Communication method and apparatus

Abstract

Provided in the present application are a communication method and apparatus. The method comprises: a first communication apparatus receiving a first signal on a beam corresponding to a first beam position; next, using a first group of random access resources corresponding to a first sub-beam position to send a second signal; and then, receiving a third signal on a sub-beam corresponding to the first sub-beam position, wherein the first signal is used for indicating at least one sub-beam position, the at least one sub-beam position is included in the first beam position, the at least one sub-beam position can each correspond to a group of random access resources, and the first sub-beam position is a sub-beam position where the first communication apparatus is located. By using a first group of random access resources corresponding to a first sub-beam position to send a second signal, a receiving apparatus can effectively determine, on the basis of the first group of random access resources, that a first communication apparatus is located at the first sub-beam position, such that the receiving apparatus can further effectively schedule, in a timely manner, a sub-beam corresponding to the first sub-beam position to send a third signal, thereby helping to improve the link budget of a public downlink signal.

Description

A communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202410434483.X, filed on April 11, 2024, and entitled “A communication method and apparatus”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication method and apparatus. BACKGROUND

[0004] With the development of information technology, more urgent requirements are put forward for efficient, mobile, and diverse communication. At present, a development focus in the field of wireless communication is global mobile communication, and an important part of global mobile communication is non-terrestrial network (NTN) (such as satellite communication). In some important fields, such as space communication, aviation communication, maritime communication, etc., NTN plays an irreplaceable role.

[0005] Compared with traditional ground networks (such as the 4th generation (4G) mobile communication system or the 5th generation (5G) mobile communication system), NTN has the characteristics of wider coverage, faster speed, and lower cost. In particular, in places where ground networks cannot be directly deployed, such as the sea, desert, and air, NTN can serve as a supplement or extension to ground networks, achieve the purpose of wide-area seamless coverage or even global coverage by using high, medium, and low-orbit satellites, and can provide differentiated communication services for global users, effectively solving the problem of Internet access in areas where communication infrastructure is scarce.

[0006] As a typical example of NTN, satellite communication has the characteristics of long communication distance, large coverage area, and flexible networking, and can provide services for both fixed terminal devices and various mobile terminal devices. Satellite communication is introduced into traditional communication systems (such as the 5G communication system), and the base station or part of the base station function is deployed on the satellite, which not only provides seamless coverage for terminal devices, but also avoids the impact of natural disasters and ensures the reliability of the communication system. For example, taking the 5G communication system as an example, the satellite communication system and the 5G communication system are mutually integrated, complement each other, and fully exert their respective advantages to jointly form a global seamless coverage of sea, land, air, and sky integrated communication network, which meets the needs of users for various services everywhere and provides more comprehensive and high-quality services for users.

[0007] In order to support wide area coverage of satellite communication, multiple service areas under a satellite need to be served in a time-division manner (or referred to as beam scanning, beam hopping or beam polling, etc.). The number of beams that can be provided by a satellite is limited (for example, a satellite can provide tens of beams at the same time, and at most hundreds of beams), and it is impossible to simultaneously cover all areas that can be covered by the satellite. Generally, the areas that can be covered by a satellite are calculated according to a minimum elevation angle, for example, according to a minimum 30-degree elevation angle, and it is necessary to use thousands of beam directions to cover all areas that can be covered by the satellite. In order to cover all areas that can be covered by the satellite, a limited number of beams can be used to cover different areas in a time-division manner. If the coverage area corresponding to a beam is referred to as a beam position, the coverage area of a low-orbit satellite can include thousands of beam positions. In the existing standard, the default scanning period of an access beam is 20 ms, and when a terminal device searches for a cell, it can detect according to the candidate frequency points of the downlink synchronization signal according to the default period. If the scanning period of the access beam is increased, the terminal device can not be able to search for a cell that can provide services at all times. Therefore, the network side needs to satisfy that the scanning period of the access beam cannot be greater than 20 ms. As described above, in the case where the number of beams that can be provided by a satellite is limited and the coverage area of the satellite is very large, if the scanning is performed according to beams with a beam width of 3 dB, it is difficult for the satellite to scan all coverage areas in 20 ms in a time-division manner. In view of this, a possible implementation manner is to perform beam widening to make the width of the beam relatively wide (the difference in link budget between the edge of the beam and the center of the beam will be relatively large), so that all coverage areas of the satellite can be covered. However, this implementation manner will cause the gain of the beam to decrease. Before the terminal device completes access to the network, the network side cannot obtain the accurate position of the terminal device, and therefore can only transmit a common downlink signal in the direction determined by the downlink synchronization signal, that is, the common downlink signal also needs to be transmitted using a wide beam, which will cause the link budget of the common downlink signal to decrease. SUMMARY

[0008] The present application provides a communication method and device to improve the link budget of a common downlink signal.

[0009] In a first aspect, the present application provides a communication method, which can be performed by a first communication device. Optionally, the method can also be implemented by a logic node, a logic module or software capable of implementing all or part of the functions of the first communication device. For example, the first communication device can be a terminal device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the terminal device. The method can include the following steps: the first communication device receives a first signal on a beam corresponding to a first wave position, then the first communication device transmits a second signal using a first group of random access resources corresponding to a first sub-wave position, and then the first communication device receives a third signal on a sub-beam corresponding to the first sub-wave position, wherein the first signal can be used to indicate at least one sub-wave position, the at least one sub-wave position is included in the first wave position, and the at least one sub-wave position can correspond to a group of random access resources respectively, and the first sub-wave position is a sub-wave position where the first communication device is located.

[0010] In the method, the first wave position can include at least one sub-wave position (or can be understood as the first wave position being divided into at least one sub-wave position), and each of the at least one sub-wave position corresponds to a group of random access resources. In this way, after the first communication device determines that the sub-wave position where it is located is the first sub-wave position, it can transmit the second signal using the first group of random access resources corresponding to the first sub-wave position. This can enable the receiving device (such as the second communication device) to effectively determine that the first communication device is located in the first sub-wave position according to the first group of random access resources used to carry the second signal, so as to further enable the receiving device to timely and effectively schedule the sub-beam corresponding to the first sub-wave position to transmit the third signal (i.e., a common downlink signal), thereby helping to improve the link budget of the common downlink signal.

[0011] Correspondingly, in a second aspect, the present application provides a communication method, which can be performed by a second communication device. Optionally, the method can also be implemented by a logic node, a logic module or software capable of implementing all or part of the functions of the second communication device. For example, the second communication device can be a network device (such as a satellite) or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the network device. The method can include the following steps: the second communication device transmits a first signal using a beam corresponding to a first wave position, then the second communication device receives a second signal, and then the second communication device transmits a third signal using a sub-beam corresponding to a first sub-wave position, wherein the first signal can be used to indicate at least one sub-wave position, the at least one sub-wave position is included in the first wave position, the at least one sub-wave position can correspond to a group of random access resources respectively, the second signal is carried on the first group of random access resources, and the first sub-wave position corresponds to (or can be referred to as having an association relationship or a mapping relationship or a binding relationship with) the first group of random access resources.

[0012] The technical effects achieved by the second aspect can refer to the technical effects achieved by the first aspect, which will not be repeated here.

[0013] In a possible implementation of the first aspect or the second aspect, the first signal can be used to indicate an index of the at least one sub-wave position, or the first signal can also be used to indicate a reference point corresponding to the at least one sub-wave position.

[0014] In the implementation, through the flexible indication of the first signal (such as indicating the index of the at least one sub-wave position or indicating the reference point corresponding to the at least one sub-wave position), the first communication device can flexibly determine the number of sub-wave positions included in the first wave position, so that the first communication device can accurately allocate a corresponding random access resource to each sub-wave position according to the number of sub-wave positions.

[0015] In a possible implementation of the first aspect or the second aspect, the first signal is used to indicate one of the following:

[0016] a position coordinate of the reference point corresponding to the at least one sub-wave position included in the first wave position; or

[0017] a position coordinate corresponding to the first wave position and at least one first difference value, wherein the at least one first difference value can be a difference value between the position coordinate of the reference point corresponding to the at least one sub-wave position and the position coordinate corresponding to the first wave position; or

[0018] a second difference value and at least one first difference value, wherein the second difference value can be a difference value between the position coordinate corresponding to the first wave position and a position coordinate of a reference point of a first cell, and the first cell is a current serving cell corresponding to the first communication device; or

[0019] at least one third difference value, wherein the at least one third difference value can be a difference value between the position coordinate of the reference point corresponding to the at least one sub-wave position and the position coordinate of the reference point of the first cell.

[0020] In the implementation manner, the first communication device can learn the reference point corresponding to each sub-wave position included in the first wave position in time, so that the first communication device can accurately determine the number of sub-wave positions included in the first wave position. In addition, the position coordinates of the first wave position can be used as a reference for differential indication, or the position coordinates of a cell reference point (for example, a reference point of a serving cell of the terminal device) can be used as a reference for differential indication, or the position coordinates of the first wave position can be used as a reference for differential indication, or the position coordinates of the cell reference point can be used as a reference for differential indication, so that the first communication device can further determine the number of sub-wave positions included in the first wave position through differential indication, which helps to reduce signaling overhead.

[0021] In a possible implementation manner of the first aspect, the at least one group of random access resources corresponding to the at least one sub-wave position can be included in the random access resources corresponding to the first wave position.

[0022] In the implementation manner, the group of random access resources corresponding to each sub-wave position in the first wave position is obtained from the random access resources corresponding to the first wave position, so that the first communication device can effectively use the corresponding random access resources to send the second signal, so that the second communication device can successfully receive the second signal.

[0023] In a possible implementation manner of the first aspect, the at least one group of random access resources corresponding to the at least one sub-wave position can be determined by the first communication device according to the first signal.

[0024] In the implementation manner, the relevant information carried in the first signal can be used to accurately allocate the corresponding random access resources to each sub-wave position, so that the first communication device can select a matching group of random access resources according to its own position (it can be understood that the first communication device accurately selects a group of random access resources corresponding to the sub-wave position in which the first communication device is located), and use the group of random access resources to send the second signal.

[0025] In a possible implementation manner of the first aspect, the at least one group of random access resources corresponding to the at least one sub-wave position can be determined by the first communication device according to the number of at least one sub-wave position indicated by the first signal.

[0026] In the implementation manner, the first wave position corresponding random access resource can be accurately grouped according to the number of the at least one sub-wave position indicated by the first signal, so that the first communication device can select a suitable group of random access resources according to its own position (it can be understood that the first communication device determines which sub-wave position the first communication device is located in according to its own position, and selects a group of random access resources corresponding to the sub-wave position) to send the second signal, which can facilitate the receiving device (such as the second communication device) to timely and effectively schedule the sub-beam corresponding to the sub-wave position to send the common downlink signal (such as the third signal).

[0027] In a possible implementation manner provided in the first aspect, the first signal can also be used to indicate at least one delay offset, wherein the at least one delay offset can correspond to the first wave position (or it can be understood that one delay offset can be associated with or bound to or mapped to one wave position, such as the first wave position), or the at least one delay offset can correspond to the at least one sub-wave position in one-to-one manner.

[0028] The first communication device receives the third signal, including: the first communication device can receive the third signal in the first response window, wherein the first response window can be determined by the first communication device according to the second response window and the delay offset corresponding to the first wave position, or the first response window can be determined by the first communication device according to the second response window and the delay offset corresponding to the first sub-wave position.

[0029] In the implementation manner, the delay offset can be associated with the primary wave position (such as the first wave position) (it can be understood that different primary wave positions correspond to different delay offsets), or the delay offset can also be associated with the secondary wave position (such as the first sub-wave position) (it can be understood that different secondary wave positions correspond to different delay offsets), so that the flexibility of the delay offset can be realized, thereby increasing the flexibility of the third signal scheduling in the case of limited beam number and large coverage area.

[0030] In a possible implementation manner provided in the first aspect or the second aspect, the first signal can be a system message, the second signal can be a random access request message, and the third signal can be a random access response message.

[0031] In a possible implementation manner provided in the second aspect, the first signal can also be used to indicate at least one delay offset, wherein the at least one delay offset can correspond to the first wave position, or the at least one delay offset can correspond to the at least one sub-wave position in one-to-one manner.

[0032] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the corresponding implementation manners provided in the first aspect, which will not be described herein.

[0033] In a possible implementation manner of the second aspect, the method further includes: the second communication device can determine the delay offset corresponding to the first wave position according to the current service condition; or the second communication device can determine the delay offset corresponding to each of the at least one sub-wave position according to the current service condition.

[0034] In the implementation manner, the second communication device can dynamically determine the delay offset corresponding to each primary wave position (such as the first wave position) according to the actual service condition, which helps to achieve the purpose of flexibly configuring the delay offset corresponding to each primary wave position by the second communication device. In addition, the second communication device can also dynamically determine the delay offset corresponding to each secondary wave position (such as the first sub-wave position) according to the actual service condition, which helps to achieve the purpose of flexibly configuring the delay offset corresponding to each secondary wave position by the second communication device.

[0035] In a third aspect, the present application provides a communication method, which can be executed by a first communication device. Optionally, the method can also be implemented by a logical node, a logical module or software capable of implementing all or part of the functions of the first communication device. For example, the first communication device can be a terminal device or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the terminal device. The method can include the following steps: the first communication device receives a fourth signal on a beam corresponding to a first wave position, then the first communication device transmits a fifth signal, and then the first communication device receives a sixth signal on a sub-beam corresponding to a first sub-wave position, wherein the fifth signal can include an index of the first sub-wave position, the first sub-wave position is a sub-wave position where the first communication device is located, and the first sub-wave position is included in the first wave position.

[0036] In the method, the first communication device carries the index of the first sub-wave position in the fifth signal, so that the receiving device (such as the second communication device) can timely and accurately know that the sub-wave position where the first communication device is located is the first sub-wave position, so that the receiving device can timely and effectively schedule the sub-beam corresponding to the first sub-wave position to transmit the third signal (i.e., the common downlink signal), and thus the link budget of the common downlink signal can be improved.

[0037] Correspondingly, in a fourth aspect, the present application provides a communication method, which can be executed by the second communication device. Optionally, the method can also be implemented by a logic node, a logic module or software which can realize all or part of the functions of the second communication device. For example, the second communication device can be a network device (such as a satellite) or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the network device. The method can include the following steps: the second communication device can send a fourth signal using a beam corresponding to a first wave position, then the second communication device can receive a fifth signal, and then the second communication device can send a sixth signal using a sub-beam corresponding to a first sub-wave position, wherein the fifth signal can include an index of the first sub-wave position, and the first sub-wave position is included in the first wave position.

[0038] The technical effects achieved by the fourth aspect can refer to the technical effects achieved by the third aspect, which will not be repeated here.

[0039] In a possible implementation of the third aspect or the fourth aspect, the fourth signal can be used to indicate the index of the at least one sub-wave position, or the fourth signal can also be used to indicate the reference point corresponding to the at least one sub-wave position.

[0040] The technical effects achieved by the above implementation can refer to the technical effects achieved by the related implementation of the first aspect or the second aspect, which will not be repeated here.

[0041] In a possible implementation of the third aspect or the fourth aspect, the fourth signal is used to indicate one of the following contents:

[0042] The position coordinates of the reference point corresponding to the at least one sub-wave position included in the first wave position; or,

[0043] The position coordinates corresponding to the first wave position and the at least one first difference value, wherein the at least one first difference value can be a difference value between the position coordinates of the reference point corresponding to the at least one sub-wave position and the position coordinates corresponding to the first wave position; or,

[0044] The second difference value and the at least one first difference value, wherein the second difference value can be a difference value between the position coordinates corresponding to the first wave position and the position coordinates of the reference point of the first cell, and the first cell is a current serving cell corresponding to the first communication device; or,

[0045] The at least one third difference value, wherein the at least one third difference value can be a difference value between the position coordinates of the reference point corresponding to the at least one sub-wave position and the position coordinates of the reference point of the first cell.

[0046] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the related implementation manners provided in the first aspect or the second aspect, which will not be described herein.

[0047] In a possible implementation manner provided in the third aspect, the fourth signal can further be used to indicate at least one delay offset, where the at least one delay offset can correspond to the first wave position, or the at least one delay offset can correspond to the at least one sub-wave position one by one.

[0048] The first communication device receives the sixth signal, including: the first communication device can receive the sixth signal in a first response window, where the first response window can be determined by the first communication device according to the second response window and the delay offset corresponding to the first wave position, or the first response window can be determined by the first communication device according to the second response window and the delay offset corresponding to the first sub-wave position.

[0049] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the related implementation manners provided in the first aspect, which will not be described herein.

[0050] In a possible implementation manner provided in the third aspect or the fourth aspect, the fourth signal is a system message.

[0051] The fifth signal is a random access request message, and the sixth signal can be a random access response message, or the fifth signal is an uplink scheduling message, and the sixth signal can be a radio resource control setup response message.

[0052] In the above implementation manner, when the first communication device is allowed to carry data in the random access sequence, the index of the first sub-wave position can be carried in the random access request message, so that the receiving device (such as the second communication device) can use the sub-beam corresponding to the index of the first sub-wave position to carry the random access response message when scheduling the random access response message, which can help to improve the link budget of the random access response message (i.e., the common downlink signal). In the case where the first communication device is not allowed to carry data in the random access sequence, the index of the first sub-wave position is not carried in the random access request message, so that the receiving device (such as the second communication device) still needs to use the beam corresponding to the first wave position to carry the random access response message when scheduling the random access response message. Then, the first communication device can carry the index of the first sub-wave position in the uplink scheduling message, so that the receiving device (such as the second communication device) can use the sub-beam corresponding to the index of the first sub-wave position to carry the radio resource control setup response message when scheduling the radio resource control setup response message.

[0053] In a possible implementation manner of the fourth aspect, the fourth signal can further be used to indicate at least one delay offset, where the at least one delay offset can correspond to the first wave position, or the at least one delay offset can correspond to the at least one sub-wave position one by one.

[0054] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the related implementation manners of the second aspect, which will not be repeated here.

[0055] In a possible implementation manner of the fourth aspect, the method further includes: the second communication device can determine a delay offset corresponding to the first wave position according to a current service condition; or the second communication device can determine delay offsets corresponding to the at least one sub-wave position respectively according to the current service condition.

[0056] The technical effects achieved by the above implementation manners can refer to the technical effects achieved by the related implementation manners of the second aspect, which will not be repeated here.

[0057] In the fifth aspect, the present application provides a communication device, which has the functions related to the first aspect to the fourth aspect, for example, the communication device includes modules or units or means corresponding to the operations related to the first aspect to the fourth aspect, and the functions or units or means can be implemented by software or hardware, or the corresponding software can be executed by hardware.

[0058] In a possible implementation manner, the communication device includes a transceiver module (or can be referred to as a communication module or a transceiver unit or a communication unit, which is used for transmitting and receiving data) and a processing module (or can be referred to as a processing unit), where the transceiver module can be used for transceiving signals to realize the communication between the communication device and other devices, for example, the transceiver unit is used for transmitting data to the cloud; the processing module can be used for performing some internal operations of the communication device. The functions performed by the transceiver module and the processing module can correspond to the operations related to the first aspect to the fourth aspect.

[0059] In a possible implementation manner, the communication device includes a processor, which can be used for coupling with a memory. The memory can save necessary computer programs or instructions for implementing the functions related to the first aspect to the fourth aspect. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication device can implement the method in any possible implementation manner of the first aspect to the fourth aspect.

[0060] In a possible implementation, the communication apparatus includes a processor and a memory, and the memory can store necessary computer programs or instructions for implementing the functions related to the first aspect to the fourth aspect. The processor can execute the computer programs or instructions stored in the memory, and when the computer programs or instructions are executed, the communication apparatus can implement the method in any possible implementation of the first aspect to the fourth aspect.

[0061] In a possible implementation, the communication apparatus includes a processor and an interface circuit, where the processor is configured to communicate with other apparatuses through the interface circuit and implement the method in any possible implementation of the first aspect to the fourth aspect.

[0062] It can be understood that, in the fifth aspect, the processor can be implemented by hardware or software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, or the like. When implemented by software, the processor can be a general-purpose processor, which implements the functions by reading software codes stored in the memory. In addition, the processor can be one or more, and the memory can be one or more. The memory can be integrated with the processor, or the memory and the processor can be separately arranged. In a specific implementation, the memory and the processor can be integrated on the same chip, or can be separately arranged on different chips. The type of the memory and the arrangement manner of the memory and the processor are not limited in the embodiments of the present application.

[0063] In the sixth aspect, the present application provides a possible communication system, which can include the first communication apparatus and the second communication apparatus mentioned in the first aspect or the second aspect or the third aspect or the fourth aspect. The functions of the first communication apparatus or the second communication apparatus can be implemented as described in the first aspect or the second aspect or the third aspect or the fourth aspect, and will not be repeated here.

[0064] For example, the communication system can include one or more first communication apparatuses and one or more second communication apparatuses.

[0065] In the seventh aspect, the present application provides a computer program product, which includes computer programs or instructions, and when the computer programs or instructions are run on a communication apparatus (or a computer), the communication apparatus (or the computer) can execute the method in any possible implementation of any one of the first aspect to the fourth aspect.

[0066] In an eighth aspect, the present application provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed by a communication device (or a computer), the communication device (or the computer) is caused to perform the method in any possible implementation manner of any one of the first aspect to the fourth aspect.

[0067] In a ninth aspect, the present application provides a chip, which can include a processor, and can further include a memory (or the chip is coupled with the memory), and the processor executes program instructions in the memory, so as to cause the chip to perform the method in any possible implementation manner of any one of the first aspect to the fourth aspect. Wherein, the "coupled" means that two components are directly or indirectly combined with each other, and the coupling can mean that the two components are electrically connected.

[0068] In a tenth aspect, the present application further provides a chip system, which includes a processor, and is used for supporting a computer device to implement the method in any possible implementation manner of any one of the first aspect to the fourth aspect. In a possible implementation manner, the chip system further includes a memory, which is used for saving necessary program and data of the computer device. The chip system can be composed of a chip, or can include the chip and other discrete devices.

[0069] On the basis of the implementation manners of the aspects provided in the present application, further combinations can be made to provide more implementation manners. BRIEF DESCRIPTION OF DRAWINGS

[0070] FIG. 1 exemplarily shows a schematic diagram of a beam coverage area of a network device provided by an embodiment of the present application;

[0071] FIG. 2 exemplarily shows a schematic diagram of an architecture of a ground communication system provided by an embodiment of the present application;

[0072] FIG. 3 exemplarily shows a schematic diagram of a possible satellite communication system architecture provided by an embodiment of the present application;

[0073] FIG. 4 exemplarily shows a schematic diagram of a flow of a communication method provided by an embodiment of the present application;

[0074] FIG. 5a exemplarily shows a schematic diagram of a satellite coverage scenario provided by an embodiment of the present application;

[0075] FIG. 5b exemplarily shows a schematic diagram of another satellite coverage scenario provided by an embodiment of the present application;

[0076] FIG. 6 exemplarily shows a schematic diagram of a flow of another communication method provided by an embodiment of the present application;

[0077] FIG. 7 exemplarily shows a schematic diagram of a structure of a communication device provided by an embodiment of the present application;

[0078] FIG. 8 illustrates a structural schematic diagram of another communication apparatus provided by an embodiment of the present application. DETAILED DESCRIPTION

[0079] Before introducing the technical solutions provided by the present application, first, some terms involved in the present application are explained and described so as to facilitate understanding by those skilled in the art.

