Satellite multiple access method, device and electronic equipment

Abstract

The application discloses a satellite multiple access method and device and electronic equipment. The method comprises the following steps: receiving a first downlink broadcast signal from a satellite, wherein the first downlink broadcast signal comprises time-frequency resource information and first position information of the satellite; obtaining codebook mapping information corresponding to the satellite; generating an access request based on the first position information, second position information of a user terminal and the codebook mapping information; and sending the access request to the satellite on target time-frequency resources determined based on the time-frequency resource information. Through the above method, the time-frequency resource utilization rate can be improved, and based on the codebook mapping information and the position of the user terminal, different code words or power levels can be used on the same time-frequency resources, thereby improving the spectrum utilization rate, increasing the system capacity and realizing access of a large number of terminals. In addition, the user terminal does not need to interact with the satellite when accessing the satellite, and real-time and efficient access of the terminal can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of satellite communication, and particularly relates to a satellite multiple access method and device and electronic equipment. BACKGROUND

[0002] The existing satellite Internet of Things access technology mainly includes orthogonal time-frequency resource allocation and non-orthogonal multiple access. The orthogonal allocation mechanism relies on the static division of time-frequency resources, and allocates resources to each terminal to avoid collision, but when the terminal scale surges, it is difficult for the fixed resource block to dynamically adapt to the sparsity and burstiness of the business, and the resource utilization rate is low. Although non-orthogonal multiple access can break through the orthogonal resource capacity limit to a certain extent, when a large number of user terminals compete for access, the orthogonal resource allocation efficiency deteriorates sharply, and the mutual information of non-orthogonal access quickly approaches the saturation point, the interference increases, the bit error rate presents a platform effect, and the dynamic adaptation fails, which requires frequent scheduling of user terminals.

[0003] At present, there is no effective solution to the problem of low time-frequency resource utilization and inability to realize efficient terminal access. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a satellite multiple access method, device and electronic equipment, which can improve the time-frequency resource utilization efficiency, reduce the terminal access scheduling requirement, realize efficient terminal access, and improve the system capacity.

[0005] The first aspect of the present application provides a satellite multiple access method applied to a user terminal, comprising:

[0006] receiving a first downlink broadcast signal from a satellite, wherein the first downlink broadcast signal comprises time-frequency resource information and first position information of the satellite;

[0007] obtaining codebook mapping information corresponding to the satellite, and generating an access request based on the first position information, second position information of the user terminal and the codebook mapping information;

[0008] sending the access request to the satellite on target time-frequency resources determined based on the time-frequency resource information.

[0009] In some embodiments of the present application, the codebook mapping information is stored in the user terminal, and the codebook mapping information comprises a codebook library of the satellite and codebook position mapping information, wherein the codebook position mapping information is used to represent the mapping relationship between each position in the beam coverage area of the satellite and the code word of the spread spectrum codebook in the codebook library.

[0010] In some embodiments of the present application, the codebook mapping information comprises a codebook library of the satellite and a codebook mapping matrix, a row index in the codebook mapping matrix corresponds to a position in a beam coverage area of the satellite, and a column index in the codebook mapping matrix corresponds to a code word of a spreading codebook in the codebook library.

[0011] In some embodiments of the present application, based on the first position information, second position information of the user terminal, and the codebook mapping information, an access request is generated, comprising:

[0012] Based on the first position information and the second position information, a target position of the user terminal in a beam coverage area of the satellite is determined.

[0013] Based on the target position and the codebook mapping information, a target code word corresponding to the user terminal is determined.

[0014] The access request is generated based on the target code word.

[0015] In some embodiments of the present application, the first position information is a sub-satellite point position information of the satellite, and based on the first position information and the second position information, a target position of the user terminal in a beam coverage area of the satellite is determined, comprising:

[0016] Based on the second position information and the sub-satellite point position information, a distance from the user terminal to a sub-satellite point of the satellite is determined.

