A satellite-ground spectrum sharing method

Abstract

The present invention relates to the technical field of non-terrestrial networks, and particularly to a satellite-terrestrial spectrum sharing method. The satellite-terrestrial spectrum sharing method of the present invention proposes a static downlink spectrum sharing mechanism for the problems of scarce spectrum resources, strong interference between satellites and the ground during spectrum sharing, and large coordination signaling overhead. The present invention divides terrestrial cells into three regions with reference to the distance from users to the base station. In particular, the satellite wide beam and the center of the terrestrial cell share the spectrum, and are orthogonal to the working spectra of the sub-center and the edge of the cell. The satellite narrow beam shares the terrestrial network spectrum resources through spatial isolation. The satellite-terrestrial spectrum sharing mechanism designed by the present invention can achieve global seamless coverage without signaling coordination between the terrestrial and satellite networks. At the same time, in the satellite network, only the wide beam interferes with the users at the center of the terrestrial cell, and the useful signal of the users in the terrestrial cell is strong, while the signal of the wide beam is weak. Therefore, the proposed satellite-terrestrial spectrum sharing mechanism causes a relatively low loss of the capacity of the terrestrial network.

Description

Technical Field

[0001] The present invention relates to the technical field of non-terrestrial networks, and in particular to a satellite-terrestrial spectrum sharing method. Background Art

[0002] Satellite networks have the advantage of wide-area coverage, and can provide coverage supplementation for existing terrestrial communication networks, constructing a globally seamless satellite-terrestrial integrated network to achieve the vision of ubiquitous connection in 6G. The mobile phone direct satellite communication technology enables ordinary smartphone terminals to directly access the satellite network without passing through a base station relay. 3GPP has formulated relevant non-terrestrial network technical standards in 5G Release 17 and 18 to support the development of satellite-terrestrial integrated networks. Companies such as AST and SpaceX in the United States have successfully verified the ability of low-earth orbit satellites to provide broadband services for ordinary smartphone terminals in orbit by using large-scale phased array antennas. In China, China Mobile launched a low-earth orbit test satellite that complies with the 3GPP R17 standard at the beginning of 2024. The Huawei Mate 60 Pro mobile phone achieved two-way satellite voice communication through the Tiantong-1 satellite. However, the scarcity of spectrum resources severely limits the service capabilities of satellite networks. When a mobile phone operates in the mobile satellite service frequency band, it must integrate a dedicated satellite mobile communication chip, otherwise it cannot access the satellite network. In addition, when a satellite operates in the mobile satellite service frequency band, the limited bandwidth is difficult to support the access needs of a large number of users in a wide area. Therefore, the use of terrestrial mobile network spectrum by satellites has become a very attractive solution.

[0003] Most existing satellite spectrum sharing mechanisms achieve interference isolation between satellites and the ground by setting up a protection zone between the satellite service area and the ground network service area. Among them, there are no ground base stations in the protection zone, and the satellite beam does not provide signal coverage to the protection zone. Although this solution can achieve satellite-terrestrial spectrum sharing, there are coverage holes in the network within the protection zone, making it impossible for users to achieve seamless handover between ground base stations and satellites. In order to achieve global seamless coverage, the ground base station service area and the satellite beam service area need to overlap. However, when the satellite and the ground overlap and share the same frequency band of spectrum resources, the satellite-terrestrial interference will cause a sharp drop in the communication rate of users, significantly reducing the overall network capacity. To cope with inter-cell interference, some solutions propose a dynamic spectrum sharing mechanism to achieve satellite-terrestrial spectrum sharing through spectrum coordination between ground base stations and satellite networks. However, due to the time-varying network topology and cell load, this solution will bring high satellite and inter-cell signaling overheads. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem of high signaling overhead in the prior art.