[0080] (1) Beam: refers to the main lobe of a directional array diagram. A network device (such as a satellite (also referred to as a high-altitude platform, a high-altitude flying vehicle, or a satellite base station, etc.)) can adjust the weight of the antenna so that the beam of the network device can point to different directions, with different coverage ranges (or coverage areas or coverage geographical ranges). In the present application, the coverage range of the beam refers to the coverage range of the beam on the ground. For example, the coverage range of the beam can contain at least one location point. As the satellite moves and the weight is adjusted, the coverage range of the beam will also change.

[0081] It can be understood that the beam can be a wide beam, or a narrow beam, or other types of beams. The technology for forming the beam can be beamforming technology or other technology. The beamforming technology can be digital beamforming technology, analog beamforming technology, or hybrid digital / analog beamforming technology, etc. The beam can correspond to a resource, for example, when performing beam measurement, the network device measures different beams through different resources, and the terminal device feeds back the measured resource quality, so that the network device knows the quality of the corresponding beam. In data transmission, beam information is also indicated through its corresponding resource. For example, the network device indicates the information of the physical downlink shared channel (PDSCH) beam of the terminal device through the transmission configuration indicator (TCI) field in the downlink control information (DCI).

[0082] For example, the network device can generate different beams pointing to different transmission directions. In downlink data transmission, when the network device sends data to the terminal device using a specific beam, it needs to inform the terminal device of the sending beam information it uses, so that the terminal device can use the receiving beam corresponding to the sending beam to receive the data sent by the network device.

[0083] Optionally, in some embodiments, multiple beams with the same or similar communication characteristics can be considered as one beam. One beam can include one or more antenna ports for transmitting data channels, control channels, sounding signals, and the like. One or more antenna ports forming a beam can also be regarded as an antenna port set.

[0084] In this application, if not specified, the beam refers to the transmitting beam of the network device. In beam measurement, each beam of the network device corresponds to a resource, so the beam corresponding to the resource can be uniquely identified by the index of the resource.

[0085] (2) Beam position: The service area of the satellite network can be divided into multiple small geographical areas according to geographical position or the coverage direction of the beam, and each geographical area can be referred to as a beam position. The beam position (or can be understood as the coverage range of the beam or the coverage geographical range of the beam or the physical position information of the beam) can be represented in different shapes. For example, the physical position information of the beam can include position coordinates, latitude and longitude, area identifier, and the like. It can be understood that the beam position can be the coverage range of a beam (or can be referred to as the projection range of the beam on the ground). The network device (such as a satellite) can adjust the weight of the antenna, so that the beam transmitted by the network device can be directed to different directions and have different coverage ranges. For example, a satellite is configured with 16 beams, each beam has different coverage range, and the coverage range of each beam can be a beam position.

[0086] (3) Synchronization signal and physical broadcast channel (PBCH) block (SSB) (or can be referred to as synchronization signal block): the SSB is composed of three parts of primary synchronization signal (PSS), secondary synchronization signal (SSS) and PBCH. Among them, the PSS and the SSS are both synchronization signals. The PSS can be used to transmit the cell number, and the SSS can be used to transmit the cell group number, and the cell number and the cell group number jointly determine the multiple physical cell identities (PCIs) in the communication system. The PBCH can be used to acquire the information of the accessed cell by the terminal device. For example, the PBCH can be used to indicate the physical downlink shared channel (PDSCH) carrying the system information block 1 (SIB1), and the SIB1 can be used to configure the random access resource. The terminal device can access the network according to the random access resource.

[0087] (4) Relationship between SSB and beam: the network device (such as a base station or a satellite) can use multiple antennas to enhance coverage, but using multiple antennas will cause the antenna radiation to be very narrow beam, and a single narrow beam is difficult to cover the entire cell. At the same time, due to hardware limitations, the network device cannot simultaneously transmit signals through multiple beams to cover the entire cell, therefore, the communication system introduces a beam sweeping technology, that is, the access network device can transmit signals through different beams at different times. Therefore, the communication system introduces a method of covering the entire cell through beam sweeping, that is, the network device can cover part of the area of the cell through part of the beam at a certain time, and then cover another part of the area of the cell through another part of the beam at another time.

[0088] Referring to FIG. 1, the network device transmits a beam in a certain direction at a certain time, and covers the entire cell by transmitting beams in different directions at multiple times. It can be understood that each beam can be indicated by the index (which can be referred to as the SSB index) of the SSB transmitted on the beam. For example, the network device covers the entire cell through beam 0 (used to transmit SSB#0), beam 1 (used to transmit SSB#1), …, beam N-1 (used to transmit SSB#N-1) and beam N (used to transmit SSB#N). It can be seen that the directions of any two beams can be different, and the SSB indexes corresponding to the two SSBs transmitted by any two beams are also different.

[0089] (5) Random access resource: The random access resource in this application can include at least one of a time domain resource, a frequency domain resource, or a code domain resource, etc.

[0090] For example, the time domain resource can include at least one of a radio frame, a subframe, a slot, a mini slot, or an orthogonal frequency division multiplexing (OFDM) symbol. Wherein, one radio frame can include a plurality of subframes, one subframe can include one or more slots, and one slot can include at least one symbol. Alternatively, one radio frame can include a plurality of slots, and one slot can include at least one symbol. It should be noted that one OFDM symbol can also be referred to as one symbol. The frequency domain resource can include at least one of a resource element (RE), a resource block (RB), a channel, a sub channel, a carrier, or a bandwidth part (BWP). In this application, the channel can also be equivalent to a resource block set (RB set), and the frequency domain bandwidth of one RB set can be 20 mega hertz (MHz).

[0091] (6) Random access: Before accessing the network, the terminal device needs to perform cell search. For example, when the terminal device is turned off and then turned on, cell search can be performed. The purpose of cell search is to enable the terminal device to obtain time synchronization and frequency synchronization of the system, so that the terminal device can read system information (such as information of the cell to be accessed, system bandwidth, and other cell broadcast information, etc.) and perform subsequent data transmission. Then, the terminal device can perform random access. Random access is a process of obtaining uplink synchronization between the terminal device and the network device (such as a satellite) after the terminal device and the network device obtain downlink synchronization. For example, random access can be divided into contention-based random access (also referred to as 4-step random access) and contention-free random access (also referred to as 2-step random access).

[0092] (7) Resource for random access: a random access request is transmitted on a physical random access channel occasion (RO), one RO is understood as one random access resource, and the terminal device can send a random access preamble sequence on a specific RO (i.e., on a specific time-frequency resource). The random access preamble sequence can also be referred to as a preamble, a random access sequence, a random access preamble, or a preamble sequence, etc. The format of the RO can correspond to the format of the preamble sequence.

[0093] It can be understood that the configuration information of the RO and the preamble sequence for random access in the existing standard (3GPP TS 38.331) is indicated by a system message, for example, it can be configured by random access channel (RACH)-ConfigCommon. For example, the parameter rach-ConfigGeneric in RACH-ConfigCommon indicates the PRACH sequence generation related information, which can include, for example, root indication, frequency-division multiplexing (FDM) number (number of frequency domain ROs), and frequency domain location information, etc. Optionally, RACH-ConfigCommon can also include information such as the association relationship between SSB and RO.

[0094] It should be noted that in the embodiments of the present application, "sending a signal (or data or information)" can be understood as a device sending a signal (or data or information) to another device, or it can also be understood as a logical module in a device sending a signal (or data or information) to another logical module. For example, "terminal device sending a signal" can be understood as the terminal device sending a signal to another device (such as a network device), or it can be understood as a logical module 1 in the terminal device sending a signal to a logical module 2 in the network device.

[0095] In the embodiments of the present application, the "receiving signal (or data or information)" can be understood as that a device receives signal (or data or information) from another device, or can also be understood as that a logical module in the device receives signal (or data or information) from another logical module. For example, "the network device receives signal" can be understood as that the network device receives signal from another device (such as a terminal device), or can be understood as that a logical module 1 in the network device receives signal from a logical module 2 in the terminal device.

[0096] In the embodiments of the present application, "sending signal to the terminal device" can be understood as that the destination of the signal is the terminal. It can include directly or indirectly sending signal to the terminal. "Receiving signal from the terminal" can be understood as that the source of the signal is the terminal. It can include directly or indirectly receiving signal from the terminal. The signal can be processed as necessary between the source and the destination of the signal, for example, format change, etc., but the destination can understand the effective information from the source. Similar expressions in the embodiments of the present application can be similarly understood, which will not be described here.

[0097] The embodiments of the present application will be described in detail below with reference to the drawings.

[0098] The communication system architecture to which the communication method provided by the present application is applicable will be introduced below. It should be noted that the introduction is for the purpose of facilitating understanding by those skilled in the art, and does not constitute limitation on the protection scope required by the present application.

[0099] The communication scheme provided by the embodiments of the present application can be applied to various communication systems, such as a satellite communication system, a high altitude platform station (HAPS) communication system, a non-terrestrial network (NTN) communication system such as a drone, and the like. For example, the NTN communication system can include, but is not limited to, an integrated communication and navigation (IcaN) system, a global navigation satellite system (GNSS), an ultra-dense low earth orbit satellite communication system, and the like. The communication system to which the embodiments of the present application are applied can be integrated with a ground communication system. For example, the ground communication system can be a fourth generation (4G) communication system (for example, a long term evolution (LTE) system), a worldwide interoperability for microwave access (WiMAX) communication system, a fifth generation (5G) communication system (for example, a new radio (NR) system), and a future mobile communication system, and the like.

[0100] A network element in a communication system can send a signal to another network element or receive a signal from another network element. The signal can include information, signaling, or data, and the like. The network element can also be replaced by an entity, a network entity, a device, a communication device, a communication module, a node, a communication node, and the like.

[0101] For example, the ground communication system can include at least one terminal device and at least one network device. The network device can send a downlink signal to the terminal device, and / or the terminal device can send an uplink signal to the network device. It can also be understood that if the communication system includes multiple terminal devices, the multiple terminal devices can also send signals to each other, that is, the sending network element of the signal and the receiving network element of the signal can both be terminal devices.

[0102] Figure 2 illustrates an architecture of a ground communication system to which embodiments of the present application can be applied. The communication system 200 can include a network device 210 and terminal devices 201-206. It should be understood that more or less network devices or terminal devices can be included in the communication system 200. The network device or the terminal device can be hardware, or software functionally divided, or a combination of the two. In addition, the terminal devices 204-206 can also form a communication system, for example, the terminal device 205 can send downlink data to the terminal device 204 or the terminal device 206. The network device and the terminal device can communicate through other devices or network elements. The network device 210 can send downlink data to the terminal devices 201-206, and can receive uplink data sent by the terminal devices 201-206. Of course, the terminal devices 201-206 can also send uplink data to the network device 210, and can receive downlink data sent by the network device 210.

[0103] The network device 210 is a node in a radio access network (RAN), which can also be referred to as a base station, and can also be referred to as a RAN node (or device) or a RAN entity or an access network device or an access node, etc. Currently, some examples of the access network device are: an evolved NodeB (eNodeB), an access point (AP), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), a next generation Node B (gNB) in a 5G network, a transmitting point (TP), a transmission reception point (TRP), a home base station (e.g., a home evolved NodeB, or a home Node B (HNB)), a macro base station, a micro base station (also referred to as a small station), a relay station, a satellite station, a base band unit (BBU), or a network device in a communication system evolved after 5G. The network device 210 can also be other devices with network device functions, for example, it can also be a gNB or a TRP or a TP in a 5G system, or one or a group (including multiple antenna panels) of antenna panels of a base station in a 5G system. In addition, the network device 210 can also be a device in a device-to-device (D2D) communication system, a vehicle-to-everything (V2X) communication system, an Internet of Things (IoT) communication system, a machine-to-machine (M2M) communication system, or other communication systems with base station functions, etc., and can also include a CU and a DU in a cloud radio access network (C-RAN) system, a network device in a non-terrestrial network (NTN) communication system, i.e., can be deployed on a high-altitude platform or a satellite. The embodiments of the present application do not make specific limitations in this regard.

[0104] Exemplarily, in some possible network structures, the network device can be a CU, a DU, a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be separately arranged, or can also be included in the same network element, for example, a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, for example, included in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). In the network architecture, signaling generated by the CU can be sent to the terminal device through the DU, or signaling generated by the terminal device can be sent to the CU through the DU. The DU can not analyze the signaling, but directly transmit the signaling to the terminal device or the CU through protocol layer encapsulation. In the network architecture, the CU is divided into a network device on the radio access network side, and in addition, the CU can also be divided into a network device on the core network side, which is not limited in the present application. For example, the functions of the PDCP layer and above protocol layers are arranged in the CU, and the functions of the protocol layers below the PDCP layer (for example, the RLC layer and the MAC layer, etc.) are arranged in the DU. It can be understood that the above division of the processing functions of the CU and the DU according to the protocol layers is only an example, and the division can also be performed in other manners. For example, the functions of the protocol layers above the RLC layer are arranged in the CU, and the functions of the protocol layers below the RLC layer are arranged in the DU, or for example, the CU or the DU can be divided into functions of more protocol layers, or the CU or the DU can also be divided into partial processing functions of the protocol layers.

[0105] It can be understood that the CU (or CU-CP and CU-UP), DU or RU can also have different names in different systems, but those skilled in the art can understand their meanings. For example, in an ORAN system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. For the convenience of description, the CU, the CU-CP, the CU-UP, the DU and the RU are taken as examples for description in the present application. Any one of the CU (or the CU-CP, the CU-UP), the DU and the RU in the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0106] Optionally, if the network device adopts a CU-DU separation architecture, which can also be referred to as a distributed deployment architecture, or can also adopt a CU-DU-RU separation architecture. For example, the network device can logically include a CU and one or more DUs, each DU can be connected with the CU through an F1 interface, and information interaction between different DUs can be completed based on forwarding of the CU. The CU and the DU can be physically arranged together or physically separated, which is not limited. The CU can support functions of RRC layer protocol, PDCP protocol and SDAP protocol; the DU can support functions of RLC layer protocol, MAC layer protocol and part of PHY layer or all PHY layer. For specific description of each protocol layer, reference can be made to relevant technical specifications of 3GPP. For another example, the access network device can logically include a CU, a DU and an RU. The CU and the DU can be physically arranged together or physically separated, which is not limited. The CU can support functions of RRC layer protocol, PDCP protocol and SDAP protocol; the DU can support functions of RLC layer protocol and MAC layer protocol, and can also support part of PHY layer protocol; the RU can support part of PHY layer or all PHY layer. For example, the DU is mainly responsible for high layer protocol functions such as data encryption and integrity protection, and the RU is mainly responsible for transmission and reception of radio frequency signals. It can be understood that in the CU-DU-RU separation architecture, the interface between the DU and the RU can be referred to as front transmission, the interface between the CU and the DU can be referred to as middle transmission, and the interface between the CU and the core network can be referred to as back transmission.

[0107] The terminal device 201 to the terminal device 206 are devices that provide voice or data connectivity to users, and can also be Internet of Things devices, and can also be referred to as terminals, user equipment (UE), access terminal devices, vehicle-mounted terminals, industrial control terminals, UE units, UE stations, mobile stations, mobile stations (MS), mobile terminals (MT), remote stations, remote terminal devices, mobile devices, UE terminal devices, terminal devices, wireless communication devices, UE agents, or UE apparatuses, etc. For example, the terminal device 201 to the terminal device 206 include handheld devices having wireless connection functions, vehicle-mounted devices, and the like.At present, the terminal device 201 to the terminal device 206 can be a mobile phone, a tablet computer (Pad), a customer-premises equipment (CPE), a subscriber unit, a satellite phone, a cellular phone, a smart phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a wireless data card, a personal digital assistant (PDA) computer, a wireless modem, a handset, a laptop computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a head mounted display (HMD), a wireless terminal in industrial control, a mobile internet device (MID), a vehicle-mounted terminal device (for example, a car, a bicycle, an electric vehicle, an airplane, a ship, a train, a high-speed rail, etc.), a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a wearable terminal device (for example, a smart watch, a smart bracelet, a pedometer, etc.), a vehicle, a drone, a helicopter, an airplane, a factory machine / device, a machine type communication (MTC) terminal, a ship, or a robot, etc. The terminal device 201 to the terminal device 206 can also be other devices with terminal function, for example, the terminal device 201 to the terminal device 206 can also be a device with terminal function in D2D communication.

[0108] Based on the description of the ground communication system architecture shown in FIG. 2, the non-terrestrial network (NTN) communication system can be exemplified for the embodiments of the present application. The NTN includes satellite networks, high-altitude platforms, and unmanned aerial vehicles, etc. nodes, which have global coverage, long-distance transmission, flexible networking, easy deployment, and are not limited by geographical conditions, etc. significant advantages, which have been widely used in maritime communication, positioning and navigation, disaster relief, scientific experiments, video broadcasting, and earth observation, etc. multiple fields. The ground communication system and the NTN communication system such as satellite network are integrated, complement each other, and jointly constitute a global seamless coverage of sea, land, air, sky, and earth integrated communication network to meet the user's ubiquitous business needs. In the embodiments of the present application, the NTN communication takes the satellite communication as an example, or the NTN communication system takes the satellite communication system as an example. FIG. 3 is a possible satellite communication system architecture applicable to the embodiments of the present application. As shown in FIG. 3, the satellite communication system architecture can include at least one terminal device (such as terminal device 1, terminal device 2, etc.), at least one satellite (such as satellite 1, satellite 2, etc.) (or a base station deployed on a satellite, such as a 5G base station), a ground station, a core network (CN) (such as a 5G core network), and a data network (DN). Among them, the terminal device and the satellite (or the base station deployed on the satellite) can communicate through the air interface (which can be various types of air interfaces, such as 5G new air interface). For example, taking the terminal device 1 as an example, the terminal device 1 can access the satellite 1 through the 5G new air interface. There is a wireless link (such as an Xn interface) between the satellites (or the base stations deployed on the satellites), which can be used for signaling interaction and user data transmission between base stations. For example, the satellites (or the base stations deployed on the satellites) can communicate through the Xn interface. The satellite and the ground station can communicate through the NG interface. The ground station can be connected with the core network through the NG interface, which can be in wired or wireless form. The core network and the data network can communicate through the N6 interface. The satellite can usually form multiple beams, and each beam is similar to a cell / sector in a ground mobile communication system (such as LTE / NR).

[0109] The devices and interfaces included in the satellite communication system architecture are briefly introduced below.

[0110] (1) Base station: mainly used to provide wireless access services, schedule wireless resources to access terminal devices, provide reliable wireless transmission protocols and data encryption protocols, etc. For example, the base station can be regarded as including the network device 210 in the communication system 200, or a device (such as a chip or a chip system, etc.) for realizing the functions of the network device 210.

[0111] (2) Core network: mainly used to provide user access control, mobility management, session management, user security authentication, charging and other functions. The core network is composed of multiple functional units, which can be divided into control plane network elements (or control plane functional units) and user plane network elements (or user plane processing units), for example. Among them, the user plane network element is responsible for the transmission of service data, for example, the user plane network element can include but is not limited to the user plane function (UPF) network element. The control plane network element can be used to manage the mobile network, for example, the control plane network element can include but is not limited to the access and mobility management function (AMF) network element, the session management function (SMF) network element. Among them, the AMF network element is responsible for user access management, security authentication, and mobility management. The SMF network element is responsible for session management of the terminal device (including establishment, modification and release of the session), selection and reselection of the UPF network element, IP address allocation of the terminal device, QoS control, selection of the UPF network element providing message forwarding function, etc. The UPF is used to manage the transmission of user plane data, traffic statistics and other functions.

[0112] (3) Data network: a data network that provides service (such as data and / or voice service) for users. Generally, the client is located in the terminal device, and the server is located in the data network. The data network can be a private network, such as a local area network, or an external network not under the control of the operator, such as the Internet, or a dedicated network jointly deployed by operators, such as a network providing IP multimedia core network subsystem (IMS) services.

[0113] (4) Ground station: mainly responsible for forwarding signaling and service data between the satellite and the core network.

[0114] (5) 5G New Radio: represents the wireless link between the terminal device and the satellite.

[0115] (6) Xn interface: represents the interface between satellites (or base stations deployed on satellites), mainly used for signaling interaction such as handover.

[0116] (7) NG interface: represents the interface between the satellite and the core network, mainly for interaction of non-sccess stratum (NAS) signaling of the core network and service data of the user.

[0117] In the embodiments of the present application, the network device in the ground communication system and the satellite in the NTN communication system can be regarded as network devices. The apparatus for implementing the function of the network device can be the network device, or can be an apparatus capable of supporting the network device to implement the function, such as a chip system, which can be installed in the network device. In the following description of the technical solutions provided by the embodiments of the present application, the apparatus for implementing the function of the network device is taken as an example of the satellite to describe the technical solutions provided by the embodiments of the present application. It can be understood that when the method provided by the embodiments of the present application is applied to the ground communication system, the actions performed by the satellite can be applied to the base station or the network device to perform.

[0118] In the embodiments of the present application, the apparatus for implementing the function of the terminal device can be the terminal device, or can be an apparatus capable of supporting the terminal device to implement the function, such as a chip system, a hardware circuit, a software module, or a hardware circuit plus a software module, which can be installed in the terminal device or used in combination with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices. In the technical solutions provided by the embodiments of the present application, the apparatus for implementing the function of the terminal device is taken as an example of the terminal device to describe the technical solutions provided by the embodiments of the present application.

[0119] It should be noted that the communication system and the service scenario described in the embodiments of the present application are for more clearly illustrating 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. It can be known by those skilled in the art that with the evolution of network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0120] The specific implementation of the communication method in the embodiments of the present application will be described in detail below based on the communication system architecture shown in FIG. 2 or FIG. 3 in combination with the drawings. It can be understood that the first communication apparatus and the second communication apparatus are taken as an example of the execution subject of the interaction in the present application, but the present application does not limit the execution subject of the interaction. For example, the first communication apparatus can be a terminal device (such as a UE) or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) in the terminal device; and the second communication apparatus can be a network device (such as a satellite or a base station, etc.) or a module (such as a processor, a processing unit, a chip system, a circuit or a chip, etc.) of the network device. It should be understood that the method executed by the first communication apparatus in the present application can also be implemented by a logical node, a logical module or software capable of implementing all or part of the function of the first communication apparatus; and the method executed by the second communication apparatus in the present application can also be implemented by a logical node, a logical module or software capable of implementing all or part of the function of the second communication apparatus.

[0121] FIG. 4 shows a flow diagram of a communication method according to an embodiment of the present application. The method is applicable to the communication system architecture shown in FIG. 2 or FIG. 3. As shown in FIG. 4, the method comprises the following steps.