[0017] Based on the distance, a target circle layer of the user terminal in a plurality of power circle layers corresponding to the satellite is determined as the target position, the plurality of power circle layers being divided based on powers of signals from positions in the beam coverage area reaching the satellite.

[0018] In some embodiments of the present application, based on the target position and the codebook mapping information, a target code word corresponding to the user terminal is determined, comprising:

[0019] A target codebook set corresponding to the target circle layer is determined in the codebook mapping information, and the target codebook set comprises a plurality of candidate code words.

[0020] A candidate code word is randomly selected from the plurality of candidate code words as the target code word.

[0021] In some embodiments of the present application, the access request is generated based on the target code word, comprising:

[0022] A first request is generated, and a symbol in the first request is spread based on the target code word, to obtain the access request.

[0023] In some embodiments of the present application, the time-frequency resource information comprises a plurality of time-frequency resource sub-regions and an Internet of Things service type corresponding to each time-frequency resource sub-region.

[0024] In some embodiments of the present application, the Internet of Things service type is obtained by classifying the Internet of Things service based on a priority of the Internet of Things service and an encoding rate.

[0025] In some embodiments of the present application, the target time-frequency resource is determined by:

[0026] determining a target service type of the Internet of Things service to which the user terminal accesses based on attribute information of the user terminal and / or uplink service data to be transmitted by the user terminal;

[0027] determining the target time-frequency resource in time-frequency resources corresponding to a plurality of time-frequency resource sub-regions based on the plurality of time-frequency resource sub-regions included in the time-frequency resource information, the Internet of Things service type corresponding to each time-frequency resource sub-region, and the target service type.

[0028] In some embodiments of the present application, the target time-frequency resource is located on at least one time-frequency resource sub-region of the plurality of time-frequency resource sub-regions.

[0029] In some embodiments of the present application, the codebook mapping information is determined by:

[0030] constructing an optimization model, the optimization model taking maximum of system transmission and capacity in a beam coverage area of the satellite as a target, and taking an initial codebook of the satellite, the beam coverage area, and a received power corresponding to a signal transmitted at each position in the beam coverage area as a constraint condition;

[0031] optimizing and solving the optimization model to obtain the codebook mapping information, the codebook mapping information comprising a target number of power circle layers, a boundary radius of each power circle layer, and a codebook set corresponding to each power circle layer.

[0032] In some embodiments of the present application, a difference in received power of signals transmitted by the user terminal at each position in a same power circle layer to the satellite satisfies a first power interval, and a difference in received power of signals transmitted by the user terminal in different power circle layers to the satellite satisfies a second power interval.

[0033] In some embodiments of the present application, the optimization model is represented by the following formula:

[0034] ;

[0035] wherein Q represents the target number, and N represents a code word number of the initial codebook. denotes the average received power in the qth power circle layer, N q denotes the number of user terminals in the qth power circle layer, r q denotes the boundary radius of the qth power circle layer, PL(d) denotes the path loss of the signal transmitted by the user terminal with a distance of d from the subsatellite point of the satellite to the satellite, P1 denotes a first power threshold corresponding to the difference in received power of the signals transmitted by the user terminal at different positions in the same power circle layer to the satellite, and P2 denotes a second power threshold corresponding to the difference in received power of the signals transmitted by the user terminal in different power circle layers to the satellite; denotes the distance from the center point of the qth power circle layer to the subsatellite point of the satellite, denotes the distance from the center point of the qth+1 power circle layer to the subsatellite point of the satellite, A q,m denotes the mth code word index corresponding to the qth power circle layer, and R denotes the radius of the beam coverage area, denotes the noise power, denotes the codebook set cross-correlation strength in the qth power circle layer.

