Construction method of asynchronous asymmetric channel hopping sequence set for low-altitude intelligent network

Abstract

The present invention discloses a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network, which belongs to the field of data transmission and network communication technology, and includes the following steps: constructing a public receiving sequence set; constructing a corresponding sending sequence for each group of public receiving sequences in the public receiving sequence set to obtain a sending sequence set; based on the public receiving sequence set and the corresponding sending sequence set, constructing a target public receiving sequence set and a target sending sequence set of any length, and completing the construction of an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network. The present invention solves the problems of insufficient system processing capacity and low channel utilization rate regarding communication convergence in the low-altitude intelligent network.

Description

Technical Field

[0001] The present invention belongs to the technical field of data transmission and network communication, and in particular to a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network. Background Art

[0002] Spectrum resource management is a key concern in the field of low-altitude intelligent networking. With the rapid development of low-altitude intelligent networking, a large number of users need to share limited spectrum resources to achieve integrated air-space-ground communications. Dynamic spectrum access technology manages and allocates spectrum resources used by all devices, allowing secondary users to dynamically identify and switch to licensed channels that are not currently occupied by primary users. Before data transmission, secondary users need to first achieve channel convergence to establish a communication link.

[0003] At present, there are two main methods for achieving channel rendezvous in dynamic spectrum access technology. One is a centralized method: secondary users exchange control information through a common control channel to determine the rendezvous channel. However, with the rapid increase in the number of users, the common control channel often faces channel conflicts and congestion. Therefore, in comparison, another distributed channel hopping sequence method pre-allocates licensed channels for secondary users. When two secondary users using channel hopping sequences switch to the same idle licensed channel within a limited number of hops, rendezvous is achieved. Usually, channel hopping sequences can be divided into synchronous / asynchronous channel hopping sequences, and symmetric / asymmetric levels. In synchronous mode, all secondary users share a synchronized global clock, which is difficult to achieve in actual low-altitude intelligent network scenarios, and has weak anti-eavesdropping and interference capabilities; in symmetric mode, secondary users use the same channel hopping sequence when sending and receiving data, which makes it difficult to efficiently schedule nodes for data transmission and reception, and is not suitable for network structures with clearly defined node roles, such as emergency communication networks in low-altitude intelligent networks. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network, which solves the problems of insufficient system processing capacity and low channel utilization regarding communication convergence in the low-altitude intelligent network.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] The present invention provides a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network, comprising the following steps:

[0007] S1. Construct a common receiving sequence set;

[0008] S2. construct corresponding transmission sequences for each group of public receiving sequences in the public receiving sequence set to obtain a transmission sequence set;

[0009] S3. Based on the public receiving sequence set and the corresponding transmitting sequence set, a target public receiving sequence set and a target transmitting sequence set of arbitrary length are constructed to complete the construction of an asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network.

[0010] The beneficial effects of the present invention are as follows: the present invention provides a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network, constructs a common receiving sequence set in a prime number domain, and obtains a transmitting sequence set by constructing a corresponding transmitting sequence for each group of common receiving sequences in the common receiving sequence set, and based on the common receiving sequence set and the transmitting sequence set, realizes the construction of a target common receiving sequence set and a target transmitting sequence set of arbitrary length, that is, the method of the present invention constructs a class of asynchronous asymmetric channel hopping sequence sets with flexible lengths, and based on the asynchronous asymmetric channel hopping sequence set, it is possible to enable two secondary nodes in the low-altitude intelligent network to communicate with each other. The maximum rendezvous time and the maximum first rendezvous time of users during communication rendezvous are better, the parameters are more flexible, and the interference and data packet loss caused by communication failures can be effectively alleviated, thereby improving the system throughput and channel utilization. The asynchronous asymmetric channel hopping sequence set provided by the method of the present invention can adapt to different channel availabilities and user needs in a dynamically changing wireless communication environment, thereby better supporting diversified services and applications. At the same time, the asynchronous asymmetric channel hopping sequence set ensures that a common receiving sequence and an arbitrary sending sequence can be rendezvous under any time delay, and the rendezvous time is uneven and unpredictable.