[0122] In step 401, the second communication device transmits a first signal using a beam corresponding to a first wave position. Correspondingly, the first communication device receives the first signal on the beam corresponding to the first wave position.

[0123] Optionally, in the embodiments of the present application, if the first communication device is a functional module such as a chip, the functional module can not be aware of which device the received information is from; if the second communication device is a functional module such as a chip, the functional module can not be aware of which device the transmitted information is sent to.

[0124] It should be understood that in the embodiments of the present application, the second communication device transmitting the first signal using the beam corresponding to the first wave position can be replaced by "the second communication device transmits the first signal, and the first signal is carried on the beam corresponding to the first wave position".

[0125] For example, the first signal can be a system information (SI) (or can be referred to as a broadcast message or system information or system message block or system information block) or a system signal.

[0126] For example, the first signal can be used to indicate at least one sub-wave position, which can be included in the first wave position (or can be understood as one first wave position corresponding to at least one sub-wave position). The first wave position is one of the at least one wave position included in the coverage area of the second communication device. Optionally, the first signal can also be used to indicate at least one of the following: a random access resource corresponding to the first wave position, or at least one delay offset, etc. The delay offset can be used to represent the delay of the response window of the first communication device monitoring the third signal (or monitoring the physical downlink control channel (PDCCH)). For example, the third signal can be a random access response message (or can be referred to as a random access response or message 2 (Msg2)) or a random access response signal.

[0127] It should be understood that one beam position (or can be referred to as a primary beam position or an SSB beam position, such as a first beam position) can correspond to one beam, and one sub-beam position (or can be referred to as a secondary beam position) can correspond to one sub-beam. For example, it can also be understood that one beam position (such as a first beam position or a second beam position) corresponds to one beam, which means that one SSB corresponds to one beam. Wherein, one SSB can be identified by using one SSB index, and one SSB can correspond to one transmission direction (or beam transmission direction). Further, one SSB index can also be used to identify the corresponding beam position, or can also be used to identify the corresponding beam.

[0128] The implementation process of the first signal for indicating the at least one sub-beam included in the first beam position is introduced below through the following possible implementation manners.

[0129] Manner one: The first signal can indicate the at least one sub-beam included in the first beam position by indicating the index (or can be referred to as the identifier) of the at least one sub-beam included in the first beam position.

[0130] In the embodiment of the present application, the second communication device can carry the index of the at least one sub-beam included in the first beam position in the first signal, so that the first communication device can know the at least one sub-beam through the index of the at least one sub-beam, and the first communication device can further accurately determine the group of random access resources corresponding to each sub-beam in the at least one sub-beam according to the number of the at least one sub-beam.

[0131] For example, taking the first signal as a system message, the first communication device as a terminal device, and the second communication device as a satellite, and taking the area covered by the satellite as an example including six beam positions (such as beam position a, beam position b, beam position c, beam position d, beam position e, and beam position f). As shown in FIG. 5a, the beam position a includes one sub-beam, i.e., sub-beam a1; the beam position b includes three sub-beams, i.e., sub-beam b1, sub-beam b2, and sub-beam b3; the beam position c includes three sub-beams, i.e., sub-beam c1, sub-beam c2, and sub-beam c3; the beam position d includes three sub-beams, i.e., sub-beam d1, sub-beam d2, and sub-beam d3; the beam position e includes two sub-beams, i.e., sub-beam e1 and sub-beam e2; and the beam position f includes three sub-beams, i.e., sub-beam f1, sub-beam f2, and sub-beam f3. For example, each sub-beam shown in FIG. 5a can include one or more reference points (not shown in FIG. 5a).

[0132] It can be understood that different beams correspond to different beam positions, and the SSB indexes corresponding to different beams can also be used to identify different beam positions corresponding to different beams. In this way, beam position a, beam position b, beam position c, beam position d, beam position e and beam position f can correspond to different beams respectively, and can also correspond to different beam transmission directions respectively. For example, beam position a corresponds to beam a, beam position b corresponds to beam b, beam position c corresponds to beam c, beam position d corresponds to beam d, beam position e corresponds to beam e, and beam position f corresponds to beam f. Among them, it is assumed that the index corresponding to sub-beam a1 included in beam position a is index a1. It is assumed that the index corresponding to sub-beam b1 included in beam position b is index b1, the index corresponding to sub-beam b2 is index b2, and the index corresponding to sub-beam b3 is index b3. It is assumed that the index corresponding to sub-beam c1 included in beam position c is index c1, the index corresponding to sub-beam c2 is index c2, and the index corresponding to sub-beam c3 is index c3. It is assumed that the index corresponding to sub-beam d1 included in beam position d is index d1, the index corresponding to sub-beam d2 is index d2, and the index corresponding to sub-beam d3 is index d3. It is assumed that the index corresponding to sub-beam e1 included in beam position e is index e1, and the index corresponding to sub-beam e2 is index e2. It is assumed that the index corresponding to sub-beam f1 included in beam position f is index f1, the index corresponding to sub-beam f2 is index f2, and the index corresponding to sub-beam f3 is index f3. It should be understood that the indexes of the SSBs corresponding to different beam positions can be used to identify the beams corresponding to different beam positions, or can be used to identify the corresponding different beam positions, such as the index (such as index a) of the SSB corresponding to beam position a, which can be used to identify beam a or beam position a.

[0133] In a possible implementation, the satellite can broadcast the system messages corresponding to different beam positions respectively on the corresponding beams. Among them, the system message corresponding to each beam position can include the indexes of the sub-beam positions included in the beam position. For example, the satellite can broadcast the index a1 of the sub-beam a1 included in the beam position a on the beam a, broadcast the index b1 of the sub-beam b1, the index b2 of the sub-beam b2 and the index b3 of the sub-beam b3 included in the beam position b on the beam b, broadcast the index c1 of the sub-beam c1, the index c2 of the sub-beam c2 and the index c3 of the sub-beam c3 included in the beam position c on the beam c, broadcast the index d1 of the sub-beam d1, the index d2 of the sub-beam d2 and the index d3 of the sub-beam d3 included in the beam position d on the beam d, broadcast the index e1 of the sub-beam e1 and the index e2 of the sub-beam e2 included in the beam position e on the beam e, and broadcast the index f1 of the sub-beam f1, the index f2 of the sub-beam f2 and the index f3 of the sub-beam f3 included in the beam position f on the beam f.

[0134] Afterwards, the terminal device located in the sub-beam f can receive the corresponding system message on the beam f. The system message can include the index f1 of the sub-beam f1, the index f2 of the sub-beam f2, and the index f3 of the sub-beam f3. Optionally, the system message can also include the coverage geographical range corresponding to the index f1, the coverage geographical range corresponding to the index f2, and the coverage geographical range corresponding to the index f3. Then, the terminal device can obtain the index f1 of the sub-beam f1, the index f2 of the sub-beam f2, and the index f3 of the sub-beam f3 from the system message, and can determine the number of sub-beams included in the beam f, i.e., the number 3, according to the index f1 of the sub-beam f1, the index f2 of the sub-beam f2, and the index f3 of the sub-beam f3.

[0135] In one example, when the system message carried by the beam f does not include the coverage geographical range corresponding to the index f1, the coverage geographical range corresponding to the index f2, and the coverage geographical range corresponding to the index f3, the terminal device can divide the coverage geographical range of the beam f according to the index order of the three sub-beams included in the beam f, and determine the coverage geographical range of the sub-beam f1, the coverage geographical range of the sub-beam f2, and the coverage geographical range of the sub-beam f3. It should be understood that, in this example, the global area can be divided into a plurality of beams in a grid manner, and at least one sub-beam can be divided for each beam in the plurality of beams. In this way, the terminal device can determine the beam in which the terminal device is located as the beam f according to the index f of the beam f used to carry the system message, and can further determine the coverage geographical range of the beam f. Afterwards, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located (or can be understood as determining in which sub-beam the terminal device is currently located or in which sub-beam the terminal device is currently located) according to the location (or can be referred to as the location coordinates or the geographical position) of the terminal device itself and the coverage geographical range of the sub-beam f1, the coverage geographical range of the sub-beam f2, and the coverage geographical range of the sub-beam f3, such as the terminal device being located in the coverage geographical range of the sub-beam f2. Optionally, the coverage geographical range of the sub-beam included in each beam can also be predefined by a protocol.

[0136] In another example, when the system message carried by the beam f includes the coverage geographical range corresponding to the index f1, the coverage geographical range corresponding to the index f2, and the coverage geographical range corresponding to the index f3, the terminal device can obtain the coverage geographical range corresponding to the index f1, the coverage geographical range corresponding to the index f2, and the coverage geographical range corresponding to the index f3 from the system message. Afterwards, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device itself and the coverage geographical range of the sub-beam f1, the coverage geographical range of the sub-beam f2, and the coverage geographical range of the sub-beam f3, such as the terminal device being located in the coverage geographical range of the sub-beam f2.

[0137] In another possible implementation, the satellite can broadcast the same system message on different beams respectively, where the same system message can include the mapping relationship (or can be referred to as the association relationship or the corresponding relationship, such as the mapping relationship of beam a and sub-beam a1 (for example, the mapping relationship between the index of beam a (such as the index a used to identify SSB0) and the index of sub-beam a1) and the mapping relationship of beam b and sub-beams b1, b2 and b3 (for example, the mapping relationship between the index of beam b (such as the index b used to identify SSB1) and the index of sub-beam b1, the index of sub-beam b2, and the index of sub-beam b3)) of each beam and the sub-beams included in the beam, or the same system message can include which sub-beams are included in each of the above 6 beams (for example, beam a includes sub-beam a1). Optionally, the same system message can also include the coverage geographical range of the sub-beams included in each of the above 6 beams (such as the coverage geographical range of sub-beam a1, the coverage geographical range of sub-beam b1, the coverage geographical range of sub-beam b2, etc.). For example, taking the same system message including the mapping relationship of each of the above 6 beams and the sub-beams included in the beam as an example. The satellite can broadcast the mapping relationship of each of the above 6 beams and the sub-beams included in the beam as the same system message on beam a, beam b, beam c, beam d, beam e, and beam f respectively. Wherein, the index corresponding to beam a is index a (or can be understood as the index a of SSB0), the index corresponding to beam b is index b (or can be understood as the index b of SSB1), the index corresponding to beam c is index c (or can be understood as the index c of SSB2), the index corresponding to beam d is index d (or can be understood as the index d of SSB3), the index corresponding to beam e is index e (or can be understood as the index e of SSB4), and the index corresponding to beam f is index f (or can be understood as the index f of SSB5).

[0138] After that, the terminal device located in beam f can receive the system message on beam f. Wherein, the system message can include the mapping relationship of each of the above 6 beams and the sub-beams included in the beam. Optionally, the system message can also include the coverage geographical range of the sub-beams included in each of the above 6 beams. Then, the terminal device can obtain the mapping relationship of beam f and the 3 sub-beams included in beam f (such as the mapping relationship between the index f of beam f and the index f1 of sub-beam f1, the index f2 of sub-beam f2, and the index f3 of sub-beam f3) from the system message according to the index f corresponding to beam f, and can determine the number of sub-beams included in beam f, i.e., the number 3, according to the mapping relationship of beam f and the 3 sub-beams included in beam f.

[0139] In one example, when the same system message does not include the coverage geographical range of the sub-beam included in each of the above-mentioned 6 beams, the terminal device can determine the index order of the 3 sub-beams included in the beam f according to the mapping relationship between the beam f and the 3 sub-beams included in the beam f, and can divide the coverage geographical range of the beam f according to the index order of the 3 sub-beams to determine the coverage geographical range of the sub-beam f1, the coverage geographical range of the sub-beam f2 and the coverage geographical range of the sub-beam f3. It should be understood that in this example, the global area can be divided into multiple beams in a grid manner, and at least one sub-beam can be divided for each of the multiple beams. In this way, the terminal device can determine that the beam in which the terminal device is located is the beam f according to the index f of the beam f used to carry the system message, and can further determine the coverage geographical range of the beam f. Then, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device and the coverage geographical range of the sub-beam f1, the coverage geographical range of the sub-beam f2 and the coverage geographical range of the sub-beam f3, such as that the terminal device is located in the coverage geographical range of the sub-beam f2. Optionally, the coverage geographical range of the sub-beam included in each beam can also be predefined by a protocol.

[0140] In another example, when the same system message includes the coverage geographical range of the sub-beam included in each of the above-mentioned 6 beams, the terminal device can obtain the coverage geographical range of the 3 sub-beams corresponding to the index f (such as the coverage geographical range corresponding to the index f1, the coverage geographical range corresponding to the index f2 and the coverage geographical range corresponding to the index f3) from the system message according to the index f corresponding to the beam f. Then, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device and the coverage geographical range of the 3 sub-beams corresponding to the index f, such as that the terminal device is located in the coverage geographical range of the sub-beam f2.

[0141] Method two: the first signal can indicate the at least one sub-beam included in the first beam by indicating the reference point corresponding to the at least one sub-beam.

[0142] In the embodiments of the present application, the second communication device can carry the reference point corresponding to the at least one sub-beam included in the first beam in the first signal, so that the first communication device can accurately determine the number of the at least one sub-beam through the reference point corresponding to the at least one sub-beam, and can facilitate the first communication device to further determine the group of random access resources corresponding to each of the at least one sub-beam according to the number of the at least one sub-beam.

[0143] For example, taking the first signal as a system message, the first communication device as a terminal device, and the second communication device as a satellite, and taking an example in which the area covered by the satellite includes two wave positions (such as wave position g and wave position h). As shown in FIG. 5b, the wave position g includes three sub-wave positions, namely, sub-wave position g1, sub-wave position g2, and sub-wave position g3; and the wave position h includes two sub-wave positions, namely, sub-wave position h1 and sub-wave position h2. Among them, the sub-wave position g1 includes a reference point g1, the sub-wave position g2 includes a reference point g2, the sub-wave position g3 includes a reference point g3, the sub-wave position h1 includes a reference point h1, and the sub-wave position h2 includes a reference point h2. It can be understood that different wave positions correspond to different beams, and the SSB index corresponding to different beams can also be used to identify different corresponding different wave positions. In this way, the wave position g and the wave position h can correspond to different beams respectively, or different beam transmission directions respectively. For example, the wave position g corresponds to a beam g, and the wave position h corresponds to a beam h. It should be understood that the index of the SSB corresponding to different wave positions can be used to identify the beams corresponding to different wave positions, or can be used to identify the corresponding different wave positions, such as the index of the SSB corresponding to the wave position g (such as index g), which can be used to identify the beam g or the wave position g.

[0144] In one example, the satellite can broadcast the system messages corresponding to different wave positions respectively on the corresponding beams. Among them, the system message corresponding to each wave position (such as a first wave position) can include the reference points corresponding to at least one sub-wave position included in the wave position. For example, the satellite can broadcast the reference point g1 corresponding to the sub-wave position g1, the reference point g2 corresponding to the sub-wave position g2, and the reference point g3 corresponding to the sub-wave position g3 included in the wave position g on the beam g, and can broadcast the reference point h1 corresponding to the sub-wave position h1 and the reference point h2 corresponding to the sub-wave position h2 included in the wave position h on the beam h.

[0145] In another example, the satellite can broadcast the same system message respectively on different beams. Among them, the same system message can include the reference points corresponding to at least one sub-wave position included in each wave position in different wave positions. For example, the satellite can broadcast the reference point g1 corresponding to the sub-wave position g1, the reference point g2 corresponding to the sub-wave position g2, and the reference point g3 corresponding to the sub-wave position g3 included in the wave position g, and the reference point h1 corresponding to the sub-wave position h1 and the reference point h2 corresponding to the sub-wave position h2 included in the wave position h as the same system message respectively on the beam g and the beam h.

[0146] The following is an example of the first wave position, and the implementation process of the first signal indicating the reference points corresponding to at least one sub-wave position included in the first wave position is introduced through the following possible examples.

[0147] Example one: The first signal can be used to indicate the position coordinates of the reference points corresponding to at least one sub-wave position included in the first wave position.

[0148] In a possible implementation, under the scheme provided in example one, the satellite can broadcast the system messages corresponding to different wave positions on corresponding beams respectively. Each system message corresponding to a wave position can include the position coordinates of the reference points corresponding to the sub-wave positions included in the wave position. For example, the satellite can broadcast the position coordinates of the reference point g1 corresponding to the sub-wave position g1, the position coordinates of the reference point g2 corresponding to the sub-wave position g2, and the position coordinates of the reference point g3 corresponding to the sub-wave position g3 included in the wave position g on the beam g, and can broadcast the position coordinates of the reference point h1 corresponding to the sub-wave position h1 and the position coordinates of the reference point h2 corresponding to the sub-wave position h2 included in the wave position h on the beam h. Then, the terminal device located in the wave position g can receive the corresponding system message on the beam g. The system message can include the position coordinates of the reference point g1 corresponding to the sub-wave position g1, the position coordinates of the reference point g2 corresponding to the sub-wave position g2, and the position coordinates of the reference point g3 corresponding to the sub-wave position g3. Then, the terminal device can obtain the position coordinates of the reference point g1 corresponding to the sub-wave position g1, the position coordinates of the reference point g2 corresponding to the sub-wave position g2, and the position coordinates of the reference point g3 corresponding to the sub-wave position g3 from the system message, and can determine the number of reference points included in the wave position g, that is, the number of sub-wave positions included in the wave position g, that is, 3, according to the position coordinates of the reference point g1 corresponding to the sub-wave position g1, the position coordinates of the reference point g2 corresponding to the sub-wave position g2, and the position coordinates of the reference point g3 corresponding to the sub-wave position g3.

[0149] In another possible implementation, under the scheme provided in Example One, the satellite can broadcast the same system message on different beams respectively. The same system message can include the position coordinates of the reference points corresponding to the sub-beams included in each wave position (for example, the position coordinates of which reference points correspond to wave position g or the position coordinates of which reference points correspond to the index of wave position g). For example, the satellite can broadcast the position coordinates of reference point g1 corresponding to sub-beam g1 included in wave position g, the position coordinates of reference point g2 corresponding to sub-beam g2, the position coordinates of reference point g3 corresponding to sub-beam g3, the position coordinates of reference point h1 corresponding to sub-beam h1 included in wave position h, and the position coordinates of reference point h2 corresponding to sub-beam h2 on beams g and h respectively as the same system message. The terminal device located in wave position g can receive the system message on beam g. The system message can include the position coordinates of reference point g1 corresponding to sub-beam g1, the position coordinates of reference point g2 corresponding to sub-beam g2, the position coordinates of reference point g3 corresponding to sub-beam g3, the position coordinates of reference point h1 corresponding to sub-beam h1, and the position coordinates of reference point h2 corresponding to sub-beam h2. After receiving the system message, the terminal device can obtain the position coordinates of reference point g1 corresponding to sub-beam g1 included in wave position g, the position coordinates of reference point g2 corresponding to sub-beam g2, and the position coordinates of reference point g3 corresponding to sub-beam g3 from the system message according to the index g corresponding to beam g. Then, the terminal device can determine the number of reference points included in wave position g, that is, the number of sub-beams included in wave position g, that is, 3, according to the position coordinates of reference point g1 corresponding to sub-beam g1, the position coordinates of reference point g2 corresponding to sub-beam g2, and the position coordinates of reference point g3 corresponding to sub-beam g3.

[0150] It should be understood that the above Example One can facilitate the terminal device located in each wave position to learn the reference points corresponding to each sub-beam included in the wave position in time and can calculate the number of sub-beams included in the wave position in time by directly carrying the position coordinates of the reference points corresponding to each sub-beam included in the wave position in the system message corresponding to the wave position.

[0151] Example Two: The first signal can be used to indicate at least one first difference value corresponding to the first wave position and the position coordinates corresponding to the first wave position.

[0152] The at least one first difference value corresponding to the first wave position can be a difference value between the position coordinates of the reference points corresponding to the at least one sub-wave position included in the first wave position and the position coordinates corresponding to the first wave position. For example, the position coordinates corresponding to the first wave position can be the position coordinates of the beam center corresponding to the first wave position, or can be the position coordinates of a certain reference point corresponding to the first wave position (such as the center position coordinates of the first wave position), or can be the position coordinates of other reference points corresponding to the first wave position (such as a reference point that can be used to reflect the characteristics (or attributes) of the first wave position).

[0153] In a possible implementation, under the scheme provided in Example Two, the satellite can broadcast the system messages corresponding to different wave positions on the corresponding beams respectively. The system message corresponding to each wave position can include the position coordinates corresponding to the wave position and the first difference values corresponding to the reference points corresponding to the at least one sub-wave position included in the wave position. For example, the satellite can broadcast 3 first difference values corresponding to the wave position g and the position coordinates (such as the position coordinates of the beam center corresponding to the wave position g) corresponding to the wave position g on the beam g, and can broadcast 2 first difference values corresponding to the wave position h and the position coordinates (such as the position coordinates of the beam center corresponding to the wave position h) corresponding to the wave position h on the beam h. For example, the 3 first difference values corresponding to the wave position g can include the difference value g1 corresponding to the reference point g1 (that is, the difference value between the position coordinates of the reference point g1 corresponding to the sub-wave position g1 and the position coordinates corresponding to the wave position g), the difference value g2 corresponding to the reference point g2 (that is, the difference value between the position coordinates of the reference point g2 corresponding to the sub-wave position g2 and the position coordinates corresponding to the wave position g), and the difference value g3 corresponding to the reference point g3 (that is, the difference value between the position coordinates of the reference point g3 corresponding to the sub-wave position g3 and the position coordinates corresponding to the wave position g). The 2 first difference values corresponding to the wave position h can include the difference value h1 corresponding to the reference point h1 (that is, the difference value between the position coordinates of the reference point h1 corresponding to the sub-wave position h1 and the position coordinates corresponding to the wave position h), and the difference value h2 corresponding to the reference point h2 (that is, the difference value between the position coordinates of the reference point h2 corresponding to the sub-wave position h2 and the position coordinates corresponding to the wave position h).

[0154] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3. After receiving the system message, the terminal device can obtain the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3 from the system message. Then, the terminal device can determine the position coordinate of the reference point g1 according to the position coordinate corresponding to the wave position g and the differential value g1 corresponding to the reference point g1, determine the position coordinate of the reference point g2 according to the position coordinate corresponding to the wave position g and the differential value g2 corresponding to the reference point g2, and determine the position coordinate of the reference point g3 according to the position coordinate corresponding to the wave position g and the differential value g3 corresponding to the reference point g3. Then, the terminal device can determine the number of reference points included in the wave position g, that is, the number of sub-wave positions included in the wave position g, that is, the number 3, according to the position coordinate of the reference point g1, the position coordinate of the reference point g2, and the position coordinate of the reference point g3.

[0155] In another possible implementation, under the scheme provided in Example Two, the satellite can broadcast the same system message on different beams respectively. The same system message can include the position coordinate corresponding to each wave position and the first differential value corresponding to the reference point corresponding to the sub-wave position included in the wave position (for example, the first differential value corresponding to the reference point corresponding to the wave position g or the first differential value corresponding to the reference point index corresponding to the wave position g index). For example, the satellite can broadcast the three first differential values corresponding to the wave position g, the position coordinate corresponding to the wave position g (for example, the position coordinate of the beam center corresponding to the wave position g), the two first differential values corresponding to the wave position h, and the position coordinate corresponding to the wave position h (for example, the position coordinate of the beam center corresponding to the wave position h) as the same system message on the beam g and the beam h respectively. It can be understood that the related description of the three first differential values corresponding to the wave position g and the related description of the two first differential values corresponding to the wave position h can refer to the related description in the possible implementation of Example Two, which will not be described here.