[0005] To solve the above technical problems, the present invention provides a satellite-ground spectrum sharing method, including:

[0006] Dividing the internal area of a terrestrial cell into a cell center, a cell sub-center, and a cell edge according to the distance from a terrestrial base station;

[0007] Determining the area where a user is located within the terrestrial cell, and dividing the ground network spectrum into three orthogonal parts to serve users in the cell center, cell sub-center, and cell edge respectively;

[0008] Sharing the ground network spectrum exclusive to the cell center with a satellite wide beam;

[0009] Sharing the ground network spectrum exclusive to the cell sub-center and the cell edge with satellite narrow beams, and setting the size of the protection area of the terrestrial cell according to the antenna pattern of the satellite narrow beams, where no active satellite narrow beams are allowed in the protection area.

[0010] Preferably, the determining the area where a user is located within the terrestrial cell includes:

[0011] Calculating the distance between the user and the terrestrial base station according to the timing advance value of the user, and determining the area range where the user is located within the internal area of the terrestrial cell.

[0012] Preferably, the dividing the ground network spectrum into three orthogonal parts to serve users in the cell center, cell sub-center, and cell edge respectively includes:

[0013] Providing the ground network spectrum between f2 - f3 to users in the cell center for use;

[0014] Providing the ground network spectrum between f1 - f2 to users in the cell sub-center for use;

[0015] Providing the ground network spectrum between f0 - f1 to users in the cell edge for use;

[0016] When the load of the cell center is higher than a preset threshold, temporarily providing the ground network spectrum between f0 - f2 to users in the cell center for use;

[0017] When the load of the cell sub-center is higher than a preset threshold, temporarily providing the ground network spectrum between f0 - f1 to users in the cell sub-center for use.

[0018] Preferably, both the cell center and the cell sub-center adopt a full frequency reuse scheme, that is, the cell centers of different cells can all use all the ground network spectrum resources between f2 - f3, and the cell sub-centers of different cells can all use all the ground network spectrum resources between f1 - f2.

[0019] Preferably, the transmission power used when serving the cell-edge users is greater than the transmission power used when serving the cell-center users and the cell-subcenter users.

[0020] Preferably, a frequency multi-color reuse scheme is adopted both between the satellite wide beams and at the cell edge, that is, orthogonal spectrum resources are used between adjacent terrestrial cells and between adjacent satellite wide beams.

[0021] Preferably, the satellite narrow beam and the satellite wide beam with overlapping service areas operate on orthogonal spectra, and a frequency multi-color reuse scheme is adopted for all satellite narrow beams within the coverage range of the same satellite wide beam.

[0022] Preferably, when the satellite adopts an adaptive beamforming scheme and the beam projection and the cell shape are accurately aligned, the radius of the protection area is set to n times the radius of the narrow beam cell, where n is a constant.

[0023] Preferably, the satellite-ground spectrum sharing method further includes:

[0024] When the user is located in the satellite service area, downlink synchronization is achieved by identifying the synchronization signal and the physical broadcast block of the satellite wide beam and cell configuration information is obtained, and a preamble sequence is sent on the uplink time-frequency resources specified by the satellite to access the user to the satellite network.

[0025] Preferably, after the user accesses the satellite network:

[0026] The area where the user is located and the transmission service authorization application are provided to the satellite;

[0027] The satellite network is used to determine whether to activate the corresponding satellite narrow beam by identifying whether the area where the user is located is within the protection area;

[0028] When the user is outside the protection area, the satellite is used to activate the corresponding satellite narrow beam to provide high-rate services for the user, otherwise, the satellite wide beam continues to be used to provide services for the user.

