A wave position division method and device in satellite communication

Abstract

The application discloses a wave position division method and device in satellite communication, specifically comprising the following steps: firstly, a network side device calculates the geographic coordinates of a satellite foot point at a current time, and obtains the geographic coordinates of a center point of a current serving random wave beam coverage area; then, the foot point coordinates and the wave beam center point coordinates are compared to determine whether the two points coincide; if yes, a starting reference direction is determined as a projection direction of a satellite movement direction on the ground; if not, the starting reference direction is determined as a line direction from the foot point to the wave beam center point; then, the starting reference direction is taken as a 0-degree reference line, and the circular coverage area of the whole random wave beam is divided into N sector areas clockwise; finally, the network side device allocates a position configuration to each sector area and associates a specific random access resource. The application realizes fair allocation of satellite resources, improves the access performance of a satellite communication network, and improves the resource utilization rate and the access efficiency of the system.

Description

Technical Field

[0001] This invention relates to the field of wireless satellite communication technology, and in particular to a method and apparatus for wavelet division in satellite communication. Background Technology

[0002] Satellite communication beamout allocation involves dividing antenna beams into spatial regions according to geographical or angular rules to achieve efficient coverage of the Earth's surface. During random access, the network side (such as the base station) can indirectly determine the approximate beamout location of the terminal by using the preamble sequence sent by the terminal or the random access channel timing (RO) used by the terminal, thereby allocating appropriate service beam resources to the terminal. Alternatively, the terminal can also calculate its beamout number based on its own location information (such as latitude and longitude).

[0003] The existing satellite communication beam position allocation technology starts from the north direction of the beam center and divides the coverage area of ​​the random beam clockwise. The specific features of this technology are as follows: (1) Fixed starting reference direction for allocation: Regardless of the actual positional relationship between the satellite's nadir point and the center point of the random beam, this scheme always uses the geographic north direction as the starting reference direction for dividing the beam position area. (2) Beam position area allocation method: Starting from the north direction, the coverage area of ​​the random beam is divided into N sector areas clockwise (e.g., numberOfLocationPerCoverage=4, i.e., divided into 4 90-degree sectors). Each sector area corresponds to a location index (n_location_index). (3) Association of random access resources: The network side statically associates different location indices with specific random access channel timings (RO) and a set of contention access preamble sequences (Preamble ID) through configuration parameters (such as loc-perRACH-Occasion and CB-PreamblesPerLoc). The terminal initiates random access using the corresponding RO and preamble according to its location index. (4) Existing technical problems: The current protocol standard uses a fixed due north direction as the starting point for dividing the beam when the satellite sub-satellite point deviates from the center of the random beam. This will result in unequal actual coverage areas for each beam position. This unequal area will lead to a series of problems such as uneven allocation of user access resources, congestion in some areas, reduced overall system access efficiency, and inaccurate judgment of terminal geographical location by the base station.

[0004] Existing technologies that use the geographic north direction of the beam center as a fixed starting reference for dividing the beam position region have the following technical drawbacks:

[0005] (1) Unequal area of ​​wave position regions leads to unfair allocation of random access resources and congestion;

[0006] When the satellite's nadir point does not coincide with the center point of the random beam, the actual coverage area of ​​each wavefront region divided using a fixed due north direction varies significantly. This will directly lead to:

[0007] The inherent imbalance in resource allocation: The network allocates the same number of random access channel opportunities and preamble sequences to each bandwidth region. However, larger regions, which may accommodate more users, only receive the same access resources as smaller regions, resulting in a mismatch between resource allocation and actual user distribution.

[0008] Degraded access performance: When users are evenly distributed or concentrated in a large area, users in the large area will compete for limited access resources, significantly increasing the probability of preamble collision and random access failure rate, resulting in an increase in the average access latency for users in that area. Meanwhile, access resources in small areas may be idle, reducing the overall resource utilization and access efficiency of the system.