[0156] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, the differential value g3 corresponding to the reference point g3, the position coordinate corresponding to the wave position h, the differential value h1 corresponding to the reference point h1, and the differential value h2 corresponding to the reference point h2. After receiving the system message, the terminal device can obtain the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3 from the system message according to the index g corresponding to the beam g. Then, the terminal device can determine the position coordinate of the reference point g1 according to the position coordinate corresponding to the wave position g and the differential value g1 corresponding to the reference point g1, determine the position coordinate of the reference point g2 according to the position coordinate corresponding to the wave position g and the differential value g2 corresponding to the reference point g2, and determine the position coordinate of the reference point g3 according to the position coordinate corresponding to the wave position g and the differential value g3 corresponding to the reference point g3. Then, the terminal device can determine the number of reference points included in the wave position g, that is, the number of sub-wave positions included in the wave position g, that is, 3, according to the position coordinate of the reference point g1, the position coordinate of the reference point g2, and the position coordinate of the reference point g3.

[0157] It should be understood that, since the distance between the reference points in one beam will not be too large, the above-mentioned example two can make the terminal device located at the wave position determine the position coordinates of the reference points corresponding to each sub-wave position included in the wave position through the differential indication by taking the position coordinate corresponding to each wave position as a reference, and can further calculate the number of sub-wave positions included in the wave position, which helps to reduce the signaling overhead.

[0158] Example three: The first signal can be used to indicate a second differential value corresponding to the first wave position and at least one first differential value corresponding to the first wave position.

[0159] Optionally, the related description of the at least one first differential value in example three can refer to the related description of the at least one first differential value in the above-mentioned example two, which will not be described here again.

[0160] For example, the second difference value corresponding to the first wave position can be a difference value between the position coordinate corresponding to the first wave position and the position coordinate of the reference point of the first cell (which can be understood as a reference point broadcast by the network side at the cell level). The first cell is the current serving cell of the terminal device. Optionally, the related description of the position coordinate corresponding to the first wave position in Example Three can refer to the related description of the position coordinate corresponding to the first wave position in Example Two, which will not be repeated here. It should be understood that the reference point of the first cell can be determined by the first communication device (such as the terminal device) according to the relevant information provided by the second communication device (such as the satellite), such as ephemeris information provided by the satellite (such as the speed information, position information, etc. of the satellite at different times), relative ephemeris position information (such as angle information), associated cell information or absolute time, etc. or can be configured by the second communication device. For example, the reference point of the first cell can be the center position point of the first cell, or can be other position points of the first cell, and the embodiments of the present application do not limit this. In addition, the reference point can also be described as a reference position, a reference point position, a position reference point, and the like.

[0161] In a possible implementation, under the scheme provided in Example Three, the satellite can broadcast the system messages corresponding to different wave positions on the corresponding beams respectively. The system message corresponding to each wave position can include the second difference value corresponding to the wave position and the first difference value corresponding to the reference point of at least one sub-wave position included in the wave position. For example, the satellite can broadcast 3 first difference values corresponding to the wave position g and the second difference value corresponding to the wave position g on the beam g, and can broadcast 2 first difference values corresponding to the wave position h and the second difference value corresponding to the wave position h on the beam h. The second difference value corresponding to the wave position g can be a difference value between the position coordinate corresponding to the wave position g and the position coordinate of the reference point of the current serving cell of the terminal device (such as the center position point of the current serving cell). The second difference value corresponding to the wave position h can be a difference value between the position coordinate corresponding to the wave position h and the position coordinate of the reference point of the current serving cell of the terminal device (such as the center position point of the current serving cell). It can be understood that the related description of the 3 first difference values corresponding to the wave position g in Example Three and the related description of the 2 first difference values corresponding to the wave position h can refer to the related description in Example Two, which will not be repeated here.

[0162] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the second differential value corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3. After receiving the system message, the terminal device can obtain the second differential value corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3 from the system message. Then, the terminal device can determine the position coordinates corresponding to the wave position g according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the second differential value corresponding to the wave position g. Next, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates corresponding to the wave position g and the differential value g1 corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates corresponding to the wave position g and the differential value g2 corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates corresponding to the wave position g and the differential value g3 corresponding to the reference point g3. Then, the terminal device can determine the number of reference points included in the wave position g, that is, the number of sub-wave positions included in the wave position g, that is, 3, according to the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3.

[0163] In another possible implementation, under the scheme provided in Example Three, the satellite can broadcast the same system message on different beams respectively. The same system message can include the second differential value corresponding to each wave position (such as the second differential value corresponding to the wave position g) and the first differential value corresponding to the reference point corresponding to the sub-wave position included in the wave position. For example, the satellite can broadcast the 3 first differential values corresponding to the wave position g, the second differential value corresponding to the wave position g, the 2 first differential values corresponding to the wave position h, and the second differential value corresponding to the wave position h as the same system message on the beam g and the beam h respectively. It can be understood that the related description of the second differential value corresponding to the wave position g and the related description of the second differential value corresponding to the wave position h can refer to the related description in one possible implementation of Example Three, which will not be described here.

[0164] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include three first difference values corresponding to the wave position g, a second difference value corresponding to the wave position g, two first difference values corresponding to the wave position h, and a second difference value corresponding to the wave position h. After receiving the system message, the terminal device can obtain, according to the index g corresponding to the beam g, the three first difference values corresponding to the wave position g and the second difference value corresponding to the wave position h from the system message. Then, the terminal device can determine the position coordinates of the wave position g according to the position coordinates of the reference point of the current serving cell of the terminal device and the second difference value corresponding to the wave position g. Next, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates of the wave position g and the difference value g1 corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates of the wave position g and the difference value g2 corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates of the wave position g and the difference value g3 corresponding to the reference point g3. Then, the terminal device can determine the number of reference points included in the wave position g, that is, the number of sub-wave positions included in the wave position g, that is, the number 3, according to the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3.

[0165] It should be understood that, since the distance between the reference points in one beam will not be too large, the above-mentioned example three can enable the terminal device to determine the position coordinates of the wave position corresponding to the terminal device by differential indication based on the position coordinates of the reference point of the cell (such as the reference point of the serving cell of the terminal device) as a reference, and determine the position coordinates of the reference point corresponding to each sub-wave position included in the wave position based on the position coordinates of the wave position corresponding to the wave position as a reference, so as to further calculate the number of sub-wave positions included in the wave position, which helps to reduce the signaling overhead.

[0166] Example four: The first signal can be used to indicate at least one third difference value corresponding to the first wave position.

[0167] The at least one third difference value corresponding to the first wave position can be the difference value between the position coordinates of the reference point corresponding to at least one sub-wave position included in the first wave position and the position coordinates of the reference point of the first cell. Optionally, the related description of the reference point of the first cell in example four can refer to the related description of the reference point of the first cell in the above-mentioned example three, which will not be described here.

[0168] In a possible implementation, under the scheme provided in Example Four, the satellite can broadcast the system messages corresponding to different wave positions on corresponding beams respectively. Each system message corresponding to a wave position can include at least one third difference value corresponding to the wave position (or can be understood as a third difference value corresponding to at least one sub-wave position included in the wave position or a third difference value corresponding to a reference point corresponding to at least one sub-wave position included in the wave position). For example, the satellite can broadcast 3 third difference values corresponding to wave position g (such as a third difference value corresponding to sub-wave position g1 (or can be understood as a third difference value corresponding to reference point g1), a third difference value corresponding to sub-wave position g2 (or can be understood as a third difference value corresponding to reference point g2), and a third difference value corresponding to sub-wave position g3 (or can be understood as a third difference value corresponding to reference point g3)) on beam g, and 2 third difference values corresponding to wave position h (such as a third difference value corresponding to sub-wave position h1 (or can be understood as a third difference value corresponding to reference point h1) and a third difference value corresponding to sub-wave position h2 (or can be understood as a third difference value corresponding to reference point h2)) on beam h. The third difference value corresponding to sub-wave position g1 can refer to a difference value between the position coordinates of reference point g1 and the position of the reference point of the current serving cell where the terminal device is located; the third difference value corresponding to sub-wave position g2 can refer to a difference value between the position coordinates of reference point g2 and the position of the reference point of the current serving cell where the terminal device is located; the third difference value corresponding to sub-wave position g3 can refer to a difference value between the position coordinates of reference point g3 and the position of the reference point of the current serving cell where the terminal device is located; the third difference value corresponding to sub-wave position h1 can refer to a difference value between the position coordinates of reference point h1 and the position of the reference point of the current serving cell where the terminal device is located; and the third difference value corresponding to sub-wave position h2 can refer to a difference value between the position coordinates of reference point h2 and the position of the reference point of the current serving cell where the terminal device is located.

[0169] The terminal device located at the beam g can receive a system message on the beam g. The system message can include a third difference value corresponding to the reference point g1, a third difference value corresponding to the reference point g2, and a third difference value corresponding to the reference point g3. After receiving the system message, the terminal device can obtain the third difference value corresponding to the reference point g1, the third difference value corresponding to the reference point g2, and the third difference value corresponding to the reference point g3 from the system message. Then, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g3. Then, the terminal device can determine the number of reference points included in the beam g, that is, the number of sub-beams included in the beam g, that is, the number 3, according to the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3.

[0170] In another possible implementation, under the scheme provided in Example Four, the satellite can broadcast the same system message on different beams respectively. The same system message can include a third difference value corresponding to a reference point corresponding to at least one sub-beam corresponding to each beam (for example, a third difference value corresponding to a reference point associated with the beam g or a third difference value corresponding to a reference point index associated with the index of the beam g). For example, the satellite can broadcast the third difference value corresponding to the reference point of at least one sub-beam corresponding to the beam g (for example, the third difference value corresponding to the reference point g1, the third difference value corresponding to the reference point g2, and the third difference value corresponding to the reference point g3) and the third difference value corresponding to the reference point of at least one sub-beam corresponding to the beam h (for example, the third difference value corresponding to the reference point h1 and the third difference value corresponding to the reference point h2) as the same system message on the beam g and the beam h respectively. It can be understood that the third difference value corresponding to the reference point g1, the third difference value corresponding to the reference point g2, the third difference value corresponding to the reference point g3, the third difference value corresponding to the reference point h1, and the third difference value corresponding to the reference point h2 can refer to the related description in one possible implementation in Example Four, which will not be described here.

[0171] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include a third difference value corresponding to the reference point g1 corresponding to the sub-wave position g1 included in the wave position g, a third difference value corresponding to the reference point g2 corresponding to the sub-wave position g2 included in the wave position g, a third difference value corresponding to the reference point g3 corresponding to the sub-wave position g3 included in the wave position g, a third difference value corresponding to the reference point h1 corresponding to the sub-wave position h1 included in the wave position h, and a third difference value corresponding to the reference point h2 corresponding to the sub-wave position h2 included in the wave position h. After receiving the system message, the terminal device can obtain the third difference value corresponding to the reference point g1 corresponding to the sub-wave position g1 included in the wave position g, the third difference value corresponding to the reference point g2 corresponding to the sub-wave position g2 included in the wave position g, and the third difference value corresponding to the reference point g3 corresponding to the sub-wave position g3 included in the wave position g from the system message according to the index g corresponding to the beam g. Then, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g3. Then, the terminal device can determine the number of reference points included in the wave position g, that is, the number of sub-wave positions included in the wave position g, that is, the number 3, according to the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3.

[0172] It should be understood that, since the spacing between the reference points in one beam will not be too large, the above-mentioned example four can make the terminal device determine the position coordinates of the reference point corresponding to each sub-wave position included in the wave position where the terminal device is located through the differential indication by taking the position coordinates of the cell reference point (such as the reference point of the serving cell where the terminal device is located) as the reference, so as to further calculate the number of sub-wave positions included in the wave position, which helps to reduce the signaling overhead.

[0173] In addition, the at least one sub-wave position indicated by the first signal can correspond to a group of random access resources respectively. For example, the group of random access resources corresponding to the at least one sub-wave position included in the first wave position can be included in the random access resources corresponding to the first wave position. It can be understood that the random access resources corresponding to the first wave position can be included in the first signal, or the random access resources corresponding to the first wave position are indicated by the first signal.

[0174] For example, the random access resources corresponding to the first wave position or the group of random access resources corresponding to each of the at least one sub-wave position can include at least one of the following: time domain resources, frequency domain resources, or code domain resources, etc.

[0175] The determination process of the group of random access resources corresponding to each of the at least one sub-beam position is introduced below through the following possible implementations.

[0176] Implementation one: The group of random access resources corresponding to each of the at least one sub-beam position can be determined by the first communication device (such as a terminal device) according to the first signal.

[0177] In one example, the first communication device first determines which random access resources correspond to the first beam position carried by the first signal, such as random access resource 1 and random access resource 2 corresponding to the first beam position. Then, the first communication device can group the random access resources corresponding to the first beam position according to the number of at least one sub-beam position included in the first beam position, to obtain a group of random access resources corresponding to each of the at least one sub-beam position. In this way, the method provided in this example can enable the first communication device (such as a terminal device) to select a group of random access resources corresponding to (or can be called matched) the sub-beam position where the first communication device is located according to the number of at least one sub-beam position included in the first beam position, and further enable the second communication device (such as a satellite) to determine (or identify) the sub-beam position where the terminal device currently sending the second signal is located according to the group of random access resources where the second signal (such as a random access request signal or a random access request message) is received (i.e., the group of random access resources used to carry the second signal), and then transmit a common downlink signal (such as a third signal) using a sub-beam covering the sub-beam position when responding to the terminal device (such as a narrow beam with a width smaller than the beam corresponding to the first beam position). Optionally, the number of sub-beam positions included in each beam (such as the first beam position) can be carried by the second communication device in the first signal, or can be predefined through a protocol, or can be pre-configured by the second communication device to the first communication device.

[0178] It can be understood that the grouping manner (or can be referred to as the division manner) of the random access resources corresponding to the first wave position described above can be determined according to a resource grouping strategy pre-negotiated (or pre-defined by a protocol) by the first communication device and the second communication device. For example, the resource grouping strategy can be that the first communication device sequentially allocates the random access resources corresponding to the first wave position to at least one sub-wave position according to the index order of the at least one sub-wave position included in the first wave position (or the index order of the reference points corresponding to the at least one sub-wave position included in the first wave position), so that the second communication device can also pre-know the mapping relationship between the at least one sub-wave position (or the reference points corresponding to the at least one sub-wave position) and the corresponding group of random access resources. For example, taking the first communication device as a terminal device, the second communication device as a satellite, and the first signal including the reference points corresponding to the 3 sub-wave positions included in the wave position g (such as the reference point g1 corresponding to the sub-wave position g1, the reference point g2 corresponding to the sub-wave position g2, and the reference point g3 corresponding to the sub-wave position g3) as an example. The terminal device and the satellite can pre-define by a protocol that the random access resources corresponding to the wave position g are sequentially allocated to the 3 reference points according to the index order of the 3 reference points. For example, the random access resources corresponding to the wave position g are 3, that is, the random access resource s1, the random access resource s2, and the random access resource s3, so that the terminal device can allocate the random access resource s1 to the sub-wave position g1 corresponding to the reference point g1, the random access resource s2 to the sub-wave position g2 corresponding to the reference point g2, and the random access resource s3 to the sub-wave position g3 corresponding to the reference point g3 according to the index order of the 3 reference points. For another example, the random access resources corresponding to the wave position g are 2, that is, the random access resource s1 and the random access resource s2, so that the terminal device can allocate the time-frequency domain resources in the random access resource s1 to the sub-wave position g1 and the sub-wave position g2 (that is, the sub-wave position g1 and the sub-wave position g2 share the time-frequency domain resources in the random access resource s1) and can divide the code domain resources in the random access resource s1 into two parts, one part of the code domain resources being allocated to the sub-wave position g1 and the other part of the code domain resources being allocated to the sub-wave position g2 according to the index order of the 3 reference points. In addition, the terminal device can allocate the random access resource s2 to the sub-wave position g3 corresponding to the reference point g3. Optionally, the terminal device can also allocate the random access resource s1 to the sub-wave position g1 corresponding to the reference point g1, and can allocate the time-frequency domain resources in the random access resource s2 to the sub-wave position g2 and the sub-wave position g3 (that is, the sub-wave position g2 and the sub-wave position g3 share the time-frequency domain resources in the random access resource s2), and divide the code domain resources in the random access resource s2 into two parts, one part of the code domain resources being allocated to the sub-wave position g2 and the other part of the code domain resources being allocated to the sub-wave position g3.

[0179] For example, taking the first signal as a system message, the first communication device as a terminal device, the second communication device as a satellite, and the first wave position of the terminal device as wave position h shown in FIG. 5b, there are two random access resources (for example, random access resource t1 and random access resource t2) corresponding to the wave position h. The terminal device can first obtain from the system message that the random access resource corresponding to the wave position h is random access resource t1 and random access resource t2. Then, the terminal device can group the random access resources corresponding to the wave position h according to the number of sub-wave positions included in the wave position h, to obtain a group of random access resources corresponding to each sub-wave position included in the wave position h, for example, a group of random access resources corresponding to sub-wave position h1 is random access resource t1, and a group of random access resources corresponding to sub-wave position h2 is random access resource t2.

[0180] For example, taking the first signal as a system message, the first communication device as a terminal device, the second communication device as a satellite, and the first wave position of the terminal device as wave position h shown in FIG. 5b, there is one random access resource (for example, random access resource t1) corresponding to the wave position h. The terminal device can first obtain from the system message that the random access resource corresponding to the wave position h is random access resource t1. Then, the terminal device can group the random access resource t1 corresponding to the wave position h according to the number of sub-wave positions included in the wave position h, to obtain a group of random access resources corresponding to each sub-wave position included in the wave position h, for example, a group of random access resources corresponding to sub-wave position h1 is resource sequence group 00, and a group of random access resources corresponding to sub-wave position h2 is resource sequence group 01. Wherein, the resource sequence group 00 and the resource sequence group 01 are included in the random access resource t1. Optionally, the resource sequence group 00 and the resource sequence group 01 are the same in the time-frequency domain resources (that is, the sub-wave position h1 and the sub-wave position h2 share a group (or can be called a set) of time-frequency domain resources (for example, the sub-wave position h1 and the sub-wave position h2 share the time-frequency domain resources in the random access resource t1)), but the code domain resources are different. In other words, the resource sequence group 00 and the resource sequence group 01 include the same group of time-frequency domain resources (for example, the time-frequency domain resources in the random access resource t1), but the code domain resources included by the two are different (for example, the code domain resources in the random access resource t1 are divided into two parts, one part of the code domain resources is given to the resource sequence group 00, and the other part of the code domain resources is given to the resource sequence group 01). It should be understood that the resource sequence group 00 and the resource sequence group 01 can also be different in the time domain resources, the same in the frequency domain resources and the code domain resources, or the same in the time domain resources and the code domain resources, and different in the frequency domain resources, and the embodiments of the present application do not limit this.

[0181] In another example, after the first communication device determines the number of sub-beams included in the first beam according to the first signal from the second communication device, the first communication device can group the random access resources corresponding to the first beam according to the number of sub-beams included in the first beam, to obtain a group of random access resources corresponding to each of the at least one sub-beam. In this way, the method provided in this example can enable the first communication device (such as a terminal device) to select the corresponding group of random access resources according to the sub-beam in which it is located, and further enable the second communication device (such as a satellite) to determine the sub-beam in which the terminal device currently sending the second signal (such as a random access request signal or a random access request message) is located according to the group of random access resources in which the second signal is received, and then transmit a common downlink signal (such as a third signal) using a sub-beam (such as a narrow beam with a width smaller than the beam corresponding to the first beam) covering the sub-beam in response to the terminal device. It should be understood that the grouping method (or division method) of the random access resources corresponding to the first beam described above can be determined according to a resource grouping strategy agreed upon in advance (or defined in advance through a protocol) by the first communication device and the second communication device. For example, the resource grouping strategy can be that the first communication device sequentially allocates the random access resources corresponding to the first beam to the at least one sub-beam according to the index order of the at least one sub-beam included in the first beam (or the index order of the reference points corresponding to the at least one sub-beam), so that the second communication device can also pre-know the mapping relationship between the at least one sub-beam (or the reference points corresponding to the at least one sub-beam) and the corresponding group of random access resources.

[0182] For example, continuing with the first signal as a system message, the first communication device as a terminal device, and the second communication device as a satellite, the first beam in which the terminal device is located is the beam h shown in FIG. 5b, and the random access resources corresponding to the beam h have two (such as random access resource t1 and random access resource t2) as an example. After the terminal device determines that the beam h includes two sub-beams according to the system message from the satellite, the terminal device can group the random access resources corresponding to the beam h carried by the system message according to the number of sub-beams included in the beam h, to obtain a group of random access resources corresponding to each of the sub-beams included in the beam h, such as a group of random access resources corresponding to the sub-beam h1 as the random access resource t1 and a group of random access resources corresponding to the sub-beam h2 as the random access resource t2.

[0183] For another example, continuing with the first signal being a system message, the first communication device being a terminal device, the second communication device being a satellite, the first wave position where the terminal device is located being the wave position h as shown in FIG. 5b, and the random access resource corresponding to the wave position h having one (for example, the random access resource t1) as an example, after the terminal device determines that the number of sub-wave positions included in the wave position h is 2 according to the system message from the satellite, the terminal device can group the random access resource t1 corresponding to the wave position h carried by the system message according to the number of sub-wave positions included in the wave position h, to obtain a group of random access resources corresponding to each sub-wave position included in the wave position h, for example, the group of random access resources corresponding to the sub-wave position h1 being the resource sequence group 00, and the group of random access resources corresponding to the sub-wave position h2 being the resource sequence group 01. The resource sequence group 00 and the resource sequence group 01 are included in the random access resource t1. Optionally, the resource sequence group 00 and the resource sequence group 01 are the same in the time-frequency domain (that is, the sub-wave position h1 and the sub-wave position h2 share a group of time-frequency domain resources (for example, the random access resource t1)), but different in the code domain. In other words, the resource sequence group 00 and the resource sequence group 01 include the same group of time-frequency domain resources (for example, the time-frequency domain resources in the random access resource t1), but the code domain resources included in the two groups are different (for example, the code domain resources in the random access resource t1 are divided into two parts, one part of the code domain resources is allocated to the resource sequence group 00, and the other part of the code domain resources is allocated to the resource sequence group 01). It should be understood that the resource sequence group 00 and the resource sequence group 01 can also be different in the time domain, the same in the frequency domain and the code domain, or the same in the time domain and the code domain, and different in the frequency domain, and the embodiments of the present application do not limit this.

[0184] Implementation mode two: the group of random access resources corresponding to each sub-wave position can be determined according to the number of sub-wave positions indicated by the first signal.