[0011] Furthermore, the S1 comprises the following steps:

[0012] S11. Get a prime number p, where ;

[0013] S12. Based on the prime number p, define a first sequence element construction factor i and a second sequence element construction factor h, wherein the value ranges of the first sequence element construction factor i and the second sequence element construction factor h are as follows:

[0014] ,

[0015] ;

[0016] S13. Construct several groups of common receiving sequences based on the first sequence element construction factor i and the second sequence element construction factor h to obtain a common receiving sequence set.

[0017] Furthermore, the calculation expression of the common receiving sequence set is as follows:

[0018] , ,

[0019] in, represents the hth group of common receiving sequences, represents the hth group of common receiving sequences The i-th sequence element in , mod represents the modular operation.

[0020] Furthermore, the S2 comprises the following steps:

[0021] S21. Based on the prime number p, define a first transmission sequence element construction factor j and a second transmission sequence element construction factor k, wherein the value ranges of the first transmission sequence element construction factor j and the second transmission sequence element construction factor k are respectively as follows:

[0022] ,

[0023] , ;

[0024] S22. Based on the first sending sequence element construction factor j and the second sending sequence element construction factor k, construct p-2 sending sequences corresponding to each group of public receiving sequences in the public receiving sequence set to obtain a sending sequence data set.

[0025] Furthermore, the calculation expression of the sending sequence data set is as follows:

[0026] ,

[0027] in, represents the hth group of common receiving sequences The corresponding k-th group sending sequence is, represents the hth group of common receiving sequences The corresponding k-th group sending sequence The jth sequence element in Indicates rounding down.

[0028] Furthermore, S3 comprises the following steps:

[0029] S31. Define a first target sequence construction factor m and a second target sequence construction factor n, wherein the value ranges of the first target sequence construction factor m and the second target sequence construction factor n are as follows:

[0030] , ;

[0031] S32, constructing a target common receiving sequence set of any length based on the common receiving sequence set according to the first target sequence construction factor m and the second target sequence construction factor n;

[0032] The calculation expression of the target common receiving sequence set is as follows:

[0033] ,

[0034] in, Indicates that the hth group of n common receiving sequences The target common receiving sequence formed by cascading, Indicates that the hth group of n common receiving sequences Cascaded target common receiving sequence The mth sequence element in , Indicates cascade;

[0035] S33, constructing a target sending sequence set of any length based on the sending sequence set according to the first target sequence construction factor m and the second target sequence construction factor n;

[0036] ,

[0037] in, Indicates that the hth group of n common receiving sequences The corresponding k-th group sending sequence The target sending sequence composed of cascade, Indicates that the hth group of n common receiving sequences The corresponding k-th group sending sequence Cascaded target transmission sequence The mth sequence element in ;

[0038] S34. Use the target common receiving sequence set and the target transmitting sequence set as an asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network, and complete the construction of the asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network.

[0039] Compared with the prior art, the advantages of the method of the present invention are: the present invention provides a method for constructing a target public receiving sequence set and a target sending sequence set of arbitrary length in a prime number domain, which can simultaneously meet the requirements of uniform channel utilization and full rendezvous degree, and while ensuring the pseudo-randomness of the sequence, the maximum rendezvous time is shortened to p+1, and the maximum first rendezvous time is shortened to p, which can adapt to various communication scenarios of the low-altitude intelligent network.

[0040] Other advantages of the present invention will be analyzed in more detail in subsequent embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 The present invention is a flowchart of the steps of a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network in an embodiment of the present invention.

[0043] Figure 2 This is a comparison diagram of the maximum rendezvous time of the sequence set of this solution, the asynchronous symmetric channel hopping sequence set, and the asynchronous asymmetric channel hopping sequence set under the same channel resources in an embodiment of the present invention.

[0044] Figure 3 This is a comparison diagram of the average values ​​of the convergence time of the sequence set of this solution, the asynchronous symmetric channel hopping sequence set, and the asynchronous asymmetric channel hopping sequence set under the same channel resources in an embodiment of the present invention.

[0045] Figure 4 This is a comparison diagram of the convergence time variance of the sequence set of this solution, the asynchronous symmetric channel hopping sequence set, and the asynchronous asymmetric channel hopping sequence set under the same channel resources in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0047] Maximum-Time-to-Rendezvous (MTTR) refers to the maximum time interval required for two sequences to reunite.

[0048] Maximum-First-Time-to-Rendezvous (MFTTR) refers to the maximum time interval between two sequences for the first rendezvous.

