Communication method and device

Abstract

A communication method and device are applied to a satellite communication system. The method comprises the following steps: a first satellite determines first information and sends the first information; the first information comprises synchronization information of at least one second satellite, and the synchronization information of each second satellite comprises at least one synchronization index. The first satellite can plan a mode in which a plurality of second satellites send synchronization signals, for example, synchronization indexes corresponding to the synchronization signals sent by the second satellites are different. Through the method, interference of synchronization signals among satellites can be reduced or even avoided, and the communication performance is improved.

Description

Technical Field

[0001] This application relates to the field of satellite technology, and in particular, to a communication method and apparatus. Background Art

[0002] Considering the coverage and capacity of the network, multi-layer constellation networks are a new development trend in satellite communication networks. In a multi-layer constellation network, multiple deployed satellites have multiple orbital altitudes, and the satellites at the same orbital altitude can be regarded as one layer. Each satellite independently sends a synchronization signal and a physical downlink broadcast channel block (SSB), and the terminal device determines which satellite to access based on the received SSB. Each layer of satellites is relatively independent, and the satellites move at high speeds. If each satellite independently sends an SSB, it may occur that the SSBs of multiple satellites correspond to the same geographical area, that is, there is relatively serious interference between the SSBs of multiple satellites. Summary of the Invention

[0003] Embodiments of this application provide a communication method and apparatus for reasonably planning the manner in which satellites send SSBs, thereby reducing or even avoiding interference between SSBs of multiple satellites and improving communication performance.

[0004] To achieve the above object, the embodiments of this application adopt the following technical solutions:

[0005] In a first aspect, embodiments of this application provide a communication method that can be executed by a first communication device. The first communication device can be a combined device, component, etc. used to implement the functions of a satellite. For example, the first communication device is a satellite, or the first communication device is a unit / module, circuit, or chip inside the satellite, etc. The method provided in the first aspect is described below taking the first communication device as the first satellite itself as an example.

[0006] The communication method includes: the first satellite determines first information and sends the first information. The first information includes synchronization information of at least one second satellite, and the synchronization information of each second satellite includes at least one synchronization index.

[0007] Relatively speaking, the first satellite can be the anchor satellite of the terminal device, and the second satellite can be a satellite within the coverage area of the first satellite, also known as a sub-satellite or a slave satellite. The first satellite can schedule the second satellite. The terminal device within the coverage area (or coverage region) of the first satellite can access any second satellite within the coverage area of the first satellite. The synchronization index can indicate the synchronization signal. This method plans for multiple second satellites to send synchronization signals by the first satellite. For example, the first satellite can instruct different second satellites to send synchronization signals indicated by different synchronization indexes. Through this method, interference between synchronization signals of each satellite can be reduced or even avoided, improving communication performance.

[0008] In one implementation, the synchronization information of each second satellite further includes the time corresponding to at least one synchronization index.

[0009] In this solution, the first satellite can also plan the time for each second satellite to send synchronization signals. For example, different second satellites send different synchronization signals at the same time, or different second satellites send the same synchronization signal at different times, or different second satellites send different synchronization signals at different times. By planning the time for each second satellite to send synchronization signals, while reducing interference between synchronization signals of multiple second satellites, it can also save resources for sending synchronization signals and try to ensure the coverage area.

[0010] In one implementation, the first information further includes: the ephemeris information of at least one second satellite, the identification information of at least one second satellite, or the identification information of at least one transmission reception point (TRP), where one TRP corresponds to one second satellite.

[0011] The identification information of the second satellite and the identification information of the TRP can both indirectly indicate the ephemeris information of the second satellite. By carrying the information related to the ephemeris information of at least one second satellite in the first information, the second satellite receiving the first information can determine which synchronization information in the first information belongs to itself. In this way, the first satellite can broadcast the first information, thus saving signaling overhead.

[0012] In one implementation, at least one second satellite includes multiple second satellites, and the cell identifiers corresponding to the multiple second satellites are the same. In this way, for the terminal device, when moving from the coverage area of one second satellite to the coverage area of another second satellite, it is always in one cell and does not need to execute the cell handover process. Through this solution, the process of the terminal device executing cell handover can be reduced, improving communication efficiency.

[0013] In one implementation, the method further includes: The first satellite sends second information to satellite A among a plurality of second satellites, where the second information includes first time information and a first synchronization index, and is used to instruct satellite A to send a synchronization signal indicated by the first synchronization index at the time indicated by the first time information. Among them, the time indicated by the first time information does not belong to the time when satellite B among the plurality of second satellites provides services based on the first synchronization index.

[0014] In this solution, satellite B cannot provide services for the terminal device based on the first synchronization index at the information indicated by the first time information, or satellite B cannot send the synchronization signal indicated by the first synchronization index at the time indicated by the first time information. In this case, the first satellite can decide to have satellite A replace satellite B to provide services for the terminal device through the first synchronization index at the time indicated by the first time information, so as to reduce the impact on the data transmission performance of the terminal device.

[0015] In one implementation, the method further includes: The first satellite receives third information from satellite B, where the third information includes first time information and a first synchronization index.

[0016] In this solution, when satellite B cannot provide services for the terminal device based on the first synchronization index at the information indicated by the first time information, it reports this to the first satellite through the third information, so that the first satellite can reselect satellite A to replace satellite B to serve the terminal device, reducing the impact on the data transmission performance of the terminal device.

[0017] In a second aspect, an embodiment of the present application provides a communication method, which can be executed by a second communication device. The second communication device can be a combined device, component, etc. used to implement the functions of a satellite. For example, the second communication device is a satellite, or the second communication device is a unit / module, circuit, or chip inside the satellite, etc. Hereinafter, the method provided in the second aspect will be described by taking the second communication device as the second satellite itself as an example.

[0018] The communication method includes: The second satellite determines a first synchronization signal and sends the first synchronization signal. The first synchronization signal includes a second synchronization index, and the second synchronization index is associated with second ephemeris information, and the second ephemeris information is different from the ephemeris information associated with the synchronization indexes corresponding to other second satellites.

[0019] In one implementation, the first synchronization signal further includes: second ephemeris information or a first association relationship, where the first association relationship is an association relationship between at least one synchronization index and at least one ephemeris information.

[0020] In one implementation, the method further includes: a second satellite receives first information from a first satellite, where the first information includes synchronization information of at least one second satellite, and the synchronization information of each second satellite includes at least one synchronization index.

[0021] In one implementation, the synchronization information of each second satellite further includes a time corresponding to at least one synchronization index.

[0022] In one implementation, the first information further includes: ephemeris information of at least one second satellite, identification information of at least one second satellite, or identification information of at least one TRP, where one TRP corresponds to one second satellite.

[0023] In one implementation, the method further includes: a second satellite receives second information from the first satellite and sends a second synchronization signal at the time indicated by first time information. The second information includes the first time information and a first synchronization index, and is used to indicate that the second satellite sends the synchronization signal indicated by the first synchronization index at the time indicated by the first time information. Wherein, the time indicated by the first time information does not belong to the time when other second satellites provide services based on the first synchronization index. The second synchronization signal includes the first synchronization index.

[0024] In one implementation, the method further includes: the second satellite sends fourth information to the first satellite, where the fourth information includes second time information and a third synchronization index, and the third synchronization index cannot provide services at the time indicated by the second time information.

[0025] Regarding the beneficial effects of the second aspect and its various implementations, reference may be made to the beneficial effects of the foregoing first aspect and its various implementations, which will not be elaborated herein.

[0026] In a third aspect, an embodiment of the present application provides a communication method, which can be executed by a third communication device. The third communication device may be a combined device, component, etc. for implementing the functions of a terminal device. For example, the third communication device is a terminal device, or the third communication device is a unit / module, circuit, or chip inside the terminal device, etc. Hereinafter, the method provided in the second aspect will be described by taking the third communication device as the terminal device itself as an example.

[0027] The communication method includes: a terminal device receives a first synchronization signal, where the first synchronization signal includes a second synchronization index; determines second ephemeris information according to the second synchronization index and a first association relationship, where the first association relationship is an association relationship between at least one synchronization index and at least one ephemeris information; determines a timing advance (TA) amount according to the second ephemeris information; and sends a random access preamble according to the TA amount.

[0028] For the beneficial effects of the second aspect and each implementation manner, reference may be made to the beneficial effects of the foregoing first aspect and its each implementation manner, which will not be elaborated herein.

[0029] Fourth aspect, an embodiment of the present application provides a communication method, which may be executed by a first communication device. The first communication device may be a combined device, component, etc. for implementing the functions of a satellite. For example, the first communication device is a satellite, or the first communication device is a unit / module, circuit or chip inside the satellite, etc. The method provided in the first aspect will be described below taking the first communication device as the first satellite itself as an example.

[0030] The communication method includes: the first satellite uses the resources in the first resource set to send a third synchronization signal; receives a first random access preamble from a terminal device; determines a second satellite A according to the first random access preamble and a second association relationship, and sends a random access response message to the terminal device. The second association relationship includes the association relationships between multiple sub-resource sets and multiple second satellites. The resource of the first random access preamble belongs to the first sub-resource set among the multiple sub-resource sets, and the second satellite A belongs to the multiple second satellites. The random access response message includes the ephemeris information and resource information of the second satellite A, and the resource information is used to indicate the resources for the second satellite A to send a synchronization signal.

[0031] In this solution, the first resource set is a set composed of the random access resources corresponding to the first satellite. The first resource set may be divided into multiple sub-resource sets, one sub-resource set corresponds to one second satellite, and one second satellite may correspond to one or more sub-resource sets. When the terminal device has a data transmission requirement, it may select a resource from the sub-resource set corresponding to the second satellite corresponding to the terminal device to send the first random access preamble. In this way, the first satellite can determine which second satellite's coverage range the terminal device is located in through the resource used by the first random access preamble, so as to schedule the second satellite to provide services for the terminal device. Through this solution, in the case where the terminal device has no data transmission requirement, there is no need to schedule any second satellite to send a synchronization signal, which can reduce the unnecessary sending of synchronization signals, thereby saving resources and reducing the power consumption of the satellite.

[0032] In one implementation manner, the method further includes: the first satellite sends fifth information, and the fifth information indicates the second association relationship, and the second association relationship further includes the association relationships between multiple sub-resource sets and the first resource set, where the multiple sub-resource sets are obtained by dividing the first resource set.

[0033] The first satellite can notify the terminal device of the association relationship between the first resource set and the multiple sub-resource sets through dynamic signaling, which is more flexible.

[0034] In a fifth aspect, an embodiment of the present application provides a communication method, which can be executed by a third communication device. The third communication device can be a combined device, component, etc. for implementing the functions of a terminal device. For example, the third communication device is a terminal device, or the third communication device is a unit / module, circuit, or chip inside the terminal device, etc. The method provided in the second aspect is described below by taking the third communication device as the terminal device itself as an example.

[0035] The communication method includes: the terminal device receives a third synchronization signal from a first satellite, and the third synchronization signal is sent using resources within a first resource set; the terminal device sends a first random access preamble to the first satellite and receives a random access response message, where the random access response message includes ephemeris information and resource information of a second satellite, and the resource information is used to indicate the resources for the second satellite to send a synchronization signal; the terminal device receives a synchronization signal from the second satellite on the resources indicated by the resource information.

[0036] In one implementation, the method further includes: the terminal device determines a first sub-resource set according to the first resource set and a second association relationship, where the second association relationship includes the association relationship between the first resource set and multiple sub-resource sets, the multiple sub-resource sets are obtained by dividing the first resource set, and the first sub-resource set belongs to the multiple sub-resource sets. The terminal device sending a first random access preamble to the first satellite includes: the terminal device sends a first random access preamble to the first satellite using resources within the first sub-resource set.