[0185] In the embodiment of the present application, the first communication device can group the random access resources corresponding to the first wave position according to the number of at least one sub-wave position included in the first wave position indicated by the first signal, to obtain a group of random access resources corresponding to each of the at least one sub-wave position. In this way, the implementation manner can enable the first communication device (such as a terminal device) to select the corresponding group of random access resources according to the sub-wave position in which the terminal device is located, and further enable the second communication device (such as a satellite) to determine the sub-wave position in which the terminal device currently sending the second signal (such as a random access request signal or a random access request message) is located according to the group of random access resources in which the second signal is received, and then transmit a common downlink signal (such as a third signal) using a sub-beam (such as a narrow beam with a width smaller than that of the beam corresponding to the first wave position) covering the sub-wave position in response to the terminal device. It can be understood that the grouping manner of the random access resources corresponding to the first wave position described above can be determined according to a resource grouping strategy agreed by the first communication device and the second communication device in advance. For example, the resource grouping strategy can be that the first communication device sequentially allocates the random access resources corresponding to the first wave position to the at least one sub-wave position in the index order of the at least one sub-wave position included in the first wave position (or the index order of the reference points corresponding to the at least one sub-wave position), so that the second communication device can also pre-know the mapping relationship between the at least one sub-wave position (or the reference points corresponding to the at least one sub-wave position) and the corresponding group of random access resources.

[0186] In one example, the first signal is a system message, the first communication device is a terminal device, the second communication device is a satellite, the first wave position is the wave position g as shown in FIG. 5b, and the system message carries 3 random access resources (such as random access resource s1, random access resource s2 and random access resource s3) corresponding to the wave position g. After the terminal device determines the number of sub-wave positions included in the wave position g (i.e., the number 3) according to the system message from the satellite, the terminal device can group the random access resources corresponding to the wave position g carried by the system message according to the number 3 of sub-wave positions included in the wave position g, to obtain a group of random access resources corresponding to each of the sub-wave positions included in the wave position g, such as a group of random access resources corresponding to the sub-wave position g1 being the random access resource s1, a group of random access resources corresponding to the sub-wave position g2 being the random access resource s2, and a group of random access resources corresponding to the sub-wave position g3 being the random access resource s3.

[0187] In another example, the first signal is a system message, the first communication device is a terminal device, the second communication device is a satellite, the first wave position is wave position k, the wave position k includes 4 sub-wave positions (such as sub-wave position k1, sub-wave position k2, sub-wave position k3 and sub-wave position k4), the system message carries 2 random access resources (such as random access resource r1 and random access resource r2) corresponding to the wave position k, and the random access resource includes time domain resource, frequency domain resource and code domain resource. Wherein, the reference point corresponding to the sub-wave position k1 is reference point k1, the reference point corresponding to the sub-wave position k2 is reference point k2, the reference point corresponding to the sub-wave position k3 is reference point k3, and the reference point corresponding to the sub-wave position k4 is reference point k4. After the terminal device determines the number of sub-wave positions included in the wave position k (i.e. the number 4) according to the system message from the satellite, the terminal device can group the random access resources corresponding to the wave position k carried by the system message according to the number 4 of the sub-wave positions included in the wave position k, to obtain a group of random access resources corresponding to each sub-wave position included in the wave position k, such as a group of random access resources corresponding to the sub-wave position k1 is resource sequence group 11, a group of random access resources corresponding to the sub-wave position k2 is resource sequence group 12, a group of random access resources corresponding to the sub-wave position k3 is resource sequence group 21, and a group of random access resources corresponding to the sub-wave position k2 is resource sequence group 22. Wherein, the resource sequence group 11 and the resource sequence group 12 are included in the random access resource group r1, and the resource sequence group 21 and the resource sequence group 22 are included in the random access resource group r2. Optionally, the resource sequence group 11 and the resource sequence group 12 in the random access resource group r1 are the same in time-frequency domain resource (i.e. the sub-wave position k1 and the sub-wave position k2 share a group of time-frequency domain resources), but different in code domain resource; the resource sequence group 21 and the resource sequence group 22 in the random access resource group r2 are the same in time-frequency domain resource (i.e. the sub-wave position k3 and the sub-wave position k4 share a group of time-frequency domain resources), but different in code domain resource. In other words, the resource sequence group 11 and the resource sequence group 12 include the same group of time-frequency domain resources (such as time-frequency domain resources in the random access resource r1), but the code domain resources included by the two are different (such as the code domain resources in the random access resource r1 are divided into two parts, one part of the code domain resources is allocated to the resource sequence group 11, and the other part of the code domain resources is allocated to the resource sequence group 12); the resource sequence group 21 and the resource sequence group 22 include the same group of time-frequency domain resources (such as time-frequency domain resources in the random access resource r2), but the code domain resources included by the two are different (such as the code domain resources in the random access resource r2 are divided into two parts, one part of the code domain resources is allocated to the resource sequence group 21, and the other part of the code domain resources is allocated to the resource sequence group 22). It should be understood that the resource sequence group 11 and the resource sequence group 12 (or the resource sequence group 21 and the resource sequence group 22) can also be different in time domain resource, the same in frequency domain resource and code domain resource, or the same in time domain resource and code domain resource, different in frequency domain resource, which is not limited by the embodiments of the present application.

[0188] Step 402: The first communication device sends the second signal using the first group of random access resources corresponding to the first sub-wave position. Correspondingly, the second communication device receives the second signal on the first group of random access resources.

[0189] It should be understood that in the embodiments of the present application, the first communication device sending the second signal using the first group of random access resources corresponding to the first sub-wave position can be replaced by "the first communication device sends the second signal, and the second signal is carried on the first group of random access resources corresponding to the first sub-wave position".

[0190] Optionally, the second signal can be used to indicate that the first communication device requests access to the second communication device in the random access process. For example, the second signal can be a random access request signal (or can be referred to as a random access request message or a random access request or message 1 (Msg1)), or the second signal can also be a random access sequence.

[0191] For example, when the second signal is a random access request signal, the second signal can carry (or include or contain) a random access sequence. Wherein, the second signal can be sent (or carried) through a physical random access channel (PRACH). Optionally, the random access sequence carried by the second signal can be a random access sequence selected by the first communication device from a random access sequence set configured by the second communication device for the first communication device.

[0192] The following describes the implementation process of the first communication device sending the second signal using the first group of random access resources corresponding to the first sub-wave position through the following several possible implementation manners, taking the first communication device as a terminal device as an example.

[0193] Manner one: In the case where the first signal is used to indicate the index of at least one sub-wave position included in the first wave position, after the terminal device determines the group of random access resources corresponding to the at least one sub-wave position included in the first wave position respectively, the terminal device can determine the random access resource required by the terminal device to send the second signal as the first group of random access resources corresponding to the first sub-wave position in which the terminal device is located according to the coverage geographical range of the terminal device. Then, the terminal device can send the second signal using the first group of random access resources corresponding to the first sub-wave position. Wherein, the first sub-wave position is included in the at least one sub-wave position included in the first wave position.

[0194] In one example, the first wave position is wave position f as shown in FIG. 5a, and the random access resource corresponding to the wave position f has 3 (for example, random access resource 01, random access resource 02 and random access resource 03). After the terminal device determines that the 3 sub-wave positions included in the wave position f correspond to a group of random access resources (for example, sub-wave position f1 corresponds to random access resource 01, sub-wave position f2 corresponds to random access resource 02, and sub-wave position f3 corresponds to random access resource 03), the terminal device can determine that the random access resource required for the terminal device to send the second signal is the random access resource 02 corresponding to the sub-wave position f2 where the terminal device is located, according to the fact that the terminal device is located in the coverage geographical range of the sub-wave position f2. Then, the terminal device can send the second signal using the random access resource 02 corresponding to the sub-wave position f2.

[0195] In another example, the first wave position is wave position f as shown in FIG. 5a, and the random access resource corresponding to the wave position f has 2 (for example, random access resource 01 and random access resource 02), and the time-frequency domain resource in the random access resource 01 is shared by the sub-wave position f1 and the sub-wave position f2. After the terminal device determines that the 3 sub-wave positions included in the wave position f correspond to a group of random access resources (for example, sub-wave position f1 corresponds to resource sequence group 010, sub-wave position f2 corresponds to resource sequence group 011, and sub-wave position f3 corresponds to random access resource 02), the terminal device can determine that the random access resource required for the terminal device to send the second signal is the resource sequence group 011 corresponding to the sub-wave position f2 where the terminal device is located, according to the fact that the terminal device is located in the coverage geographical range of the sub-wave position f2. Then, the terminal device can send the second signal using the resource sequence group 011 corresponding to the sub-wave position f2. Wherein, the resource sequence group 010 and the resource sequence group 011 are included in the random access resource 01, and the resource sequence group 010 and the resource sequence group 011 include the same group of time-frequency domain resources (i.e., the time-frequency domain resources in the random access resource 01), but the code domain resources included by the two are different (i.e., the code domain resources in the random access resource 01 are divided into two parts, one part of the code domain resources is allocated to the resource sequence group 010, and the other part of the code domain resources is allocated to the resource sequence group 011).

[0196] In a second mode, in a case that the first signal is used to indicate that the at least one sub-wave position corresponding to the reference point, the terminal device can select a first reference point from the reference points corresponding to the at least one sub-wave position according to the location of the terminal device after determining a set of random access resources corresponding to the at least one sub-wave position included in the first wave position. Then, the terminal device can determine a first sub-wave position corresponding to the first reference point, and can determine a first set of random access resources corresponding to the first sub-wave position. Then, the terminal device can send the second signal using the first set of random access resources corresponding to the first sub-wave position. The first sub-wave position is included in the at least one sub-wave position included in the first wave position. The first reference point is a reference point corresponding to the at least one sub-wave position and having a distance less than or equal to a distance threshold from the location of the terminal device, for example, the first reference point can be the closest reference point to the location of the terminal device among the reference points corresponding to the at least one sub-wave position. For example, the terminal device can calculate the distance interval (or distance interval) between the location coordinates of the reference points corresponding to the at least one sub-wave position and the location of the terminal device. Then, the terminal device can determine which reference point (or reference point) has a distance interval less than or equal to the distance threshold.

[0197] In one example, the first wave position is wave position g as shown in FIG. 5b, and the random access resources corresponding to the wave position g are 3 (for example, random access resource s1, random access resource s2 and random access resource s3). After determining a set of random access resources corresponding to the 3 sub-wave positions included in the wave position g (for example, sub-wave position g1 corresponds to random access resource s1, sub-wave position g2 corresponds to random access resource s2, and sub-wave position g3 corresponds to random access resource s3), the terminal device can first determine which sub-wave position corresponds to a reference point having a distance interval less than or equal to a distance threshold from the location of the terminal device, for example, the distance interval between the location coordinates of the reference point g1 corresponding to the sub-wave position g1 and the location of the terminal device is less than or equal to the distance threshold. Then, the terminal device can determine that the reference point g1 corresponds to the sub-wave position g1, so the terminal device can also determine that the random access resource corresponding to the sub-wave position g1 is the random access resource s1. Then, the terminal device can send the second signal using the random access resource s1 corresponding to the sub-wave position g1.

[0198] In another example, the first wave position is wave position g as shown in FIG. 5b, the random access resource corresponding to the wave position g has 2 (such as random access resource s1 and random access resource s2), and the time-frequency domain resource in the random access resource s1 is shared by the sub-wave position g1 and the sub-wave position g2. After determining that the three sub-wave positions included in the wave position g correspond to a group of random access resources respectively (such as the sub-wave position g1 corresponds to the resource sequence group 11', the sub-wave position g2 corresponds to the resource sequence group 12', and the sub-wave position g3 corresponds to the random access resource s2), the terminal device can first determine that the distance interval between the position coordinates of the reference point corresponding to the sub-wave position and the position of the terminal device is less than or equal to the distance threshold, such as the distance interval between the position coordinates of the reference point g1 corresponding to the sub-wave position g1 and the position of the terminal device is less than or equal to the distance threshold. Then, the terminal device can determine that the sub-wave position g1 corresponds to the reference point g1, so that the terminal device can also determine that the random access resource corresponding to the sub-wave position g1 is the resource sequence group 11'. Then, the terminal device can send the second signal using the resource sequence group 11' corresponding to the sub-wave position g1. Wherein, the resource sequence group 11' and the resource sequence group 12' are included in the random access resource s1, and the resource sequence group 11' and the resource sequence group 12' include the same group of time-frequency domain resources (i.e. the time-frequency domain resources in the random access resource s1), but the code domain resources included by the two are different (i.e. the code domain resources in the random access resource s1 are divided into two parts, one part of the code domain resources is allocated to the resource sequence group 11', and the other part of the code domain resources is allocated to the resource sequence group 12').

[0199] Step 403: The second communication device sends the third signal using the sub-beam corresponding to the first sub-wave position. Correspondingly, the first communication device receives the third signal on the sub-beam corresponding to the first sub-wave position.

[0200] It should be understood that in the embodiments of the present application, the second communication device sends the third signal using the sub-beam corresponding to the first sub-wave position can be replaced by "the second communication device sends the third signal, and the third signal is carried on the sub-beam corresponding to the first sub-wave position".

[0201] The third signal can be a response of the second communication device to the received second signal. For example, the third signal can include a random access response (RAR) message, etc. For example, the random access response message can include a random access preamble identifier (RA-preamble identifier), timing alignment information, an initial uplink grant, a temporary cell radio network temporary identity (TC-RNTI), etc. Optionally, the third signal can also include downlink control information (DCI). The downlink control information can be used to demodulate the random access response message.

[0202] In the embodiments of the present application, after receiving the second signal, the second communication device can determine a first sub-beam position (i.e., the sub-beam position where the first communication device is located) corresponding to the first group of random access resources according to the first group of random access resources used to carry the second signal. Then, the second communication device can schedule (or use or adopt or through) a sub-beam corresponding to the first sub-beam position to send the third signal. It should be understood that the width of the sub-beam corresponding to the first sub-beam position is smaller than the width of the beam corresponding to the first beam position.

[0203] It can be understood that the second communication device can also schedule the sub-beam corresponding to the first sub-beam position to send other common downlink signals (such as a radio resource control (RRC) setup response message (or can be referred to as a radio resource control setup response signal or message 4 (Msg4) or a contention resolution message)) before the first communication device accesses the network.

[0204] In one example, the first communication device is a terminal device, the second communication device is a satellite, the second communication device and the first communication device predefine the resource grouping strategy of the random access resource corresponding to the first wave position through a protocol, the first wave position is the wave position f as shown in FIG. 5a, the terminal device is located in the sub-wave position f2 included in the wave position f, and the sub-wave position f2 corresponds to the random access resource 02 for example. In the case that the random access resource corresponding to the wave position f is predefined by the terminal device and the satellite through a protocol, the satellite can pre-know the mapping relationship of the three sub-wave positions included in the wave position f and the corresponding group of random access resources respectively (for example, the sub-wave position f1 corresponds to the random access resource 01, the sub-wave position f2 corresponds to the random access resource 02, and the sub-wave position f3 corresponds to the random access resource 03). Then, the satellite can determine the sub-wave position corresponding to the random access resource 02 used to carry the second signal as the sub-wave position f2 according to the mapping relationship of the three sub-wave positions and the corresponding group of random access resources respectively. Then, the satellite can send the third signal using the sub-beam corresponding to the sub-wave position f2. The width of the sub-beam corresponding to the sub-wave position f2 is smaller than the width of the beam corresponding to the wave position f.

[0205] In another example, the first communication device is a terminal device, the second communication device is a satellite, the second communication device and the first communication device predefine the resource grouping strategy of the random access resource corresponding to the first wave position through a protocol, the first wave position is the wave position f as shown in FIG. 5a, the terminal device is located in the sub-wave position f2 included in the wave position f, and the sub-wave position f2 corresponds to the resource sequence group 011 for example. In the case that the random access resource corresponding to the wave position f is predefined by the terminal device and the satellite through a protocol, the satellite can pre-know the mapping relationship of the three sub-wave positions included in the wave position f and the corresponding group of random access resources respectively (for example, the sub-wave position f1 corresponds to the resource sequence group 010, the sub-wave position f2 corresponds to the resource sequence group 011, and the sub-wave position f3 corresponds to the random access resource 02). Then, the satellite can determine the sub-wave position corresponding to the resource sequence group 011 used to carry the second signal as the sub-wave position f2 according to the mapping relationship of the three sub-wave positions and the corresponding group of random access resources respectively. Then, the satellite can send the third signal using the sub-beam corresponding to the sub-wave position f2. The width of the sub-beam corresponding to the sub-wave position f2 is smaller than the width of the beam corresponding to the wave position f.

[0206] In yet another example, the first communication device is a terminal device, and the second communication device is a satellite. The second communication device and the first communication device predefine a resource grouping strategy of the random access resources corresponding to the first beam position through a protocol. The first beam position is beam position g as shown in FIG. 5b. The terminal device is located in sub-beam position g1 included in the beam position g. For example, the sub-beam position g1 corresponds to a random access resource s1. In the case that the random access resources corresponding to the beam position g are predefined by the terminal device and the satellite through the protocol, the satellite can pre-know the mapping relationship between the three sub-beam positions included in the beam position g and a corresponding group of random access resources (for example, the sub-beam position g1 corresponds to the random access resource s1, the sub-beam position g2 corresponds to the random access resource s2, and the sub-beam position g3 corresponds to the random access resource s3). Then, the satellite can determine, according to the mapping relationship between the three sub-beam positions and the corresponding group of random access resources, that the sub-beam position corresponding to the random access resource s1 used to carry the second signal is the sub-beam position g1. Then, the satellite can send the third signal using the sub-beam corresponding to the sub-beam position g1. The width of the sub-beam corresponding to the sub-beam position g1 is smaller than the width of the beam corresponding to the beam position g.

[0207] In yet another example, the first communication device is a terminal device, and the second communication device is a satellite. The second communication device and the first communication device predefine a resource grouping strategy of the random access resources corresponding to the first beam position through a protocol. The first beam position is beam position g as shown in FIG. 5b. The terminal device is located in sub-beam position g1 included in the beam position g. For example, the sub-beam position g1 corresponds to a resource sequence group 11’. In the case that the random access resources corresponding to the beam position g are predefined by the terminal device and the satellite through the protocol, the satellite can pre-know the mapping relationship between the three sub-beam positions included in the beam position g and a corresponding group of random access resources (for example, the sub-beam position g1 corresponds to the resource sequence group 11’, the sub-beam position g2 corresponds to the resource sequence group 12’, and the sub-beam position g3 corresponds to the random access resource s2). Then, the satellite can determine, according to the mapping relationship between the three sub-beam positions and the corresponding group of random access resources, that the sub-beam position corresponding to the resource sequence group 11’ used to carry the second signal is the sub-beam position g1. Then, the satellite can send the third signal using the sub-beam corresponding to the sub-beam position g1. The width of the sub-beam corresponding to the sub-beam position g1 is smaller than the width of the beam corresponding to the beam position g.

[0208] Optionally, in order to reduce the time for the first communication device to monitor (or can be referred to as monitor) the third signal (such as Msg2), or to have more delay to schedule the third signal on the side of the second communication device, the second communication device can also indicate the corresponding delay offset through the first signal. It should be understood that the corresponding delay offset can be flexibly determined by the second communication device on the basis of the existing random access response window (RAR window) of the first communication device.

[0209] For example, taking the first communication device as a terminal device, the second communication device as a satellite, and the third signal as Msg2 as an example. When the satellite cannot schedule Msg2 to the corresponding terminal device (or terminal device 1) in time in the case of limited beams, the satellite can configure a larger delay offset (such as offset1) for the terminal device 1. In this way, the terminal device 1 can determine a new random access response window according to the delay offset offset1 and the existing random access response window, and can monitor PDCCH in the new random access response window to wait for obtaining a random access response message from the satellite. Optionally, the random access response message can be carried in Msg2, or the random access response message can also be Msg2. In this way, the satellite schedules Msg2 for the terminal device 1 later than for other terminal devices, so that the terminal device 1 monitors PDCCH after the existing random access response window to obtain the corresponding random access response message, which helps to increase the flexibility of the satellite scheduling Msg2.

[0210] In the embodiments of the present application, the delay offset indicated by the first signal can have a corresponding relationship (or can be referred to as a mapping relationship or an association relationship or a binding relationship) with the first wave position, such as that different wave positions each correspond to a delay offset, or the delay offset indicated by the first signal can also have a corresponding relationship with the first sub-wave position, such as that different sub-wave positions each correspond to a delay offset. Then, the first communication device can receive the third signal in the first response window after sending the second signal. The first response window can be determined by the first communication device according to the second response window (that is, the existing response window corresponding to the first communication device, such as the existing random access response window) and the corresponding delay offset (such as the delay offset corresponding to the first wave position or the delay offset corresponding to the first sub-wave position).

[0211] The following describes the implementation process of the first communication device receiving the third signal in the first response window through the following possible examples.

[0212] Example 1: When the delay offset indicated by the first signal has a corresponding relationship with the first wave position (that is, the wave position), the first communication device can obtain the delay offset corresponding to the first wave position from the first signal after receiving the first signal. Then, the first communication device can determine the first response window according to the second response window and the delay offset corresponding to the first wave position. Then, the first communication device can receive the third signal in the first response window.

[0213] For example, taking the first communication device as a terminal device, the second communication device as a satellite, the first signal as a system message, the second response window as [T1, T2], and the delay offset offset2 corresponding to the first wave position (such as the wave position f shown in FIG. 5a or the wave position g shown in FIG. 5b) as an example, after the terminal device receives the system message from the satellite on the beam corresponding to the first wave position, the terminal device can obtain the delay offset offset2 corresponding to the first wave position from the system message, and can determine the first response window as [T1+offset2, T2+offset2] according to the second response window [T1, T2] and the delay offset offset2 corresponding to the first wave position. Then, the terminal device can monitor the PDCCH in the first response window [T1+offset2, T2+offset2] to obtain the third signal. Optionally, the third signal can carry a random access response message, or the third signal can be a random access response message.

[0214] In the embodiment of the present application, the second communication device can determine the delay offset corresponding to the first wave position according to the current service situation (such as the number of services, the service transmission delay requirement, the service transmission situation, the service congestion situation, etc.). It should be understood that the second communication device can also determine the delay offset corresponding to other wave positions according to the current service situation. In this way, the scheme provided in this example can realize that the second communication device dynamically determines (or flexibly determines or flexibly updates or flexibly determines) the delay offset corresponding to each primary wave position (such as the first wave position) according to the actual service situation, and realizes the purpose of the second communication device flexibly configuring the delay offset corresponding to each primary wave position. In this way, different wave positions (or different SSB wave positions or different SSBs or different wave positions corresponding to beams) can correspond to different delay offsets. For example, if the delay offset is associated with the SSB (or it can be understood that the delay offset is associated with the primary wave position), the first signal (such as a broadcast message) sent by the second communication device can indicate the delay offset corresponding to each SSB index (or a certain SSB index), or the first signal sent by the second communication device can be used to indicate the delay offset corresponding to each wave position (or a certain wave position). Then, the terminal device receiving the first signal can obtain the delay offset corresponding to the SSB index according to the detected SSB index, that is, obtain the delay offset corresponding to the wave position (such as the first wave position) identified by the SSB index.