[0029] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0030] The satellite-ground spectrum sharing method described in the present invention proposes a static downlink spectrum sharing mechanism for the problems of scarce spectrum resources, strong interference between satellites and ground during spectrum sharing, and large coordination signaling overhead. The present invention divides terrestrial cells into three regions with reference to the distance from users to the base station. In particular, the satellite wide beam and the center of the terrestrial cell share the spectrum, and are orthogonal to the working spectrum of the sub-center and the edge of the cell. The satellite narrow beam shares the terrestrial network spectrum resources through spatial isolation. The satellite-ground spectrum sharing mechanism designed by the present invention can achieve seamless global coverage without signaling coordination between the terrestrial and satellite networks. At the same time, in the satellite network, only the wide beam interferes with the users in the center of the terrestrial cell, and the useful signal of the users in the terrestrial cell is strong, while the signal of the wide beam is weak. Therefore, the proposed satellite-ground spectrum sharing mechanism causes a low loss of terrestrial network capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in conjunction with the drawings, where:

[0032] Figure 1 is the implementation flowchart of a satellite-ground spectrum sharing method provided by the present invention;

[0033] Figure 2 is the scenario diagram of the satellite-ground integrated network of the present invention;

[0034] Figure 3 is the spectrum sharing mechanism diagram of the wide beam and the terrestrial communication network of the present invention;

[0035] Figure 4 is the spectrum sharing mechanism diagram of the narrow beam of the present invention;

[0036] Figure 5 is the example diagram of the spatial isolation between the narrow beam and the terrestrial cell of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The core of the present invention is to provide a satellite-ground spectrum sharing method, which effectively reduces the coordination signaling overhead.

[0038] In order to enable those skilled in the art to better understand the solution of the present invention, the following further details the present invention in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Please refer to Figure 1 , Figure 1 is the implementation flowchart of a satellite-ground spectrum sharing method provided by the present invention; the specific operation steps are as follows:

[0040] S101: Divide the internal area of the terrestrial cell into a cell center, a cell sub - center, and a cell edge according to the distance from the terrestrial base station.

[0041] S102: Determine the area where the user is located within the terrestrial cell, and divide the terrestrial network spectrum into three orthogonal parts to serve the cell - center users, cell - sub - center users, and cell - edge users respectively.

[0042] S103: Share the terrestrial network spectrum exclusive to the cell center with the satellite wide - beam.

[0043] S104: Share the terrestrial network spectra exclusive to the cell sub - center and the cell edge with the satellite narrow - beam, and set the size of the protection area of the terrestrial cell according to the antenna pattern of the satellite narrow - beam. No active satellite narrow - beam is allowed within the protection area.

[0044] Based on the above embodiments, this embodiment details step S101:

[0045] As Figure 2 shown, divide the inside of the cell into three parts according to the distance from the center of the terrestrial cell, that is, the distance from the terrestrial base station, and name them the cell center, the cell sub - center, and the cell edge respectively.

[0046] Among them, the cell - center area is the closest to the base station, the cell - edge area is the farthest from the base station, and the cell sub - center is located between the cell center and the cell edge.

[0047] Among them, when dividing, the cell - center, sub - center, and cell - edge areas can respectively occupy 1 / 3 of the cell area.

[0048] Based on the above embodiments, this embodiment details step S102:

[0049] The determination of the area where the user is located within the terrestrial cell includes:

[0050] Calculate the distance between the user and the terrestrial base station according to the user's timing advance value, and judge the area range where the user is located within the internal area of the terrestrial cell:

[0051] The base station uses the timing - advance parameter of the user in the random - access process and the distance value of the internal division area of the cell to estimate the internal area of the cell where the user is located.

[0052] Among them, the distance d from the user to the base station can be approximately calculated through the timing - advance parameter as:

[0053]

[0054] Wherein, TA is the timing advance value of the user, and c is the speed of light;

[0055] Wherein, when the user is located at the center of the cell. When the user is located at the sub-center of the cell. When the user is located at the edge of the cell;

[0056] Wherein, R t is the radius of the terrestrial cell.

[0057] For example, Figure 3 dividing the terrestrial network spectrum into three orthogonal parts to serve the cell center users, cell sub-center users, and cell edge users respectively includes:

[0058] Providing the terrestrial network spectrum between f2 - f3 to the cell center users for use;

[0059] Providing the terrestrial network spectrum between f1 - f2 to the cell sub-center users for use;

[0060] Providing the terrestrial network spectrum between f0 - f1 to the cell edge users for use;

[0061] When the network load is high, the frequency planning within the frequency cell can be temporarily adjusted. Specifically:

[0062] When the load at the cell center is higher than the preset threshold, temporarily provide the terrestrial network spectrum between f0 - f2 to the cell center users for use;

[0063] When the load at the cell sub-center is higher than the preset threshold, temporarily provide the terrestrial network spectrum between f0 - f1 to the cell sub-center users for use.

