Satellite constellation-based random access method and device, and storage medium
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YINHE HANGTIAN (XIAN) TECHNOLOGY CO LTD
- Filing Date
- 2026-03-23
- Publication Date
- 2026-07-14
Smart Images
Figure CN122395745A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of satellite and satellite communication technology, and in particular to a random access method, apparatus and storage medium based on a satellite constellation. Background Technology
[0002] Satellite communication uses satellites as relays to achieve communication. Compared to 4G, 5G, and fiber optic communication, satellite communication has a wider coverage area and can even reach areas with weak signals, such as mountainous regions. Therefore, satellite communication is a communication method that can supplement existing commonly used communication methods.
[0003] In existing technologies, terminal devices access satellite-provided communication services via RACH.
[0004] In practical applications, satellites operate in orbit according to a predetermined pattern. However, after a terminal device accesses the wireless communication network via RACH for a period of time, the satellite may move away from its original position, thereby reducing the quality of service provided by the wireless communication network to the terminal device.
[0005] There is currently no effective solution to the technical problem in the existing technology that the quality of service of the wireless communication network provided to terminal devices is reduced because the satellite is far from its original position. Summary of the Invention
[0006] The embodiments of this disclosure provide a random access method, apparatus, and storage medium based on a satellite constellation, to at least solve the technical problem in the prior art where the quality of service of the wireless communication network provided to terminal devices is reduced due to the satellites being far from their original positions.
[0007] According to one aspect of the present disclosure, a random access method based on a satellite constellation is provided, comprising: a first satellite receiving a preamble sent by a terminal device; the first satellite determining the location of the terminal device based on the preamble; the first satellite determining whether a target satellite in the same constellation exists based on ephemeris information and the location of the terminal device, wherein the target satellite refers to a satellite in the same constellation that is more suitable than the first satellite for providing communication services to the terminal device after a preset time period; if a target satellite is determined to exist, the first satellite forwarding the preamble to the target satellite; upon receiving the preamble, the target satellite allocating uplink resources to the terminal device based on the preamble and sending uplink resource information to the terminal device; and the terminal device receiving the uplink resource information and sending its own identifier to the target satellite based on the uplink resources corresponding to the uplink resource information.
[0008] According to another aspect of the present disclosure, a storage medium is also provided, the storage medium including a stored program, wherein, when the program is executed, a processor performs any of the methods described above.
[0009] According to another aspect of the present disclosure, a satellite constellation-based random access device is also provided, comprising: a receiving module for receiving a preamble sent by a terminal device via a first satellite; a location determination module for determining the location of the terminal device via the first satellite based on the preamble; a target satellite determination module for determining whether a target satellite in the same constellation exists via the first satellite based on ephemeris information and the location of the terminal device, wherein the target satellite refers to a satellite in the same constellation that is more suitable than the first satellite for providing communication services to the terminal device after a preset duration; a forwarding module for forwarding the preamble to the target satellite via the first satellite when the existence of the target satellite is determined; an uplink resource allocation module for allocating uplink resources to the terminal device based on the preamble when the target satellite receives the preamble, and sending uplink resource information to the terminal device; and a receiving module for the terminal device to receive the uplink resource information and send its own identifier to the target satellite based on the uplink resources corresponding to the uplink resource information.
[0010] According to another aspect of the present disclosure, a satellite constellation-based random access device is also provided, comprising: a processor; and a memory connected to the processor, configured to provide the processor with instructions for processing the following steps: receiving a preamble sent by a terminal device via a first satellite; determining the location of the terminal device via the first satellite based on the preamble; determining whether a target satellite in the same constellation exists via the first satellite based on ephemeris information and the location of the terminal device, wherein the target satellite is a satellite in the same constellation that is more suitable than the first satellite for providing communication services to the terminal device after a preset duration; if a target satellite is determined to exist, forwarding the preamble to the target satellite via the first satellite; upon receiving the preamble, allocating uplink resources to the terminal device via the target satellite based on the preamble and sending uplink resource information to the terminal device; and receiving the uplink resource information via the terminal device and sending its own identifier to the target satellite based on the uplink resources corresponding to the uplink resource information.