[0037] For the beneficial effects of the fifth aspect and each implementation, reference can be made to the beneficial effects of the foregoing fourth aspect and its various implementations, which will not be elaborated here.

[0038] In a sixth aspect, an embodiment of the present application provides a communication method, which can be executed by a first communication device, a second communication device, and a third communication device. Among them, the first communication device and the second communication device can be combined devices, components, etc. for implementing the functions of a satellite. For example, the first communication device is a first satellite, or the first communication device is a unit / module, circuit, or chip inside the first satellite, etc. The second communication device is a second satellite, or the second communication device is a unit / module, circuit, or chip inside the second satellite, etc. The third communication device can be a combined device, component, etc. for implementing the functions of a terminal device. For example, the third communication device is a terminal device, or the third communication device is a unit / module, circuit, or chip inside the terminal device, etc.

[0039] For example, taking the first communication device as the first satellite itself, the second communication device as the second satellite itself, and the third communication device as the terminal device, the communication method includes: the first satellite sends first information, the first information includes synchronization information of at least one second satellite, and the synchronization information of each second satellite includes at least one synchronization index; the second satellite sends a first synchronization signal, the first synchronization signal includes a second synchronization index, the second synchronization index is associated with second ephemeris information, and the ephemeris information associated with the synchronization index corresponding to other second satellites is different. The terminal device receives the first synchronization signal, and the first synchronization signal includes the second synchronization index; determines the second ephemeris information according to the second synchronization index and the first association relationship, and the first association relationship is the association relationship between at least one synchronization index and at least one ephemeris information; determines the TA quantity according to the second ephemeris information, and sends a random access preamble according to the TA quantity.

[0040] For another example, the first satellite uses the resources within the first resource set to send a third synchronization signal, the terminal device receives the third synchronization signal and sends a first random access preamble to the first satellite; the first satellite receives the first random access preamble and sends a random access response message to the terminal device, and the random access response message includes the ephemeris information and resource information of the second satellite, and the resource information is used to indicate the resources for the second satellite to send the synchronization signal; the terminal device receives the synchronization signal from the second satellite on the resources indicated by the resource information.

[0041] In a seventh aspect, an embodiment of the present application provides a communication device, and the communication device has the function of implementing the behaviors in the method examples of any one of the first aspect to the fifth aspect above. The beneficial effects can be seen in the relevant descriptions of the first aspect or the fourth aspect and will not be elaborated here. For example, the communication device may be the first satellite in the first aspect or the fourth aspect, or the communication device may be a device capable of supporting the satellite to implement the functions required by the method provided in the first aspect or the fourth aspect. For example, the communication device may be a chip or a chip system in the satellite. For another example, the communication device may be the second satellite in the second aspect, or the communication device may be a device capable of supporting the satellite to implement the functions required by the method provided in the second aspect. For example, the communication device may be a chip or a chip system in the satellite. For example, the communication device may be the terminal device in the third aspect or the fifth aspect, or the communication device may be a device capable of supporting the terminal device to implement the functions required by the method provided in the third aspect or the fifth aspect. For example, the communication device may be a chip or a chip system in the terminal device.

[0042] In a possible design, the communication device includes a baseband device and a radio frequency device.

[0043] In a possible design, the communication device includes corresponding means or modules for performing the method according to any one of the first to fifth aspects. For example, the communication device includes a processing unit (sometimes also referred to as a processing module or a processor) and / or a transceiver unit (sometimes also referred to as a transceiver module or a transceiver). The transceiver unit can implement the sending function and the receiving function. When the transceiver unit implements the sending function, it can be referred to as a sending unit (sometimes also referred to as a sending module). When the transceiver unit implements the receiving function, it can be referred to as a receiving unit (sometimes also referred to as a receiving module). The sending unit and the receiving unit can be the same functional unit, and this functional unit is called the transceiver unit, which can implement the sending function and the receiving function; or, the sending unit and the receiving unit can be different functional units, and the transceiver unit is a general term for these functional units. These units (modules) can perform the corresponding functions in the method examples according to any one of the first to fifth aspects above. For specific details, refer to the detailed description in the method examples and will not be elaborated here.

[0044] In an eighth aspect, an embodiment of the present application provides a communication device, which can be the communication device in the seventh aspect in the above embodiments, or a chip or a chip system disposed in the communication device in the seventh aspect. The communication device includes a communication interface and a processor. Optionally, it further includes a memory. The memory is used to store computer programs or instructions or data. The processor is coupled to the memory and the communication interface. When the processor reads the computer programs or instructions or data, it causes the communication device to execute the method performed by the terminal device in the above method embodiments. For example, the communication device can be a terminal device or a functional module in the terminal device, such as a baseband chip and a radio frequency chip. Or, when the processor reads the computer programs or instructions or data, it causes the communication device to execute the method performed by the first satellite or the second satellite in the above method embodiments. For example, the communication device can be a satellite or a functional module in the satellite, such as a baseband chip and a radio frequency chip.

[0045] In a ninth aspect, an embodiment of the present application provides a chip system, which includes a processor and may further include a communication interface for implementing the method according to any one of the first to fifth aspects. Optionally, the chip system further includes a memory. The memory is used to store computer programs (which can also be referred to as code or instructions). The processor is used to call and run the computer programs from the memory, so that the device equipped with the chip system executes the method according to any one of the first to fifth aspects and any one of its implementation manners. The chip system can be composed of chips or can include chips and other discrete devices.

[0046] Tenth aspect, an embodiment of the present application provides a communication device, which includes an input / output interface and a logic circuit. The input / output interface is used for inputting and / or outputting information. The input / output interface can be an interface circuit, an output circuit, an input circuit, a pin or a related circuit, etc. The logic circuit is used to execute the method described in any one of the first aspect to the fifth aspect.

[0047] In a specific implementation process, the above communication device can be a chip. The input circuit can be an input pin, the output circuit can be an output pin, and the logic circuit can be a transistor, a gate circuit, a flip-flop and various logic circuits, etc. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver. The signal output by the output circuit can be output to, for example, but not limited to, a transmitter and transmitted by the transmitter. And the input circuit and the output circuit can be the same circuit, which is used as the input circuit and the output circuit at different times respectively. The present application does not limit the specific implementation manners of the input / output interface and the logic circuit.

[0048] In one implementation manner, when the communication device is a wireless communication device, the wireless communication device can be a terminal device such as a mobile phone, or the wireless communication device can be a network device such as a satellite. The interface circuit can be a radio frequency processing chip in the wireless communication device, and the processing circuit can be a baseband processing chip in the wireless communication device.

[0049] Eleventh aspect, an embodiment of the present application provides a communication system, the communication system includes a terminal device and multiple satellites, where the multiple satellites include a first satellite and a second satellite. Among them, the first satellite is used to implement the functions of the method described in the first aspect, the second satellite is used to implement the functions of the method described in the second aspect, and the terminal device is used to implement the functions of the method described in the third aspect. Or, the first satellite is used to implement the functions of the method described in the fourth aspect, and the terminal device is used to implement the functions of the method described in the fifth aspect.

[0050] Twelfth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program or instruction. When it runs, the method described in any one of the first aspect to the fifth aspect and any of its implementation manners is implemented.

[0051] Thirteenth aspect, an embodiment of the present application further provides a computer program product containing instructions. When it runs on a computer, the method described in any one of the first aspect to the fifth aspect and any of its implementation manners is implemented.

[0052] The beneficial effects of the above sixth aspect to the thirteenth aspect and their implementation manners can refer to the beneficial effects of the first aspect or the fourth aspect and any of its implementation manners. Brief Description of the Drawings

[0053] Figure 1 It is a schematic diagram of an architecture of the communication system provided by an embodiment of the present application;

[0054] Figure 2 It is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0055] Figure 3 It is another schematic diagram of an architecture of the communication system provided by an embodiment of the present application;

[0056] Figure 4 It is a schematic flowchart of the communication method 400 provided by an embodiment of the present application;

[0057] Figure 5 It is a schematic diagram of the staring service during the satellite movement provided by an embodiment of the present application;

[0058] Figure 6 It is a schematic flowchart of the communication method 600 provided by an embodiment of the present application;

[0059] Figure 7 It is a network architecture diagram of a satellite communication system provided by an embodiment of the present application;

[0060] Figure 8 It is a schematic flowchart of the communication method 800 provided by an embodiment of the present application;

[0061] Figure 9 It is a schematic diagram of a structure of the communication device provided by an embodiment of the present application;

[0062] Figure 10 It is another schematic diagram of a structure of the communication device provided by an embodiment of the present application. Detailed Description of the Embodiments

[0063] The method provided by the embodiment of the present application can reduce or even avoid the interference of synchronization signals between multiple satellites and improve the communication performance. The solution provided by the embodiment of the present application will be introduced below with reference to the drawings.

[0064] The technical solution provided by the embodiments of the present application can be applied to a non-terrestrial network (NTN) system. The NTN system is a communication system formed by networking non-terrestrial network devices. Non-terrestrial network devices include, for example, satellites, high altitude platform stations (HAPS), unmanned aerial vehicles, and other devices. The non-terrestrial network devices involved in the embodiments of the present application are not limited to the above examples. The non-terrestrial network devices in the present application can also be referred to as aerial network devices. In the embodiments of the present application, the satellite communication system can be integrated with the traditional mobile communication system. The mobile communication system can be a long term evolution (LTE) communication system, a fifth generation (5G) mobile communication system (e.g., a new radio (NR) system), or can also be applied to other next-generation mobile communication systems, such as a sixth generation (6G) communication system, or other similar communication systems. Other similar communication systems can include wireless fidelity (WIFI), vehicle to everything (V2X), internet of things (IoT) systems, narrow band internet of things (NB-IoT) systems, and so on.

[0065] As an example, please refer to Figure 1 , which is a schematic diagram of the network architecture of a communication system provided by the embodiments of the present application. The communication system includes a radio access network 100 and a core network 200. Optionally, the communication system may further include the Internet ( Figure 1 take this as an example).

[0066] Among them, the radio access network 100 may include at least one network device (such as Figure 1 110a, 110b, and 110c in Figure 1 ) and at least one terminal device (such as Figure 1 120a - 120j in Figure 1It is not shown in the figure. Those of ordinary skill in the art will know that as the network architecture evolves, the technical solutions provided in the embodiments of the present application are equally applicable to similar technical problems. When applying the technical solutions of the embodiments of the present application to other communication systems, the devices, components, modules, etc. in the embodiments can be replaced with the corresponding devices, components, modules in other communication systems without limitation.

[0067] In the embodiments of the present application, the network device refers to a radio access network (RAN) device. The RAN can be a 3GPP-related cellular system, for example, a 5G / new radio (NR) mobile communication system, or an evolved system for the future (such as a 6G mobile communication system). The RAN can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a virtualized RAN (vRAN), etc. The RAN can also be a communication system that integrates two or more of the above systems. The RAN device can also be referred to as an RAN node, an RAN entity, or an access node, etc.

[0068] In a possible scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a TRP, a next generation NodeB (gNB), a next generation base station in a 6G mobile communication system, a base station in a future mobile communication system, etc. The RAN node can be a macro base station, a micro base station, an indoor station, a relay node, a donor node / host node, or a radio controller, etc. The RAN node can also be a server, a wearable device, a vehicle or in-vehicle device, etc. For example, the RAN node in V2X technology can be a roadside unit (RSU).

