in the sequence set, and between the sequences in the sequence set. The maximum value of the aperiodic Hamming cross-correlation between the internal sequences is 0, indicating that there is no frequency slot conflict between the reference sequence and the sequence set within this time delay range.

[0142] In summary, this invention demonstrates excellent performance in terms of structural integrity and collision-free zone expansion, and can meet the orthogonal frequency hopping networking requirements in scenarios with large relative time delay differences.

Claims

1. A method for constructing a collision-free region frequency hopping sequence set in the form of "1+M", characterized in that, include: (1) Two frequency hopping sequence sets with different collision-free regions are generated using the collision-free region construction method, namely: Collision-free zone frequency hopping sequence set , Collision-free zone frequency hopping sequence set , in, for The size of the frequency gap, The length of the sequence in the sequence set. for The size of the collision-free zone for Frequency gap size, for The number of sequences in the middle, for The size of the collision-free region in the sequence. ; (2) Combine the sequences in the two sequence sets above to obtain 1+M frequency hopping sequences. : , in For the first The first in the sequence One element, , ,and ; (3) The above 1+M frequency hopping sequences According to the set length Segmentation, to obtain the first sequence segment : , , The total number of segments into which a sequence is divided; (4) Let A random number uniformly distributed between 0 and 1. To determine the total size of the frequency gap set for the final construction of the frequency hopping sequence set, for The frequency gap set, in which For the first One available frequency band, ; and utilize the aforementioned , , , and Construction satisfies: The zeroth dynamic frequency gap set and the first dynamic frequency slot set ; (5) Utilizing the aforementioned frequency gap set , and sequence segments By performing frequency slot mapping, a collision-free frequency hopping sequence set consisting of 1+M frequency hopping sequences is obtained: .

2. The method according to claim 1, characterized in that, The method for constructing collision-free regions in (1) generates two sets of frequency hopping sequences with different collision-free regions. Its implementation includes: (1a) Encrypt the known frequency hopping sequence using the local key KEY and time synchronization information TOD to generate the base sequence. , For the first in the sequence One element; (1b) Expanding vectors via sequence base sequence Expanding the elements in the sequence yields a sequence family consisting of M orthogonal sequences of length L. : ， in For the extended vector, the first One element, ; (1c) For sequence families Different values ​​are superimposed on elements at different positions, and frequency mapping is used to achieve this. get The collision-free zone is The frequency hopping sequence forms Collision-free zone frequency hopping sequence set ; (1d) base sequence Elements at different positions are superimposed with different values, and frequency mapping is used. The collision-free zone is obtained as The frequency hopping sequence forms Collision-free zone frequency hopping sequence set .

3. The method according to claim 1, characterized in that: In (3), there are 1+M frequency hopping sequences. According to the set length Segmentation, the implementation of which includes: (3a) Set segment length for: ; (3b) Based on sequence length and segment length The number of sequence segments is obtained: ; (3c) The sequence Each sequence in the sequence is ordered as follows: Segmentation processing yields the sequence set. sequence segment : ， 。 4. The method according to claim 1, characterized in that, The use of the above in (4) , , , and Construct satisfying The zeroth dynamic frequency gap set and the first dynamic frequency slot set Its implementation includes: (4a) The zeroth dynamic slot set before element update The first dynamic frequency slot set before element update The element is denoted as : ， in Before updating the element The remaining frequency slot set; (4b) Set the zeroth dynamic frequency gap First dynamic frequency slot set and remaining frequency slot set elements in exist The initial state is set to ,in For frequency slot set The available frequencies in, then , and exist The initial states at time are as follows: ； ； ； Here, the initial state only needs to satisfy... , Anything is acceptable, not limited to ; (4c) Obtain the zeroth dynamic frequency slot set according to the following iteration rule. First dynamic frequency slot set and remaining frequency slot set exist Elements of time: if ,and Then the next state element Compared to the previous state, the first element correspond; if ,exist When, the next state element Compared to the previous state, the first element Correspondingly, in When, the next state element Compared to the previous state, the first element Correspondingly, this process yields the zeroth dynamic frequency gap set. ; if ,exist When, the next state element Compared to the previous state, the first element Correspondingly, in When, the next state element Compared to the previous state, the first element correspond; if ,and Then the next state element Compared to the previous state, the first element Correspondingly, the first dynamic frequency slot set is obtained. ; if ,and Then the next state element Compared to the previous state, the first element correspond; if ,and Then the next state element Compared to the previous state, the first element Correspondingly, the remaining frequency slot set is obtained. ; Its formula is expressed as: ； In this dynamic update rule, each formula only updates elements within the range corresponding to the "same category" in the previous sequence, without crossing to other ranges. Although each update is random, since the randomness only occurs "within the same range," the three frequency slot sets generated by the above update process still satisfy the same correspondence as the initial frequency slot set. , .