[0011] In this embodiment, the first satellite receives a preamble sent by the terminal device and determines the location of the terminal device based on the preamble. Then, the first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If a target satellite is determined to exist, the first satellite forwards the preamble to the target satellite. Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device according to the preamble and sends uplink resource information to the terminal device; and the terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information. Thus, after receiving the preamble sent by the terminal device, the first satellite determines whether there is a target satellite that is more suitable than itself to provide communication services to the terminal device after a preset time period. If a target satellite can be identified, it means that the first satellite may soon move away from its original position, and there is a target satellite in the same constellation that can subsequently replace the first satellite to provide communication services to the terminal device. Therefore, once the first satellite identifies the target satellite, it forwards the preamble to the target satellite, which then performs the remaining RACH procedure with the corresponding terminal device. Thus, the method provided in this embodiment can improve the quality of service of the wireless communication network provided to the terminal device to a certain extent. Attached Figure Description
[0012] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings: Figure 1 This is a schematic diagram of the satellite communication system according to Embodiment 1 of this disclosure; Figure 2 This is a schematic diagram of the satellite structure according to Embodiment 1 of this disclosure; Figure 3 This is a flowchart illustrating the random access method based on a satellite constellation according to the first aspect of Embodiment 1 of this disclosure; Figure 4 This is a schematic diagram of the overlapping coverage area between the first satellite and other satellites according to the first aspect of Embodiment 1 of this disclosure; Figure 5 This is a schematic diagram of the interaction process between the first satellite, the terminal device, and the target satellite according to the first aspect of Embodiment 1 of this disclosure; Figure 6 This is a schematic diagram illustrating the relative positional relationship between the satellite and the terminal according to the first aspect of Embodiment 1 of this disclosure; Figure 7This is a schematic diagram of a satellite constellation-based random access device according to the first aspect of Embodiment 2 of this disclosure; and Figure 8 This is a schematic diagram of a satellite constellation-based random access device according to the first aspect of Embodiment 3 of this disclosure. Detailed Implementation
[0013] To enable those skilled in the art to better understand the technical solutions of this disclosure, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.
[0014] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. Example 1
[0015] According to this embodiment, a random access method based on a satellite constellation is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.
[0016] Figure 1A schematic diagram of a satellite communication system according to this embodiment is shown. The system includes satellites in the same constellation and terminal devices. In this embodiment, the terminal device sends a preamble (i.e., sends a RACH access request) to a first satellite via RACH. The first satellite can be a satellite selected by the terminal device itself. When the terminal device sends the preamble, the coverage area of the first satellite covers the location of the terminal device. However, there is a situation where, shortly after the first satellite receives the preamble from the terminal device, it moves away from its original position, resulting in poor quality of the wireless communication network used by the terminal device shortly after it accesses the wireless communication network provided by the first satellite.
[0017] Therefore, the satellite constellation-based random access method provided in this application addresses this problem by having the first satellite, upon receiving a preamble from the terminal device, determine the terminal device's location based on the preamble. Then, the first satellite, based on ephemeris information and the terminal device's location, determines whether a target satellite in the same constellation exists. The target satellite refers to a satellite in the same constellation that, after a preset time period, is more suitable than the first satellite to provide communication services to the terminal device. If a target satellite is found to exist, the first satellite forwards the received preamble to it. Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device according to the corresponding preamble and sends the uplink resource information to the terminal device. The terminal device receives the uplink resource information and sends its own identifier to the target satellite based on the corresponding uplink resources.
[0018] In this way, after receiving the preamble from the terminal device, the first satellite determines whether, after a preset time interval, there exists a target satellite more suitable than itself to provide communication services to the terminal device. If a target satellite can be identified, it means that the first satellite may soon move away from its original position, and there is a subsequent target satellite in the same constellation that can replace the first satellite to provide communication services to the terminal device. Therefore, when the first satellite identifies a target satellite, it forwards the preamble to the target satellite, which then performs the remaining RACH process with the corresponding terminal device. Thus, the method provided in this embodiment can improve the quality of service of the wireless communication network provided to the terminal device to a certain extent.
[0019] Figure 2 Further shown Figure 1 A schematic diagram of the hardware architecture of the satellite. (Reference) Figure 2As shown, the satellite includes an integrated electronic system, which comprises a processor, a memory, a bus management module, and a communication interface. The memory is connected to the processor, allowing the processor to access the memory, read program instructions stored in the memory, and read or write data to the memory. The bus management module is connected to the processor and also to a bus such as a CAN bus. Thus, the processor can communicate with onboard peripherals connected to the bus through the bus managed by the bus management module. Furthermore, the processor also communicates with devices such as cameras, star sensors, telemetry and command transponders, and data transmission equipment via the communication interface. Those skilled in the art will understand that… Figure 2 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, a satellite system may also include... Figure 2 The more or fewer components shown, or having the same Figure 2 The different configurations shown.
[0020] It should be noted that, Figure 2 One or more processors and / or other data processing circuits shown herein may generally be referred to as "data processing circuitry". This data processing circuitry may be embodied, in whole or in part, in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuitry may be a single, independent processing module, or may be integrated, in whole or in part, into any other element in a computing device. As involved in embodiments of this disclosure, the data processing circuitry serves as processor control (e.g., selection of a variable resistor termination path connected to an interface).
[0021] Figure 2 The memory shown can be used to store software programs and modules of application software, such as the program instruction / data storage device corresponding to the satellite constellation-based random access method in this embodiment of the present disclosure. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the above-mentioned application's satellite constellation-based random access method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. It should be noted here that, in some optional embodiments, the above... Figure 2 The device shown may include hardware elements (including circuitry), software elements (including computer code stored on a computer-readable medium), or a combination of both hardware and software elements. It should be noted that... Figure 2 This is only one instance of a specific particular instance, and is intended to illustrate the types of components that may exist in the aforementioned devices.