[0009] (2) Inaccurate judgment of terminal geographical location affects the accuracy of subsequent service beam scheduling;

[0010] The base station infers the wavelength region to which the terminal belongs by using the preamble sequence or RO used by the terminal. This is because the regions have varying areas and irregular shapes.

[0011] Large coarse-grained positioning error: Base station judgments of terminal geographical location are inaccurate and inconsistent. For terminals covering large areas, the uncertainty range of their actual physical location is even greater.

[0012] Inadequate service beam assignment: This inaccurate location information may cause the network to assign a service beam to a terminal that is not the optimal beam for its location (for example, assigning a beam at the coverage edge instead of the center beam), thereby affecting the link quality and stability of subsequent communication and potentially increasing unnecessary beam switching.

[0013] (3) System capacity and user experience are compromised;

[0014] The combined effect of these defects ultimately results in a loss of system-level performance:

[0015] System capacity is limited: Unfair resource allocation and increased access collisions reduce the number of users the system can successfully serve under the same resources, thus limiting the system access capacity under random beam coverage.

[0016] Inconsistent user experience: Users in different frequency bands will experience drastically different access performance and communication service quality, which violates the principle of fairness that network services should pursue. Summary of the Invention

[0017] The purpose of this invention is to provide a method and apparatus for dividing satellite communication into multiple wavelet regions of equal area, so as to improve satellite communication access performance, system resource utilization and access efficiency, thereby improving the link quality and stability of satellite communication.

[0018] The technical solution to achieve the purpose of this invention is: a wavelet partitioning method in satellite communication, comprising the following steps:

[0019] Obtain the geographic coordinates of the satellite's nadir point and the geographic coordinates of the center point of the random beam coverage area;

[0020] Determine whether the satellite nadir point coincides with the center point of the random beam coverage area;

[0021] The initial reference direction is determined based on the judgment result, where:

[0022] If they coincide, then the initial reference direction is determined to be the projection direction of the satellite's motion direction onto the ground.

[0023] If they do not coincide, the starting reference direction is determined to be the direction of the line connecting the satellite nadir point to the center point of the random beam coverage area;

[0024] Using the starting reference direction as the 0-degree baseline, the entire circular coverage area of ​​the random beam is divided into N fan-shaped regions at equal angles clockwise, each fan-shaped region being a wave position region, where N is an integer greater than or equal to 2;

[0025] Random access resources are allocated and associated for each of the said wavelength regions.

[0026] A wavelet division device for satellite communication, comprising:

[0027] The acquisition module is used to acquire the geographic coordinates of the satellite's nadir point and the geographic coordinates of the center point of the random beam coverage area;

[0028] The judgment module is used to determine whether the satellite nadir point coincides with the center point of the random beam coverage area;

[0029] The direction determination module is used to determine the starting reference direction based on the judgment result, wherein:

[0030] If they coincide, then the initial reference direction is determined to be the projection direction of the satellite's motion direction onto the ground.

[0031] If they do not coincide, the starting reference direction is determined to be the direction of the line connecting the satellite nadir point to the center point of the random beam coverage area;

[0032] The division module is used to divide the entire circular coverage area of ​​the random beam into N fan-shaped regions at equal angles clockwise, with the starting reference direction as the 0-degree baseline. Each fan-shaped region is a wave position region, where N is an integer greater than or equal to 2.

[0033] The resource allocation module is used to allocate and associate random access resources for each of the wave positions.

[0034] A satellite communication system, characterized in that it comprises:

[0035] At least one satellite;

[0036] Network-side equipment, the network-side equipment including:

[0037] One or more processors;

[0038] Memory, used to store program instructions;

[0039] Communication interface, used for data interaction with satellites and the core network;

[0040] The processor executes program instructions in the memory to implement the wavelet division method in satellite communication.

[0041] A terminal for the satellite communication system, the terminal comprising:

[0042] The positioning module is used to obtain the current geographical location of the terminal itself;

[0043] The receiving module is used to receive the wavelet partitioning configuration information broadcast by the network-side device. The configuration information includes the rules for determining the starting reference direction and the number N of the sector regions divided at equal angles.