5. The method according to claim 1, characterized in that, The frequency gap set used in (5) , and sequence segments Frequency slot mapping is performed, and its implementation includes: (5a) Based on the position of the sequence Generate sequences with distinct bars: when That is, to generate the 0th sequence: : First, based on the position of the generated sequence elements... Size determines segment position Value: This allows for the determination of the frequency slot set of the mapped frequency. and : Then divide the element values ​​in the segmented sequence As selected frequency slot set element In Select the element Corresponding to the 0th sequence element middle, when That is, generate the remaining M sequences: : First, based on the position of the generated sequence elements... Size determines segment position Value: This allows for the determination of the frequency slot set of the mapped frequency. and ; Then divide the element values ​​of the segmented sequence Plus As selected frequency slot set element In Select the element Corresponding to the first of the remaining M sequences element middle; The first two cases generated above element Its formula is expressed as: ； (5b) Arrange the obtained sequences according to Arranged sequentially, we obtain 1+M frequency hopping sequences. That is, a set of collision-free frequency hopping sequences in the form of "1+M": .

6. A system for constructing a collision-free frequency hopping sequence set in the form of "1+M", characterized in that, include: The base sequence generation module receives the local key KEY and time synchronization information TOD, encrypts the known frequency hopping sequence, and generates the base sequence. ; The collision-free region construction module is used to construct two frequency-hopping sequence sets with different collision-free region sizes based on the base sequence. This includes expanding the base sequence, superimposing offsets, and performing frequency mapping to obtain... Collision-free zone frequency hopping sequence set and Collision-free zone frequency hopping sequence set ,in for The size of the frequency gap set, for The size of the frequency gap set, The length of the sequence in the sequence set. for The number of sequences in the middle, for The size of the collision-free zone for The size of the collision-free zone; Sequence combination module, used to combine and The sequences from the two collision-free frequency hopping sequence sets are combined according to a preset rule to generate 1+M initial frequency hopping sequences. ; The sequence segmentation module is used to segment sequences according to a set length. Each frequency hopping sequence is divided into sequence segments. ; The dynamic frequency gap set generation module is used to generate frequency gap sets based on the total frequency gap set size. , The size of the frequency gap set , The size of the frequency gap set Available frequency slots in the total frequency slot set Generate the zeroth dynamic frequency gap set First dynamic frequency slot set and remaining frequency slot set initial state , and And update according to the iteration rules to obtain the zeroth dynamic frequency slot set. First dynamic frequency slot set and remaining frequency slot set ; The frequency gap mapping module is used to map the frequency gaps according to the sequence position. Zero dynamic frequency gap set and the first dynamic frequency slot set Elements of frequency gap concentration Mapped to the corresponding frequency hopping sequence element Finally, a collision-free zone frequency hopping sequence set in the form of "1+M" is generated. .

7. The system according to claim 6, characterized in that, The collision-free zone construction module includes: The sequence expansion submodule is used to expand the sequence vector. base sequence Expand into M orthogonal sequences of length L, forming a sequence family. ; The collision-free region construction submodule is used for sequence families. The elements in the array are superimposed with different offsets and frequency-mapped to obtain... Collision-free zone frequency hopping sequence set , for the base sequence By superimposing different offsets and mapping them, we obtain Collision-free zone frequency hopping sequence set .

8. The system according to claim 6, characterized in that, The dynamic frequency gap set generation module includes: The initial dynamic slot set generation submodule is used to generate the zeroth dynamic slot set. First dynamic frequency slot set and remaining frequency slot set initial state , and The middle element is set to ,in, The elements of the initial state of the frequency slot set satisfy the following conditions: , ,in For the total frequency slot set; The dynamic frequency slot set iterative submodule is used to... and , Different iteration methods are selected to obtain the zeroth dynamic frequency gap set through iteration. First dynamic frequency slot set and remaining frequency slot set .

9. The system according to claim 6, characterized in that, The frequency gap mapping module includes: The zeroth sequence mapping submodule is used to determine the position of generated sequence elements. Size determines segment position Then, the element values ​​in the segmented sequence As selected frequency slot set element In Select the element Corresponding to the 0th sequence element middle; The M-sequence mapping submodule is used to map sequences based on their positions in the generated sequence elements. Size determines segment position Then divide the element values ​​of the segmented sequence Plus As selected frequency slot set element In Select the element Corresponding to the first of the remaining M sequences element middle.

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