[0069] In another possible scenario, the RAN node may be a module or unit that completes some functions of the base station; or multiple RAN nodes cooperate to assist the terminal device in achieving wireless access, and different RAN nodes respectively implement some functions of the base station. For example, the RAN node may be a central unit (CU), a distributed unit (DU), or a radio unit (RU), etc. The functions of the CU may be implemented by one entity, or may also be implemented by different entities. For example, the functions of the CU may be further divided, that is, the control plane and the user plane are separated and implemented by different entities, namely the control plane CU entity (i.e., the CU-control plane (CP) entity) and the user plane CU entity (i.e., the CU-user plane (UP) entity). The CU-CP entity and the CU-UP entity may be coupled with the DU to jointly complete the functions of the RAN node. The CU and the DU may be set separately, or may also be included in the same network element, such as the baseband unit (BBU).

[0070] In different systems, the CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU may also be called O-CU (open CU), the DU may also be called O-DU, the CU-CP may also be called O-CU-CP, the CU-UP may also be called O-CU-UP, and the RU may also be called O-RU. For the convenience of description, the CU, CU-CP, CU-UP, DU, and RU are used as examples in this application. Any one of the CU (or CU-CP, CU-UP), DU, and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0071] The CU and DU can be configured according to the protocol layer functions of the wireless network they implement. For example, the CU is configured to implement the functions of the packet data convergence protocol (PDCP) layer and the protocol layers above (such as the radio resource control (RRC) layer and / or the service data adaptation protocol (SDAP) layer, etc.); the DU is configured to implement the functions of the protocol layers below the PDCP layer (such as the radio link control (RLC) layer, the media access control (MAC) layer, and / or the physical (PHY) layer, etc.). Another example is that the CU is configured to implement the functions of the protocol layers above the PDCP layer (such as the RRC layer and / or the SDAP layer), and the DU is configured to implement the functions of the PDCP layer and the protocol layers below (such as the RLC layer, the MAC layer, and / or the PHY layer, etc.). For the specific descriptions of the above-mentioned protocol layers, reference can be made to the relevant technical specifications of 3GPP or the technical specifications of other applicable communication protocols. The division of the processing functions of the CU and DU according to the protocol layer above is only an example, and it can also be divided in other ways, which is not limited in this application. For example, in one design, the CU or DU can also be divided into parts with partial processing functions of the protocol layer. In one design, part of the functions of the RLC layer and the functions of the protocol layers above the RLC layer are set in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are set in the DU.

[0072] In the embodiments of this application, the device for implementing the functions of the network device can be the network device itself, or a device that can support the network device to implement such functions, such as a chip system or a combined device or component that can implement the functions of the network device. This device can be installed in the network device. The embodiments of this application do not limit the specific technologies and specific device forms adopted by the network device.

[0073] A terminal device is also referred to as a terminal, terminal device, user equipment (UE), mobile station, or mobile terminal, etc. In the embodiments of this application, anything that can communicate data with a base station can be regarded as a terminal device. Terminal devices can be widely applied in various scenarios. For example, terminal devices can be: mobile phones, computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, stations (STAs), robotic arms, cameras, robots, vehicles, drones, helicopters, airplanes, ships, or smart home devices (such as TVs, air conditioners, floor sweepers, speakers, set-top boxes), relays, customer premise equipment (CPEs), smart cars (or intelligent cars), roadside units (RSUs), etc. Terminal devices can also be terminal devices in an IoT system. For example, water meters, electricity meters, etc.

[0074] Among the various terminal devices introduced above, if they are located on a vehicle (for example, placed / installed inside the vehicle), they can all be considered in-vehicle terminal devices. An in-vehicle terminal device can be built into a vehicle's in-vehicle module, in-vehicle module group, in-vehicle component, in-vehicle chip, or in-vehicle unit as one or more components or units. The vehicle can implement the methods of this application through the built-in in-vehicle module, in-vehicle module group, in-vehicle component, in-vehicle chip, or in-vehicle unit. An in-vehicle terminal device can be a vehicle device, in-vehicle module, vehicle, on-board unit (OBU), roadside unit (RSU), telematics box (T-box) (or in-vehicle transmission unit), chip, or system-on-chip (SOC), etc. The above-mentioned chip or SOC can be installed in a vehicle, OBU, RSU, or T-box.

[0075] In the embodiments of this application, the device for implementing the functions of a terminal device can be the terminal device itself, or a device that can support the terminal device in realizing these functions, such as a chip system or a combined device or component that can implement the functions of the terminal device. This device can be installed in the terminal device. The embodiments of this application do not limit the specific technologies and specific device forms adopted by the terminal device.

[0076] In the embodiments of this application, network devices can be deployed on satellites. When network devices are deployed on satellites, a typical communication scenario is as Figure 2 shown.Figure 2 The communication system shown includes two terminal devices (which can be simply referred to as terminals), two base stations, a ground station, and core network equipment. The core network equipment includes a control plane function and a user plane function. For example, the functions of the control plane include an access and mobility management function (AMF) and a session management function (SMF). The user plane function includes: a user plane function (UPF), which is responsible for managing the transmission of user plane data, traffic statistics, and other functions. (Including the control plane function and the user plane function). Among them, the base stations are deployed on satellites, also known as satellite base stations or spaceborne base stations (satellite gNB, S-gNB). The air interface refers to the communication interface between the terminal device and the base station. The Xn interface refers to the interface between base stations, mainly used for signaling interactions such as handover. The NG interface refers to the interface between the base station and the core network, or the interface between the ground station and the core network, mainly for interacting non-access stratum (NAS) and other signaling of the core network, as well as the service data of users. The NG interface can be in a wired form or a wireless form. In Figure 2 it, the satellite base station communicates with the ground station through the air interface, and the ground station is connected to the core network through the NG interface. The ground terminal device communicates with the satellite base station through the air interface, so as to access the communication network. The embodiments of the present application do not limit the type and number of satellites. For example, the satellite can be a highly elliptical orbiting (HEO) satellite, a geostationary earth orbit (GEO) satellite, a medium earth orbit (MEO) satellite, and a low-earth orbit (LEO) satellite.

[0077] Considering the coverage and capacity distribution of the communication system, satellites with multiple orbital altitudes are usually deployed, and the inclination angles of the deployed satellites are more. Such a communication system is also called a multi-layer satellite network / multi-layer constellation network. Satellites at the same orbital altitude can be regarded as one layer. A constellation is a set of satellites that are launched into orbit and can work properly, also known as a satellite constellation. The satellite can inform the terminal device of its existence by means of beam scanning. The process of the satellite performing beam scanning is also the process of the satellite sending SSB. When the satellite sends SSB, the terminal within the coverage range of the satellite can receive the SSB, so that the terminal device can connect to the satellite to access the network.

[0078] In a multi-layer satellite network, each layer of satellites is relatively independent, and the satellites move at high speeds. If each satellite independently transmits the SSB, it may cause the SSBs of multiple satellites to correspond to one geographical area, or there may be a large overlap in the geographical areas corresponding to the SSBs of multiple satellites. For terminal devices, the received SSBs are subject to significant interference, and it is difficult to demodulate the SSBs corresponding to each satellite from the received signals.

[0079] To solve the above problems, the solution of the embodiments of the present application is proposed. In the embodiments of the present application, the anchor satellite of the terminal device plans the manner in which each satellite within the coverage area of the anchor satellite transmits the SSB, so as to reduce or even avoid the interference of the SSBs between each satellite. Relatively speaking, the satellites within the coverage area of the anchor satellite can be referred to as sub-satellites or slave satellites. The coverage area of the anchor satellite is larger than that of the sub-satellite, and the movement speed of the anchor satellite is faster than the movement speed of the sub-satellite. The terminal device within the coverage area (or coverage region) of the anchor satellite can access any sub-satellite within the coverage area of the anchor satellite. The anchor satellite knows the location of the terminal device, and thus knows the sub-satellites that the terminal device may access.

[0080] For example, please refer to Figure 3 , which is another schematic diagram of the architecture of the communication system applicable to the embodiments of the present application. Figure 3 The system shown includes an anchor satellite and multiple sub-satellites (such as Figure 3 sub-satellite 1 to sub-satellite 4 therein) and a terminal device. Among them, sub-satellite 1 to sub-satellite 4 are all within the coverage area of the anchor satellite. The coverage areas of each sub-satellite may overlap or may not overlap. For example, sub-satellite 1 corresponds to coverage area A, sub-satellite 2 corresponds to coverage area B, sub-satellite 3 corresponds to coverage area C, and sub-satellite 4 corresponds to coverage area D. The anchor satellite can plan the manner in which sub-satellite 1 to sub-satellite 4 each transmit the SSB, or the anchor satellite can instruct sub-satellite 1 to sub-satellite 4 how to transmit the SSB. In this way, the SSBs transmitted by sub-satellite 1 to sub-satellite 4 can be made not to interfere with each other, so that the terminal device can clearly identify which sub-satellite the received SSB belongs to, and then access the network.

[0081] In the embodiments of the present application, "association" can also be replaced by "mapping", "correlation", or "correspondence". For example, the association relationship between at least one synchronization index and at least one ephemeris information can also be the correspondence relationship between at least one synchronization index and at least one ephemeris information. The ephemeris information associated with the synchronization index can be: the ephemeris information corresponding to the synchronization index. The embodiments of the present application do not limit the specific implementation form of the association relationship. For example, the association relationship can be a table, and sending the first association relationship can be sending a table representing the first association relationship.

[0082] In the embodiments of the present application, a beam can be understood as / replaced by "spatial filter", "spatial parameters", "outer layer weight", "analog weight", or "analog beam". A random access preamble is also referred to as preamble, leading code, preamble code, random access preamble code, etc. Pre-configuration, equivalent to (pre-)configuration, may refer to predefined or signaling configuration / indication between inter-satellite links.

[0083] "When", "if", and "in case of" all refer to the situation where the device will perform corresponding processing under certain objective circumstances, rather than limiting the time. It does not require the device to have a judgment action when implemented, nor does it mean there are other limitations. Unless otherwise specified, "if" and "in case of" can be replaced, and "when" can be replaced with "in the case of". "When" can be replaced with "if" / "in case of". Words such as "exemplary" or "for example" are used to give examples, illustrations, or explanations. Any embodiment or design described as "exemplary" or "for example" in the present application should not be construed as being more preferred or having more advantages than other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner. "For indicating" may include direct indication and indirect indication. For example, when describing that a certain indication information is used to indicate information I, it may include that the indication information directly indicates I or indirectly indicates I, rather than meaning that I must be carried in the indication information.

[0084] In the embodiments of the present application, for the number of nouns, unless otherwise specified, it means "singular noun or plural noun", that is, "one or more". "At least one" means one or more, and "multiple" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. For example, A / B means: A or B. "At least one of the following" or its similar expressions refer to any combination of these items, including any combination of single item or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0085] In the embodiments of the present application, ordinal numbers such as "first" and "second" are used to distinguish multiple objects, and are not used to limit the size, content, order, time sequence, priority, or importance of multiple objects. For example, the first satellite and the second satellite refer to two different satellites, and do not indicate differences in their priority or importance. For a technical feature, the technical features in this kind of technical feature are distinguished by "A", "B", "C", and "D", etc., and there is no sequence or size order among the technical features described by this "A", "B", "C", and "D". For example, the second satellite A and the second satellite B in this article are only for distinguishing different contents, and do not limit the sequence, size order, priority, or importance between the second satellite A and the second satellite B.