[0064] Based on the above embodiments, since the interference signals received by the cell center and sub-center users are weak, both the cell center and the cell sub-center adopt a full frequency reuse scheme, that is, the cell centers of different cells can all use all the terrestrial network spectrum resources between f2 - f3, and the cell sub-centers of different cells can all use all the terrestrial network spectrum resources between f1 - f2.

[0065] Based on the above embodiments, since the path loss from the base station to the terrestrial cell edge users is large, the useful signal strength received by the edge users is low, and they are vulnerable to interference from neighboring base stations. Compared with the cell center and sub-center areas, a higher transmit power will be used when the base station serves the cell edge users to improve the service quality.

[0066] Based on the above embodiments, this embodiment elaborates on steps S103 and S104 in detail:

[0067] The satellite is equipped with wide beams and narrow beams simultaneously. The wide beams have relatively low signal quality and provide access and low-rate communication services for areas lacking terrestrial base station coverage to meet the global coverage requirement. The narrow beams have high service quality and provide high-rate communication services for users;

[0068] Among them, the coverage range of the wide beams far exceeds that of the narrow beams. For example, the diameter of the wide beams can reach several hundred kilometers, while the diameter of the narrow beams is generally dozens of kilometers;

[0069] Among them, the wide beams can overlap with the coverage areas of terrestrial cells and narrow beams, and the service area of the narrow beams is spatially isolated from the terrestrial cell airspace.

[0070] Based on the above embodiments, since the service signal quality in the central area of the terrestrial cell is relatively high and the interference level from the satellite wide beams is relatively low, the terrestrial network can share the spectrum exclusively occupied by the cell center with the wide beams, that is, the wide beams can operate on the spectrum f2 - f3.

[0071] Based on the above embodiments, in order to suppress the interference between beams and the interference at the edge of the terrestrial cell, a frequency multi-color reuse scheme is adopted both between the satellite wide beams and at the cell edge, that is, orthogonal spectrum resources are used between adjacent terrestrial cells and between adjacent satellite wide beams.

[0072] Based on the above embodiments, when the beam-serving cell is far from the terrestrial communication network, the satellite can use all the terrestrial spectrum resources to improve the spectrum efficiency. Since the coverage areas of the wide beams and narrow beams overlap, when the narrow beams and wide beams use the same spectrum, serious interference between beams will affect user access and service performance. Therefore, as Figure 4 , the satellite narrow beams and the satellite wide beams with overlapping service areas operate on orthogonal spectrums.

[0073] Based on the above embodiments, all the satellite narrow beams within the coverage range of the same satellite wide beam adopt a frequency multi-color reuse scheme to reduce the interference between beams.

[0074] Based on the above embodiments, since the narrow beams share the spectrum with the sub-central and edge users of the terrestrial cells, in order to reduce the interference between the satellite and the ground, it is necessary to set the size of the protection area of the terrestrial cell according to the antenna pattern of the satellite narrow beams. As Figure 5 shown, each terrestrial cell has a protection area, and no active narrow beams are allowed within the protection area;

[0075] Among them, when the satellite adopts an adaptive beamforming scheme and the beam projection and cell shape are accurately aligned, the radius of the protection area is set to n times the radius of the narrow beam cell, where n is a constant. In one embodiment, n = 3.

[0076] Based on the above embodiments, the satellite-ground spectrum sharing method further includes:

[0077] When the user is located in the satellite service area, downlink synchronization is achieved by identifying the synchronization signal and physical broadcast block of the satellite wide beam, and cell configuration information is obtained. A preamble sequence is sent on the uplink time-frequency resources designated by the satellite to access the user to the satellite network.