[0049] Even Channel Use (ECU) means that the sequences in a sequence set use all licensed channels evenly.

[0050] Degree-of-Rendezvous (DoR) refers to the minimum number of times two channel hopping sequences can successfully rendezvous on different permitted channels within a period. When any two sequences in the sequence set can rendezvous on all permitted channels, the DoR is called full.

[0051] like Figure 1 As shown, in one embodiment of the present invention, the present invention provides a method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network, comprising the following steps:

[0052] S1. Construct a common receiving sequence set;

[0053] The S1 comprises the following steps:

[0054] S11. Get a prime number p, where ;

[0055] S12. Based on the prime number p, define a first sequence element construction factor i and a second sequence element construction factor h, wherein the value ranges of the first sequence element construction factor i and the second sequence element construction factor h are as follows:

[0056] ,

[0057] ;

[0058] S13. Construct several groups of common receiving sequences based on the first sequence element construction factor i and the second sequence element construction factor h to obtain a common receiving sequence set.

[0059] The calculation expression of the common receiving sequence set is as follows:

[0060] , ,

[0061] in, represents the hth group of common receiving sequences, represents the hth group of common receiving sequences The i-th sequence element in , mod represents the modular operation.

[0062] S2. construct corresponding transmission sequences for each group of public receiving sequences in the public receiving sequence set to obtain a transmission sequence set;

[0063] The S2 comprises the following steps:

[0064] S21. Based on the prime number p, define a first transmission sequence element construction factor j and a second transmission sequence element construction factor k, wherein the value ranges of the first transmission sequence element construction factor j and the second transmission sequence element construction factor k are respectively as follows:

[0065] ,

[0066] , ;

[0067] S22. Based on the first sending sequence element construction factor j and the second sending sequence element construction factor k, construct p-2 sending sequences corresponding to each group of public receiving sequences in the public receiving sequence set to obtain a sending sequence data set.

[0068] The calculation expression of the sending sequence data set is as follows:

[0069] ,

[0070] in, represents the hth group of common receiving sequences The corresponding k-th group sending sequence is, represents the hth group of common receiving sequences The corresponding k-th group sending sequence The jth sequence element in Indicates rounding down.

[0071] S3. Based on the public receiving sequence set and the corresponding transmitting sequence set, a target public receiving sequence set and a target transmitting sequence set of arbitrary length are constructed to complete the construction of an asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network.

[0072] The S3 comprises the following steps:

[0073] S31. Define a first target sequence construction factor m and a second target sequence construction factor n, wherein the value ranges of the first target sequence construction factor m and the second target sequence construction factor n are as follows:

[0074] , ;

[0075] S32, constructing a target common receiving sequence set of any length based on the common receiving sequence set according to the first target sequence construction factor m and the second target sequence construction factor n;

[0076] The calculation expression of the target common receiving sequence set is as follows:

[0077] ,

[0078] in, Indicates that the hth group of n common receiving sequences The target common receiving sequence formed by cascading, Indicates that the hth group of n common receiving sequences Cascaded target common receiving sequence The mth sequence element in , Indicates cascade;

[0079] S33, constructing a target sending sequence set of any length based on the sending sequence set according to the first target sequence construction factor m and the second target sequence construction factor n;

[0080] ,

[0081] in, Indicates that the hth group of n common receiving sequences The corresponding k-th group sending sequence The target sending sequence composed of cascade, Indicates that the hth group of n common receiving sequences The corresponding k-th group sending sequence Cascaded target transmission sequence The mth sequence element in ;

[0082] S34. Use the target common receiving sequence set and the target transmitting sequence set as an asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network, and complete the construction of the asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network.

[0083] In a practical example of the present invention, a communication convergence example based on the present solution is as follows:

[0084] Let prime number , construct the common receiving sequence of each group, and construct the corresponding sending sequence for each group of common receiving sequences, forming a common receiving sequence set and a corresponding sending sequence set, and by cascading, the length of the common receiving sequence and the sending sequence can be extended to any length ; Taking the case where the construction factors h of the second sequence elements are 1 and 3 respectively as an example, then The common receiving sequence and sending sequence are shown in Table 1:

[0085] Table 1

[0086]

[0087] The common receiving sequence and sending sequence are shown in Table 2:

[0088] Table 2

[0089]

[0090] Take Table 1 and , and let the second target sequence construction factor n=1, and observe different time delays The convergence of the downward shift is as follows:

[0091]

[0092] Among them, different time delays Under the shift, the sequence position where the sequence elements in the public receiving sequence and the sending sequence are the same is the meeting point. It can be seen that the target public receiving sequence set and the corresponding sending sequence set constructed by this scheme can achieve meeting under all delays, and also have more flexible parameters, so that the sequence set can be widely used in low-altitude intelligent networks to improve communication security, system throughput and channel utilization.