[0022] Under the aforementioned operating environment, according to the first aspect of this embodiment, a random access method based on a satellite constellation is provided. This method can be... Figure 1 The satellite and terminal equipment shown are implemented. Figure 3 A flowchart illustrating the method is shown below. (Refer to...) Figure 3 As shown, the method includes: S302: Preamble sent by the first satellite receiving terminal equipment; S304: The first satellite determines the location of the terminal device based on the preamble; S306: The first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. S308: If the existence of a target satellite is confirmed, the first satellite will forward the preamble to the target satellite; S310: Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device based on the preamble and sends the uplink resource information to the terminal device; and S312: The terminal device receives uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information.
[0023] The terminal device in this embodiment is not limited to mobile phones, smart wearable devices, etc.
[0024] First, the preamble (S302) is sent by the first satellite receiving terminal equipment.
[0025] Then, the first satellite determines the location of the terminal device based on the preamble (S304).
[0026] How the first satellite determines the location of the terminal device based on the corresponding preamble will be explained later.
[0027] Then, based on ephemeris information and the location of the terminal device, the first satellite determines whether there is a target satellite in the same constellation. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset duration (S306).
[0028] It should be noted that the preset duration mentioned above can refer to a duration set manually based on the satellite's operational patterns. For example, the preset duration could be set to 30 minutes.
[0029] The ephemeris information mentioned above can represent the operational patterns of each satellite in the constellation. For example, ephemeris information can include satellite identifiers, orbital information, satellite speeds at various times, and satellite positions at different times. Therefore, based on the ephemeris information, the positions of each satellite in the constellation after a preset time period can be determined (including the position of the first satellite in the constellation and the positions of other satellites in the corresponding constellation). Thus, based on the ephemeris information and the location of the terminal device, it can be determined whether the first satellite is about to move away from its current position (i.e., whether the first satellite is about to move away from a suitable location to provide communication services to the corresponding terminal device), and whether other satellites will move to positions where they can replace the first satellite to provide communication services to the corresponding terminal device. Therefore, based on the ephemeris information and the location of the terminal device, it can be determined whether there are target satellites in the same constellation.
[0030] If the presence of a target satellite is confirmed, the first satellite can forward the preamble to the target satellite (S308).
[0031] Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device based on the preamble and sends the uplink resource information to the terminal device (S310).
[0032] The terminal device receives uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information (S312).
[0033] In other words, once the presence of a target satellite is confirmed, the target satellite continues the RACH process with the terminal device. The first satellite forwards the preamble sent by the terminal device to the target satellite. The target satellite allocates uplink resources to the terminal device based on the corresponding preamble and sends the corresponding uplink resource information to the terminal device. After receiving the uplink resource information, the terminal device sends its own identifier (ID) to the target satellite. The target satellite can then broadcast the terminal device's ID to complete the RACH process with the terminal device.
[0034] As described in the background section, in practical applications, when a satellite operates in its orbit in a predetermined manner, there may be a situation where, after a terminal device accesses the wireless communication network to the satellite via RACH for a period of time, the satellite moves away from its original position, thereby reducing the quality of service provided by the wireless communication network to the terminal device.
[0035] In view of this, in this embodiment, the first satellite receives the preamble sent by the terminal device and determines the location of the terminal device based on the corresponding preamble. Then, the first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If a target satellite is determined to exist, the first satellite forwards the preamble to the target satellite. Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device according to the preamble and sends uplink resource information to the terminal device; and the terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information. Thus, when the first satellite receives the preamble sent by the terminal device, it determines whether there is a target satellite that is more suitable than itself to provide communication services to the terminal device after a preset time period. If a target satellite can be determined, it means that the first satellite may soon move away from its original position, and there is a target satellite in the same constellation that can subsequently replace the first satellite to provide communication services to the terminal device. Therefore, once the first satellite identifies the target satellite, it forwards the preamble to the target satellite, which then performs the remaining RACH procedure with the corresponding terminal device. Thus, the method provided in this embodiment can improve the quality of service of the wireless communication network provided to the terminal device to a certain extent.
[0036] Optionally, the operation of the first satellite determining whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device includes: if the first satellite determines that the terminal device is located in the overlapping coverage area between the first satellite and other nearby satellites, the first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device.
[0037] refer to Figure 4 As shown, the first satellite can determine the location of the terminal device, for example... Figure 4 In cases of overlapping coverage areas, the presence of a target satellite from the same constellation is then determined. In other words, when the terminal device is located within a corresponding overlapping coverage area, it is more likely that in subsequent stages, the first satellite will move away from its original position and in a direction away from the terminal device, or that other nearby satellites will approach the first satellite's original position. Therefore, in this situation (where the first satellite determines the overlapping coverage area of the terminal device's location), the first satellite can determine whether a target satellite exists. If a target satellite exists, it can then replace the first satellite in continuing the RACH process with the terminal device.
