Satellite node inter-satellite link random alignment access alignment method
By constructing pseudo IDs and generating beam sequences, the problem of space-time uncertainty among satellite nodes is solved, efficient inter-star beam alignment without prior information is achieved, and the dynamic networking capability and strike resistance of satellite node platforms are improved.
Patent Information
- Application Number
- CN202411821402.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-04-11
AI Technical Summary
In the inter-satellite links between satellite nodes, the space-time uncertainty between satellite nodes due to the decentralized networking method, making it difficult to achieve efficient beam alignment and information forwarding.
By constructing the pseudo ID of the satellite node and generating a beam sequence based on the pseudo ID, efficient beam alignment between satellite nodes is achieved without prior information. Specific steps include pseudo ID construction, beam sequence construction, on-star antenna adjustment method, and establishing a communication link after adjacent satellite nodes are aligned.
It realizes rapid inter-star beam alignment in scenarios without prior knowledge, improves the dynamic networking capability of the multi-function satellite node platform, and improves the scalability and strike resistance of the network.
Smart Images
Figure CN119814113A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of satellite node intersatellite links, in particular to a random alignment access alignment method for satellite node intersatellite links. Background Art
[0002] In the case of limited spectrum resources and power constraints on satellite nodes, it is necessary to study the dynamic access technology of the corresponding multifunctional satellite node platform; in addition, due to the layout restrictions of ground stations, global coverage networking requires satellite nodes to be networked in space, so that each satellite node can achieve random access and complete information forwarding.
[0003] The core idea of random access is to adopt the decentralized principle for intersatellite networking. On the one hand, satellite nodes can freely access and exit the network according to demand without the control of the central satellite node, which improves the scalability of the satellite node network and is conducive to providing multiple types of network services. On the other hand, the failure of some satellite nodes will not cause the paralysis of the entire network, which improves the anti-strike capability and robustness of the satellite node network, which is an advantage that centralized networks do not have.
[0004] However, the use of a decentralized networking approach will inevitably lead to the lack of unified coordination or prior information, resulting in the lack of synchronization between satellite nodes in time and the uncertainty of the relative positions of satellite nodes in space. Summary of the invention
[0005] The invention provides a satellite node inter-satellite link random alignment access alignment method, aiming at realizing efficient beam alignment when satellite nodes meet and align to establish a link in the absence of specific information of docking satellite nodes.
[0006] In a first aspect, a method for aligning intersatellite links of satellite nodes by random alignment access is provided, comprising:
[0007] Construct a pseudo satellite node
[0008] According to the pseudo Construct a beam sequence that satisfies:
[0009]
[0010] 2n is the number of grids traversed by the satellite node, X(t) is the number of grid rows corresponding to the traversal order t, and Y(t) is the number of grid rows corresponding to the traversal order t. For fake The tmodLth value in a1,...,a n ,b1,...,b nare all prime numbers, a1<...<a n <b1<...<b n , mod is the remainder operator, rand is the random number operator, generates random integers within 2n, and the number of beam sequences is 4n 2 ;
[0011] Determine the on-board antenna adjustment method according to the beam sequence;
[0012] When adjacent satellite nodes are aligned with each other, a communication link is established for communication; if the link is interrupted, the search continues according to the designed beam sequence to complete a new round of inter-satellite beam alignment.
[0013] In combination with the first aspect, in some implementations of the first aspect, constructing the pseudo ID includes: dividing the ID having a length of s bits into A subsequence of bits 1 and The ID of length s bits is extended to a pseudo sequence of length L bits by adding a number of digits after subsequence 1 and / or subsequence 2, where L>s>1.
[0014] In combination with the first aspect, in some implementations of the first aspect, L=11, n=2, and a1, a2, b1, and b2 are 4 values selected from 3, 5, 7, 11, 13, and 17.
[0015] In combination with the first aspect, in some implementations of the first aspect, for a satellite node k, the generated beam sequence U k ={(X k ,Y k )}, the beam pointing sequence used at time t is (X k (t),Y k (t)), the actual direction of the corresponding satellite node antenna is is the antenna angle rotation coefficient, and X k (t) or Y k (t) after multiplication, it represents the change in antenna angle relative to the initial moment, θ hk (t) is the horizontal reference angle at time t, θ vk (t) is the vertical reference angle at time t.
[0016] In combination with the first aspect, in certain implementations of the first aspect, t0 is the starting time of the adjustment. By calculating each adjustment moment after t0, the expected docking direction of the satellite node antenna based on the attitude coordinate system, combined with the scanning trajectory, and based on the principle of adjusting once per second, the corresponding adjustment angle at each moment is obtained, and the adjustment angle is injected into the satellite node.
[0017] In combination with the first aspect, in certain implementations of the first aspect, the pitch angle of the desired direction at time t0 is injected into the satellite node; the satellite node adjusts the antenna to the specified direction at time t0; the pitch adjustment angles at times t1, t2, t3, ... are injected into the satellite node; the satellite node adjusts the antenna pointing according to the injected pitch adjustment angle at its set time, and sends a docking signal in the specified direction.