[0086] The following will introduce in detail the solution provided by the embodiments of the present application with reference to the accompanying drawings. In the following description, it is assumed that the communication method provided by the embodiments of the present application is applied to Figure 1 , Figure 2 or Figure 3 the network architecture shown. The network architecture and application scenarios described in the embodiments of the present application are for more clearly explaining the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art know that with the evolution of the network architecture and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0087] In the following, it is assumed that the communication methods provided by the embodiments of the present application (such as communication method 400, communication method 600, and communication method 800) are executed by the first satellite, the second satellite, and the terminal device. The steps executed by the satellite can be implemented by the satellite itself or by components in the satellite (such as a baseband chip, or other processing units or processor modules). For example, the first satellite can be Figure 3 the anchor satellite in Figure 3 , or it can also be Figure 3 the chip (system) of the anchor satellite in Figure 3 . The second satellite can be Figure 3 any sub-satellite in Figure 3 , or it can also be

[0088] the chip (system) of the sub-satellite in Figure 4 . Figure 4 The steps executed by the terminal device can be implemented by the terminal device itself or by components in the terminal device (such as a chip, a processing unit, or a processor module). The terminal device can be Figure 4This method will be introduced from the perspective of the interaction among the first satellite, the second satellite, and the terminal device. It should be understood that the communication method 400 can also be implemented by other devices, such as a chip or a communication device with communication functions. It should be noted that the embodiments of this application only take the execution by the first satellite, the second satellite, and the terminal device as an example, and do not limit the number of the second satellites and the terminal devices. For example, the embodiments of this application can also be executed by more second satellites and more terminal devices. When more second satellites are involved, the execution processes of each of the multiple second satellites are the same. As Figure 4 shown, the process of the communication method 400 includes the following steps. Substantially, the communication method 400 is to plan how multiple second satellites send synchronization signals. Correspondingly, the synchronization index is the index of the synchronization signal. For the convenience of description, in the following, it is taken that the synchronization signal is the SSB as an example. Correspondingly, the synchronization index is the index of the SSB.

[0089] S401. The first satellite sends the first information, and the first information includes the synchronization information of at least one second satellite.

[0090] The first satellite is the anchor satellite of the terminal device, and the second satellite is the sub-satellite within the coverage of the first satellite. Continuing Figure 3 with the example, at least one second satellite is Sub-satellite 1 to Sub-satellite 4. The synchronization information of each second satellite can be used for the terminal device to synchronize with the second satellite, and this synchronization includes time synchronization and frequency synchronization. The embodiments of this application do not limit the specific name of the synchronization information. For example, the synchronization information can be called a synchronization signal or an SSB.

[0091] The synchronization information of each second satellite may include at least one synchronization index (which can be simply referred to as an index), and this synchronization index can indicate the synchronization signal to be sent by the corresponding second satellite. Continuing Figure 3 with the example, taking Sub-satellite 1 as an example, the synchronization signal of Sub-satellite 1 includes at least one synchronization index, and this at least one synchronization index is the index of the SSB sent by Sub-satellite 1. The number of synchronization indexes included in the synchronization information of different second satellites can be the same or different, and the synchronization indexes corresponding to different second satellites are different. The first satellite can plan the SSBs to be sent by each second satellite so that the interference between the SSBs sent by each second satellite is small, or even there is no interference. For example, the synchronization information corresponding to Sub-satellite 1 includes SSB index 0 to SSB index 3, the synchronization information corresponding to Sub-satellite 2 includes SSB index 4 to SSB index 8, and so on. In this way, compared with each second satellite independently sending the SSB according to its own plan, the interference between the SSBs sent by multiple second satellites can be reduced or even avoided.

[0092] Optionally, at least one synchronization index may exist in tabular form. In this case, the first information may include at least one list, one list corresponding to one second satellite, and one list including at least one synchronization index. Alternatively, the first information may include indices of at least one list. The terminal device may store multiple lists and the indices corresponding to each list. In this way, when each satellite receives the first information, it can determine the corresponding list according to the index carried in the first information, and then determine at least one synchronization index included in the list. Alternatively, the terminal device may store a table indicating multiple groups of synchronization indices. Each group of synchronization indices has a corresponding index. One group of synchronization indices corresponds to one second satellite and includes at least one synchronization index, as shown in Table 1. Accordingly, the first information may include the indices of at least one group of synchronization indices corresponding to at least one second satellite among multiple groups of synchronization indices.

[0093] Table 1

[0094]

[0095]

[0096] It should be noted that the number of synchronization indices in each synchronization index group in Table 1 is only an example. The number of synchronization indices in different synchronization index groups may be the same or different. Also, the number of synchronization index groups in Table 1 is only an example, and there may be more synchronization index groups. One or more synchronization indices in different synchronization index groups are different.

[0097] In addition, the synchronization information of each second satellite may further include time information corresponding to at least one synchronization index, and this time information can be used for the time when at least the second satellite sends a synchronization signal. The time information corresponding to at least one synchronization index may be the same or different. The time indicated by the time information included in the synchronization information of different second satellites may be the same or different. For example, the first information includes the synchronization information A of the second satellite A, and the synchronization information A includes at least one synchronization index and at least one time information, where at least one time information corresponds to at least one synchronization index. For example, at least one time information may be one time information to indicate that the second satellite A sends the SSB corresponding to at least one synchronization index at the time indicated by this time information. Or, at least one time information corresponds one-to-one with at least one synchronization index, and each time information indicates that the second satellite sends the SSB indicated by the synchronization index corresponding to this time information at the time indicated by this time information. Another example is that the first information includes the synchronization information A of the second satellite A and the synchronization information B of the second satellite B. The synchronization information A includes at least one synchronization index and at least one time information, and the synchronization information B includes at least one synchronization index and at least one time information. One time information in the synchronization information A corresponds to at least one synchronization index, and at least one time information in the synchronization information B corresponds to at least one synchronization index. The at least one time information in the synchronization information A and the at least one time information in the synchronization information B may be the same or different. The time information and synchronization index carried by the synchronization information of each second satellite can be determined by the first satellite. In this way, the SSBs sent by different second satellites can be different, which can reduce the interference of the SSBs between multiple second satellites. Or, different second satellites send different SSBs at the same time, or different second satellites send the same SSB at different times. While reducing the interference of the SSBs between multiple second satellites, it can also save SSB resources and try to ensure the coverage area.

[0098] In a possible implementation manner, the first satellite may send the first information in a unicast manner. Each time the first information sent includes the synchronization information of one second satellite. For example, for the second satellite A, the first satellite sends the first information to the second satellite A, and the first information includes the synchronization information of the second satellite A. For the second satellite B, the first satellite sends the first information to the second satellite B, and the first information includes the synchronization information of the second satellite A. By sending the first information in a unicast manner, the first satellite can reduce the processing complexity of the second satellite for the first information.

[0099] Alternatively, the first satellite may also broadcast the first information to save signaling overhead. In this case, each second satellite receives the first information and needs to determine which of the at least one synchronization information carried in the first information is its own. For this purpose, the first information may further include the ephemeris information of at least one second satellite, that is, the first information includes at least one synchronization information and the identification information of at least one second satellite, where one synchronization information may correspond to the identification information of one or more second satellites. Each second satellite receives the first information and can determine its own synchronization information according to the identification information of at least one second satellite and the corresponding relationship between the identification information of at least one second satellite and at least one synchronization information.

[0100] The embodiments of the present application do not limit the specific implementation form of the identification information of at least one second satellite. For example, the identification information of at least one second satellite is the ephemeris information of at least one second satellite. Another example is that the identification information of at least one second satellite is the ID of at least one second satellite. Another example is that the identification information of at least one second satellite is the ID of at least one TRP, and one TRP corresponds to one second satellite.

[0101] S402. The second satellite sends the first synchronization signal. Correspondingly, the terminal device within the coverage area of the second satellite receives the first synchronization signal.

[0102] The second satellite in S402 refers to any one of the at least one second satellites. For the convenience of description, in the following, this second satellite is taken as the second satellite A among the at least one second satellites. The second satellite A receives the first information, can obtain the synchronization information corresponding to the second satellite A, and send the first synchronization signal according to this synchronization information. If the first information is sent in unicast mode, the second satellite A determines that the synchronization information carried in the first information is the synchronization information of the second satellite A. If the first information is sent in broadcast mode, the second satellite A receives the first information and can determine the synchronization information of the second satellite A according to the identification information of at least one second satellite in the first information and the corresponding relationship between the identification information of at least one second satellite and at least one synchronization information.

[0103] The second satellite A sends a synchronization signal according to the synchronization information of the second satellite A. For example, at least one synchronization index included in the synchronization information of the second satellite A includes a second synchronization index, and the first synchronization signal includes the second synchronization index and the ephemeris information corresponding to the second synchronization index (for example, the second ephemeris information in this article). Taking the first synchronization signal as the first SSB as an example, if at least one synchronization index includes multiple synchronization indexes, then the first SSB sent by the second satellite A includes the multiple synchronization indexes and multiple ephemeris information, and one synchronization index corresponds to one ephemeris information. Or, if at least one synchronization index includes multiple synchronization indexes, the second satellite A sends multiple SSBs corresponding one-to-one to the multiple synchronization indexes, and each SSB includes the corresponding synchronization index and the ephemeris information corresponding to the synchronization index. Among them, the ephemeris information corresponding to the synchronization indexes of different second satellites is different. Taking the second satellite A and other second satellites (such as the second satellite B) as an example, the synchronization information of the second satellite A includes a second synchronization index, and the second synchronization index corresponds to the second ephemeris information. The synchronization information of the second satellite B includes a third synchronization index, and the third synchronization index corresponds to the third ephemeris information. Among them, the second satellite information and the third ephemeris information are different. The ephemeris information corresponding to the synchronization index can be carried in the first field of the system information block (SIB) included in the SSB. The first field can be an existing field in the SIB or a newly added field.

[0104] Optionally, the second ephemeris information carried in the first SSB sent by the second satellite A can be represented by the ID of the second satellite A or the ID of the TRP indicating the second satellite A. Therefore, the first SSB includes the second synchronization index and the second ephemeris information can be replaced with: the first SSB includes the second synchronization index and the ID of the second satellite A, or the first SSB includes the second synchronization index and the ID of the second TRP, where the second TRP indicates the second satellite A. When the first BSS includes the second synchronization index and the ID of the second satellite A, the first satellite or the second satellite A can also broadcast the correspondence between the IDs of at least one second satellite and at least one ephemeris information to the terminal device. In this way, the terminal device can determine the second ephemeris information corresponding to the second synchronization index according to the correspondence between the IDs of at least one second satellite and at least one ephemeris information and the received first SSB. Similarly, when the first BSS includes the second synchronization index and the ID of the second TRP, the first satellite or the second satellite A can also broadcast the correspondence between the IDs of at least one TRP and at least one ephemeris information to the terminal device.

[0105] In a possible implementation, the first SSB sent by the second satellite A may include a second synchronization index and an association relationship between at least one synchronization index and at least one ephemeris information, and this association relationship is called the first association relationship. Alternatively, the first SSB includes the second synchronization index and the second ephemeris information including: the first SSB includes the second synchronization index and the first association relationship. The first association relationship may be carried in a field of the SIB included in the first SSB. The first association relationship may also be broadcast by the first satellite. The first association relationship may exist in tabular form, as shown in Table 2. In the first association relationship, one ephemeris information may correspond to one or more synchronization indexes. It should be noted that the relationship between the synchronization index and the ephemeris information in Table 2 is only an example for illustration, and the value of N in Table 2 is greater than or equal to 2.

[0106] Table 2

[0107] Synchronous Index Ephemeris Information 0 Ephemeris Information_0 1 Ephemeris Information_1 … … N Ephemeris Information_N

[0108] S403. The terminal device determines the second ephemeris information according to the first synchronization signal, and sends a random access preamble according to the second ephemeris information.