[0036] In some embodiments of the present application, the optimization model is optimized and solved to obtain the codebook mapping information, including:

[0037] A deep reinforcement model is constructed, and a state space, an action space, a policy network, a value network, and an optimization target of the deep reinforcement model are determined based on the optimization model. A policy function of codebook allocation is arranged in the policy network, and a reward function is arranged in the value network;

[0038] Parameters in the policy network and the value network are optimized based on the optimization target, the policy function, and the reward function until system and capacity convergence or a preset training number is reached, and the codebook mapping information is obtained.

[0039] In some embodiments of the present application, the policy function is represented by the following formula:

[0040] ;

[0041] wherein τ q denotes a preset adaptive threshold corresponding to the qth power circle layer, z m denotes the weight of the mth code word corresponding to the power circle layer, A q,m denotes the mth code word corresponding to the qth power circle layer.

[0042] In some embodiments of the present application, the reward function is represented by the following formula:

[0043] ;

[0044] ;

[0045] ;

[0046] ;

[0047] wherein r(s, a) represents a reward, Viol intra represents a first penalty term, Viol inter represents a second penalty term, C sum represents a sum capacity of the system, λ1 and λ2 represent weight coefficients of the first penalty term and the second penalty term respectively, PL max,q represents a maximum power loss corresponding to a signal transmitted by the user terminal at each position in the qth power circle layer, PL min,q represents a minimum power loss corresponding to a signal transmitted by the user terminal at each position in the qth power circle layer, represents a constraint on a difference in received power of signals transmitted by the user terminal at different power circle layers at the satellite, represents a constraint on a difference in received power of signals transmitted by the user terminal at each position in the same power circle layer at the satellite.

[0048] The second aspect of the present application further provides a satellite multiple access method, applied to a satellite, comprising:

[0049] sending a first downlink broadcast signal to a user terminal, wherein the first downlink broadcast signal comprises time-frequency resource information and first position information of the satellite;

[0050] receiving an access request sent by the user terminal, wherein the access request is generated based on the first position information, second position information of the user terminal and codebook mapping information corresponding to the satellite obtained by the user terminal after receiving the first downlink broadcast signal.

[0051] The third aspect of the present application further provides a satellite multiple access device, applied to a user terminal, comprising:

[0052] a receiving module, configured to receive a first downlink broadcast signal from a satellite, wherein the first downlink broadcast signal comprises time-frequency resource information and first position information of the satellite;

[0053] a generating module, configured to obtain codebook mapping information corresponding to the satellite, and generate an access request based on the first position information, second position information of the user terminal and the codebook mapping information;

[0054] The sending module is configured to send the access request to the satellite at a target time-frequency resource determined based on the time-frequency resource information.

[0055] The fourth aspect of the present application further provides a satellite multiple access device, applied to a satellite, comprising:

[0056] The sending module is configured to send a first downlink broadcast signal to the user terminal, wherein the first downlink broadcast signal comprises the time-frequency resource information and the first position information of the satellite.

[0057] The receiving module is configured to receive an access request sent by the user terminal, wherein the access request is generated based on the first position information, the second position information of the user terminal and the codebook mapping information of the satellite obtained by the user terminal after receiving the first downlink broadcast signal.

[0058] The fifth aspect of the present application provides an electronic device, comprising a processor and a memory for storing processor-executable instructions, wherein the processor executes the instructions to implement the steps of the method of the first aspect.

[0059] The sixth aspect of the present application provides a computer storage medium, which stores computer program instructions, wherein the computer program instructions are executed by a processor to implement the steps of the method of the first aspect.

[0060] The seventh aspect of the present application provides a computer program product, comprising a computer program, wherein the computer program is executed by a processor to implement the steps of the method of the first aspect.