[0044] The calculation module is used to calculate the location index of the wave position region to which the terminal belongs based on the terminal's current geographical location and the wave position division configuration information;

[0045] The access module is used to determine the corresponding random access channel timing and contention access preamble sequence group based on the location index, and to send the selected preamble sequence on the random access channel timing to initiate random access.

[0046] Compared with the prior art, the present invention has the following significant advantages: (1) It dynamically determines the starting reference direction for dividing the coverage area of ​​the random beam and determines the satellite communication beam division based on the positional relationship between the satellite nadir point and the center point of the random beam, thereby ensuring that the area of ​​the multiple beam regions divided is always equal regardless of the satellite's attitude, thus realizing the fair allocation of random access resources and the accurate judgment of terminal location, improving access performance, and improving the overall resource utilization and access efficiency of the system; (2) It binds each equal-area beam region to a specific random access channel timing and competitive access preamble sequence group, ensuring that the allocation of user access resources is proportional to the actual area of ​​the beam region and the potential user capacity, thus realizing the fairness of resource allocation; (3) It improves the accuracy of the base station's judgment of the terminal's geographical location, reduces unnecessary beam switching, improves link quality and stability, and provides high-quality location information input for the accurate scheduling of subsequent service beams. Attached Figure Description

[0047] Figure 1 This is a flowchart illustrating a satellite communication wavelet partitioning method based on nadir point geographic coordinates according to the present invention.

[0048] Figure 2 This is a schematic diagram of the random access process of the terminal in an embodiment of the present invention.

[0049] Figure 3 This is a schematic diagram of equal-area wave position division when the sub-satellite point coincides with the beam center in an embodiment of the present invention.

[0050] Figure 4 This is a schematic diagram of equal-area wave position division when the sub-satellite point and the beam center do not coincide in an embodiment of the present invention. Detailed Implementation

[0051] This invention provides a method and apparatus for wavelet partitioning in satellite communication. The core of the method lies in dynamically determining the starting reference direction for partitioning the coverage area of ​​the random beam, specifically based on the positional relationship between the satellite's nadir point and the center point of the random beam. This ensures that regardless of the satellite's attitude, the areas of the partitioned wavelet regions are always equal, thereby achieving fair allocation of random access resources and accurate determination of terminal locations.

[0052] This invention discloses a wavelet partitioning method in satellite communication, comprising the following steps:

[0053] Obtain the geographic coordinates of the satellite's nadir point and the geographic coordinates of the center point of the random beam coverage area;

[0054] Determine whether the satellite nadir point coincides with the center point of the random beam coverage area;

[0055] The initial reference direction is determined based on the judgment result, where:

[0056] If they coincide, then the initial reference direction is determined to be the projection direction of the satellite's motion direction onto the ground.

[0057] If they do not coincide, the starting reference direction is determined to be the direction of the line connecting the satellite nadir point to the center point of the random beam coverage area;

[0058] Using the starting reference direction as the 0-degree baseline, the entire circular coverage area of ​​the random beam is divided into N fan-shaped regions at equal angles clockwise, each fan-shaped region being a wave position region, where N is an integer greater than or equal to 2;

[0059] Random access resources are allocated and associated for each of the said wavelength regions.

[0060] As a specific example, determining whether the satellite nadir point coincides with the center point of the random beam coverage area specifically involves: calculating the distance between the satellite nadir point and the center point of the random beam coverage area; if the distance is less than a preset threshold, it is determined to coincide; otherwise, it is determined not to coincide.

[0061] As a specific example, the circular coverage area of ​​the entire random beam is divided into N fan-shaped regions at equal clockwise angles. Specifically, the theoretical center angle of each fan-shaped region is 360 / N degrees, and the theoretical area of ​​all fan-shaped regions is equal.