[0109] After receiving the first synchronization signal, the terminal device determines the second ephemeris information according to the first synchronization signal. For example, if the first synchronization signal includes the second synchronization index and the second ephemeris information, the terminal device can directly obtain the second ephemeris information from the first synchronization signal. If the first synchronization signal includes the second synchronization index and the first association relationship, the terminal device can determine the second ephemeris information corresponding to the second synchronization index according to the second synchronization index and the first association relationship. If the first synchronization signal includes the second synchronization index and the ID of the second satellite A, the terminal device can determine the second ephemeris information according to the corresponding relationship between the ID of at least one second satellite and at least one ephemeris information and the ID of the second satellite A.

[0110] After the terminal device determines the second ephemeris information, it determines the TA amount according to the second ephemeris information, and then sends a random access preamble according to the determined TA amount to access the second satellite A. It can be understood that if the terminal device is within the coverage area of the second satellite B, the terminal device can receive the synchronization signal from the second satellite B, determine the TA amount calculated according to the ephemeris information of the second satellite B received, and send a random access preamble according to this TA amount to access the second satellite B.

[0111] When the synchronization information of the second satellite A includes at least one synchronization index and the time information corresponding to the at least one synchronization index, the second satellite A sends a first synchronization signal according to the time information included in the synchronization information. For example, if the synchronization information of the second satellite A includes a second synchronization index and the time information corresponding to the second synchronization index, then the second satellite A sends the first synchronization signal at the time indicated by the time information, and the first synchronization signal includes the second synchronization index.

[0112] Due to the movement of the second satellite, the terminal device moves from the coverage area of one second satellite to the coverage area of another second satellite. For example, in the initial stage, the terminal device is located in the coverage area of the second satellite A. After a period of time, the terminal device moves to the coverage area of the second satellite C, which requires the terminal device to switch from the second satellite A to the second satellite C. To reduce the interruption of communication services, the terminal device needs to switch from the cell of the second satellite A to the cell of the second satellite C, which affects the data transmission performance of the terminal device. Therefore, in the embodiments of the present application, the cell identifiers of multiple second satellites are the same. In this way, when the terminal device moves from the coverage area of one second satellite to the coverage area of another second satellite, it is considered that the cell has not changed, so the cell switching process will not be executed, and the impact on the data transmission performance of the terminal device is reduced. The embodiments of the present application do not limit the specific implementation form of the cell identifier of the second satellite. For example, the cell identifier may be a physical cell identifier (PCI).

[0113] In the communication method 400, the first satellite plans the SSBs sent by each second satellite, so that the SSBs sent by different second satellites are different, thereby reducing the interference of the SSBs between multiple second satellites. For example, different second satellites send different SSBs at the same time, which can not only reduce the interference of the SSBs between multiple second satellites, but also save SSB resources. For another example, different second satellites send the same SSB at different times to minimize or even avoid the interference of the SSBs between multiple second satellites.

[0114] It should be noted that in the communication method 400, the SSBs to be sent by each second satellite may also be pre-configured. Therefore, S401 is not a necessary step, which is shown by a dotted line in Figure 4 for illustration.

[0115] In a possible scenario, the orbital altitude of the first satellite is higher than that of the second satellite, so the relative ground movement speed of the first satellite is lower than that of the second satellite relative to the ground. As the first satellite and the second satellite move, there will be a situation where the second satellite cannot provide services to the terminal device. For example, please refer to Figure 5, which is a schematic diagram of the staring service during the movement of the satellite provided by the embodiment of the present application. "Staring" refers to a working mode of a payload (such as a beam) in a satellite communication system. In the staring mode, the satellite will dynamically adjust its beam pointing through technologies such as satellite attitude adjustment in the air and phased array parameter adjustment, so that the beam approximately covers the same area on the ground. As Figure 5 In the figure, the staring service area of the anchor satellite (i.e., the first satellite in this article) in the initial stage is the area indicated by the dotted line in the figure. After the anchor satellite and each sub-satellite (i.e., the second satellite) move for a certain distance, the staring service area of the anchor satellite is the area indicated by the solid line in the figure. For the terminal device, the second satellite that could originally provide services to the terminal device may no longer be able to provide services to the terminal device. As Figure 5 As shown in the figure, the terminal device is within the coverage area A of the sub-satellite 1. As the sub-satellite 1 moves, the terminal device is no longer within the coverage area of the sub-satellite 1. At this time, the sub-satellite 1 can no longer provide services to the terminal device.

[0116] In response to Figure 5 the situation shown in the figure, the embodiment of the present application also provides a communication method. In this communication method, when a certain sub-satellite cannot provide services to the terminal device, the anchor satellite decides to replace the sub-satellite that cannot provide services with another sub-satellite to continue providing services to the terminal device, so as to reduce the impact on the data transmission performance of the terminal device. Please refer to Figure 6 , which is a schematic flowchart of the communication method 600 provided by the embodiment of the present application. Figure 6 This method is introduced from the perspective of the interaction between the first satellite, the second satellite A, the second satellite B, and the terminal device. It should be understood that the communication method 600 can also be implemented by other devices, such as a chip or a communication device with communication functions.

[0117] S601. The second satellite B sends the third information to the first satellite. Correspondingly, the first satellite receives the third information from the second satellite B.

[0118] The second satellite B cannot provide services to the terminal device. The second satellite B's inability to provide services to the terminal device includes that the second satellite B cannot provide services to the terminal device at a certain or certain times. Or, the second satellite B's inability to provide services to the terminal device includes that the second satellite B cannot provide services for a certain or certain synchronization indices, that is, the second satellite B cannot send synchronization signals including a certain or certain synchronization indices. Or, the second satellite B's inability to provide services to the terminal device includes that the second satellite B cannot provide services for a certain or certain synchronization indices at a certain or certain times. For ease of description, hereinafter, it is assumed that the second satellite B cannot send a synchronization signal including a first synchronization index at the time indicated by the first time information. Among them, the first time information can indicate one or more times, and these one or more times do not belong to the times when the second satellite B provides services based on the first synchronization index. The first synchronization index can indicate one or more synchronization indices.

[0119] Due to reasons such as the antenna scanning range, the second satellite B cannot provide services at the wave position where the first synchronization index is located. The wave position can be understood as an area within the coverage range of the second satellite B. The wave position where the first synchronization index is located can be understood as the area covered by the synchronization signal indicated by the first synchronization index. When the second satellite B determines that it cannot provide services for the first synchronization index at the time indicated by the first time information, it can notify the first satellite. For example, the second satellite B sends a third message to the first satellite, and this third message is used to indicate the time and synchronization index for which the second satellite B cannot provide services. For example, this third message includes the first time information and the first synchronization index. Among them, both the first time information and the first synchronization index can exist in tabular form. Correspondingly, the third message can include a first list and a second list. The first list includes the times indicated by the first time information, and the second list includes the first synchronization index.

[0120] If the first satellite can know the times and synchronization indices for which each second satellite within its coverage range cannot provide services, then S601 does not need to be executed. That is to say, S601 is not a necessary step, and it is schematically shown by a dashed line in Figure 6 the figure.

[0121] S602. The first satellite sends a second message to the second satellite A. Correspondingly, the second satellite A receives the second message from the first satellite.

[0122] The second satellite A is a satellite that can replace the services provided by the second satellite B for the terminal device. The first satellite receives the third information from the second satellite B, determines that the second satellite B cannot provide services for the terminal device based on the first synchronization index at the time indicated by the first time information, and the first satellite determines a satellite (such as the second satellite A) that can replace the services provided by the second satellite B for the terminal device. The second satellite A can provide services for the terminal device through the first synchronization index at the first time information. After the first satellite determines the second satellite A, it instructs the second satellite A to send the synchronization signal indicated by the first synchronization index at the time indicated by the first time information. For example, the first satellite sends the second information to the second satellite A, and the second information includes the first time information and the first synchronization index, which are used to instruct the second satellite A to send the synchronization signal indicated by the first synchronization index at the time indicated by the first time information.

[0123] S603. The second satellite A sends a second synchronization signal, and the second synchronization signal includes the first synchronization index.

[0124] The second satellite A receives the second information from the first satellite and sends a synchronization signal according to the second information. For example, the second satellite A sends the second synchronization signal at the time indicated by the first time information, and the second synchronization signal includes the first synchronization index. Optionally, the second synchronization signal further includes the first ephemeris information corresponding to the first synchronization index, that is, the second synchronization signal includes the first synchronization index and the first ephemeris information. In this way, the terminal device receives the second synchronization signal, determines the TA value according to the first ephemeris information, and then sends a random access preamble according to the TA value to access the network. The specific implementation manner in which the second synchronization signal includes the first synchronization index and the first ephemeris information may refer to the specific implementation manner in which the first synchronization signal includes the second synchronization index and the second ephemeris information described above. For example, the second synchronization signal includes the first synchronization index, and the second synchronization signal further includes SIB, and SIB carries the association relationship between at least one synchronization index and at least one ephemeris information, which will not be elaborated here. When the second satellite A sends the second synchronization signal, it can update the stored first association relationship, and in the updated first association relationship, the first synchronization index corresponds to the first ephemeris information.

[0125] Similar to the second satellite B, when the second satellite A cannot provide services through a certain or certain synchronization indexes at a certain or certain times, the second satellite A can notify the first satellite. For example, the second satellite A can send the fourth information to the first satellite, and the fourth information indicates the time and synchronization index when the second satellite A cannot provide services. For example, the fourth information includes the second time information and the third synchronization index, and the third synchronization index cannot provide services at the time indicated by the second time information. Among them, both the second time information and the third synchronization index can exist in the form of a table.

[0126] S604. The terminal device determines the first ephemeris information based on the second synchronization signal, and sends a random access preamble according to the first ephemeris information.

[0127] After receiving the second synchronization signal, the terminal device can obtain the first ephemeris information, determine the TA quantity according to the first ephemeris information, and then send a random access preamble according to the determined TA quantity to access the second satellite A. For the specific implementation of the terminal device to obtain the first ephemeris information, reference can be made to the specific implementation of the terminal device receiving the first synchronization signal and obtaining the second ephemeris information in the foregoing S403, which will not be elaborated here.

[0128] In the communication method 600, when a certain sub-satellite cannot provide services for the terminal device, the anchor satellite decides to replace the sub-satellite that cannot provide services with another sub-satellite to continue to provide services for the terminal device, which can reduce the impact on the data transmission performance of the terminal device.

[0129] The communication method 600 and the communication method 400 can be combined. For example, after S401 - S403 are executed, S601 - S603 can be executed. Among them, the execution order of each step in S401 - S403 and S601 - S603 is not limited, and not all of these steps must be executed. For example, S602, S603, S604, S401, S402, and S403 can be executed in sequence.

[0130] In a possible scenario, if the terminal device has no data transmission requirements for a period of time, if the satellite still sends synchronization signals during this period, it is unnecessary for the terminal device, which will cause resource waste and additional power consumption of the satellite. Therefore, the embodiment of the present application also provides a communication method. In this communication method, the anchor satellite schedules a suitable sub-satellite to send synchronization signals according to the actual needs of the terminal device, which can reduce the sending of unnecessary synchronization signals, thereby saving resources and reducing the power consumption of the satellite.

[0131] In this method, the random access resources of the first satellite can be (pre)-configured. For ease of description, the set composed of the random access resources of the first satellite is called the first resource set. The first resource set can be divided into multiple sub-resource sets. One sub-resource set corresponds to one second satellite, and one second satellite can correspond to one or more sub-resource sets. In this way, the first satellite can determine which second satellite's coverage range the terminal device is located in by using the resources of the random access preamble received from the terminal device, so as to schedule this second satellite to provide services for the terminal device.