[0078] Among them, the cell configuration includes wide beam configuration information, narrow beam configuration information, etc.

[0079] Among them, the wide beam configuration information includes the time-frequency resource configuration information for uplink access, etc.

[0080] Among them, the narrow beam configuration information includes the regional scope of narrow beam services, etc.

[0081] Preferably, after the user accesses the satellite network:

[0082] Provide the area where the user is located and the transmission service authorization application to the satellite;

[0083] Use the satellite network to determine whether to activate the corresponding satellite narrow beam by identifying whether the area where the user is located is within the protection area;

[0084] When the user is outside the protection area, use the satellite to activate the corresponding satellite narrow beam to provide high-rate services for the user. Otherwise, continue to use the satellite wide beam to provide services for the user.

[0085] The present invention relates to the technical field of non-terrestrial networks, and in particular to a satellite-terrestrial spectrum sharing method. The satellite-terrestrial spectrum sharing method of the present invention proposes a static downlink spectrum sharing mechanism for the problems of scarce spectrum resources, strong interference between the satellite and the ground during spectrum sharing, and large coordination signaling overhead. The present invention divides the terrestrial cell into three regions with reference to the distance from the user to the base station. In particular, the satellite wide beam and the center of the terrestrial cell share the spectrum, and are orthogonal to the working spectrum of the cell sub-center and the edge; the satellite narrow beam shares the terrestrial network spectrum resources through the method of spatial isolation. The satellite-terrestrial spectrum sharing mechanism designed by the present invention can achieve global seamless coverage without signaling coordination between the terrestrial and satellite networks. At the same time, since the wide beam only interferes with the center of the terrestrial cell and the signal of the wide beam is weak, the capacity loss of the terrestrial network is low.

[0086] The satellite-terrestrial spectrum sharing mechanism proposed by the present invention makes full use of the advantage of wide beam wide coverage and can achieve global seamless coverage. At the same time, since the useful signal in the cell center area is strong, the interference of the wide beam on the performance of the terrestrial cell can be significantly reduced, the problem of scarce spectrum resources can be solved, and high spectrum efficiency can be achieved. The satellite-terrestrial spectrum sharing mechanism proposed by the present invention does not require signaling coordination between the terrestrial base station and the satellite network, and significantly reduces the complexity of implementing spectrum sharing in the existing network.

[0087] An embodiment of the present invention also provides a satellite-ground spectrum sharing device; the specific device may include:

[0088] A region division module, configured to divide the internal region of a terrestrial cell into a cell center, a cell sub-center, and a cell edge according to the distance from a terrestrial base station;

[0089] A spectrum division module, configured to determine the region where a user is located in a terrestrial cell, and divide the ground network spectrum into three orthogonal parts to provide services for cell center users, cell sub-center users, and cell edge users respectively;

[0090] A wide beam sharing module, configured to share the ground network spectrum exclusively occupied by the cell center with a satellite wide beam;

[0091] A narrow beam sharing module, configured to share the ground network spectrum exclusively occupied by the cell sub-center and the cell edge with a satellite narrow beam, and set the size of a protection region of the terrestrial cell according to the antenna pattern of the satellite narrow beam, and no active satellite narrow beam is allowed in the protection region.

[0092] The satellite-ground spectrum sharing device in this embodiment is used to implement the foregoing satellite-ground spectrum sharing method. Therefore, the specific implementation manners in the satellite-ground spectrum sharing device can be seen in the embodiment part of the foregoing satellite-ground spectrum sharing method. For example, the region division module, the spectrum division module, the wide beam sharing module, and the narrow beam sharing module are respectively used to implement steps S101, S102, S103, and S104 in the foregoing satellite-ground spectrum sharing method. Therefore, the specific implementation manners can refer to the descriptions of the corresponding respective part embodiments and will not be elaborated herein.