[0038] The ephemeris information may include the coverage area (or service area) for each satellite, which refers to the ground area where the satellite's signal can be transmitted. Therefore, the first satellite can determine the overlapping coverage area with neighboring satellites based on the coverage areas of each satellite, and then determine whether the terminal device is within the corresponding overlapping coverage area.
[0039] Optionally, the operation of the first satellite determining whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device includes: the first satellite determining the distance between itself and the terminal device after a preset time period based on its own location in ephemeris information and the location of the terminal device, as a first distance; and the first satellite determining the distance between other satellites near itself and the terminal device after a preset time period based on the locations of other satellites near itself in ephemeris information and the location of the terminal device, as a second distance; and determining whether there is a target satellite based on the first distance and the second distance.
[0040] In other words, the first satellite determines its own position and the positions of other satellites from the ephemeris information. The ephemeris information can directly provide the position of the first satellite and the positions of other satellites after a preset time period, so the first satellite does not need to calculate it itself.
[0041] Then, the first satellite can determine the distance between itself and the terminal device after the preset time period based on its own location (its location after the preset time period) and the location of the terminal device, as the first distance. Furthermore, the first satellite can determine the distance between the corresponding other satellites and the terminal device after the preset time period based on the locations of other nearby satellites (the locations of other satellites after the preset time period) and the location of the terminal device, as the second distance. The first satellite can then determine whether a target satellite exists based on the first and second distances. For example, if the first distance is very far and the second distance is relatively close compared to the first distance, the first satellite can identify the target satellite for the terminal device.
[0042] Optionally, the operation of determining whether a target satellite exists based on the first distance and the second distance includes: determining whether the first distance exceeds a first preset distance threshold; if the first distance exceeds the first preset distance threshold, determining whether there are other satellites whose distance from the terminal device does not exceed the second preset distance threshold based on the second distance, and selecting satellites whose distance from the terminal device does not exceed the second preset distance threshold as candidate satellites; if yes, selecting a target satellite from the candidate satellites; if no, determining that no target satellite exists.
[0043] The aforementioned first preset distance threshold is greater than the second preset distance threshold. Both the first and second preset distances can be preset by relevant personnel.
[0044] In other words, if the distance to the terminal device exceeds a first preset distance threshold, the first satellite can determine whether there are other satellites whose distance to the terminal device does not exceed a second preset distance threshold, and select these satellites as candidate satellites. Furthermore, if the first satellite determines that there is a satellite whose distance to the terminal device does not exceed the second preset distance threshold, it can select a target satellite from the candidate satellites (e.g., selecting the one with the shortest distance). If the first satellite determines that there is no satellite whose distance to the terminal device does not exceed the second preset distance threshold, it means that there is no target satellite. In the case of no target satellite (or the case where the first satellite has not determined a target satellite), the first satellite itself continues the RACH process with the terminal device.
[0045] refer to Figure 5 As shown, when the first satellite identifies the target satellite, the first satellite forwards the preamble sent by the terminal device to the target satellite, which then allocates uplink resources to the terminal device and sends the corresponding uplink resource information to the terminal device.
[0046] refer to Figure 6 As shown, the first satellite can determine its relative movement speed based on the Doppler frequency offset. This determines the relative position of the terminal to itself, thereby determining the location of the terminal.
[0047] Optionally, the operation of the first satellite determining the location of the terminal device based on the preamble includes: the first satellite determining the Doppler frequency offset corresponding to the preamble; the first satellite determining its relative speed with respect to the terminal device based on the Doppler frequency offset; the first satellite determining the cosine value of a first angle and the length of the distance projected onto a first plane based on its own altitude and the distance between itself and the terminal device, wherein the first plane represents the horizontal plane where the first satellite is located, and the first angle represents the direction angle of the terminal device's movement relative to the first satellite within the first plane; the first satellite determining the cosine value of a second angle based on the relative speed, the actual speed of the first satellite, and the cosine value of the first angle, wherein the second angle represents the direction angle of the terminal device's movement relative to the first satellite within a second plane, and the second plane represents the vertical plane where the first satellite and the terminal device are located; and the first satellite determining the location of the terminal device based on the second angle and the length of the distance projected onto the first plane.
[0048] First, the first satellite can determine the Doppler frequency offset corresponding to the preamble.
[0049] Table 1 below shows an example of the time-domain structure of the preamble: Table 1 Where CP stands for Cyclic Prefix, and the middle column of Table 1 represents the symbol sequence: referring to the sequence passed through m subcarriers Sub1~Sub m m symbols are transmitted in parallel, and GP represents the guard time.