[0132] For ease of understanding, please refer to Figure 7 , which is a schematic diagram of an architecture of the satellite communication system provided by the embodiment of the present application. Figure 7The projection of the beam of the anchor satellite on the ground is larger than the projections of the beams of multiple sub-satellites on the ground, or the wave positions of the anchor satellite nest the wave positions of each sub-satellite. Figure 7 Taking wave position A as a wave position of the anchor satellite, and wave positions a, b, and c as wave positions of multiple sub-satellites under the anchor satellite as an example, wave positions a, b, and c are nested within wave position A. One wave position can correspond to a random access resource set. For example, wave position A corresponds to a random access resource set, and each of wave beams a, b, and c corresponds to a random access resource set. The random access resource sets corresponding to wave beams a, b, and c are nested within the random access resource set corresponding to wave position A. For example, the random access resource set corresponding to wave position A becomes random access resource set A, the random access resource set corresponding to wave position a becomes random access resource set a, the random access resource set corresponding to wave position b becomes random access resource set b, and the random access resource set corresponding to wave position c becomes random access resource set c. Among them, random access resource set a, random access resource set b, and random access resource set c are subsets of random access resource set A, and there is no overlap between random access resource set a, random access resource set b, and random access resource set c. If the random access resource set used by the terminal device corresponds to the wave position of a certain sub-satellite, then the anchor satellite can determine that the sub-satellite can provide services for the terminal device.

[0133] Correspondingly, please refer to Figure 8 , which is a schematic flow diagram of communication method 800 provided by an embodiment of the present application. Figure 8 This method is introduced from the perspective of the interaction between the first satellite, the second satellite A, and the terminal device. It should be understood that communication method 800 can also be implemented by other devices, such as a chip or a communication device with communication functions.

[0134] S801. The first satellite sends fifth information to the terminal device. Correspondingly, the terminal device receives the fifth information from the first satellite.

[0135] The fifth piece of information is used to indicate a second association relationship, which includes the association relationship between a plurality of sub-resource sets and a first resource set. The first resource set can be a set composed of the random access resources of the first satellite, or a set composed of the random access resources corresponding to a certain wave position of the first satellite. The plurality of sub-resource sets can be a plurality of sub-resource sets obtained by partitioning the first resource set, or a part of the sub-resource sets after partitioning the first resource set. One sub-resource set corresponds to one second satellite, and one second satellite can correspond to a plurality of sub-resource sets, as shown in Table 3. In Table 3, the first resource set can be a set composed of the random access resources of the first satellite, or a set composed of the random access resources corresponding to a certain wave position of the first satellite. The second association relationship can be the association relationship shown in Table 3, or the association relationship shown in the first two columns of Table 3.

[0136] Table 3

[0137]

[0138] Taking the first resource set in Table 3 as the set of random access resources corresponding to wave position A of the first satellite as an example, wave position A nests wave positions a, b, and c. The first sub-resource set is the set of random access resources of wave position a nested in wave position A, the second sub-resource set is the set of random access resources of wave position b nested in wave position A, and the third sub-resource set is the set of random access resources of wave position c nested in wave position A. Wave position a corresponds to the second satellite A, beam b corresponds to the second satellite A, and wave position c corresponds to the second satellite B. The first sub-resource set, the second sub-resource set, and the third sub-resource set are subsets of the first resource set, and the first sub-resource set, the second sub-resource set, and the third sub-resource set do not overlap with each other. The non-overlap of the resource sets here means that the resources in the set are different in at least one of the three dimensions of time domain, frequency domain, or code domain. Taking the first sub-resource set and the second sub-resource set as an example, the resources in the first sub-resource set and the resources in the second sub-resource set are the same in time domain and frequency domain, but the corresponding sequences are different; or, the resources in the first sub-resource set and the resources in the second sub-resource set are the same in time domain and the corresponding sequences are the same, but different in frequency domain; or, the resources in the first sub-resource set and the resources in the second sub-resource set have the same corresponding sequences, the same in frequency domain, but different in time domain; or, the resources in the first sub-resource set and the resources in the second sub-resource set are different in time domain and frequency domain, but the corresponding sequences are the same or different, and so on.

[0139] Among them, the second association relationship can be pre-configured, and the terminal device and the first satellite can store the second association relationship shown in Table 3. In this case, S801 does not need to be executed, that is, S801 is an optional step. In Figure 8It is schematically shown by a dashed line in the figure. Alternatively, the second association relationship may be sent by the first satellite to the terminal device. For example, the first satellite may send a synchronization signal to the terminal device, and the synchronization signal includes indication information of the second association relationship. For example, the synchronization signal is an SSB, and the indication information may be carried in the SIB.

[0140] S802. The first satellite sends a third synchronization signal. Correspondingly, the terminal device receives the third synchronization signal.

[0141] The first satellite sending the third synchronization signal includes the first satellite broadcasting the third synchronization signal. The first satellite may use the resources within the first resource set to send the third synchronization signal. Thus, when the terminal device receives the third synchronization signal, it can determine that the resources used to send the third synchronization signal come from the first resource set according to the third synchronization signal.

[0142] S803. The terminal device sends a first random access preamble. Correspondingly, the first satellite receives the first random access preamble from the terminal device.

[0143] When the terminal device has a data transmission requirement, it may request to access the network. For example, the terminal device may send a first random access preamble. The first satellite receives the first random access preamble from the terminal device and determines that the terminal device has a data transmission requirement. In this case, the first satellite can determine which second satellite to schedule to serve the terminal device, without scheduling all the second satellites to send synchronization signals, thereby saving resources and reducing the power consumption of other second satellites.

[0144] The terminal device may send the first random access preamble according to the second association relationship. For example, based on the relationship shown in Table 3, the terminal device may randomly select a resource from the sub-resource set corresponding to its wave position to send the first random access preamble. For example, if the terminal device is located in the wave position covered by the second satellite A, the terminal device may randomly select a resource from the first sub-resource set or the second sub-resource set to send the first random access preamble.

[0145] S804. The first satellite determines the second satellite A according to the first random access preamble and the second association relationship.

[0146] The second satellite A is a terminal device that provides services to the terminal device among multiple second satellites in the system. The second association relationship further includes the association relationship between multiple sub-resource sets and multiple second satellites, as shown in Table 3. It can be seen from Table 3 that each sub-resource set has a corresponding second satellite. Therefore, the first satellite can determine the second satellite that can provide services to the terminal device according to the second association relationship shown in Table 3 and the random access preamble sent by the terminal device, and then schedule this second satellite. For example, the terminal device sends a first random access preamble, and this first random access preamble belongs to the first sub-resource set, then the second satellite that can provide services to the terminal device is the second satellite A.

[0147] After the first satellite determines the second satellite A, it can schedule the second satellite A to send a synchronization signal. For example, the first satellite can send a sixth message to the second satellite A, and this sixth message can be used for at least the second satellite A to send a synchronization signal. For example, this sixth message includes information related to the second satellite A sending a synchronization signal. For example, the information includes information about the resources used by the second satellite A to send a synchronization signal. The second satellite A receives the sixth message and sends a synchronization signal according to the sixth message.

[0148] S805. The first satellite sends a random access response message to the terminal device. Correspondingly, the terminal device receives this random access response message.

[0149] This random access response message includes the ephemeris information and resource information of the second satellite A. The resource information is used to indicate the resources for the second satellite A to send a synchronization signal. The ephemeris information of the second satellite A can be information associated with the ephemeris information of the second satellite A, as long as it can enable the terminal device to determine the ephemeris information of the second satellite A. For example, the ephemeris information of the second satellite A includes the ID of the second satellite A or the ID of the TRP corresponding to the second satellite A, or the PCI of the cell under the second satellite A. The association relationship between one or more of the above information and the ephemeris information of the second satellite A can be sent by the first satellite to the terminal device, or the first satellite and the terminal device can agree on this association relationship.

[0150] The resource information can be replaced with information related to the second satellite A sending a synchronization signal. In this way, the random access response message including the ephemeris information and resource information of the second satellite A can be replaced with the random response message including the ephemeris information of the second satellite A and a seventh message. This sixth message is information related to the second satellite A sending a synchronization signal. For example, the seventh message includes resource information, and this resource information indicates the resources used by the second satellite A to send a synchronization signal. The resource information may include time domain resource information, frequency domain resource information, the center frequency of the synchronization signal occupied by the synchronization signal, or one or more of the time domain offset value and / or frequency domain offset value of the synchronization signal of the second satellite A relative to the synchronization signal of the first satellite.

[0151] S806. The terminal device receives a synchronization signal from the second satellite A on the resource indicated by the resource information.

[0152] After receiving the random access response message, the terminal device can determine the resource used by the second satellite A to send the synchronization signal, that is, the resource indicated by the resource information, so as to receive the synchronization signal from the second satellite A on the resource indicated by the resource information to access the network.

[0153] In the communication method 800, the first satellite can tune to a suitable second satellite to send a synchronization signal according to the actual needs of the terminal device. When the terminal device has no information transmission requirements, it is not necessary to schedule any second satellite within the coverage area, thereby saving resources and reducing the power consumption of the second satellite.

[0154] The above communication method 800 can be combined with the communication methods 400 and 600. For example, the communication method 800 and the communication method 400 can be combined with each other, the communication method 800 and the communication method 600 can be combined with each other, and the communication method 800, the communication method 400, and the communication method 600 can also be combined with each other.

[0155] In the above embodiments provided in the present application, the methods provided in the embodiments of the present application are introduced by taking satellites (such as the first satellite and / or the second satellite) and terminal devices as examples. In the present application, each embodiment can be implemented independently or in combination based on certain internal relationships; in each embodiment, different implementation manners can be implemented in combination or independently. To implement the various functions in the methods provided in the above embodiments of the present application, the steps executed by the terminal device can be implemented by different functional entities constituting the terminal device. The steps executed by the satellite can be implemented by different functional entities constituting the satellite. To implement the various functions in the methods provided in the above embodiments of the present application, the terminal device and the satellite can include a hardware structure and / or a software module, and implement the above various functions in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether a certain function among the above various functions is executed in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the specific application and design constraints of the technical solution.

[0156] Based on the same inventive concept as the method embodiment, an embodiment of the present application provides a communication device. The communication device used to implement the above method in the embodiment of the present application is introduced below with reference to the accompanying drawings. The content above can be used in the subsequent embodiments, and the repeated content will not be described again.

[0157] Figure 9 It is a schematic block diagram of the communication device 900 provided in the embodiment of the present application. The communication device 900 can be the terminal device or the satellite in the above embodiments. For example, the communication device 900 can be Figure 1The terminal device in; or, the communication device 900 is a chip (system) in the terminal device; or, the communication device 900 is a software module of the terminal device. The communication device 900 can correspondingly implement the functions or steps implemented by the terminal device in the above various method embodiments. For another example, the communication device 900 can be Figure 1 The satellite in; or, the communication device 900 is a chip (system) in the satellite; or, the communication device 900 is a software module of the satellite. The communication device 900 can correspondingly implement the functions or steps implemented by the first satellite or the second satellite in the above various method embodiments. The communication device 900 can include a processing module 910 and a transceiver module 920. Optionally, it can further include a storage module, and the storage module can be used to store instructions (codes or programs) and / or data. The storage module can be, for example, a memory. The processing module 910 and the transceiver module 920 can be coupled to the storage module. For example, the processing module 910 can read the instructions (codes or programs) and / or data in the storage module to implement the corresponding method. When the communication device 900 is a chip in the terminal device or the satellite, the storage module can be the storage module inside the chip, such as registers, caches, etc. For example, the storage module can also be the storage module outside the chip in the terminal device or the satellite, such as a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM), etc. The above various units can be set independently, or partially or fully integrated.