[0062] As a specific example, the random access resources include random access channel timing and contention access preamble sequence groups; allocating and associating random access resources for each of the wavelet regions specifically includes:

[0063] Assign a unique location index to each of the wave positions;

[0064] Associate each of the location indices with at least one random access channel timing;

[0065] A dedicated set of contention access preamble sequence identifiers is assigned to each of the location indices.

[0066] As a specific example, the method is applied to network-side equipment in a satellite communication system, which includes a satellite gateway station, a baseband processing unit, or a satellite.

[0067] The present invention also provides a wavelet division device for satellite communication, comprising:

[0068] The acquisition module is used to acquire the geographic coordinates of the satellite's nadir point and the geographic coordinates of the center point of the random beam coverage area;

[0069] The judgment module is used to determine whether the satellite nadir point coincides with the center point of the random beam coverage area;

[0070] The direction determination module is used to determine the starting reference direction based on the judgment result, wherein:

[0071] If they coincide, then the initial reference direction is determined to be the projection direction of the satellite's motion direction onto the ground.

[0072] If they do not coincide, the starting reference direction is determined to be the direction of the line connecting the satellite nadir point to the center point of the random beam coverage area;

[0073] The division module is used to divide the entire circular coverage area of ​​the random beam into N fan-shaped regions at equal angles clockwise, with the starting reference direction as the 0-degree baseline. Each fan-shaped region is a wave position region, where N is an integer greater than or equal to 2.

[0074] The resource allocation module is used to allocate and associate random access resources for each of the wave positions.

[0075] The present invention also provides a satellite communication system, comprising:

[0076] At least one satellite;

[0077] Network-side equipment, the network-side equipment including:

[0078] One or more processors;

[0079] Memory, used to store program instructions;

[0080] Communication interface, used for data interaction with satellites and the core network;

[0081] The processor executes program instructions in the memory to implement the wavelet division method in satellite communication.

[0082] The present invention also provides a terminal for the aforementioned satellite communication system, the terminal comprising:

[0083] The positioning module is used to obtain the current geographical location of the terminal itself;

[0084] The receiving module is used to receive the wavelet partitioning configuration information broadcast by the network-side device. The configuration information includes the rules for determining the starting reference direction and the number N of the sector regions divided at equal angles.

[0085] The calculation module is used to calculate the location index of the wave position region to which the terminal belongs based on the terminal's current geographical location and the wave position division configuration information;

[0086] The access module is used to determine the corresponding random access channel timing and contention access preamble sequence group based on the location index, and to send the selected preamble sequence on the random access channel timing to initiate random access.

[0087] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0088] Example 1

[0089] like Figure 1 As shown, this embodiment provides a satellite communication spectral allocation method based on nadir point geographic coordinates, including the following steps:

[0090] Step 1: The network-side device calculates the geographic coordinates of the satellite's nadir point at the current moment based on the received real-time satellite ephemeris data. At the same time, the network-side device obtains the geographic coordinates of the center point of the current service's random beam coverage area.

[0091] Step 2: The processor of the network-side device compares the coordinates of the nadir point with the coordinates of the beam center point to determine whether they coincide. If they do, the starting reference direction is determined to be the projection direction of the satellite's motion direction on the ground; otherwise, the starting reference direction is determined to be the direction of the line connecting the nadir point to the beam center point.

[0092] Step 3: Using the initial reference direction as the 0-degree baseline, divide the entire circular coverage area of ​​the random beam into N sector regions clockwise.

[0093] Step 4: The network-side device assigns a location configuration to each of the divided sector areas and associates it with specific random access resources.

[0094] Preferably, the coincidence of the sub-satellite point coordinates and the beam center point coordinates in step 2 is defined as the distance between the two points being less than a preset threshold.

[0095] Preferably, the center angle of each sector region described in step 3 is 360 / N degrees, and all the divided sector regions have equal theoretical areas.

[0096] Preferably, N mentioned in step 3 is a system configuration parameter.