[0215] In the second example, when the delay offset indicated by the first signal corresponds to a secondary wave position (i.e., a sub-wave position), the first communication device can obtain, from the first signal, a delay offset corresponding to each of the at least one sub-wave position included in the first wave position, and can determine (or select) a delay offset corresponding to a first sub-wave position according to the first sub-wave position in which the first communication device is located. Then, the first communication device can determine a third response window according to the second response window and the delay offset corresponding to the first sub-wave position, and the third response window can be used as the first response window. Then, the first communication device can receive a third signal in the first response window.

[0216] For example, the first communication device is a terminal device, the second communication device is a satellite, the first signal is a system message, the second response window is [T1, T2], and the delay offset offset2' corresponding to the first sub-wave position (e.g., the sub-wave position f2 in FIG. 5a or the sub-wave position g1 in FIG. 5b) is taken as an example. After the terminal device receives the system message from the satellite in the beam corresponding to the first wave position, the terminal device can obtain the delay offset offset2' corresponding to the first sub-wave position from the system message, and can determine a third response window [T1+offset2', T2+offset2'] according to the second response window [T1, T2] and the delay offset offset2' corresponding to the first sub-wave position, and the third response window [T1+offset2', T2+offset2'] can be used as the first response window. Then, the terminal device can monitor the PDCCH in the third response window [T1+offset2', T2+offset2'] to obtain a third signal. Optionally, the third signal can carry a random access response message, or the third signal can be a random access response message.

[0217] In the embodiments of the present application, the second communication device can determine the delay offset corresponding to each sub-wave position included in the first wave position according to the current service condition (such as the number of services, the service transmission delay requirement, the service transmission condition, the service congestion condition, etc.). It should be understood that the second communication device can also determine the delay offset corresponding to the sub-wave position included in other wave positions according to the current service condition. In this way, the scheme provided in this example can dynamically determine the delay offset corresponding to each secondary wave position (such as the first sub-wave position) according to the actual service condition, thereby achieving the purpose of flexibly configuring the delay offset corresponding to each secondary wave position by the second communication device. In this way, different sub-wave positions (or reference points corresponding to different sub-wave positions or sub-beams corresponding to different sub-wave positions) can correspond to different delay offsets. For example, if the delay offset is associated with the sub-wave position (or it can be understood that the delay offset is associated with the secondary wave position), the first signal (such as a broadcast message) sent by the second communication device can indicate the delay offset corresponding to at least one sub-wave position associated with each SSB index (or a certain SSB index). Then, the terminal device receiving the first signal can know the delay offset corresponding to at least one sub-wave position associated with the SSB index according to the detected SSB index, that is, know the delay offset corresponding to at least one sub-wave position included in the wave position identified by the SSB index.

[0218] As can be seen from the above steps 401 to 403, the first wave position can include at least one sub-wave position, and each sub-wave position in the at least one sub-wave position corresponds to a group of random access resources. In this way, after determining that the sub-wave position where the first communication device is located is the first sub-wave position (for example, the first communication device can determine in which sub-wave position the first communication device is located according to its own location), the first communication device can use the first group of random access resources corresponding to the first sub-wave position (which can be understood as the first communication device selecting the matching random access resources according to its own location) to send the second signal. In this way, the second communication device can effectively determine that the first communication device is located in the first sub-wave position according to the first group of random access resources used to carry the second signal, so that the receiving device can further effectively schedule the sub-beam corresponding to the first sub-wave position to send the subsequent common downlink signal (such as the third signal), thereby helping to improve the link budget of the common downlink signal. It can be understood that since the second communication device uses the sub-beam corresponding to the first sub-wave position when sending the common downlink signal before the first communication device accesses the network, the width of the sub-beam is smaller than the width of the beam corresponding to the first wave position, so the link budget of the common downlink signal can be improved. In addition, this method not only can realize short-period (such as 20ms) common signal scanning, support wide-area coverage of the second communication device (such as a satellite), but also can realize the reception and decoding of the common downlink signal without affecting the downlink synchronization signal.

[0219] FIG. 6 shows a flowchart of another communication method according to an embodiment of the present application. The method is applicable to the communication system architecture shown in FIG. 2 or FIG. 3. As shown in FIG. 6, the method comprises the following steps.

[0220] In step 601, the second communication device transmits a fourth signal using the beam corresponding to the first wave position. Correspondingly, the first communication device receives the fourth signal on the beam corresponding to the first wave position.

[0221] Optionally, in the embodiments of the present application, if the first communication device is a functional module such as a chip, the functional module can not be aware of which device the received information is from; if the second communication device is a functional module such as a chip, the functional module can also not be aware of which device the transmitted information is sent to.

[0222] It should be understood that in the embodiments of the present application, the second communication device transmits a fourth signal using the beam corresponding to the first wave position can be replaced by "the second communication device transmits a fourth signal, and the fourth signal is carried on the beam corresponding to the first wave position".

[0223] For example, the fourth signal can be a system message (or can be referred to as a broadcast message or system information or a system message block or a system information block) or a system signal. The first wave position can include at least one sub-wave position.

[0224] Optionally, the fourth signal can include a random access resource corresponding to the first wave position or at least one delay offset, etc. The random access resource corresponding to the first wave position can be used to assist the terminal device located at the first wave position to transmit a corresponding signal (such as a fifth signal) to the second communication device using the corresponding random access resource; the delay offset can be used to indicate the delay amount of the response window of the first communication device monitoring the sixth signal. For example, the first wave position is one of at least one wave position included in the coverage area of the second communication device.

[0225] It should be understood that one wave position (or can be referred to as a primary wave position or an SSB wave position, such as the first wave position) can correspond to one beam, and one sub-wave position (or can be referred to as a secondary wave position) can correspond to one sub-beam. For example, one wave position (such as the first wave position or the second wave position, etc.) corresponding to one beam can also be understood as one SSB corresponding to one beam. Wherein, one SSB can be identified by using one SSB index, and one SSB can correspond to one transmission direction (or beam transmission direction). Further, one SSB index can also be used to identify the corresponding wave position, or can also be used to identify the corresponding beam.

[0226] The indication content of the fourth signal is introduced below through the following possible implementation manners.

[0227] The fourth signal can be used to indicate the index of the at least one sub-beam included in the first beam.

[0228] In the embodiments of the present application, the second communication device can carry the index of the at least one sub-beam included in the first beam in the first signal, so that the first communication device can learn the coverage geographical range corresponding to the at least one sub-beam through the index of the at least one sub-beam, and the first communication device can further determine in which coverage geographical range corresponding to the sub-beam the first communication device is located.

[0229] In a possible implementation, the second communication device can broadcast the system messages corresponding to different beams respectively on the corresponding beams. The system message corresponding to each beam can include the index of the sub-beam included in the beam. For example, taking the first signal as the system message, the first communication device as the terminal device shown in FIG. 5b, and the second communication device as the satellite shown in FIG. 5b, the area covered by the satellite includes two beams (for example, beam g and beam h). The satellite can broadcast the index g1 of the sub-beam g1, the index g2 of the sub-beam g2, and the index g3 of the sub-beam g3 included in the beam g on the beam g, and broadcast the index h1 of the sub-beam h1 and the index h2 of the sub-beam h2 included in the beam h on the beam h.

[0230] Then, the terminal device located in the beam g can receive the corresponding system message on the beam g. The system message can include the index g1 of the sub-beam g1, the index g2 of the sub-beam g2, and the index g3 of the sub-beam g3. Optionally, the system message can further include the coverage geographical range corresponding to the index g1, the coverage geographical range corresponding to the index g2, and the coverage geographical range corresponding to the index g3. Then, the terminal device can obtain the index g1 of the sub-beam g1, the index g2 of the sub-beam g2, and the index g3 of the sub-beam g3 from the system message.

[0231] In one example, when the system message carried by the beam g does not include the coverage geographical range corresponding to the index g1, the coverage geographical range corresponding to the index g2, and the coverage geographical range corresponding to the index g3, the terminal device can divide the coverage geographical range of the beam g according to the index order of the three sub-beams included in the beam g, and determine the coverage geographical range of the sub-beam g1, the coverage geographical range of the sub-beam g2, and the coverage geographical range of the sub-beam g3. It should be understood that in this example, the global area can be divided into multiple beams in a grid manner, and at least one sub-beam can be divided for each beam. In this way, the terminal device can determine the beam in which the terminal device is located as the beam g according to the index g of the beam g used to carry the system message, and can further determine the coverage geographical range of the beam g. Then, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device and the coverage geographical range of the sub-beam g1, the coverage geographical range of the sub-beam g2, and the coverage geographical range of the sub-beam g3, such as the terminal device being located in the coverage geographical range of the sub-beam g1. Optionally, the coverage geographical range of each sub-beam included in the beam can also be predefined by a protocol.

[0232] In another example, when the system message carried by the beam g includes the coverage geographical range corresponding to the index g1, the coverage geographical range corresponding to the index g2, and the coverage geographical range corresponding to the index g3, the terminal device can obtain the coverage geographical range corresponding to the index g1, the coverage geographical range corresponding to the index g2, and the coverage geographical range corresponding to the index g3 from the system message. Then, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device and the coverage geographical range of the sub-beam g1, the coverage geographical range of the sub-beam g2, and the coverage geographical range of the sub-beam g3, such as the terminal device being located in the coverage geographical range of the sub-beam g1.

[0233] In another possible implementation, the second communication apparatus can broadcast the same system message respectively carried on different beams. The same system message can include a mapping relationship between each beam and the sub-beams included in the beam, such as a mapping relationship between beam g and sub-beam g1, sub-beam g2, and sub-beam g3 (for example, a mapping relationship between the index of beam g (such as the index g used to identify SSB0) and the index g1 of sub-beam g1, the index g2 of sub-beam g2, and the index g3 of sub-beam g3) and a mapping relationship between beam h and sub-beam h1 and sub-beam h2 (for example, a mapping relationship between the index of beam h (such as the index h used to identify SSB1) and the index h1 of sub-beam h1 and the index h2 of sub-beam h2), and the like, or the same system message can include which sub-beams are included in each of the above-mentioned two beams (for example, beam g includes sub-beam g1, sub-beam g2, and sub-beam g3). Optionally, the same system message can also include the coverage geographical range of the sub-beams included in each of the above-mentioned two beams (for example, the coverage geographical range of sub-beam g1, the coverage geographical range of sub-beam g2, the coverage geographical range of sub-beam g3, the coverage geographical range of sub-beam h1, the coverage geographical range of sub-beam h2, and the like). For example, taking the first signal as a system message, the first communication apparatus as the terminal device shown in FIG. 5b, and the second communication apparatus as the satellite shown in FIG. 5b, the satellite covers an area including two beams (such as beam g and beam h), and the same system message includes a mapping relationship between each of the above-mentioned two beams and the sub-beams included in the beam. The satellite can broadcast the mapping relationship between each of the above-mentioned two beams and the sub-beams included in the beam (such as a mapping relationship between beam g and sub-beam g1, sub-beam g2, and sub-beam g3 and a mapping relationship between beam h and sub-beam h1 and sub-beam h2) as the same system message respectively carried on beam g and beam h. The index corresponding to beam g is index g (or can be understood as the index g of SSB0), and the index corresponding to beam h is index h (or can be understood as the index h of SSB1).

[0234] After that, the terminal device located in beam g can receive the system message on beam g. The system message can include a mapping relationship between each of the above-mentioned two beams and the sub-beams included in the beam. Optionally, the system message can also include the coverage geographical range of the sub-beams included in each of the above-mentioned two beams. Then, the terminal device can obtain, from the system message, a mapping relationship between beam g and the three sub-beams included in beam g according to the index g corresponding to beam g (such as a mapping relationship between the index g of beam g and the index g1 of sub-beam g1, the index g2 of sub-beam g2, and the index g3 of sub-beam g3).

[0235] In one example, when the same system message does not include the coverage geographical range of the sub-beam included in each of the above-mentioned 2 wave positions, the terminal device can determine the index order of the 3 sub-beams included in the wave position g according to the mapping relationship between the wave position g and the 3 sub-beams included in the wave position g, and can divide the coverage geographical range of the wave position g according to the index order of the 3 sub-beams to determine the coverage geographical range of the sub-beam g1, the coverage geographical range of the sub-beam g2, and the coverage geographical range of the sub-beam g3. It should be understood that in this example, the global area can be divided into multiple wave positions in a grid manner, and at least one sub-beam can be divided for each of the multiple wave positions. In this way, the terminal device can determine that the wave position in which the terminal device is located is the wave position g according to the index g of the beam g used to carry the system message, and can further determine the coverage geographical range of the wave position g. Then, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device and the coverage geographical range of the sub-beam g1, the coverage geographical range of the sub-beam g2, and the coverage geographical range of the sub-beam g3, such as the terminal device being located in the coverage geographical range of the sub-beam g1. Optionally, the coverage geographical range of the sub-beam included in each wave position can also be predefined by a protocol.

[0236] In another example, when the same system message includes the coverage geographical range of the sub-beam included in each of the above-mentioned 2 wave positions, the terminal device can obtain the coverage geographical range of the 3 sub-beams corresponding to the index g (such as the coverage geographical range corresponding to the index g1, the coverage geographical range corresponding to the index g2, and the coverage geographical range corresponding to the index g3) from the system message according to the index g corresponding to the beam g. Then, the terminal device can determine in which coverage geographical range of the sub-beam the terminal device is located according to the location of the terminal device and the coverage geographical range of the 3 sub-beams corresponding to the index g, such as the terminal device being located in the coverage geographical range of the sub-beam g1.

[0237] Method two: The fourth signal can be used to indicate the reference point corresponding to the at least one sub-beam included in the first wave position.

[0238] In the embodiments of the present application, the second communication device can carry the reference point corresponding to the at least one sub-beam included in the first wave position in the first signal, so that the first communication device can further determine in which sub-beam (or can be understood as corresponding to which sub-beam) the first communication device is located through the reference point corresponding to the at least one sub-beam.

[0239] The following is an example of the first wave position, and the implementation process of the first signal indicating the reference point corresponding to the at least one sub-beam included in the first wave position is introduced through the following several possible examples.

[0240] Example 1: The fourth signal can be used to indicate the position coordinates of the reference point corresponding to the at least one sub-beam included in the first beam.

[0241] In a possible implementation, under the scheme provided in example 1, the second communication device (such as a satellite) can broadcast the system messages corresponding to different beams on the corresponding beams respectively. Wherein, the system message corresponding to each beam can include the position coordinates of the reference point corresponding to the sub-beam included in the beam. For example, taking the satellite coverage area shown in FIG. 5b as an example, the first communication device is a terminal device, the second communication device is a satellite, and the fourth signal is a system message. As shown in FIG. 5b, the satellite can broadcast the position coordinates of the reference point g1 corresponding to the sub-beam g1 included in the beam g, the position coordinates of the reference point g2 corresponding to the sub-beam g2, and the position coordinates of the reference point g3 corresponding to the sub-beam g3 on the beam g, and can broadcast the position coordinates of the reference point h1 corresponding to the sub-beam h1 included in the beam h and the position coordinates of the reference point h2 corresponding to the sub-beam h2 on the beam h. The terminal device located in the beam g can receive the corresponding system message on the beam g. Wherein, the system message can include the position coordinates of the reference point g1 corresponding to the sub-beam g1, the position coordinates of the reference point g2 corresponding to the sub-beam g2, and the position coordinates of the reference point g3 corresponding to the sub-beam g3. Then, the terminal device can obtain the position coordinates of the reference point g1 corresponding to the sub-beam g1, the position coordinates of the reference point g2 corresponding to the sub-beam g2, and the position coordinates of the reference point g3 corresponding to the sub-beam g3 from the system message, and can calculate the distance interval between the position of the terminal device and the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3 respectively. Then, the terminal device can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to the distance threshold, and can determine which sub-beam the reference point corresponds to (or can be understood as the terminal device can determine which sub-beam the terminal device is located in). For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-beam g1 corresponding to the reference point g1 (or can be understood as the terminal device can determine that the sub-beam where the terminal device is located is the sub-beam g1 corresponding to the reference point g1).

[0242] In another possible implementation, under the scheme provided in Example One, the second communication device can broadcast the same system message on different beams respectively. The same system message can include the position coordinates of the reference points corresponding to the sub-beams included in each wave position (for example, the position coordinates of which reference points correspond to wave position g or the position coordinates of which reference points correspond to the index of wave position g). For example, continuing with the satellite coverage area shown in FIG. 5b, the first communication device is a terminal device, the second communication device is a satellite, and the fourth signal is a system message. As shown in FIG. 5b, the satellite can broadcast the position coordinates of reference point g1 corresponding to sub-beam g1 included in wave position g, the position coordinates of reference point g2 corresponding to sub-beam g2, the position coordinates of reference point g3 corresponding to sub-beam g3, and the position coordinates of reference point h1 corresponding to sub-beam h1 included in wave position h and the position coordinates of reference point h2 corresponding to sub-beam h2 as the same system message on beams g and h respectively. The terminal device located in wave position g can receive the system message on beam g. The system message can include the position coordinates of reference point g1 corresponding to sub-beam g1, the position coordinates of reference point g2 corresponding to sub-beam g2, the position coordinates of reference point g3 corresponding to sub-beam g3, the position coordinates of reference point h1 corresponding to sub-beam h1, and the position coordinates of reference point h2 corresponding to sub-beam h2. Then, the terminal device can obtain the position coordinates of reference point g1 corresponding to sub-beam g1 included in wave position g, the position coordinates of reference point g2 corresponding to sub-beam g2, and the position coordinates of reference point g3 corresponding to sub-beam g3 from the system message according to the index g corresponding to beam g, and can calculate the distance intervals between the position of the terminal device and the position coordinates of reference point g1, the position coordinates of reference point g2, and the position coordinates of reference point g3 respectively. Then, the terminal device can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to the distance threshold, and can determine which sub-beam the reference point corresponds to (or determine which sub-beams the several reference points correspond to respectively). For example, if the terminal device determines that the distance interval corresponding to reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in sub-beam g1 corresponding to reference point g1.

[0243] It should be understood that, by directly carrying the position coordinates of the reference points corresponding to each sub-beam included in each wave position in the system message corresponding to each wave position in Example One, the terminal device located in the wave position can learn about the reference points corresponding to each sub-beam included in the wave position in time, and can determine which sub-beam the terminal device is located in in time.

[0244] Example Two: The fourth signal can be used to indicate at least one first difference value corresponding to the first wave position and the position coordinates corresponding to the first wave position.

[0245] Optionally, the description about the at least one first differential value corresponding to the first wave position in step 601 can refer to the description about the at least one first differential value corresponding to the first wave position in step 401, which will not be repeated here.

[0246] In a possible implementation, under the scheme provided in Example Two, the second communication device can broadcast the system messages corresponding to different wave positions on the corresponding beams respectively. Each system message corresponding to a wave position can include the position coordinates corresponding to the wave position and the first differential values corresponding to the reference points of at least one sub-wave position included in the wave position. For example, taking the satellite coverage area shown in FIG. 5b as an example, the first communication device is a terminal device, the second communication device is a satellite, and the fourth signal is a system message. As shown in FIG. 5b, the satellite can broadcast the 3 first differential values corresponding to the wave position g and the position coordinates corresponding to the wave position g (such as the position coordinates of the beam center corresponding to the wave position g) on the beam g, and broadcast the 2 first differential values corresponding to the wave position h and the position coordinates corresponding to the wave position h (such as the position coordinates of the beam center corresponding to the wave position h) on the beam h. Optionally, the description about the 3 first differential values corresponding to the wave position g and the 2 first differential values corresponding to the wave position h in step 601 can refer to the description about the 3 first differential values corresponding to the wave position g and the 2 first differential values corresponding to the wave position h in step 401, which will not be repeated here.

[0247] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3. After receiving the system message, the terminal device can obtain the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3 from the system message. Then, the terminal device can determine the position coordinate of the reference point g1 according to the position coordinate corresponding to the wave position g and the differential value g1 corresponding to the reference point g1, determine the position coordinate of the reference point g2 according to the position coordinate corresponding to the wave position g and the differential value g2 corresponding to the reference point g2, and determine the position coordinate of the reference point g3 according to the position coordinate corresponding to the wave position g and the differential value g3 corresponding to the reference point g3. Then, the terminal device can calculate the distance interval between the position of the terminal device and the position coordinates of the reference points g1, g2, and g3 respectively, and can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to a distance threshold, and can determine which sub-wave position (or which several sub-wave positions) corresponds to the reference point. For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1.

[0248] In another possible implementation, under the scheme provided in Example Two, the second communication device can broadcast the same system message on different beams respectively. The same system message can include the position coordinate corresponding to each wave position and the first differential value corresponding to the reference point included in the sub-wave position of the wave position (for example, the first differential value corresponding to several reference points of the wave position g or the first differential value corresponding to the index of several reference points of the index of the wave position g). For example, continuing with the satellite coverage area shown in FIG. 5b, the first communication device is the terminal device, the second communication device is the satellite, and the fourth signal is the system message. As shown in FIG. 5b, the satellite can broadcast the 3 first differential values corresponding to the wave position g, the position coordinate corresponding to the wave position g (for example, the position coordinate of the beam center corresponding to the wave position g), the 2 first differential values corresponding to the wave position h, and the position coordinate corresponding to the wave position h (for example, the position coordinate of the beam center corresponding to the wave position h) as the same system message on the beams g and h respectively. Optionally, the related description of the 3 first differential values corresponding to the wave position g in step 601 and the related description of the 2 first differential values corresponding to the wave position h can refer to the related description of the 3 first differential values corresponding to the wave position g and the related description of the 2 first differential values corresponding to the wave position h in the above step 401, which will not be described here.

[0249] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, the differential value g3 corresponding to the reference point g3, the position coordinate corresponding to the wave position h, the differential value h1 corresponding to the reference point h1, and the differential value h2 corresponding to the reference point h2. After receiving the system message, the terminal device can obtain the position coordinate corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3 from the system message according to the index g corresponding to the beam g. Then, the terminal device can determine the position coordinate of the reference point g1 according to the position coordinate corresponding to the wave position g and the differential value g1 corresponding to the reference point g1, determine the position coordinate of the reference point g2 according to the position coordinate corresponding to the wave position g and the differential value g2 corresponding to the reference point g2, and determine the position coordinate of the reference point g3 according to the position coordinate corresponding to the wave position g and the differential value g3 corresponding to the reference point g3. Then, the terminal device can calculate the distance interval between the position of the terminal device and the position coordinates of the reference points g1, g2, and g3 respectively, and can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to a distance threshold, and determine which sub-wave position corresponding to the reference point (or determine which sub-wave positions corresponding to the several reference points respectively). For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1.

[0250] It should be understood that, since the distance between the reference points in one beam cannot be too large, the above example two can make the terminal device located at the wave position determine the position coordinates of the reference points corresponding to each sub-wave position included in the wave position through differential indication by taking the position coordinate corresponding to each wave position as a reference, and can further accurately determine in which sub-wave position the terminal device is located, which helps to reduce signaling overhead.