[0158] The processing module 910 can be a processor or a controller. For example, it can be a general - purpose central processing unit (CPU), a general - purpose processor, a digital signal processing (DSP), an application specific integrated circuits (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, transistor - logic devices, hardware components, or any combination thereof. It can implement or execute various exemplary logic blocks, modules, and circuits described in connection with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. The transceiver module 920 is a transceiver, an interface circuit, a bus, a pin, or other possible communication interfaces, and is used to receive signals from other devices. For example, when the device is implemented in the form of a chip, the transceiver module 920 is the interface circuit of the chip for receiving signals from other chips or devices, or is the interface circuit of the chip for sending signals to other chips or devices.

[0159] In one implementation, the communication device 900 can correspondingly implement the behaviors and functions of the first satellite in the above - mentioned method embodiments. The communication device 900 can be a satellite, or a component applied to a satellite (such as a chip or a circuit), or a chip or a chip - set in a satellite or a part of the chip for executing relevant method functions, or a software module that can implement the method executed by the first satellite in the above - mentioned methods (such as communication method 400 and / or communication method 600, or communication method 800), without limitation. For specific references, please refer to the relevant content of the foregoing method embodiments, which will not be elaborated here.

[0160] For example, the processing module 910 can be used to determine the first information, and the first information includes the synchronization information of at least one second satellite. The synchronization information of each second satellite includes at least one synchronization index. The transceiver module 920 is used to send the first information.

[0161] As an optional implementation, the synchronization information of each second satellite further includes the time corresponding to at least one synchronization index.

[0162] As an optional implementation, the first information further includes the ephemeris information of at least one second satellite, or the identification information of at least one second satellite, or the identification information of at least one TRP, where one TRP corresponds to one second satellite.

[0163] As an alternative implementation, at least one second satellite includes a plurality of second satellites, and the cell identifiers corresponding to the plurality of second satellites are the same.

[0164] As an alternative implementation, the transceiver module 920 is further configured to send second information to the second satellite A among the plurality of second satellites. The second information includes first time information and a first synchronization index, and is used to instruct the second satellite A to send a synchronization signal indicated by the first synchronization index at the time indicated by the first time information. Among them, the time indicated by the first time information does not belong to the time when the second satellite B among the plurality of second satellites provides services based on the first synchronization index.

[0165] As an alternative implementation, the transceiver module 920 is further configured to receive third information from the second satellite B by the first satellite. The third information includes first time information and a first synchronization index.

[0166] For another example, the transceiver module 920 is configured to use the resources within the first resource set to send a third synchronization signal and receive a first random access preamble from a terminal device. The processing module 910 is configured to determine the second satellite A according to the first random access preamble and a second association relationship. The second association relationship includes the association relationship between a plurality of sub-resource sets and a plurality of second satellites. The resources of the first random access preamble belong to the first sub-resource set among the plurality of sub-resource sets, and the second satellite A belongs to the plurality of second satellites. The transceiver module 920 is further configured to send a random access response message to the terminal device. The random access response message includes the ephemeris information and resource information of the second satellite A, and the resource information is used to indicate the resources for the second satellite A to send a synchronization signal.

[0167] As an alternative implementation, the transceiver module 920 is further configured to send fifth information, and the fifth information indicates the second association relationship. The second association relationship further includes the association relationship between a plurality of sub-resource sets and the first resource set, where the plurality of sub-resource sets are obtained by dividing the first resource set.

[0168] In one implementation, the communication device 900 can correspondingly implement the behaviors and functions of the second satellite (such as the second satellite A or the second satellite B) in the above method embodiments. The communication device 900 can be a satellite, or a component applied to a satellite (such as a chip or a circuit), or a chip or a chip group in a satellite or a part of the chip for executing related method functions, or a software module capable of implementing the method executed by the satellite in the above methods (such as communication method 400 and / or communication method 600, or communication method 800), without limitation. For specific reference, please refer to the relevant content of the foregoing method embodiments, which will not be elaborated here.

[0169] For example, the processing module 910 is used to determine a first synchronization signal, which includes a second synchronization index associated with second ephemeris information that is different from the ephemeris information associated with the synchronization indices corresponding to other second satellites.

[0170] The transceiver module 920 is used to send the first synchronization signal.

[0171] As an alternative implementation, the first synchronization signal further includes: second ephemeris information, or a first association relationship, which is an association relationship between at least one synchronization index and at least one ephemeris information.

[0172] As an alternative implementation, the transceiver module 920 is further used to: receive first information from a first satellite, where the first information includes synchronization information of at least one second satellite, and the synchronization information of each second satellite includes at least one synchronization index.

[0173] As an alternative implementation, the synchronization information of each second satellite further includes a time corresponding to at least one synchronization index.

[0174] As an alternative implementation, the first information further includes ephemeris information of at least one second satellite, or identification information of at least one second satellite, or identification information of at least one TRP, where one TRP corresponds to one second satellite.

[0175] As an alternative implementation, the transceiver module 920 is further used to receive second information from the first satellite and send a second synchronization signal at the time indicated by first time information, where the second synchronization signal includes a first synchronization index. The second information includes the first time information and the first synchronization index, and is used to indicate that the second satellite sends a synchronization signal indicated by the first synchronization index at the time indicated by the first time information. Among them, the time indicated by the first time information does not belong to the time when other second satellites provide services based on the first synchronization index.

[0176] As an alternative implementation, the transceiver module 920 is further used to send fourth information to the first satellite, where the fourth information includes second time information and a third synchronization index that cannot provide services at the time indicated by the second time information.

[0177] In one implementation, the communication device 900 can correspondingly implement the behaviors and functions of the terminal device in the foregoing method embodiments. The communication device 900 can be a terminal device, or a component applied to the terminal device (such as a chip or a circuit), or a part of a chip, a chipset, or a chip in the terminal device for executing relevant method functions, or a software module capable of implementing the method executed by the terminal device in the foregoing methods (such as communication method 400 and / or communication method 600, or communication method 800), without limitation. For specific reference, please refer to the relevant content of the foregoing method embodiments, which will not be elaborated here.

[0178] For example, the transceiver module 920 is used to receive a first synchronization signal, and the first synchronization signal includes a second synchronization index. The processing module 910 is used to determine second ephemeris information according to the second synchronization index and the first association relationship, determine the TA quantity according to the second ephemeris information, and send a random access preamble according to the TA quantity. The first association relationship is an association relationship between at least one synchronization index and at least one ephemeris information.

[0179] For another example, the transceiver module 920 is used to receive a third synchronization signal from a first satellite, send a first random access preamble to the first satellite, receive a random access response message, and receive a synchronization signal from a second satellite on the resources indicated by the resource information. The third synchronization signal is sent using the resources within the first resource set. The random access response message includes the ephemeris information of the second satellite and resource information, and the resource information is used to indicate the resources for the second satellite A to send a synchronization signal;

[0180] As an alternative implementation, the processing module 910 is further used to determine a first sub-resource set according to the first resource set and the second association relationship. The second association relationship includes the association relationship between the first resource set and multiple sub-resource sets. The multiple sub-resource sets are obtained by dividing the first resource set, and the first sub-resource set belongs to the multiple sub-resource sets. The transceiver module 920 is specifically used to send the first random access preamble to the first satellite using the resources within the first sub-resource set.

[0181] When the communication device 900 is a chip-type device or a circuit, the transceiver module can be an input / output circuit and / or a communication interface; the processing module is an integrated processor, a microprocessor, or an integrated circuit.

[0182] Figure 10 FIG. is a schematic block diagram of the communication device 1000 provided in the embodiments of the present application. The communication device 1000 can be the terminal device or the satellite (such as the first satellite or the second satellite) in the foregoing embodiments. For example, the communication device 1000 can be Figure 1The terminal device in or the chip (system) in the terminal device. In the embodiments of the present application, the chip system may be composed of chips, or may include chips and other discrete devices. For the specific functions, reference may be made to the descriptions in the above method embodiments. For another example, the communication device 1000 may be Figure 1 The satellite in or the chip (system) in the satellite. In the embodiments of the present application, the chip system may be composed of chips, or may include chips and other discrete devices. For the specific functions, reference may be made to the descriptions in the above method embodiments.

[0183] The communication device 1000 includes one or more processors 1001, which are used to implement or support the communication device 1000 to implement the functions of the terminal device or the satellite in the method provided in the embodiments of the present application. For the specific details, reference may be made to the detailed descriptions in the method examples, and details are not elaborated here. The processor 1001 may also be referred to as a processing unit or a processing module, and can implement certain control functions. The processor 1001 may be a general-purpose processor or a dedicated processor, etc. For example, it includes: a baseband processor, a central processor, an application processor, a modulation and demodulation processor, a graphics processor, an image signal processor, a digital signal processor, a video codec processor, a controller, a memory, and / or a neural network processor, etc. The baseband processor may be used to process communication protocols and communication data. The central processor may be used to control the communication device 1000 (such as a satellite or a terminal device), execute software programs, and / or process data. Different processors may be independent devices, or may be integrated in one or more processors. For example, they may be integrated on one or more application-specific integrated circuits.

[0184] In one design, the processor 1001 may include a program 1003 (sometimes also referred to as code or instructions), and the program 1003 may be run on the processor 1001, so that the communication device 1000 executes the method described in the following embodiments. In another possible design, the communication device 1000 includes a circuit ( Figure 10 (not shown), and the circuit is used to implement the functions of the terminal device or the satellite in the above embodiments.

[0185] In one design, the communication device 1000 may include one or more memories 1002, on which there is a program 1004 (sometimes also referred to as code or instructions), and the program 1004 may be run on the processor 1001, so that the communication device 1000 executes the method described in the above method embodiments.

[0186] In one design, the processor 1001 and / or the memory 1002 may include artificial intelligence (AI) modules 1007, 1008, and the AI modules are used to implement AI-related functions. The AI modules may be implemented in software, hardware, or a combination of software and hardware. For example, the AI module may include a Radio Access Network (RAN) Intelligent Controller (RIC) module. For example, the AI module may be a near-real-time RIC or a non-real-time RIC.

[0187] In a possible design, data may also be stored in the processor 1001 and / or the memory 1002. The processor and the memory may be provided separately or integrated together.

[0188] In a possible design, the communication device 1000 may further include a transceiver 1005 and / or an antenna 1006. The processor 1001 is sometimes also referred to as a processing unit and controls the communication device 1000. The transceiver 1005 is sometimes also referred to as a transceiver unit, transceiver, transceiver circuit, or transceiver, etc., and is used to implement the transceiver function of the communication device 1000 through the antenna 1006.

[0189] In a possible design, the communication device 1000 may further include one or more of the following components: a wireless communication module, an audio module, an external memory interface, an internal memory, a Universal Serial Bus (USB) interface, a power management module, an antenna, a speaker, a microphone, an input / output module, a sensor module, a motor, a camera, or a display screen, etc. It can be understood that in some embodiments, the communication device 1000 may include more or fewer components, or some components are integrated, or some components are split. These components may be implemented in hardware, software, or a combination of software and hardware.