[0093] The asynchronous asymmetric channel hopping sequence set for low-altitude intelligent network provided by the solution of the present invention includes: groups, and the period of each group is , each group consists of 1 common receive sequence and The common receiving sequence in the group and its corresponding sending sequence can be combined at any time delay, and each There will be a meeting point within each element, with a total of The MTTR and MFTTR of the common receiving sequence and its corresponding sending sequence in the group are and All sequences in the group meet ECU and full DoR, which reduces the possibility of channel congestion when a large number of secondary users use it, improves spectrum utilization, and can help all secondary users to meet and establish communication links faster and more efficiently.

[0094] In this embodiment, a sequence set of this scheme is provided: an asynchronous asymmetric channel hopping sequence set for low-altitude intelligent network, and a simulation result of the maximum rendezvous time of some existing asynchronous symmetric channel hopping sequence sets and asynchronous asymmetric channel hopping sequence sets under the same channel resource N is compared; the existing asynchronous asymmetric channel hopping sequence sets include, a first sequence set: the multi-maximum-time-to-rendezvous asynchronous-asymmetric prime sequences (MAAPSs), a second sequence set: the matrix-based channel hopping sequence set (The Matrix based Sequences, MS; the existing asynchronous symmetric channel hopping sequence sets include, a third sequence set: the channel hopping sequence set controlling the maximum rendezvous time by 2p (Control-MTTR-by-2p CH, CM2P-CH), a fourth sequence set: the channel hopping sequence set based on the disjoint relaxed difference set (Disjoint RelaxedDifference Set, DRDS), the fifth sequence set: asynchronous symmetric CHS sets with new parameters based on disjoint relaxed difference sets (DRDS-NPCH).

[0095] like Figure 2 As shown in Figure 1, as the number of channels N increases, the maximum rendezvous time also increases. This is because the channel hopping sequence needs to accommodate more permitted channels in each cycle, resulting in a more dispersed selection of rendezvous channels, which increases the maximum rendezvous time. Figure 2 Among them, the maximum rendezvous time performance of the fourth sequence set is the worst, because the channel rendezvous only occurs on the vertically moving channel. This aggregation of rendezvous points causes the MTTR of the fourth sequence set to be the largest and the most unstable. The maximum rendezvous time of the sequence set of this scheme and the second sequence set is the smallest, both , and in Figure 2 In the figure, when the number of channels does not exceed 20, the red line corresponding to the sequence set of this scheme completely overlaps with the yellow line corresponding to the second sequence set. However, since the receiving sequence of the second sequence set uses the same licensed channel in N time slots to shorten the time interval required for rendezvous, the randomness of the second sequence set is reduced, making it more susceptible to tracking and interference. In contrast, the sequence set of this scheme can not only ensure the randomness of the channel hopping sequence, but also has the smallest maximum rendezvous time.

[0096] like Figure 3 and Figure 4 As shown, this embodiment also provides simulation results of the comparison of the mean and variance of the rendezvous time between the sequence set of this solution and the first, second, third, fourth and fifth sequence sets under the same channel resource N. Figure 3 and Figure 4 It can be obtained that the mean value and variance of the rendezvous time of the fourth sequence set fluctuate greatly. This is because the channel rendezvous points are concentrated on certain channels, resulting in uneven distribution of the rendezvous. Figure 3 In the above figure, the mean and variance of the rendezvous time of the first sequence set are slightly higher than those of the third and fifth sequence sets. This is because the sending sequence and the receiving sequence in the asymmetric channel hopping sequence set are constructed by different calculation methods, which will lead to more uneven intervals between the rendezvous points. Although the maximum rendezvous time of the sequence set of this scheme and the second sequence set is the smallest, and in Figure 3 In the example, when the number of channels does not exceed 20, the red line corresponding to the sequence set of this scheme completely overlaps with the yellow line corresponding to the second sequence set, but the average rendezvous time of the sequence set of this scheme and the second sequence set is slightly higher than that of the first sequence set. This is because most of the rendezvous times of the sequence set of this scheme and the second sequence set are concentrated near the maximum rendezvous time. Therefore, the average rendezvous time of the sequence set of this scheme and the second sequence set is slightly larger, but Figure 4 The variance of the rendezvous time in the second sequence set is smaller than that of the sequence set of this scheme because the rendezvous interval of the sequence set of this scheme contains and 1, where the conjunction interval value of 1 will increase the volatility of the conjunction time.