[0251] Example three: The fourth signal can be used to indicate a second differential value corresponding to the first wave position and at least one first differential value corresponding to the first wave position.

[0252] Optionally, the related description of the at least one first differential value corresponding to the first wave position and the second differential value corresponding to the first wave position in step 601 can refer to the related description of the at least one first differential value corresponding to the first wave position and the second differential value corresponding to the first wave position in the above step 401, which will not be described here.

[0253] In a possible implementation, under the scheme provided in Example Three, the second communication device can broadcast the system messages corresponding to different wave positions respectively on corresponding beams. Each system message corresponding to a wave position can include a second differential value corresponding to the wave position and first differential values corresponding to reference points of at least one sub-wave position included in the wave position. For example, taking the satellite coverage area shown in FIG. 5b as an example, the first communication device is a terminal device, the second communication device is a satellite, and the fourth signal is a system message. As shown in FIG. 5b, the satellite can broadcast 3 first differential values corresponding to wave position g and a second differential value corresponding to wave position g on beam g, and broadcast 2 first differential values corresponding to wave position h and a second differential value corresponding to wave position h on beam h. Optionally, the related description of the second differential value corresponding to wave position g and the second differential value corresponding to wave position h in step 601 can refer to the related description of the second differential value corresponding to wave position g and the second differential value corresponding to wave position h in step 401 described above, and the related description of the 3 first differential values corresponding to wave position g and the 2 first differential values corresponding to wave position h in step 601 can refer to the related description of the 3 first differential values corresponding to wave position g and the 2 first differential values corresponding to wave position h in step 401 described above, which will not be described herein again.

[0254] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the second differential value corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3. After receiving the system message, the terminal device can obtain the second differential value corresponding to the wave position g, the differential value g1 corresponding to the reference point g1, the differential value g2 corresponding to the reference point g2, and the differential value g3 corresponding to the reference point g3 from the system message. Then, the terminal device can determine the position coordinates corresponding to the wave position g according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the second differential value corresponding to the wave position g. Next, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates corresponding to the wave position g and the differential value g1 corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates corresponding to the wave position g and the differential value g2 corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates corresponding to the wave position g and the differential value g3 corresponding to the reference point g3. Then, the terminal device can calculate the distance intervals between the positions of the terminal device and the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3, respectively, and can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to a distance threshold, and can determine which sub-wave position (or determine which several sub-wave positions) corresponds to the reference point. For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1.

[0255] In another possible implementation, under the scheme provided in Example Three, the second communication device can broadcast the same system message on different beams respectively. The same system message can include the second differential value corresponding to each wave position (such as the second differential value corresponding to the wave position g) and the first differential value corresponding to the reference point corresponding to the sub-wave position included in the wave position. For example, continuing with the satellite coverage area shown in FIG. 5b, the first communication device is the terminal device, the second communication device is the satellite, and the fourth signal is the system message. As shown in FIG. 5b, the satellite can broadcast the 3 first differential values corresponding to the wave position g, the second differential value corresponding to the wave position g, the 2 first differential values corresponding to the wave position h, and the second differential value corresponding to the wave position h as the same system message on the beam g and the beam h respectively.

[0256] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the three first difference values corresponding to the wave position g, the second difference value corresponding to the wave position g, the two first difference values corresponding to the wave position h, and the second difference value corresponding to the wave position h. After receiving the system message, the terminal device can obtain the three first difference values corresponding to the wave position g and the second difference value corresponding to the wave position h from the system message according to the index g corresponding to the beam g. Then, the terminal device can determine the position coordinates corresponding to the wave position g according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the second difference value corresponding to the wave position g. Next, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates corresponding to the wave position g and the difference value g1 corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates corresponding to the wave position g and the difference value g2 corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates corresponding to the wave position g and the difference value g3 corresponding to the reference point g3. Then, the terminal device can calculate the distance intervals between the position where the terminal device is located and the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3, respectively, and can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to a distance threshold, and determine which sub-wave position (or determine which sub-wave positions) the reference point corresponds to. For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1.

[0257] It should be understood that, since the distance between the reference points in one beam cannot be too large, the above-mentioned example three can make the terminal device determine the position coordinates corresponding to the wave position where the terminal device is located through the differential indication by taking the position coordinates of the cell reference point (such as the reference point of the serving cell where the terminal device is located) as the reference, and determine the position coordinates of the reference points corresponding to each sub-wave position included in the wave position through the differential indication by taking the position coordinates corresponding to each wave position as the reference, so as to further accurately determine which sub-wave position the terminal device is located in, which helps to reduce the signaling overhead.

[0258] Example four: The fourth signal can be used to indicate at least one third difference value corresponding to the first wave position.

[0259] Optionally, the related description of the at least one third difference value corresponding to the first wave position in step 601 can refer to the related description of the at least one third difference value corresponding to the first wave position in the above-mentioned step 401, which will not be described here again.

[0260] In a possible implementation, under the scheme provided in Example Four, the satellite can broadcast the system messages corresponding to different wave positions on the corresponding beams respectively. Each system message corresponding to a wave position can include at least one third difference value corresponding to the wave position (or can be understood as at least one third difference value corresponding to a sub-wave position included in the wave position or at least one third difference value corresponding to a reference point corresponding to a sub-wave position included in the wave position). For example, taking the first communication device as a terminal device, the second communication device as a satellite, and the fourth signal as a system message as an example. As shown in FIG. 5b, the satellite can broadcast 3 third difference values (such as a third difference value corresponding to a sub-wave position g1, a third difference value corresponding to a sub-wave position g2, and a third difference value corresponding to a sub-wave position g3) corresponding to a wave position g on a beam g, and can broadcast 2 third difference values (such as a third difference value corresponding to a sub-wave position h1 and a third difference value corresponding to a sub-wave position h2) corresponding to a wave position h on a beam h. Optionally, the related description of the third difference value corresponding to the sub-wave position g1, the third difference value corresponding to the sub-wave position g2, the third difference value corresponding to the sub-wave position g3, the third difference value corresponding to the sub-wave position h1, and the third difference value corresponding to the sub-wave position h2 in step 601 can refer to the related description of the third difference value corresponding to the sub-wave position g1, the third difference value corresponding to the sub-wave position g2, the third difference value corresponding to the sub-wave position g3, the third difference value corresponding to the sub-wave position h1, and the third difference value corresponding to the sub-wave position h2 in step 401 described above, and will not be described here.

[0261] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include the third difference value corresponding to the reference point g1, the third difference value corresponding to the reference point g2, and the third difference value corresponding to the reference point g3. After receiving the system message, the terminal device can obtain the third difference value corresponding to the reference point g1, the third difference value corresponding to the reference point g2, and the third difference value corresponding to the reference point g3 from the system message. Then, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g3. Then, the terminal device can calculate the distance interval between the position of the terminal device and the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3, respectively, and can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to a distance threshold, and can determine which sub-wave position (or determine which several sub-wave positions) corresponds to the reference point. For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1.

[0262] In another possible implementation, under the scheme provided in Example Four, the second communication device can broadcast the same system message on different beams respectively. The same system message can include the third difference value corresponding to the reference point corresponding to at least one sub-wave position corresponding to each wave position (such as the third difference value corresponding to which reference point associated with the wave position g or the third difference value corresponding to which reference point index associated with the index of the wave position g). For example, taking the satellite coverage area shown in FIG. 5b as an example, the first communication device is the terminal device, the second communication device is the satellite, and the fourth signal is the system message. As shown in FIG. 5b, the satellite can broadcast the third difference value of the reference point corresponding to at least one sub-wave position corresponding to the wave position g (such as the third difference value corresponding to the reference point g1, the third difference value corresponding to the reference point g2, and the third difference value corresponding to the reference point g3) and the third difference value of the reference point corresponding to at least one sub-wave position corresponding to the wave position h (such as the third difference value corresponding to the reference point h1 and the third difference value corresponding to the reference point h2) as the same system message on the beam g and the beam h respectively.

[0263] The terminal device located at the wave position g can receive a system message on the beam g. The system message can include a third difference value corresponding to the reference point g1 corresponding to the sub-wave position g1 included in the wave position g, a third difference value corresponding to the reference point g2 corresponding to the sub-wave position g2 included in the wave position g, a third difference value corresponding to the reference point g3 corresponding to the sub-wave position g3 included in the wave position g, a third difference value corresponding to the reference point h1 corresponding to the sub-wave position h1 included in the wave position h, and a third difference value corresponding to the reference point h2 corresponding to the sub-wave position h2 included in the wave position h. After receiving the system message, the terminal device can obtain the third difference value corresponding to the reference point g1 corresponding to the sub-wave position g1 included in the wave position g, the third difference value corresponding to the reference point g2 corresponding to the sub-wave position g2 included in the wave position g, and the third difference value corresponding to the reference point g3 corresponding to the sub-wave position g3 included in the wave position g from the system message according to the index g corresponding to the beam g. Then, the terminal device can determine the position coordinates of the reference point g1 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g1, determine the position coordinates of the reference point g2 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g2, and determine the position coordinates of the reference point g3 according to the position coordinates of the reference point of the current serving cell where the terminal device is located and the third difference value corresponding to the reference point g3. Then, the terminal device can calculate the distance interval between the position where the terminal device is located and the position coordinates of the reference point g1, the position coordinates of the reference point g2, and the position coordinates of the reference point g3, respectively, and can determine which reference point (or which several reference points) corresponds to a distance interval less than or equal to a distance threshold, and can determine which sub-wave position (or determine which sub-wave positions) corresponds to the reference point. For example, if the terminal device determines that the distance interval corresponding to the reference point g1 is less than or equal to the distance threshold, the terminal device can determine that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1.

[0264] It should be understood that, since the distance between the reference points in one beam cannot be too large, the above-mentioned example four can make the terminal device determine the position coordinates of the reference point corresponding to each sub-wave position included in the wave position where the terminal device is located through differential indication by taking the position coordinates of the cell reference point (such as the reference point of the serving cell where the terminal device is located) as a reference, so as to further accurately determine which sub-wave position the terminal device is located in, which helps to reduce the signaling overhead.

[0265] Step 602: The first communication device sends a fifth signal. Correspondingly, the second communication device receives the fifth signal.

[0266] Optionally, the fifth signal can comprise an index (or an identifier or a name or other information that can be used to identify the sub-wave position) of the first sub-wave position. The first sub-wave position is the sub-wave position where the first communication device is located. The first sub-wave position is included in the first wave position.

[0267] For example, the fifth signal can be a random access request message (or can be referred to as a random access request signal or a random access request or message 1) or an uplink scheduling message (or can be referred to as an uplink scheduling signal or message 3 (Msg3) or message 2 scheduled uplink data or message 2 scheduled uplink data) and the like. The random access request message can be sent through the PRACH. Optionally, the random access request message can comprise a random access sequence. Optionally, the random access sequence can be a random access sequence selected by the first communication device from a random access sequence set configured by the second communication device for the first communication device.

[0268] In the embodiments of the present application, after receiving the fourth signal, the first communication device can also obtain from the fourth signal which random access resources correspond to the first wave position, such as one or more random access resources (such as random access resource 1, random access resource 2, etc.) corresponding to the first wave position. In one example, in the case where the fourth signal is used to indicate the index of at least one sub-wave position included in the first wave position, after determining which sub-wave position (such as the first sub-wave position) the first communication device is located in, the first communication device can select one random access resource from the at least one random access resource corresponding to the first wave position for transmitting the fifth signal. Then, the first communication device can send the fifth signal using the selected random access resource. Optionally, the index of the first sub-wave position can be carried in the fifth signal. It should be understood that in the embodiments of the present application, the first communication device can use the selected random access resource to send the fourth signal can be replaced by "the first communication device sends the fifth signal, and the fifth signal is carried on the random access resource".

[0269] For example, taking the first signal as a system message, the first communication device as a terminal device as shown in FIG. 5b, the second communication device as a satellite as shown in FIG. 5b, the first wave position as the wave position g as shown in FIG. 5b, and the wave position g corresponding to two random access resources (for example, random access resource s1 and random access resource s2) as an example. As shown in FIG. 5b, after receiving the system message from the satellite, the terminal device can obtain the two random access resources corresponding to the wave position g from the system message. Then, after determining that the terminal device is located in the sub-wave position g1, the terminal device can select one of the two random access resources corresponding to the wave position g to transmit the fifth signal. For example, taking the terminal device selecting the random access resource 1 to transmit the fifth signal as an example, the terminal device can transmit the fifth signal using the random access resource 1. Optionally, the fifth signal can carry the index g1 of the sub-wave position g1.

[0270] In another example, in the case where the fourth signal is used to indicate that the first wave position includes at least one sub-wave position corresponding to a reference point, after determining that the first communication device is located in the sub-wave position corresponding to the reference point in the first wave position (for example, the first sub-wave position corresponding to the first reference point), the first communication device can select one of the at least one random access resource corresponding to the first wave position to transmit the fifth signal. Then, the first communication device can transmit the fifth signal using the selected random access resource. Optionally, the fifth signal can carry the index of the first sub-wave position.

[0271] For example, taking the first signal as a system message, the first communication device as a terminal device as shown in FIG. 5b, the second communication device as a satellite as shown in FIG. 5b, the first wave position as the wave position g as shown in FIG. 5b, and the wave position g corresponding to two random access resources (for example, random access resource s1 and random access resource s2) as an example. As shown in FIG. 5b, after receiving the system message from the satellite, the terminal device can obtain the two random access resources corresponding to the wave position g from the system message. Then, after determining that the terminal device is located in the sub-wave position g1 corresponding to the reference point g1, the terminal device can select one of the two random access resources corresponding to the wave position g to transmit the fifth signal. For example, taking the terminal device selecting the random access resource 1 to transmit the fifth signal as an example, the terminal device can transmit the fifth signal using the random access resource 1. Optionally, the fifth signal can carry the index g1 of the sub-wave position g1.

[0272] Step 603: The second communication device transmits the sixth signal using the sub-beam corresponding to the first sub-wave position. Correspondingly, the first communication device receives the sixth signal on the sub-beam corresponding to the first sub-wave position.

[0273] It should be understood that, in the embodiments of the present application, the second communication device sending the sixth signal using the sub-beam corresponding to the first sub-wave position can be replaced by "the second communication device sending the sixth signal, and the sixth signal is carried on the sub-beam corresponding to the first sub-wave position".

[0274] For example, the sixth signal can be a random access response message (or can be referred to as a random access response or message 2 or a random access response signal) or a radio resource control establishment response message (or can be referred to as a radio resource control establishment response signal or message 4 or a contention resolution message).

[0275] The implementation process of the second communication device sending the sixth signal using the sub-beam corresponding to the first sub-wave position will be introduced below through the following possible implementation manners.

[0276] Implementation manner one: the fifth signal is a random access request message, the sixth signal is a random access response message, and the fifth signal can carry the index of the first sub-wave position. After receiving the fifth signal, the second communication device can obtain the index of the first sub-wave position from the fifth signal. Optionally, the fifth signal can also include a random access sequence. Then, the second communication device can determine (or judge) the sub-wave position of the first communication device as the first sub-wave position according to the index of the first sub-wave position. Then, the second communication device can schedule the sub-beam corresponding to the first sub-wave position to send the sixth signal. It should be understood that the width of the sub-beam corresponding to the first sub-wave position is smaller than the width of the beam corresponding to the first wave position. Optionally, the second communication device can also schedule the sub-beam corresponding to the first sub-wave position to send other common downlink signals (such as message 4) before the first communication device accesses the network. For example, the fifth signal can carry the index of the first wave position in this implementation manner one, provided that the first communication device is allowed to carry data when sending the random access sequence.

[0277] For example, taking the first communication device as the terminal device shown in FIG. 5b, the second communication device as the satellite shown in FIG. 5b, and the first wave position as the wave position g shown in FIG. 5b, the fifth signal as a random access request message, and the sixth signal as a random access response message. Among them, the random access request message can include the index g1 of the sub-wave position g1. Optionally, the random access request message can also include a random access sequence. After receiving the random access request message, the satellite can obtain the index g1 of the sub-wave position g1 from the random access request message. Then, the satellite can determine the sub-wave position of the terminal device as the sub-wave position g1 according to the index g1 of the sub-wave position g1. Then, the satellite can schedule the sub-beam corresponding to the sub-wave position g1 to send the random access response message.

[0278] In a second implementation, the fifth signal is an uplink scheduling message, the sixth signal is a radio resource control setup response message, and the fifth signal can carry the index of the first sub-beam. After receiving the fifth signal, the second communication device can obtain the index of the first sub-beam from the fifth signal. Then, the second communication device can determine, according to the index of the first sub-beam, that the sub-beam in which the first communication device is located is the first sub-beam. Then, the second communication device can schedule the sub-beam corresponding to the first sub-beam to transmit the sixth signal. It can be understood that, in the scheme provided in the second implementation, the first communication device does not carry the index of the first sub-beam in the random access request message transmitted before the uplink scheduling message is transmitted, so that the beam used by the second communication device to transmit the random access response message is the beam corresponding to the first sub-beam. The random access request message can carry a random access sequence. For example, the precondition for the random access request message not carrying the index of the first sub-beam in the second implementation is that the first communication device is not allowed to carry data when transmitting the random access sequence.

[0279] For example, the first communication device is a terminal device as shown in FIG. 5b, the second communication device is a satellite as shown in FIG. 5b, the first sub-beam is a sub-beam g as shown in FIG. 5b, the fifth signal is an uplink scheduling message, and the sixth signal is a radio resource control setup response message. The uplink scheduling message can include an index g1 of a sub-beam g1. In the case where the terminal device is not allowed to carry data when transmitting a random access sequence, after receiving the random access request message, the satellite cannot determine the sub-beam in which the terminal device is located because the random access request message does not carry the index g1 of the sub-beam g1, so that the satellite can schedule the beam corresponding to the first sub-beam g to transmit the random access response message. The random access request message can carry a random access sequence. Then, when transmitting the uplink scheduling message, the terminal device can carry the index g1 of the sub-beam g1 in which the terminal device is located in the uplink scheduling message. After receiving the uplink scheduling message, the satellite can obtain the index g1 of the sub-beam g1 from the uplink scheduling message. Then, the satellite can determine, according to the index g1 of the sub-beam g1, that the sub-beam in which the terminal device is located is the sub-beam g1. Then, the satellite can schedule the sub-beam corresponding to the sub-beam g1 to transmit the radio resource control setup response message.

[0280] It can be understood that, in the case where the first sub-beam includes multiple sub-beams, if there are at least two sub-beams in which terminal devices initiate random access at the same time or adjacent times among the multiple sub-beams included in the first sub-beam, the satellite can schedule the random access response message in a polling manner. Alternatively, if there are at least two sub-beams in which terminal devices initiate random access at the same time or adjacent times among the multiple sub-beams included in the coverage area of the satellite, the satellite can schedule the random access response message in a polling manner.

[0281] Optionally, in order to reduce the time for the first communication device to monitor the random access response message, or the second communication device can have more delay to schedule the random access response message, the second communication device can also indicate the corresponding delay offset through the fourth signal. It should be understood that the corresponding delay offset can be flexibly determined by the second communication device on the basis of the existing random access response window of the first communication device.

[0282] For example, taking the first communication device as a terminal device, the second communication device as a satellite, the fifth signal as message 1, and the sixth signal as message 2 as an example. When the satellite cannot schedule message 2 to the corresponding terminal device (or terminal device a) in time in the case of limited beams, the satellite can configure a larger delay offset (such as offset01) for the terminal device a. In this way, the terminal device a can determine a new random access response window according to the delay offset offset01 and the existing random access response window, and can monitor the PDCCH in the new random access response window to wait for obtaining the random access response message from the satellite. Optionally, the random access response message can be carried in the message 2, or the random access response message can also be the message 2. In this way, the satellite schedules the message 2 for the terminal device a later than other terminal devices, so that the terminal device a monitors the PDCCH after the existing random access response window to obtain the corresponding random access response message, which helps to increase the flexibility of the satellite scheduling the message 2.

[0283] In the embodiment of the application, the delay offset indicated by the first signal can have a corresponding relationship with the first wave position, such as different wave positions each corresponding to a delay offset, or the delay offset indicated by the first signal can also have a corresponding relationship with the first sub-wave position, such as different sub-wave positions each corresponding to a delay offset. Then, the first communication device can receive the message 2 in the first response window after sending the message 1. The first response window can be determined by the first communication device according to the second response window (i.e. the existing response window corresponding to the first communication device, such as the existing random access response window) and the corresponding delay offset (such as the delay offset corresponding to the first wave position or the delay offset corresponding to the first sub-wave position).

[0284] The following describes the implementation process of the first communication device receiving the message 2 in the first response window through the following possible examples, taking the sixth signal as the message 2 as an example.

[0285] In the example one, when the delay offset indicated by the first signal corresponds to the primary wave position (i.e., the wave position), the first communication device can obtain the delay offset corresponding to the first wave position from the fourth signal after receiving the fourth signal. Then, the first communication device can determine the first response window according to the second response window and the delay offset corresponding to the first wave position. Then, the first communication device can receive the message 2 in the first response window.

[0286] For example, the first communication device is a terminal device, the second communication device is a satellite, the fourth signal is a system message, the second response window is [T1, T2], and the delay offset offset2 corresponding to the first wave position (e.g., the wave position f in FIG. 5a or the wave position g in FIG. 5b) is taken as an example. After the terminal device receives the system message from the satellite in the beam corresponding to the first wave position, the terminal device can obtain the delay offset offset2 corresponding to the first wave position from the system message, and can determine the first response window as [T1+offset01’, T2+offset01’] according to the second response window [T1, T2] and the delay offset offset01’ corresponding to the first wave position. Then, the terminal device can monitor the PDCCH in the first response window [T1+offset01’, T2+offset01’] to obtain the message 2. Optionally, the message 2 can carry a random access response message.

[0287] In the implementation of the present application, the second communication device can determine the delay offset corresponding to each wave position according to the current service condition. It can be understood that the related description about the second communication device determining the delay offset corresponding to each wave position according to the current service condition in step 603 can refer to the related description about the second communication device determining the delay offset corresponding to each wave position according to the current service condition in step 403, which will not be described here.

[0288] In the example two, when the delay offset indicated by the first signal corresponds to the secondary wave position (i.e., the sub-wave position), the first communication device can obtain the delay offset corresponding to at least one sub-wave position included in the first wave position from the fourth signal after receiving the fourth signal, and can determine the delay offset corresponding to the first sub-wave position from the delay offsets corresponding to the at least one sub-wave position according to the first sub-wave position in which the first communication device is located. Then, the first communication device can determine the third response window according to the second response window and the delay offset corresponding to the first sub-wave position, and the third response window can be used as the first response window. Then, the first communication device can receive the message 2 in the first response window.