[0093] A specific embodiment of the present invention also provides a satellite-ground spectrum sharing device, including: a memory, configured to store a computer program; a processor, configured to implement the steps of the foregoing satellite-ground spectrum sharing method when executing the computer program.

[0094] A specific embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the foregoing satellite-ground spectrum sharing method are implemented.

[0095] Those skilled in the art should understand that the embodiments of the present application may be provided as a method, a system, or a computer program product. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0096] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0097] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0098] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0099] Obviously, the above embodiments are merely examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A satellite-ground spectrum sharing method, characterized in that: include: The internal area of ​​the land cell is divided into the cell center, the cell sub-center and the cell edge according to the distance from the land base station; Determine the area where users are located within a terrestrial cell and divide the terrestrial network spectrum into three orthogonal parts to provide services for cell center users, cell sub-center users, and cell edge users respectively; Sharing the ground network spectrum exclusively occupied by the cell center with the satellite wide beam; The ground network spectrum exclusively occupied by the cell sub-center and the cell edge is shared with the satellite narrow beam, and the size of the protection area of ​​the terrestrial cell is set according to the antenna pattern of the satellite narrow beam. No activated satellite narrow beam is allowed in the protection area.

2. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: Determining the area where the user is located in the terrestrial cell includes: The distance between the user and the land base station is calculated according to the timing advance value of the user, and the area where the user is located in the inner area of ​​the land cell is determined.

3. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: The terrestrial network spectrum is divided into three orthogonal parts to provide services for cell center users, cell sub-center users and cell edge users respectively, including: Provide the terrestrial network spectrum with frequencies between f2 and f3 for cell center users; Provide the ground network spectrum between f1 and f2 for the users in the cell sub-center; Provide the terrestrial network spectrum between f0 and f1 for cell edge users; When the cell center load is higher than the preset threshold, the ground network spectrum between f0 and f2 is temporarily provided to the cell center users; When the cell sub-center load is higher than a preset threshold, the ground network spectrum with frequencies between f0 and f1 is temporarily provided to the cell sub-center users.

4. The satellite-to-ground spectrum sharing method according to claim 3, characterized in that: The cell center and the cell sub-center both adopt a full-frequency reuse scheme, that is, the cell centers of different cells can use all ground network spectrum resources with frequencies between f2 and f3, and the cell sub-centers of different cells can use all ground network spectrum resources with frequencies between f1 and f2.

5. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: The transmission power used when providing services to the cell edge users is greater than the transmission power used when providing services to the cell center users and the cell sub-center users.

6. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: A frequency multi-color multiplexing scheme is adopted between the satellite wide beams and the cell edge, that is, orthogonal spectrum resources are used between adjacent terrestrial cells and between adjacent satellite wide beams.

7. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: The satellite narrow beam and the satellite wide beam with overlapping service areas work on orthogonal frequency spectrums, and all satellite narrow beams within the coverage area of ​​the same satellite wide beam adopt a frequency multi-color multiplexing scheme.

8. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: When the satellite adopts an adaptive beamforming solution and achieves precise alignment of beam projection and cell shape, the radius of the protection area is set to n times the radius of the narrow beam cell, where n is a constant.

9. The satellite-to-ground spectrum sharing method according to claim 1, characterized in that: The satellite-ground spectrum sharing method further includes: When the user is located in the satellite service area, downlink synchronization is achieved and cell configuration information is obtained by identifying the synchronization signal and physical broadcast block of the satellite wide beam, and a preamble sequence is sent on the uplink time and frequency resources specified by the satellite to connect the user to the satellite network.

10. The satellite-to-ground spectrum sharing method according to claim 9, characterized in that: When the user accesses the satellite network: Providing the area where the user is located and the transmission service authorization application to the satellite; Using a satellite network to identify whether the area where the user is located is within the protection area, and then determining whether to activate a corresponding satellite narrow beam; When the user is outside the protection area, the satellite activates the corresponding satellite narrow beam to provide high-speed service to the user; otherwise, the satellite wide beam continues to be used to provide service to the user.

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