[0097] From the comparative simulation results of the maximum rendezvous time, the average rendezvous time and the variance of the rendezvous time, it can be seen that the sequence set of this scheme not only ensures the randomness of the sequence, but also achieves a shorter maximum rendezvous time and rendezvous time variance; the sequence set of this scheme can enable all secondary users in the low-altitude intelligent network to establish communication links faster, thereby improving data transmission efficiency.

[0098] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for constructing an asynchronous asymmetric channel hopping sequence set for a low-altitude intelligent network, characterized in that: The steps include: S1, build a common receiving sequence set; The S1 comprises the following steps: S11, obtain a prime number p, where p≥3; S12. Based on the prime number p, define a first sequence element construction factor i and a second sequence element construction factor h, wherein the value ranges of the first sequence element construction factor i and the second sequence element construction factor h are as follows: 0≤i≤p 2 -1, 1≤h≤p-1; S13, constructing several groups of common receiving sequences based on the first sequence element construction factor i and the second sequence element construction factor h to obtain a common receiving sequence set; The calculation expression of the common receiving sequence set is as follows: Among them, R h represents the hth group of common receiving sequences, represents the hth group of common received sequence R h The i-th sequence element in , mod represents the modular operation; S2. construct corresponding transmission sequences for each group of public receiving sequences in the public receiving sequence set to obtain a transmission sequence set; The S2 comprises the following steps: S21. Based on the prime number p, define a first transmission sequence element construction factor j and a second transmission sequence element construction factor k, wherein the value ranges of the first transmission sequence element construction factor j and the second transmission sequence element construction factor k are respectively as follows: 0≤j≤p 2 -1, 1≤k≤p-1, k≠h; S22, based on the first sending sequence element construction factor j and the second sending sequence element construction factor k, construct p-2 sending sequences corresponding to each group of public receiving sequences in the public receiving sequence set to obtain a sending sequence data set; The calculation expression of the sending sequence data set is as follows: in, represents the hth group of common received sequence R h The corresponding k-th group sending sequence is, represents the hth group of common received sequence R h The corresponding k-th group sending sequence The jth sequence element in Indicates rounding down; S3. Based on the public receiving sequence set and the corresponding sending sequence set, a target public receiving sequence set and a target sending sequence set of arbitrary length are constructed to complete the construction of an asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network; The S3 comprises the following steps: S31. Define a first target sequence construction factor m and a second target sequence construction factor n, wherein the value ranges of the first target sequence construction factor m and the second target sequence construction factor n are as follows: 0≤m≤np 2 -1,n≥1; S32, constructing a target common receiving sequence set of any length based on the common receiving sequence set according to the first target sequence construction factor m and the second target sequence construction factor n; The calculation expression of the target common receiving sequence set is as follows: Among them, C h Represents n h groups of common receiving sequences R h The target common receiving sequence formed by cascading, Represents n h groups of common receiving sequences R h Cascaded target common receiving sequence C h The mth sequence element in , || indicates cascade; S33, constructing a target sending sequence set of any length based on the sending sequence set according to the first target sequence construction factor m and the second target sequence construction factor n; Among them, D k Represents n h groups of common receiving sequences R h The corresponding kth group sends sequence T h k The target sending sequence composed of cascade, Represents n h groups of common receiving sequences R h The corresponding kth group sends sequence T h k The mth sequence element in the target transmission sequence Dk formed by cascading; S34. Use the target common receiving sequence set and the target transmitting sequence set as an asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network, and complete the construction of the asynchronous asymmetric channel hopping sequence set for the low-altitude intelligent network.

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