[0097] Preferably, the network-side device in step 4 assigns a location configuration and associates it with specific random access resources for each divided sector area, as follows:

[0098] Step 4.1: Associate random access channel timing, associating each location index with one or more specific ROs;

[0099] Step 4.2: Associate the preamble sequence group and assign a dedicated set of contention access preamble sequences for each location index.

[0100] Example 2

[0101] This invention can be implemented in network-side equipment of a satellite communication system, such as a satellite gateway station, baseband processing unit, or the satellite itself. These devices typically include one or more processors, a memory, and a communication interface. The processor executes program instructions stored in the memory to implement the steps described in this invention. The memory (a non-transitory computer-readable storage medium) stores program instructions and necessary system parameters, such as satellite ephemeris, beam center coordinates, and configuration parameter N. The communication interface is used for data interaction with the satellite and the core network. These hardware components work together to complete the beam allocation and resource configuration process described in this invention.

[0102] This embodiment provides a satellite communication wavelength division method based on the geographic coordinates of the nadir point, such as... Figure 1 As shown, starting from obtaining the positions of the nadir point and the beam center point, the initial reference direction is determined based on whether the two coincide. Then, equal-angle sector regions are divided, and finally, random access resources are allocated to each region. Combined with... Figure 1 The specific process is as follows:

[0103] Step S210: The network-side device calculates the geographic coordinates of the satellite's nadir point at the current moment based on the received real-time satellite ephemeris data. Simultaneously, the network-side device obtains the geographic coordinates of the center point of the currently serving random beam coverage area.

[0104] Step S220: The processor of the network-side device compares the coordinates of the nadir point with the coordinates of the beam center point to determine whether they coincide. In engineering terms, "coincidence" can be defined as the distance between the two points being less than a preset threshold.

[0105] Step S231: If the judgment result of step S220 is "yes", then the starting reference direction is determined to be the projection direction of the satellite's motion direction on the ground.

[0106] Step S232: If the judgment result of step S220 is "no", then the starting reference direction is determined to be the direction of the line connecting the sub-satellite point to the beam center point.

[0107] Step S240: Using the starting reference direction determined in the above steps as the 0-degree baseline, divide the entire circular coverage area of ​​the random beam into N sector regions clockwise. The center angle of each sector region is 360 / N degrees. All sector regions thus divided have equal theoretical areas. N is a system configuration parameter, for example, numberOfLocationPerCoverage = 4.

[0108] Step S250: The network-side device configures and associates specific random access resources for each sector area (assigned a location index, such as n_location_index = 0, 1, ..., N-1) divided in step S240. Specifically, this includes:

[0109] Associating random access channels (ROs): This involves associating each location index with one or more specific ROs. For example, the configuration parameter `loc-perRACH-Occasion = one` means that one location index exclusively occupies one RO.

[0110] Associated Preamble Sequence Groups: Assign a dedicated set of contention-based access preamble sequences to each location index. For example, the configuration parameter CB-PreamblesPerLoc = 16 means that each location index corresponds to 16 specific preamble sequence identifiers.

[0111] Figure 1 The complete process of the beam position division method of this invention is demonstrated. Starting from obtaining the positions of the nadir point and the beam center point, the starting reference direction is determined based on whether the two coincide. Then, equal-angle sector regions are divided, and finally, random access resources are allocated to each region.

[0112] Table 1 illustrates the mapping relationship between location indices and random access resources. Each location index is associated with a specific random access channel opportunity (RO), and the same preamble sequence ID range is used within that RO to achieve fair allocation of resources.

[0113] Table 1 Random Access Resource Configuration Table

[0114]

[0115] Figure 2 The random access procedure of a terminal in a system employing the method of this invention is demonstrated. The terminal determines its own location index based on system broadcast information, and then initiates access using a specified preamble sequence on the corresponding RO.

[0116] This invention demonstrates the effectiveness of beam segmentation in various scenarios. Regardless of whether the sub-satellite point coincides with or deviates from the beam center, this invention ensures that the area of ​​each segmented region is equal, showcasing the universality and superiority of the method.