[0050] The first satellite determines the preamble transmitted by the terminal device by receiving m symbols transmitted in parallel by m subcarriers. The number of subcarriers, m, is determined by the specific configuration of the RACH. Then, the first satellite can determine the transmission frequencies rf1~rf1 corresponding to the m subcarriers of the preamble, based on the time-frequency resources corresponding to the preamble. m And satellite 10 can determine the receiving frequencies f1~f1 corresponding to the received m subcarriers. m In other words, the receiving frequency corresponding to a subcarrier refers to the frequency of the subcarrier signal actually received by the first satellite, while the transmitting frequency corresponding to a subcarrier is the frequency of the subcarrier signal transmitted by the terminal equipment. The reason the transmitting frequency can be determined based on time-frequency resources is that in RACH, the terminal equipment needs to transmit the corresponding preamble according to the corresponding time-frequency resources. Specifically, the transmitting frequencies rf1~rf corresponding to the m subcarriers can be determined based on the frequency resources within the time-frequency resources. m .
[0051] Then, the terminal device can receive frequencies f1~f1 corresponding to m subcarriers. m The transmission frequencies rf1~rf corresponding to m subcarriers m By comparing them one by one, the Doppler frequency offsets Δf1~Δf of the m subcarriers can be determined. m This serves as the Doppler frequency offset corresponding to the preamble.
[0052] Then, the terminal device can determine the relative speed based on the Doppler frequency offset. Figure 6 The one shown Specifically, the velocity value vs corresponding to the i-th subcarrier can be calculated using the following formula (1). i : (1) Among them, vs i For the velocity value corresponding to the i-th subcarrier, vs iΔf represents the satellite's speed relative to the terminal device, determined by the Doppler frequency offset of the i-th subcarrier signal. i For the Doppler frequency offset corresponding to the i-th subcarrier, rf i Let be the transmission frequency of the i-th subcarrier, c be the wave speed of the electromagnetic wave, and i = 1 ~ m.
[0053] In other words, since the first satellite receives the preamble sent by the terminal device by receiving symbols carried by m subcarrier signals, it can determine m Doppler frequency offsets. Correspondingly, it can determine m relative motion velocities (i.e., the velocity values vs1~vs ... m Therefore, the velocity values vs1~vs corresponding to the m subcarriers can be obtained through the following formula (2). m The average speed of the first satellite relative to the terminal device is determined by averaging. .
[0054] (2) Then, the first satellite, based on its own altitude and the distance between itself and the terminal device, determines the cosine value of the first angle and the length of the distance between itself and the terminal device projected onto the first plane. (Reference) Figure 6 As shown, Figure 6 The midplane ASB is called the first plane. Figure 6 The plane SoU in the middle is called the second plane. Figure 6 The angle φ in the middle is called the first angle. Figure 6 The angle θ in the equation is called the second angle. Figure 6 In the xyz coordinate system, the xoy plane represents the ground, with the x-axis parallel to the direction of the first satellite's movement and the z-axis passing through the centroid of the first satellite. The SoU plane is perpendicular to the xoy plane and contains the centroids of the first satellite and the terminal equipment. The ASB plane is parallel to the xoy plane and contains the centroid of the first satellite. It can be seen that the first angle is the angle between lines SU and SA, and the second angle is the angle between lines SA and SB.
[0055] It can be seen that, by using the height h and the distance r, the cosine value cosφ corresponding to the first angle (angle φ) and the length value d of the distance r projected onto the first plane can be determined.
[0056] Then, based on the relative speed, the following formula (3) can be used. The actual speed of the first satellite Given the cosine value of the first angle, cosφ, determine the cosine value of the second angle, cosθ.
[0057] (3) Then, based on the cosine value of the second angle (cosθ), the sine value of the second angle (sinθ), and the length d of the distance projected onto the first plane, the first satellite can determine the ground position of the terminal device relative to the first satellite. , ).
[0058] Therefore, the ground position of the terminal device relative to the first satellite can be determined. , This is used to determine the location of the terminal device.
[0059] It should be noted that the first satellite can determine the distance between itself and the terminal device in the following ways. Specifically, the first satellite can determine the transmission time of the preamble sent by the terminal device and the reception time of the preamble itself. Since time-frequency resources define the timing for the terminal device to send the preamble, the first satellite can determine the transmission time of the preamble by considering the corresponding transmission timing of the preamble in the time-frequency resources and its own reception time. Therefore, the first satellite can determine the distance between itself and the terminal device based on the reception and transmission times. Furthermore, the first satellite can determine the duration between the reception and transmission times, and then, based on this duration and the speed of electromagnetic waves, determine the distance between itself and the terminal device.
[0060] In addition, refer to Figure 1 As shown, according to a second aspect of this embodiment, a storage medium is provided. The storage medium includes a stored program, wherein, when the program is executed, a processor performs any of the methods described above.