[0018] In combination with the first aspect, in some implementations of the first aspect, the pitch adjustment angle at the current moment t is:
[0019]
[0020] θ hk (t0) and θ vk (t0) represents the horizontal reference angle and vertical reference angle of the desired pointing direction at time t0 respectively; the natural adjustment angle caused by the satellite node displacement is The adjustment angle of the scan search satisfies Δφ hk (t i )=X k (t i )-X k (t i-1 ),Δφ vk =Y k (t i )-Y k (t i-1 ).
[0021] In a second aspect, a satellite node is provided, wherein the satellite node is used to execute the method described in any one of the implementations of the first aspect.
[0022] Compared with the prior art, the solution provided by the present invention includes at least the following beneficial technical effects:
[0023] Aiming at the characteristics of satellite node platform clock drift, attitude instability, strong device heterogeneity, and high switching frequency of satellite node platform beams, the present invention studies and designs a fast intersatellite beam alignment scheme for scenarios without prior knowledge. By gridding the search space of satellite nodes, analyzing and revealing the theoretical boundary of beam alignment delay, and designing a beam pointing sequence close to the theoretical boundary, fast intersatellite beam alignment is achieved, and the dynamic networking capability of the space information network based on the existing multifunctional satellite node platform is improved.
[0024] (1) The neighboring satellite node alignment technology proposed in this scheme does not require each satellite node to have information about other satellite nodes (position information and time information). It only needs to search and find according to the designed beam pointing sequence to achieve alignment within a limited delay.
[0025] (2) The average alignment delay of the alignment method proposed in this scheme is higher than that of the random scanning alignment method and the design complexity is much higher than that of the random scanning alignment method. However, in the worst case, it can achieve an alignment delay of approximately finite value, which is not achievable by the random scanning alignment method (in the worst case, the random scanning method does not have a finite delay).
[0026] (3) Compared with the existing Archimedean screw alignment method, this scheme can achieve faster and more reliable alignment with better performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 The present invention is a flow chart of a satellite node inter-satellite link random alignment access alignment method.
[0028] Figure 2 Schematic diagram of the satellite node A antenna beam pointing adjustment trajectory.
[0029] Figure 3 Schematic diagram of the satellite Node B antenna beam pointing adjustment trajectory. DETAILED DESCRIPTION
[0030] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0031] like Figure 1 As shown, the present invention provides a satellite node inter-satellite link random alignment access alignment method, including the following steps.
[0032] S1, Pseudo ID construction.
[0033] The pseudo ID construction includes: dividing the ID with a length of s bits into A subsequence of bits 1 and By adding digits after subsequence 1 and / or subsequence 2, the ID with a length of s bits is extended to a pseudo sequence with a length of L bits, where L>s>1.
[0034] For satellite node A, its ID length is 3 bits. In order to make the decomposed sequence unique, the length of the subsequence is non-decreasing. Therefore, its ID is divided into and The two subsequences of bits are 0 and 10. Next, add 01 after each subsequence to get 001 and 1001, respectively. Then concatenate the two sequences together to get 0011001. Finally, add 01 after the concatenated sequence. 0, and a new sequence with a length of L = 11 bits is obtained The pseudo ID generation of satellite node A is thus completed.
[0035] The pseudo ID of satellite node B is generated in the same way, and the corresponding pseudo ID is: By comparing the two sets of sequences generated, it is obvious that multiple sets of different eleven-bit sequences can be designed to distinguish satellite nodes.
[0036] S2, beam sequence construction.
[0037] like Figure 2 and Figure 3 As shown, for satellite node A and satellite node B, their grid numbers are both 4, and the length of the pseudo ID is 11. Therefore, the continuous prime numbers used are 5, 7, 13, and 17 as calculation factors and substituted into the formula to obtain.
[0038] The beam sequence construction method of A is:
[0039]
[0040] Among them, t is time, mod is the remainder operator, and rand is the random number operator, which generates a 4-bit random integer.
[0041] The beam sequence construction method of B is:
[0042]
[0043] So the beam sequence of satellite node A is U A ={(1,1),(2,2),(3,3),(0,3),(0,0),…}, the beam sequence of satellite node B is U B ={(1,1),(2,2),(3,3),(0,1),(0,0),…}, the number of sequences is defined according to the number of grids in the beam sequence construction method, and each cycle is 4*4=16. The corresponding antenna beam pointing adjustment trajectory is as follows Figure 2 and Figure 3 As shown in the figure. Each grid in the figure represents a certain area in the search area, and each small circle in the center represents the pointing position of the antenna beam covering the grid area. Therefore, the pointing adjustment angle of the satellite node antenna can be expressed as: For any satellite node k, the generated beam sequence U k ={(X k ,Y k )}, then the beam pointing sequence used at time t is (X k (t),Y k (t)), then the actual pointing direction of the corresponding satellite node antenna is is the antenna angle rotation coefficient, and X k (t) or Y k (t) after multiplication, it represents the change in antenna angle relative to the initial moment, θ hk (t) is the horizontal reference angle at time t, θvk (t) is the vertical reference angle at time t.