[0117] Example 3

[0118] To illustrate the technical solution of the present invention more intuitively, this embodiment is described in conjunction with the following two typical scenarios.

[0119] Scenario 1: The sub-satellite point coincides with the beam center.

[0120] In this scenario, the initial reference direction is the direction of satellite motion, such as due east. Based on this direction, four sector regions A0, A1, A2, and A3 are divided, and they not only have equal angles but also exactly equal areas, as shown below. Figure 3 As shown.

[0121] Figure 3 Explanation: When the sub-satellite point coincides with the beam center point O, four equal-area sector regions A0, A1, A2, and A3 are divided with the satellite's motion direction (east) as the initial reference direction.

[0122] Scenario 2: The sub-satellite point does not coincide with the beam center.

[0123] like Figure 4 As shown, this is also the key scenario that this invention aims to solve. The sub-satellite point S deviates from the beam center point O. At this time, the initial reference direction is the direction of the line SO. Based on this direction, the four sector regions B0, B1, B2, and B3 remain equal in area.

[0124] Figure 4 Explanation: When the nadir point S does not coincide with the beam center point O, the direction of the connecting line SO is used as the starting reference direction to divide the area into four equal-area sector regions B0, B1, B2, and B3. This is consistent with... Figure 3 The existing technology shown (fixed due north direction) stands in stark contrast and effectively solves the problem of unequal area.

[0125] When a terminal initiates Type I random access in an encounter beam, the process is optimized by this invention:

[0126] (1) The terminal receives the system broadcast message and obtains the configuration information of the current wavelet allocation scheme.

[0127] (2) The terminal obtains its own geographical location through the built-in positioning module and calculates its own location index n_location_index by dynamically starting from the division rule described in this invention.

[0128] (3) The terminal finds its associated RO and the competing access preamble sequence group based on the location index, and randomly selects a preamble sequence to send on the specified RO.

[0129] (4) After receiving the preamble sequence, the base station can accurately and uniquely determine the equal area beam position region to which the terminal belongs based on the RO and sequence ID range, and thus allocate appropriate service beam resources to it in the random access response.

[0130] In summary, the key technical point of this invention lies in fundamentally solving the problem of inconsistent wavefront area caused by satellite (especially low-Earth orbit satellite) attitude changes through a dynamically adaptive reference direction determination mechanism, including:

[0131] (1) Logic for dynamically determining the reference direction

[0132] The core lies in the shift in judgment logic: from the existing fixed reference direction (such as true north) to dynamic judgment based on the real-time positional relationship between the satellite nadir point and the center point of the random beam.

[0133] Specific binary judgment criteria:

[0134] When the nadir point coincides with the beam center point, the projection of the satellite's motion direction onto the ground is used as the initial reference direction.

[0135] When the nadir point does not coincide with the beam center point, the direction of the line connecting the nadir point and the beam center point is used as the starting reference direction.

[0136] (2) Equal-area wave potential partitioning method based on dynamic direction

[0137] The dynamically determined initial reference direction is used as the zero-degree baseline.

[0138] By dividing the 360 ​​degrees into N equal sectors (each sector having an angle of 360 / N degrees), the theoretical coverage area of ​​all wavefront regions remains equal regardless of the satellite's attitude.

[0139] (3) Precise and fair mapping relationship with random access resources

[0140] Each equal-area wavelet region (position index) is bound to a specific random access channel timing and contention access preamble sequence group.

[0141] This mapping relationship ensures that the allocation of user access resources (RO and preamble) is proportional to the actual area of ​​the wave position region and the potential user capacity, thus achieving fairness in resource allocation.

[0142] (4) Improved accuracy of terminal location determination

[0143] Because the beam regions are of equal area and regular shape, the network side (base station) can more accurately and consistently infer the geographical location of the terminal by detecting the RO and preamble sequence used by the terminal, providing high-quality location information input for the precise scheduling of subsequent service beams.