[0061] According to this embodiment, the first satellite receives a preamble sent by the terminal device and determines the location of the terminal device based on the preamble. Then, the first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If a target satellite is determined to exist, the first satellite forwards the preamble to the target satellite. Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device according to the preamble and sends uplink resource information to the terminal device; and the terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information. Thus, after receiving the preamble sent by the terminal device, the first satellite determines whether there is a target satellite that is more suitable than itself to provide communication services to the terminal device after a preset time period. If a target satellite can be identified, it means that the first satellite may soon move away from its original position, and there is a target satellite in the same constellation that can subsequently replace the first satellite to provide communication services to the terminal device. Therefore, once the first satellite identifies the target satellite, it forwards the preamble to the target satellite, which then performs the remaining RACH process with the corresponding terminal device. Furthermore, in this embodiment, the first satellite can determine the location of the terminal based on the Doppler frequency offset corresponding to the received preamble, thereby enabling it to identify the target satellite. Thus, the method provided in this embodiment can improve the quality of service of the wireless communication network provided to the terminal device to a certain extent.
[0062] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.
[0063] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention. Example 2
[0064] Figure 7 A satellite constellation-based random access device according to the first aspect of this embodiment is shown, which corresponds to the method described according to the first aspect of Embodiment 1. Reference Figure 7 As shown, the satellite constellation-based random access device includes: a receiving module 710, used to receive a preamble sent by a terminal device via a first satellite; a location determination module 720, used to determine the location of the terminal device based on the preamble via the first satellite; a target satellite determination module 730, used to determine whether a target satellite in the same constellation exists via the first satellite based on ephemeris information and the location of the terminal device, wherein the target satellite refers to a satellite in the same constellation that is more suitable than the first satellite for providing communication services to the terminal device after a preset duration; a forwarding module 740, used to forward the preamble to the target satellite via the first satellite if the existence of the target satellite is determined; an uplink resource allocation module 750, used to allocate uplink resources to the terminal device via the target satellite based on the preamble upon receiving the preamble, and send the uplink resource information to the terminal device; and a sending module 760, used by the terminal device to receive the uplink resource information and send its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information.
[0065] Optionally, the target satellite determination module 730 is used to determine whether there are target satellites in the same constellation when the terminal device is located in the overlapping coverage area between the first satellite and other neighboring satellites, based on the ephemeris information and the location of the terminal device.
[0066] Optionally, the target satellite determination module 730 is used to determine, based on the location of the first satellite in ephemeris information and the location of the terminal device, the distance between itself and the terminal device after a preset time period, as a first distance; and to determine, based on the location of other satellites near itself in ephemeris information and the location of the terminal device, the distance between other satellites near itself and the terminal device after a preset time period, as a second distance; and to determine whether a target satellite exists based on the first distance and the second distance.
[0067] Optionally, the target satellite determination module 730 is used to determine whether the first distance exceeds a first preset distance threshold; if the first distance exceeds the first preset distance threshold, it determines whether there are other satellites whose distance from the terminal device does not exceed the second preset distance threshold based on the second distance, and selects the satellites whose distance from the terminal device does not exceed the second preset distance threshold as candidate satellites; if yes, the target satellite is selected from the candidate satellites, otherwise, it is determined that there is no target satellite.
[0068] Optionally, the position determination module 720 is used to: determine the Doppler frequency offset corresponding to the preamble using the first satellite; determine the relative moving speed of the first satellite relative to the terminal device using the first satellite based on the Doppler frequency offset; determine the cosine value of a first angle and the length value of the distance projected onto a first plane using the first satellite based on its own height and the distance between itself and the terminal device, wherein the first plane represents the horizontal plane where the first satellite is located, and the first angle represents the direction angle of the moving direction of the terminal device relative to the first satellite in the first plane; determine the cosine value of a second angle using the first satellite based on the relative moving speed, the actual speed of the first satellite, and the cosine value of the first angle, wherein the second angle represents the direction angle of the moving direction of the terminal device relative to the first satellite in the second plane, and the second plane represents the vertical plane where the first satellite and the terminal device are located; and determine the position of the terminal device using the first satellite based on the second angle and the length value of the distance projected onto the first plane.