[0190] The communication device in the above embodiments may be a terminal device, a circuit, a chip applied to the terminal device, or other combined devices, components, etc. having the above terminal device. Or, the communication device in the above embodiments may be a network device, a circuit, a chip applied to a satellite, or other combined devices, components, etc. having the above network device. When the communication device is a terminal device or a satellite, the transceiver module may be a transceiver, which may include an antenna, a radio frequency circuit, etc., and the processing module may be a processor, for example: a CPU. When the communication device is a chip system, the communication device may be an FPGA, a dedicated ASIC, a system on chip (SoC), a CPU, a network processor (NP), a DSP, a micro controller unit (MCU), a programmable logic device (PLD), or other integrated chips. The processing module may be the processor of the chip system. The transceiver module or the communication interface may be the input / output interface or the interface circuit of the chip system. For example, the interface circuit may be a code / data read / write interface circuit. The interface circuit may be used to receive code instructions (the code instructions are stored in the memory, and may be directly read from the memory, or may also be read from the memory through other devices) and transmit them to the processor; the processor may be used to run the code instructions to execute the methods in the above method embodiments. Another example is that the interface circuit may also be a signal transmission interface circuit between the communication processor and the transceiver.

[0191] The embodiments of the present application further provide a communication system. Specifically, the communication system includes multiple satellites and at least one terminal device. The terminal device is a terminal device for implementing the related functions of at least one of the above communication methods 400, communication method 600, and communication method 800. The multiple satellites include a first satellite and a second satellite. The first satellite is a satellite for implementing the related functions of at least one of the above communication methods 400, communication method 600, and communication method 800, and the second satellite is a satellite for implementing the related functions of at least one of the above communication methods 400, communication method 600, and communication method 800. For specific reference, please refer to the relevant descriptions in the above method embodiments, which will not be elaborated here.

[0192] The embodiments of the present application further provide a computer-readable storage medium, including instructions, which when running on a computer, cause the computer to execute the methods executed by the terminal device, the first satellite, or the second satellite in at least one of the above communication methods 400, communication method 600, and communication method 800.

[0193] An embodiment of the present application also provides a computer program product, including computer program code, which, when executed, causes a computer to execute the methods performed by a terminal device, a first satellite, or a second satellite in at least one of the above communication methods 400, 600, and 800.

[0194] An embodiment of the present application provides a chip system, which includes a processor and may further include a memory for implementing the functions of a terminal device, a first satellite, or a second satellite in at least one of the foregoing methods 400, 600, and 800. The chip system may be composed of chips or may include chips and other discrete devices.

[0195] To implement the functions of the above Figures 9 - 10 communication device, an embodiment of the present application also provides a chip, including a processor, for supporting the communication device to implement the functions related to the terminal device or the satellite in the above method embodiments. In a possible design, the chip is connected to a memory or the chip includes a memory, and the memory is used to store the necessary computer programs or instructions and data of the communication device.

[0196] It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0197] Those of ordinary skill in the art can realize that the various illustrative logical blocks and steps described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0198] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0199] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical, or other forms.

[0200] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0201] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the part that essentially contributes to the technical solution of the present application 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 enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0202] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A communication method, applied to a first satellite, characterized in that, Including: Determine first information, the first information includes synchronization information of at least one second satellite, and the synchronization information of each of the second satellites includes at least one synchronization index; Send the first information.

2. The method according to claim 1, characterized in that, The synchronization information of each of the second satellites further includes the time corresponding to the at least one synchronization index.

3. The method according to claim 1 or 2, characterized in that, The first information further includes: Ephemeris information of the at least one second satellite; or, Identification information of the at least one second satellite; or, Identification information of at least one transmit-receive point (TRP), where one TRP corresponds to one second satellite.

4. The method according to any one of claims 1 to 3, characterized in that The at least one second satellite includes a plurality of second satellites, and the cell identifiers corresponding to the plurality of second satellites are the same.

5. The method according to claim 4, wherein The method further includes: Send second information to a second satellite A among the plurality of second satellites, the second information includes first time information and a first synchronization index, and is used to instruct the second satellite A to send a synchronization signal indicated by the first synchronization index at the time indicated by the first time information, where the time indicated by the first time information does not belong to the time when a second satellite B among the plurality of second satellites provides services based on the first synchronization index.

6. The method according to claim 5, characterized in that, The method further includes: Receive third information from the second satellite B, the third information includes the first time information and the first synchronization index.

7. A communication method, applied to a second satellite, characterized in that, Including: Determine a first synchronization signal, the first synchronization signal includes a second synchronization index, the second synchronization index is associated with the second ephemeris information, and the second ephemeris information is different from the ephemeris information associated with the synchronization indexes corresponding to other second satellites; Send the first synchronization signal.

8. The method according to claim 7, characterized in that The first synchronization signal further includes: The second ephemeris information, or, A first association relationship, the first association relationship is an association relationship between at least one synchronization index and at least one ephemeris information.

9. The method according to claim 7 or 8, characterized in that, The method further includes: Receive first information from a first satellite, the first information includes synchronization information of at least one second satellite, and the synchronization information of each of the second satellites includes at least one synchronization index.

10. The method according to claim 9, characterized in that, The synchronization information of each of the second satellites further includes the time corresponding to the at least one synchronization index.

11. The method according to claim 9 or 10, characterized in that, The first information further includes: Ephemeris information of the at least one second satellite; or, Identification information of the at least one second satellite; or, Identification information of at least one transmit-receive point (TRP), where one TRP corresponds to one second satellite.

12. The method according to any one of claims 9-10, characterized in that, The method further includes: Receive second information from the first satellite, the second information includes first time information and a first synchronization index, and is used to instruct the second satellite to send a synchronization signal indicated by the first synchronization index at the time indicated by the first time information, where the time indicated by the first time information does not belong to the time when other second satellites provide services based on the first synchronization index; Send a second synchronization signal at the time indicated by the first time information, the second synchronization signal includes the first synchronization index.

13. The method according to claim 12, wherein The method further includes: Send fourth information to the first satellite, the fourth information includes second time information and a third synchronization index, and the third synchronization index cannot provide services at the time indicated by the second time information.

14. A communication method, applied to a terminal device, characterized in that, Including: Receive a first synchronization signal, where the first synchronization signal includes a second synchronization index; Determine second ephemeris information according to the second synchronization index and a first association relationship, where the first association relationship is an association relationship between at least one synchronization index and at least one ephemeris information; Determine a timing advance TA value according to the second ephemeris information; Send a random access preamble according to the timing advance value.

15. A communication method, applied to a first satellite, characterized in that Includes: Use resources within a first resource set to send a third synchronization signal; Receive a first random access preamble from a terminal device; Determine a second satellite A according to the first random access preamble and a second association relationship, where the second association relationship includes an association relationship between a plurality of sub-resource sets and a plurality of second satellites, the resource of the first random access preamble belongs to a first sub-resource set among the plurality of sub-resource sets, and the second satellite A belongs to the plurality of second satellites; Send a random access response message to the terminal device, where the random access response message includes the ephemeris information and resource information of the second satellite A, and the resource information is used to indicate the resources for the second satellite A to send a synchronization signal.

16. The method according to claim 15, wherein The method further includes: Send fifth information, where the fifth information indicates the second association relationship, and the second association relationship further includes an association relationship between the plurality of sub-resource sets and the first resource set, where the plurality of sub-resource sets are obtained by dividing the first resource set.

17. A communication method, applied to a terminal device, characterized in that, Includes: Receive a third synchronization signal from a first satellite, where the third synchronization signal is sent using resources within a first resource set; Send a first random access preamble to the first satellite; Receive a random access response message, where the random access response message includes the ephemeris information and resource information of a second satellite, and the resource information is used to indicate the resources for the second satellite to send a synchronization signal; Receive a synchronization signal from the second satellite on the resources indicated by the resource information.

18. The method according to claim 17, wherein The method further includes: Determine a first sub-resource set according to the first resource set and a second association relationship, where the second association relationship includes an association relationship between the first resource set and a plurality of sub-resource sets, the plurality of sub-resource sets are obtained by dividing the first resource set, and the first sub-resource set belongs to the plurality of sub-resource sets; Send a first random access preamble to a first satellite, including: sending the first random access preamble to the first satellite using resources within the first sub-resource set.

19. A communication device, characterized in that, Includes: A processing module, configured to determine first information, where the first information includes synchronization information of at least one second satellite, and the synchronization information of each second satellite includes at least one synchronization index; A transceiver module, configured to send the first information.

20. A communication device, characterized in that, Includes: A processing module, configured to determine a first synchronization signal, where the first synchronization signal includes a second synchronization index, the second synchronization index is associated with the second ephemeris information, and the second ephemeris information is different from the ephemeris information associated with the synchronization index corresponding to other second satellites; A transceiver module, configured to send the first synchronization signal.

21. A communication device, characterized in that, Includes: A transceiver module, configured to receive a first synchronization signal, where the first synchronization signal includes a second synchronization index; A processing module, configured to determine second ephemeris information according to the second synchronization index and the first association relationship, and determine a timing advance TA amount according to the second ephemeris information, where the first association relationship is an association relationship between at least one synchronization index and at least one ephemeris information; The transceiver module is further configured to send a random access preamble according to the timing advance amount.

22. A communication device, characterized in that, It includes: A transceiver module, configured to use resources in a first resource set to send a third synchronization signal and receive a first random access preamble from a terminal device; A processing module, configured to determine a second satellite A according to the first random access preamble and a second association relationship, where the second association relationship includes an association relationship between a plurality of sub-resource sets and a plurality of second satellites, the resource of the first random access preamble belongs to a first sub-resource set among the plurality of sub-resource sets, and the second satellite A belongs to the plurality of second satellites; The transceiver module is further configured to send a random access response message to the terminal device, where the random access response message includes ephemeris information and resource information of the second satellite A, and the resource information is used to indicate resources for the second satellite A to send a synchronization signal.

23. A communication device, characterized in that, It includes: A transceiver module, configured to send and receive a third synchronization signal from a first satellite, send a first random access preamble to the first satellite, receive a random access response message, and receive a synchronization signal from a second satellite on resources indicated by the resource information, where the third synchronization signal is sent using resources in a first resource set, and the random access response message includes ephemeris information and resource information of the second satellite, and the resource information is used to indicate resources for the second satellite to send a synchronization signal; A processing module, configured to determine the first random access preamble.

24. A communication device, characterized in that, The communication device includes a processor and a memory. The memory is configured to store a computer program, and the processor is configured to execute the computer program stored on the memory, so that the communication device executes the method according to any one of claims 1 to 6, or so that the communication device executes the method according to any one of claims 7 to 13, or so that the communication device executes the method according to claim 14, or so that the communication device executes the method according to any one of claims 15 to 16, or so that the communication device executes the method according to any one of claims 17 to 18.

25. A computer-readable storage medium, characterized in that, The computer-readable storage medium is configured to store a computer program. When the computer program runs on a computer, the computer is caused to execute the method according to any one of claims 1 to 6, or the computer is caused to execute the method according to any one of claims 7 to 13, or the computer is caused to execute the method according to claim 14, or the computer is caused to execute the method according to any one of claims 15 to 16, or the computer is caused to execute the method according to any one of claims 17 to 18.

26. A computer program product, characterized in that, The computer program product includes a computer program which, when running on a computer, causes the computer to execute the method according to any one of claims 1 to 6, or causes the computer to execute the method according to any one of claims 7 to 13, or causes the computer to execute the method according to claim 14, or causes the computer to execute the method according to any one of claims 15 to 16, or causes the computer to execute the method according to any one of claims 17 to 18.

27. A chip system, characterized in that, The chip system includes: a processor and an interface, where the processor is configured to call and run instructions from the interface, and when the processor executes the instructions, implement the method according to any one of claims 1 to 6, or implement the method according to any one of claims 7 to 13, or implement the method according to claim 14, or implement the method according to any one of claims 15 to 16, or implement the method according to any one of claims 17 to 18.

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