[0044] S3, onboard antenna adjustment method:
[0045] For on-board adjustment, the direction that needs to be adjusted at each moment can be calculated through the beam sequence and the expected direction of the satellite node. Assuming t0 is the start time of the adjustment, the expected direction of the satellite node antenna based on the attitude coordinate system required for docking at each adjustment moment after t0, such as t1, t2, t3, etc., can be calculated, and then combined with the scanning trajectory, according to the principle of adjusting once per second, the corresponding adjustment angle at each moment is obtained and injected into the satellite node.
[0046] The specific adjustment steps are as follows: inject the desired elevation angle at time t0 into the satellite node. The satellite node adjusts the antenna to the specified direction at time t0; inject the required elevation adjustment angle at time t1, t2, t3, ... into the satellite node; the satellite node adjusts the antenna pointing according to the injected elevation adjustment angle at its set time and sends a docking signal in the specified direction.
[0047] The adjustment angle is calculated as follows: Let θ hk (t0) and θ vk (t0) respectively represent the horizontal reference angle and the vertical reference angle of the desired pointing direction at time t0.
[0048] The natural adjustment angle caused by the satellite node displacement is In addition, the adjustment angle for the scan search satisfies Δφ hk (t i )=X k (t i )-X k (t i-1 ),Δφ vk =Y k (t i )-Y k (t i-1 ).
[0049] Therefore, relative to the previous moment, the pitch adjustment angle required at the current moment is Therefore, the satellite node antenna can be aligned by injecting the pitch adjustment angle at the corresponding moment to control the pointing direction.
[0050] S4, when the adjacent satellite nodes are aligned with each other, a communication link can be established for communication. If the link is interrupted, the search will continue according to the designed beam sequence to complete a new round of inter-satellite beam alignment.
[0051] Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.
Claims
1. A satellite node inter-satellite link random alignment access alignment method, characterized in that: include: Constructing a pseudo ID for the satellite node According to the pseudo ID Construct a beam sequence that satisfies: 2n is the number of grids traversed by the satellite node, X(t) is the number of grid rows corresponding to the traversal order t, and Y(t) is the number of grid rows corresponding to the traversal order t. For pseudo ID The t mod L values in a1,...,a n ,b1,...,b n are all prime numbers, a1<...<a n <b1<...<b n , mod is the remainder operator, rand is the random number operator, generates random integers within 2n, and the number of beam sequences is 4n 2 ; Determine the on-board antenna adjustment method according to the beam sequence; When adjacent satellite nodes are aligned with each other, communication links are established for communication; If the link is interrupted, the search continues according to the designed beam sequence to complete a new round of intersatellite beam alignment.
2. The method according to claim 1, characterized in that The pseudo ID construction includes: dividing the ID with a length of s bits into A subsequence of bits 1 and The ID of length s bits is extended to a pseudo sequence of length L bits by adding a number of digits after subsequence 1 and / or subsequence 2, where L>s>1.
3. The method according to claim 1, characterized in that L=11, n=2, a1, a2, b1, b2 are 4 values among 3, 5, 7, 11, 13, 17.
4. The method according to claim 1, characterized in that For satellite node k, the generated beam sequence U k ={(X k ,Y k )}, the beam pointing sequence used at time t is (X k (t),Y k (t)), the actual direction of the corresponding satellite node antenna is is the antenna angle rotation coefficient, and X k (t) or Y k (t) after multiplication, it represents the change in antenna angle relative to the initial moment, θ hk (t) is the horizontal reference angle at time t, θ vk (t) is the vertical reference angle at time t.
5. The method according to claim 4, characterized in that t0 is the starting time of adjustment. By calculating each adjustment time after t0, the expected docking direction of the satellite node antenna based on the attitude coordinate system is obtained, combined with the scanning trajectory, according to the principle of adjusting once per second, the corresponding adjustment angle at each moment is obtained and injected into the satellite node.
6. The method according to claim 5, characterized in that The desired pitch angle at time t0 is injected into the satellite node; the satellite node adjusts the antenna to the specified direction at time t0; the pitch adjustment angles at times t1, t2, t3, ... are injected into the satellite node; the satellite node adjusts the antenna pointing according to the injected pitch adjustment angle at its set time, and sends a docking signal in the specified direction.
7. The method according to claim 6, characterized in that The pitch adjustment angle at the current moment t is: θ hk (t0) and θ vk (t0) represents the horizontal reference angle and vertical reference angle of the desired pointing direction at time t0 respectively; the natural adjustment angle caused by the satellite node displacement is The adjustment angle of the scan search satisfies Δφ hk (t i )=X k (t i )-X k (t i-1 ),Δφ vk =Y k (t i )-Y k (t i-1 ).
8. A satellite node, characterized in that: The satellite node is configured to perform the method according to any one of claims 1 to 7.