[0069] According to this embodiment, the first satellite receives a preamble sent by the terminal device and determines the location of the terminal device based on the preamble. Then, the first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If a target satellite is determined to exist, the first satellite forwards the preamble to the target satellite. Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device according to the preamble and sends uplink resource information to the terminal device; and the terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information. Thus, after receiving the preamble sent by the terminal device, the first satellite determines whether there is a target satellite that is more suitable than itself to provide communication services to the terminal device after a preset time period. If a target satellite can be identified, it means that the first satellite may soon move away from its original position, and there is a target satellite in the same constellation that can subsequently replace the first satellite to provide communication services to the terminal device. Therefore, once the first satellite identifies the target satellite, it forwards the preamble to the target satellite, which then performs the remaining RACH process with the corresponding terminal device. Furthermore, in this embodiment, the first satellite can determine the location of the terminal based on the Doppler frequency offset corresponding to the received preamble, thereby enabling it to identify the target satellite. Thus, this embodiment provides a wireless communication network that can improve the quality of service for terminal devices to a certain extent. Example 3
[0070] Figure 8A satellite constellation-based random access device according to the first aspect of this embodiment is shown, which corresponds to the method described according to the first aspect of Embodiment 1. Reference Figure 8 As shown, the satellite constellation-based random access device includes: a processor 810; and a memory 820 connected to the processor 810, used to provide the processor 810 with instructions to process the following steps: receiving a preamble sent by a terminal device via a first satellite; determining the location of the terminal device via the first satellite based on the preamble; determining whether a target satellite in the same constellation exists via the first satellite based on ephemeris information and the location of the terminal device, wherein the target satellite is a satellite in the same constellation that is more suitable than the first satellite for providing communication services to the terminal device after a preset time period; if a target satellite is determined to exist, forwarding the preamble to the target satellite via the first satellite; if the preamble is received, allocating uplink resources to the terminal device via the target satellite based on the preamble and sending uplink resource information to the terminal device; and receiving the uplink resource information via the terminal device and sending its own identifier to the target satellite based on the uplink resources corresponding to the uplink resource information.
[0071] Optionally, the operation of determining whether there is a target satellite in the same constellation by the first satellite based on ephemeris information and the location of the terminal device includes: if the first satellite determines that the terminal device is located in the overlapping coverage area between the first satellite and other nearby satellites, the operation of determining whether there is a target satellite in the same constellation by the first satellite based on ephemeris information and the location of the terminal device.
[0072] Optionally, the operation of determining whether a target satellite in the same constellation exists by the first satellite based on ephemeris information and the location of the terminal device includes: determining the distance between the first satellite and the terminal device after a preset time period based on its own location in ephemeris information and the location of the terminal device, as a first distance; and determining the distance between the first satellite and the terminal device after a preset time period based on the locations of other satellites near it in ephemeris information and the location of the terminal device, as a second distance; and determining whether a target satellite exists based on the first distance and the second distance.
[0073] Optionally, the operation of determining whether a target satellite exists based on the first distance and the second distance includes: determining whether the first distance exceeds a first preset distance threshold; if the first distance exceeds the first preset distance threshold, determining whether there are other satellites whose distance from the terminal device does not exceed the second preset distance threshold based on the second distance, and selecting satellites whose distance from the terminal device does not exceed the second preset distance threshold as candidate satellites; if yes, selecting a target satellite from the candidate satellites; if no, determining that no target satellite exists.
[0074] Optionally, the operation of determining the location of the terminal device using the first satellite based on the preamble includes: determining the Doppler frequency offset corresponding to the preamble using the first satellite; determining the relative speed of the first satellite relative to the terminal device using the first satellite based on the Doppler frequency offset; determining the cosine value of a first angle and the length of the distance projected onto a first plane using the first satellite based on its own height and the distance between itself and the terminal device, wherein the first plane represents the horizontal plane where the first satellite is located, and the first angle represents the direction angle of the terminal device's movement relative to the first satellite within the first plane; determining the cosine value of a second angle using the first satellite based on the relative speed, the actual speed of the first satellite, and the cosine value of the first angle, wherein the second angle represents the direction angle of the terminal device's movement relative to the first satellite within a second plane, and the second plane represents the vertical plane where the first satellite and the terminal device are located; and determining the location of the terminal device using the second angle and the length of the distance projected onto the first plane using the first satellite.
[0075] According to this embodiment, the first satellite receives a preamble sent by the terminal device and determines the location of the terminal device based on the preamble. Then, the first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If a target satellite is determined to exist, the first satellite forwards the preamble to the target satellite. Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device according to the preamble and sends uplink resource information to the terminal device; and the terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information. Thus, after receiving the preamble sent by the terminal device, the first satellite determines whether there is a target satellite that is more suitable than itself to provide communication services to the terminal device after a preset time period. If a target satellite can be identified, it means that the first satellite may soon move away from its original position, and there is a target satellite in the same constellation that can subsequently replace the first satellite to provide communication services to the terminal device. Therefore, once the first satellite identifies the target satellite, it forwards the preamble to the target satellite, which then performs the remaining RACH process with the corresponding terminal device. Furthermore, in this embodiment, the first satellite can determine the location of the terminal based on the Doppler frequency offset corresponding to the received preamble, thereby enabling it to identify the target satellite. Thus, this embodiment can improve the quality of service of the wireless communication network provided to the terminal device to a certain extent.
[0076] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0077] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.
[0078] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.
[0079] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0080] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.
[0081] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.
[0082] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made 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 random access method based on a satellite constellation, characterized in that, include: The preamble sent by the first satellite receiving terminal equipment; The first satellite determines the location of the terminal device based on the preamble. The first satellite determines whether there is a target satellite in the same constellation based on ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If the presence of the target satellite is confirmed, the first satellite will forward the preamble to the target satellite; Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device based on the preamble and sends the uplink resource information to the terminal device. as well as The terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information.