[0289] For example, taking the first communication device as a terminal device, the second communication device as a satellite, the fourth signal as a system message, the second response window as [T1, T2], and the delay offset offset02 corresponding to the first sub-beam (such as the beam f shown in FIG. 5a or the beam g shown in FIG. 5b) as an example, after the terminal device receives the system message from the satellite on the beam corresponding to the first sub-beam, the terminal device can obtain the delay offset offset02 corresponding to the first sub-beam from the system message, and can determine the fourth response window as [T1+offset02, T2+offset02] according to the second response window [T1, T2] and the delay offset offset02 corresponding to the first sub-beam, and the fourth response window [T1+offset02, T2+offset02] can be used as the first response window. Then, the terminal device can monitor the PDCCH in the fourth response window [T1+offset02, T2+offset02] to obtain message 2. Optionally, the message 2 can carry a random access response message.

[0290] In the embodiment of the present application, the second communication device can determine the delay offset corresponding to each sub-beam according to the current service situation. It can be understood that the related description about the second communication device determining the delay offset corresponding to each sub-beam according to the current service situation in step 603 can refer to the related description about the second communication device determining the delay offset corresponding to each sub-beam according to the current service situation in step 403 described above, which will not be repeated here.

[0291] As can be seen from the above steps 601 to 603, the first communication device carries the index of the sub-beam (such as the first sub-beam) in the reported signal (such as the fifth signal), so that the second communication device can timely and accurately know which sub-beam (such as the first sub-beam) the first communication device is located in, so that the second communication device can timely and effectively schedule the sub-beam corresponding to the sub-beam to transmit the subsequent common downlink signal (such as the sixth signal), thereby helping to improve the link budget of the common downlink signal. It can be understood that since the second communication device uses the sub-beam corresponding to the first sub-beam with a width smaller than that of the beam corresponding to the first beam when transmitting the common downlink signal before the first communication device accesses the network, the link budget of the common downlink signal can be improved. In addition, compared with the communication method shown in FIG. 4, this method does not need to group the random access resources corresponding to the first beam, so it will not affect the flexible allocation of the random access resources.

[0292] It should be noted that in the description of the present application, "at least one" means one or more, and "multiple" means two or more. The association relationship of "and / or" describes the associated objects, which means that there can be three relationships, for example, A and / or B can represent the cases of A alone, A and B together, and B alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. In addition, unless otherwise specified, the ordinal numbers "first", "second", "third" and the like mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the order, time sequence, priority or importance of the plurality of objects. In addition, the terms "include", "contain", "have" and their variants appearing in the present application mean "including but not limited to", unless otherwise specifically emphasized.

[0293] In addition, it should be noted that each step involved in the above various embodiments can be executed by the corresponding device, or by the components such as chips, processors or chip systems within the device, and the embodiments of the present application do not constitute any limitation.

[0294] It should be understood that in various embodiments of the present application, the size of the sequence number of the above processes does not mean the order of execution, and the execution order of the processes should be determined by their functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0295] It should be noted that in the above various embodiments, some steps can be selected for implementation, and the order of steps in the diagram can be adjusted for implementation, which is not limited in the present application. It should be understood that the implementation of part of the steps in the diagram, the adjustment of the order of the steps or the combination of the steps fall within the protection scope of the present application.

[0296] It can be understood that in order to realize the functions in the above embodiments, each device involved in the above embodiments includes corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that the units and method steps of each example described in combination with the embodiments disclosed in the present application can be realized in the form of hardware or hardware and computer software. Whether a certain function is executed by hardware or computer software driven hardware depends on the specific application scenario and design constraints of the technical solution.

[0297] It should be understood that the "step" in the embodiments of the present application is only a demonstration, which is a kind of expression method adopted for better understanding the embodiments, and does not constitute a substantial limitation on the execution of the scheme of the present application. For example, the "step" can also be understood as a "feature". In addition, the step does not constitute any limitation on the execution order of the scheme of the present application. Any step order change, step merging or step splitting operation made on this basis without affecting the overall scheme implementation, the new technical scheme formed is also within the scope disclosed by the present application.

[0298] The following is a possible structure schematic diagram of a communication apparatus provided by the embodiments of the present application. These communication apparatuses can be used to realize the functions of the first communication apparatus or the second communication apparatus in the above-mentioned method embodiments, and thus can also realize the beneficial effects possessed by the above-mentioned method embodiments.

[0299] As shown in FIG. 7, the communication apparatus 700 includes a transceiver module 701 (or can be referred to as a communication module or a transceiver unit or a communication unit, which is used to send and receive data) and a processing module 702 (or can be referred to as a processing unit). The communication apparatus 700 can be used to realize the functions of the first communication apparatus or the second communication apparatus in the above-mentioned method embodiments shown in FIG. 4, and can also be used to realize the functions of the first communication apparatus or the second communication apparatus in the above-mentioned method embodiments shown in FIG. 6.

[0300] Optionally, the transceiver module 701 can include a receiving module and / or a sending module. The receiving module can be used for the communication apparatus 700 to receive signals (information or data, etc.); the sending module can be used for the communication apparatus 700 to send signals (information or data, etc.). The sending module can send signals (information or data, etc.) under the control of the processing module 702, and the receiving module can receive signals (information or data, etc.) under the control of the processing module 702.

[0301] When the communication apparatus 700 is used to realize the functions of the first communication apparatus (such as a terminal device) in the above-mentioned method embodiments shown in FIG. 4: the transceiver module 701 is configured to receive a first signal on a beam corresponding to a first wave position. The first signal can be used to indicate at least one sub-wave position, and the at least one sub-wave position can be included in the first wave position. The at least one sub-wave position can correspond to a first group of random access resources. The transceiver module 701 is further configured to send a second signal using a first sub-wave position corresponding to the first group of random access resources. The first sub-wave position is a sub-wave position where the first communication apparatus is located. The transceiver module 701 is further configured to receive a third signal on a sub-beam corresponding to the first sub-wave position. The processing module 702 is configured to perform corresponding processing operations, such as grouping random access resources corresponding to the first wave position, etc.

[0302] When the communication apparatus 700 is configured to implement the functions of the second communication apparatus (such as a satellite) in the method embodiment shown in FIG. 4: the transceiver module 701 is configured to transmit a first signal using a beam corresponding to a first wave position. The first signal can be used to indicate at least one sub-wave position, the at least one sub-wave position can be included in the first wave position, and the at least one sub-wave position can correspond to a group of random access resources respectively. The transceiver module 701 is further configured to receive a second signal. The second signal is carried on the first group of random access resources. The transceiver module 701 is further configured to transmit a third signal using a sub-beam corresponding to a first sub-wave position. The first sub-wave position corresponds to the first group of random access resources. The processing module 702 is configured to perform corresponding processing operations, such as being configured to configure a corresponding delay offset for each wave position or being configured to configure a corresponding delay offset for each sub-wave position, etc.

[0303] When the communication apparatus 700 is configured to implement the functions of the first communication apparatus (such as a terminal device) in the method embodiment shown in FIG. 6: the transceiver module 701 is configured to receive a fourth signal on a beam corresponding to a first wave position. The transceiver module 701 is further configured to transmit a fifth signal. The fifth signal can include an index of a first sub-wave position, the first sub-wave position is a sub-wave position where the first communication apparatus is located, and the first sub-wave position can be included in the first wave position. The transceiver module 701 is further configured to receive a sixth signal on a sub-beam corresponding to the first sub-wave position. The processing module 702 is configured to perform corresponding processing operations, such as being configured to determine which sub-wave position the first communication apparatus is located in (or which sub-wave position the first communication apparatus is located in), etc.

[0304] When the communication apparatus 700 is configured to implement the functions of the second communication apparatus (such as a satellite) in the method embodiment shown in FIG. 6: the transceiver module 701 is configured to transmit a fourth signal using a beam corresponding to a first wave position. The transceiver module 701 is further configured to receive a fifth signal. The fifth signal can include an index of a first sub-wave position, and the first sub-wave position can be included in the first wave position. The transceiver module 701 is further configured to transmit a sixth signal using a sub-beam corresponding to the first sub-wave position. The processing module 702 is configured to perform corresponding processing operations, such as being configured to configure a corresponding delay offset for each wave position or being configured to configure a corresponding delay offset for each sub-wave position, etc.

[0305] Further details of the transceiver module 701 and the processing module 702 can be found in the above description of the method embodiments shown in FIG. 4 or FIG. 6, which will not be repeated here.

[0306] It should be understood that the transceiver module 701 in the embodiments of the present application can be implemented by a communication interface or a communication interface related circuit component, and the processing module 702 can be implemented by a processor or a processor related circuit component.

[0307] It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. Actual implementation can have another division manner. In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or can be physically separated, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware, or in the form of a software function unit.

[0308] If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or the like) or a processor to perform all or part of the steps of the methods in the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and various program codes that can be stored in the medium.

[0309] As another possible product form, as shown in FIG. 8, the communication device 800 includes a communication interface 801, a processor 802. Optionally, the communication device 800 further includes a memory 803. The communication interface 801, the processor 802 and the memory 803 are connected with each other. When the communication device 800 is used to implement the technical solutions related to the first communication device (such as a terminal device) or the second communication device (such as a satellite) in the above embodiments, the communication interface 801 can be used to implement the functions of the above-mentioned transceiver module 801 when the first communication device (or the second communication device) is executed. The processor 802 is configured to implement the functions of the above-mentioned processing module 802 when the first communication device (or the second communication device) is executed.

[0310] Optionally, the communication interface 801, the processor 802 and the memory 803 are connected with each other through the bus 804. The bus 804 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, only one thick line is used in FIG. 8, but it does not mean that there is only one bus or only one type of bus.

[0311] The communication interface 801 is configured to receive and send data. For example, when the communication apparatus 800 is the terminal device 201 as shown in FIG. 2, the communication interface 801 can be configured to communicate with the network device 210 as shown in FIG. 2, or can be configured to communicate with the terminal device 205 as shown in FIG. 2, or can be configured to communicate with other devices (such as other terminal devices or servers) other than the communication system architecture as shown in FIG. 2. For another example, when the communication apparatus 800 is the terminal device 1 as shown in FIG. 3, the communication interface 801 can be configured to communicate with the satellite 1 as shown in FIG. 3, or can be configured to communicate with the ground station as shown in FIG. 3, or can be configured to communicate with other devices (such as other terminal devices or servers) other than the communication system architecture as shown in FIG. 3. In one example, the communication interface can be a transceiver device integrated with data transceiving function. In another example, the communication interface can also be composed of a transmitter and a receiver, wherein the transmitter is configured to send data, and the receiver is configured to receive data.

[0312] Optionally, the communication interface 801 can include a transmitter and / or a receiver. The transmitter is configured to send signals, messages, information or data, etc. The receiver is configured to receive signals, messages, information or data, etc. Exemplarily, the transmitter sends signals, messages, information or data, etc. under the control of the processor 802. The receiver receives signals, messages, information or data, etc. under the control of the processor 802.

[0313] The functions of the processor 802 can refer to the descriptions of the corresponding functions of the first communication device or the second communication device in the above embodiments, and will not be described here. The processor 802 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP, and the like. The processor 802 can further include a hardware chip. The hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The processor 802 can be implemented by hardware, and of course, the corresponding software can be executed by hardware.

[0314] The memory 803 is configured to store program instructions and the like. Specifically, the program instructions can include program codes including computer operation instructions. The memory 803 can include a random access memory (RAM) and can also include a non-volatile memory such as at least one disk memory. The processor 802 executes the program instructions stored in the memory 803 to implement the above functions, thereby implementing the method steps required to be executed by the first communication device or the second communication device in the above embodiments.

[0315] Based on the same idea, the embodiments of the present application also provide a possible communication system. The communication system can include a first communication device (such as a terminal device) and a second communication device (such as a satellite). The first communication device can be used to implement the technical solutions related to the first communication device in the above embodiments, and the second communication device can be used to implement the technical solutions related to the second communication device in the above embodiments.

[0316] Based on the same idea, the embodiments of the present application also provide a computer program product, which includes a computer program or instructions, and when the computer program or instructions run on a communication device (or a computer), the communication device (or the computer) executes the method provided in the above embodiments.

[0317] Based on the same idea, the embodiments of the present application further provide a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed by a communication device (or a computer), the communication device (or the computer) executes the method provided by the above embodiments.

[0318] The storage medium can be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a computer.

[0319] Based on the same idea, the embodiments of the present application further provide a chip, which can include a processor, and can further include a memory (or the chip is coupled with the memory), the processor executes program instructions in the memory, so that the chip executes the method provided by the above embodiments. Wherein, "coupled" means that two components are directly or indirectly combined with each other, such as the coupling can mean that the two components are electrically connected.

[0320] Based on the same idea, the embodiments of the present application further provide a chip system, which includes a processor, and is used to support a computer device to realize the functions related to the first communication device or the second communication device in the above embodiments. In a possible implementation manner, the chip system further includes a memory, and the memory is used to save necessary programs and data of the computer device. The chip system can be composed of a chip, or can include the chip and other discrete devices.

[0321] The method provided by the embodiments of the present application can be implemented by software, hardware, firmware or any combination thereof, in whole or in part. When implemented by software, the method can be implemented in the form of a computer program product, in whole or in part. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another, for example, the computer instructions can be transferred from one website, computer, server or data center to another via wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a high-density digital video disc (DVD)), or a semiconductor medium (such as a solid state drive (SSD)), etc.

[0322] The steps of the method described in the embodiments of the present application can be directly embedded in hardware, a software unit executed by a processor, or a combination of the two. The software unit can be stored in a RAM, a ROM, an EEPROM, a register, a hard disk, a removable disk, a CD-ROM or any other form of storage medium in the art. Illustratively, the storage medium can be connected to the processor so that the processor can read information from the storage medium and can store information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and the storage medium can be arranged in an ASIC.

[0323] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks or in conjunction with the flowchart block or blocks.

[0324] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks or in conjunction with the flowchart block or blocks.

[0325] It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application cover the modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

Claims

1. A communication method, characterized in that: Applied to a first communication device, the method includes: receiving a first signal on a beam corresponding to a first wavelet, where the first signal is used to indicate at least one wavelet, the at least one wavelet being included in the first wavelet, and each of the at least one wavelet corresponding to a group of random access resources; sending a second signal using a first group of random access resources corresponding to a first wavelet, where the first wavelet is the wavelet where the first communication device is located; A third signal is received on the sub-beam corresponding to the first sub-wavelength.

2. The method according to claim 1, wherein The first signal is used to indicate an index of the at least one wavelet, or the first signal is used to indicate a reference point corresponding to the at least one wavelet.

3. The method according to claim 2, wherein The first signal is used to indicate one of the following: The position coordinates of the reference point corresponding to the at least one wavelet; or The position coordinates corresponding to the first wave position and at least one first differential value, wherein the at least one first differential value is a differential value between the position coordinates of the reference point corresponding to the at least one sub-wave position and the position coordinates corresponding to the first wave position; or a second differential value and the at least one first differential value, the second differential value being a differential value between the position coordinates corresponding to the first wave position and the position coordinates of a reference point of a first cell, the first cell being a current serving cell; or At least one third differential value, where the at least one third differential value is a differential value between the position coordinates of a reference point corresponding to the at least one wavelet and the position coordinates of a reference point of the first cell.

4. The method according to any one of claims 1 to 3, wherein A group of random access resources corresponding to the at least one sub-wavelength position is included in the random access resources corresponding to the first wavelength position.

5. The method according to any one of claims 1 to 3, wherein A group of random access resources corresponding to each of the at least one wavelet bit is determined according to the first signal.

6. The method according to any one of claims 1 to 3, wherein: A group of random access resources corresponding to each of the at least one wavelet is determined according to the number of the at least one wavelet indicated by the first signal.

7. The method according to any one of claims 1 to 6, wherein: The first signal is further used to indicate at least one delay offset, where the at least one delay offset corresponds to the first wave position, or the at least one delay offset corresponds one-to-one to the at least one sub-wave position; The receiving the third signal includes: The third signal is received within a first response window, where the first response window is determined based on a second response window and a delay offset corresponding to the first wave position, or the first response window is determined based on a delay offset corresponding to the second response window and the first sub-wave position.

8. The method according to any one of claims 1 to 7, wherein: The first signal is a system message, the second signal is a random access request message, and the third signal is a random access response message.

9. A communication method, characterized in that: Applied to a second communication device, the method includes: Sending a first signal using a beam corresponding to a first wavelet, where the first signal is used to indicate at least one wavelet, the at least one wavelet being included in the first wavelet, and each of the at least one wavelet corresponding to a group of random access resources; receiving a second signal, where the second signal is carried on a first set of random access resources; A third signal is sent using a sub-beam corresponding to a first sub-wavelength position, where the first sub-wavelength position corresponds to the first group of random access resources.

10. The method according to claim 9, wherein The first signal is used to indicate an index of the at least one wavelet, or the first signal is used to indicate a reference point corresponding to the at least one wavelet.

11. The method according to claim 10, wherein: The first signal is used to indicate one of the following: The position coordinates of the reference point corresponding to the at least one wavelet; or The position coordinates corresponding to the first wave position and at least one first differential value, wherein the at least one first differential value is a differential value between the position coordinates of the reference point corresponding to the at least one sub-wave position and the position coordinates corresponding to the first wave position; or a second differential value and the at least one first differential value, the second differential value being a differential value between the position coordinates corresponding to the first wave position and the position coordinates of a reference point of a first cell, the first cell being a current serving cell; or At least one third differential value, where the at least one third differential value is a differential value between the position coordinates of a reference point corresponding to the at least one wavelet and the position coordinates of a reference point of the first cell.

12. The method according to claim 11, wherein The first signal is further used to indicate at least one delay offset, where the at least one delay offset corresponds to the first wave position, or the at least one delay offset corresponds one-to-one to the at least one sub-wave position.

13. The method according to claim 12, wherein: The method further comprises: Determine the delay offset corresponding to the first wave position according to the current service situation; or Determine the delay offset corresponding to each of the at least one wavelet positions according to the current service situation.

14. The method according to any one of claims 9 to 13, wherein: The first signal is a system message, the second signal is a random access request message, and the third signal is a random access response message.

15. A communication method, characterized in that: Applied to a first communication device, the method includes: receiving a fourth signal on a beam corresponding to the first wave position; Sending a fifth signal, where the fifth signal includes an index of a first wavelet, where the first wavelet is a wavelet where the first communication device is located, and the first wavelet is included in the first wavelet; A sixth signal is received on the sub-beam corresponding to the first sub-wavelength position.

16. The method according to claim 15, wherein The fourth signal is used to indicate an index of the at least one wavelet, or the fourth signal is used to indicate a reference point corresponding to the at least one wavelet.

17. The method according to claim 16, wherein The fourth signal is used to indicate one of the following: The position coordinates of the reference point corresponding to the at least one wavelet; or The position coordinates corresponding to the first wave position and at least one first differential value, wherein the at least one first differential value is a differential value between the position coordinates of the reference point corresponding to the at least one sub-wave position and the position coordinates corresponding to the first wave position; or a second differential value and the at least one first differential value, the second differential value being a differential value between the position coordinates corresponding to the first wave position and the position coordinates of a reference point of a first cell, the first cell being a current serving cell; or At least one third differential value, where the at least one third differential value is a differential value between the position coordinates of a reference point corresponding to the at least one wavelet and the position coordinates of a reference point of the first cell.

18. The method according to claim 17, wherein The fourth signal is further used to indicate at least one delay offset, where the at least one delay offset corresponds to the first wave position, or the at least one delay offset corresponds one-to-one to the at least one sub-wave position; The receiving the sixth signal includes: The sixth signal is received within a first response window, where the first response window is determined based on a second response window and a delay offset corresponding to the first wave position, or the first response window is determined based on a delay offset corresponding to the second response window and the first sub-wave position.

19. The method according to any one of claims 15 to 18, wherein: The fourth signal is a system message; The fifth signal is a random access request message, and the sixth signal is a random access response message, or the fifth signal is an uplink scheduling message, and the sixth signal is a radio resource control establishment response message.

20. A communication method, characterized in that: Applied to a second communication device, the method includes: Sending a fourth signal using the beam corresponding to the first wave position; receiving a fifth signal, the fifth signal including an index of a first wavelet, the first wavelet being included in the first wavelet; A sixth signal is sent using the sub-beam corresponding to the first sub-wavelength.

21. The method according to claim 20, wherein The fourth signal is used to indicate an index of the at least one wavelet, or the fourth signal is used to indicate a reference point corresponding to the at least one wavelet.

22. The method according to claim 21, wherein The fourth signal is used to indicate one of the following: The position coordinates of the reference point corresponding to the at least one wavelet; or The position coordinates corresponding to the first wave position and at least one first differential value, wherein the at least one first differential value is a differential value between the position coordinates of the reference point corresponding to the at least one sub-wave position and the position coordinates corresponding to the first wave position; or a second differential value and the at least one first differential value, the second differential value being a differential value between the position coordinates corresponding to the first wave position and the position coordinates of a reference point of a first cell, the first cell being a current serving cell; or At least one third differential value, where the at least one third differential value is a differential value between the position coordinates of a reference point corresponding to the at least one wavelet and the position coordinates of a reference point of the first cell.

23. The method according to claim 22, wherein The fourth signal is further used to indicate at least one delay offset, where the at least one delay offset corresponds to the first wave position, or the at least one delay offset corresponds one-to-one to the at least one sub-wave position.

24. The method according to claim 23, wherein The method further comprises: Determine the delay offset corresponding to the first wave position according to the current service situation; or Determine the delay offset corresponding to each of the at least one wavelet positions according to the current service situation.

25. The method according to any one of claims 20 to 24, wherein: The fourth signal is a system message; The fifth signal is a random access request message, and the sixth signal is a random access response message, or the fifth signal is an uplink scheduling message, and the sixth signal is a radio resource control establishment response message.

26. A communication device, characterized in that: The method comprises a module or unit for executing the method according to any one of claims 1 to 8, or a module or unit for executing the method according to any one of claims 9 to 14, or a module or unit for executing the method according to any one of claims 15 to 19, or a module or unit for executing the method according to any one of claims 20 to 25.

27. A communication device, characterized in that: include: transceiver, used to receive and send data; Memory for storing computer program instructions and data; A processor, configured to execute and call computer program instructions and data in the memory to cause the communication device to perform the method according to any one of claims 1 to 8, or the method according to any one of claims 9 to 14, or the method according to any one of claims 15 to 19, or the method according to any one of claims 20 to 25.

28. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program or instructions. When the computer program or instructions are executed by the communication device, the communication device executes the method according to any one of claims 1 to 8, the method according to any one of claims 9 to 14, the method according to any one of claims 15 to 19, or the method according to any one of claims 20 to 25.

29. A computer program product, characterized in that The computer program product comprises a computer program or instructions, which, when executed on a communication device, causes the communication device to perform the method according to any one of claims 1 to 8, or the method according to any one of claims 9 to 14, or the method according to any one of claims 15 to 19, or the method according to any one of claims 20 to 25.

30. A chip, characterized in that: The chip includes a processor, which is coupled to a memory, and the processor is used to execute program instructions stored in the memory so that the chip performs the method as described in any one of claims 1-8, or the method as described in any one of claims 9-14, or the method as described in any one of claims 15-19, or the method as described in any one of claims 20-25.

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