[0144] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for wavelet partitioning in satellite communication, characterized in that, Includes the following steps: Obtain the geographic coordinates of the satellite's nadir point and the geographic coordinates of the center point of the random beam coverage area; Determine whether the satellite nadir point coincides with the center point of the random beam coverage area; The initial reference direction is determined based on the judgment result, where: If they coincide, then the initial reference direction is determined to be the projection direction of the satellite's motion direction onto the ground. If they do not coincide, the starting reference direction is determined to be the direction of the line connecting the satellite nadir point to the center point of the random beam coverage area; Using the starting reference direction as the 0-degree baseline, the entire circular coverage area of ​​the random beam is divided into N fan-shaped regions at equal angles clockwise, each fan-shaped region being a wave position region, where N is an integer greater than or equal to 2; Random access resources are allocated and associated for each of the said wavelength regions.

2. The wavelet partitioning method in satellite communication according to claim 1, characterized in that, The determination of whether the satellite nadir point coincides with the center point of the random beam coverage area specifically involves: calculating the distance between the satellite nadir point and the center point of the random beam coverage area; if the distance is less than a preset threshold, it is determined to coincide, otherwise it is determined not to coincide.

3. The wavelet partitioning method in satellite communication according to claim 1, characterized in that, The entire circular coverage area of ​​the random beam is divided into N fan-shaped regions at equal clockwise angles. Specifically, the theoretical center angle of each fan-shaped region is 360 / N degrees, and the theoretical area of ​​all fan-shaped regions is equal.

4. The wavelet partitioning method in satellite communication according to claim 1, characterized in that, The random access resources include random access channel timing and contention access preamble sequence groups; allocating and associating random access resources for each of the wavelet regions specifically includes: Assign a unique location index to each of the wave positions; Associate each of the location indices with at least one random access channel timing; A dedicated set of contention access preamble sequence identifiers is assigned to each of the location indices.

5. The wavelet partitioning method in satellite communication according to claim 1, characterized in that, The method is applied to network-side equipment in a satellite communication system, the network-side equipment including a satellite gateway station, a baseband processing unit, or a satellite.

6. A wavelet division device for satellite communication, characterized in that, include: The acquisition module is used to acquire the geographic coordinates of the satellite's nadir point and the geographic coordinates of the center point of the random beam coverage area; The judgment module is used to determine whether the satellite nadir point coincides with the center point of the random beam coverage area; The direction determination module is used to determine the starting reference direction based on the judgment result, wherein: If they coincide, then the initial reference direction is determined to be the projection direction of the satellite's motion direction onto the ground. If they do not coincide, the starting reference direction is determined to be the direction of the line connecting the satellite nadir point to the center point of the random beam coverage area; The division module is used to divide the entire circular coverage area of ​​the random beam into N fan-shaped regions at equal angles clockwise, with the starting reference direction as the 0-degree baseline. Each fan-shaped region is a wave position region, where N is an integer greater than or equal to 2. The resource allocation module is used to allocate and associate random access resources for each of the wave positions.

7. A satellite communication system, characterized in that, include: At least one satellite; Network-side equipment, the network-side equipment including: One or more processors; Memory, used to store program instructions; Communication interface, used for data interaction with satellites and the core network; The processor executes program instructions in the memory to implement the wavelet partitioning method in satellite communication as described in any one of claims 1 to 5.

8. A terminal for use in the satellite communication system of claim 7, characterized in that, The terminal includes: The positioning module is used to obtain the current geographical location of the terminal itself; The receiving module is used to receive the wavelet partitioning configuration information broadcast by the network-side device. The configuration information includes the rules for determining the starting reference direction and the number N of the sector regions divided at equal angles. The calculation module is used to calculate the location index of the wave position region to which the terminal belongs based on the terminal's current geographical location and the wave position division configuration information; The access module is used to determine the corresponding random access channel timing and contention access preamble sequence group based on the location index, and to send the selected preamble sequence on the random access channel timing to initiate random access.

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