2. The method according to claim 1, characterized in that, The operation of the first satellite determining whether there are target satellites in the same constellation based on ephemeris information and the location of the terminal device includes: If the first satellite determines that the terminal device is located in the overlapping coverage area between the first satellite and other neighboring satellites, the first satellite determines whether there are target satellites in the same constellation based on ephemeris information and the location of the terminal device.
3. The method according to claim 1, characterized in that, The operation of the first satellite determining whether there are target satellites in the same constellation based on ephemeris information and the location of the terminal device includes: The first satellite determines the distance between itself and the terminal device after a preset time period based on its own position in the ephemeris information and the position of the terminal device, as the first distance; and the first satellite determines the distance between other satellites near itself and the terminal device after a preset time period based on the positions of other satellites near itself in the ephemeris information and the position of the terminal device, as the second distance. Based on the first distance and the second distance, determine whether the target satellite exists.
4. The method according to claim 3, characterized in that, The operation of determining whether the target satellite exists based on the first distance and the second distance includes: Determine whether the first distance exceeds a first preset distance threshold; If it is determined that the first distance exceeds the first preset distance threshold, based on the second distance, it is determined whether there are any other satellites whose distance from the terminal device does not exceed the second preset distance threshold, and the satellites whose distance from the terminal device does not exceed the second preset distance threshold are selected as candidate satellites; If yes, select the target satellite from the candidate satellites; otherwise, determine that the target satellite does not exist.
5. The method according to claim 1, characterized in that, The operation of the first satellite determining the location of the terminal device based on the preamble includes: The first satellite determines the Doppler frequency offset corresponding to the preamble; The first satellite determines its relative speed to the terminal device based on the Doppler frequency offset. The first satellite determines the cosine value of the first angle and the length value of the distance projected onto the first plane based on its own altitude and the distance between itself and the terminal device. The first plane represents the horizontal plane in which the first satellite is located, and the first angle represents the direction angle of the movement direction of the terminal device relative to the first satellite in the first plane. The first satellite determines the cosine value of the second angle based on the relative moving speed, the actual speed of the first satellite, and the cosine value of the first angle, wherein the second angle represents the direction angle of the terminal device's movement relative to the first satellite within a second plane, and the second plane represents the vertical plane in which the first satellite and the terminal device are located; and The first satellite determines the location of the terminal device based on the second angle and the length value of the distance projected onto the first plane.
6. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the method described in any one of claims 1 to 5 is performed by a processor.
7. A random access device based on a satellite constellation, characterized in that, include: The receiving module is used to receive the preamble sent by the terminal equipment via the first satellite; A location determination module is used to determine the location of the terminal device using the first satellite based on the preamble. The target satellite determination module is used to determine whether there is a target satellite in the same constellation based on the first satellite's ephemeris information and the location of the terminal device. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. A forwarding module is used to forward the preamble to the target satellite via the first satellite when the existence of the target satellite is determined. An uplink resource allocation module is used to allocate uplink resources to the terminal device via the target satellite according to the preamble when the preamble is received, and to send the uplink resource information to the terminal device. as well as The transmitting module is used to receive the uplink resource information through the terminal device and transmit its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information.
8. The apparatus according to claim 7, characterized in that, The target satellite determination module is used to determine whether there are target satellites in the same constellation when the first satellite determines that the terminal device is located in the overlapping coverage area between the first satellite and other neighboring satellites.
9. The apparatus according to claim 7, characterized in that, The target satellite determination module is used to: firstly, determine the distance between itself and the terminal device after a preset time period based on its own position in the ephemeris information and the position of the terminal device, as a first distance; and secondly, determine the distance between other satellites near itself and the terminal device after a preset time period based on the positions of other satellites near itself in the ephemeris information and the position of the terminal device, as a second distance; and determine whether the target satellite exists based on the first distance and the second distance.
10. A random access device based on a satellite constellation, characterized in that, include: processor; as well as A memory, connected to the processor, for providing the processor with instructions to perform the following processing steps: The preamble sent by the first satellite receiving terminal equipment; The location of the terminal device is determined by the first satellite based on the preamble. Based on ephemeris information and the location of the terminal device, the first satellite determines whether there is a target satellite in the same constellation. The target satellite refers to a satellite in the same constellation that is more suitable than the first satellite to provide communication services to the terminal device after a preset time period. If the existence of the target satellite is confirmed, the preamble is forwarded to the target satellite via the first satellite; Upon receiving the preamble, the target satellite allocates uplink resources to the terminal device based on the preamble, and sends the uplink resource information to the terminal device. as well as The terminal device receives the uplink resource information and sends its own identifier to the target satellite according to the uplink resources corresponding to the uplink resource information.