[0061] The satellite multiple access method, device and electronic device in the embodiments of the present application can receive a first downlink broadcast signal from a satellite, wherein the first downlink broadcast signal comprises time-frequency resource information and first position information of the satellite; obtain codebook mapping information corresponding to the satellite, and generate an access request based on the first position information, the second position information of the user terminal and the codebook mapping information; and send the access request to the satellite at a target time-frequency resource determined based on the time-frequency resource information. Through the above method, the time-frequency resource utilization rate can be improved, and based on the codebook mapping information and the position of the user terminal, different code words or power levels can be used on the same time-frequency resource, thereby improving the spectrum utilization rate, increasing the system capacity and realizing access of a large number of terminals. In addition, the user terminal does not need to perform network interaction with the satellite when accessing the satellite, and real-time and efficient access of the terminal can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0063] Figure 1 A schematic diagram of a satellite multiple access method provided by an embodiment of the present specification is shown.

[0064] Figure 2 A schematic diagram of a satellite multiple access scenario provided by an embodiment of the present specification is shown.

[0065] Figure 3 A schematic diagram of a target time-frequency resource determination method provided by an embodiment of the present specification is shown.

[0066] Figure 4 A schematic diagram of a time-frequency resource sub-area division method provided by an embodiment of the present specification is shown.

[0067] Figure 5 A schematic diagram of an Internet of Things service type division method provided by an embodiment of the present specification is shown.

[0068] Figure 6 A schematic diagram of a beam coverage area of a satellite provided by an embodiment of the present specification is shown.

[0069] Figure 7 A schematic diagram of a beam coverage area of a satellite provided by an embodiment of the present specification is shown.

[0070] Figure 8 A schematic diagram of a power circle layer division level provided by an embodiment of the present specification is shown.

[0071] Figure 9 A schematic diagram of a codebook mapping information determination method provided by an embodiment of the present specification is shown.

[0072] Figure 10 A schematic diagram of a deep reinforcement model provided by an embodiment of the present specification is shown.

[0073] Figure 11 A schematic diagram of an access request generation method provided by an embodiment of the present specification is shown.

[0074] Figure 12 A schematic diagram of a satellite multiple access device provided by an embodiment of the present specification is shown.

[0075] Figure 13Fig. 1 shows a schematic diagram of a satellite multiple access method according to an embodiment of the present specification;

[0076] Figure 14 Fig. 2 shows a schematic diagram of a satellite multiple access apparatus according to an embodiment of the present specification;

[0077] Figure 15 Fig. 3 shows a schematic diagram of a satellite multiple access method according to an embodiment of the present specification;

[0078] Figure 16 Fig. 4 shows a schematic diagram of an electronic device according to an embodiment of the present specification. DETAILED DESCRIPTION

[0079] In order to enable persons skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should fall within the scope of protection of the present application.

[0080] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, device, product or apparatus that includes a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatuses.

[0081] The present specification provides method operation steps as described in the embodiments or flowcharts, but can include more or fewer operation steps based on routine or non-creative labor. The order of steps listed in the embodiments is only one of the many step execution orders, and does not represent the only execution order. In actual system or device product execution, the method order shown in the embodiments or drawings can be executed in sequence or in parallel.

[0082] It should be noted that the information involved in the present application (including but not limited to user terminal device information, user personal information, etc.) is information and data authorized by the user or authorized by all parties, and the acquisition, transmission, storage, use and processing of related data comply with relevant national and regional laws, regulations and standards.

[0083] It should be noted that in the embodiments of the present specification, some industry existing solutions such as certain software, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility in the implementation of the present technical solution, but it does not mean that the applicant has or will necessarily use the solution.

[0084] Satellite Internet of Things access technology mainly focuses on two types of frameworks: orthogonal time-frequency resource allocation and non-orthogonal multiple access (NOMA).

[0085] In some embodiment scenarios, orthogonal allocation of time-frequency resources is achieved by statically dividing time-frequency resources into fixed-size time-frequency resource blocks, and the data of user terminals is carried on each time-frequency resource block to realize uplink resource transmission. In the satellite Internet of Things scenario, the number of terminals is large and the traffic demand is scattered, and the spectral efficiency of orthogonal allocation resources is severely limited; in order to ensure orthogonality, real-time coordination of user resource allocation is required through scheduling, which has large computational overhead and high scheduling complexity; in addition, the user terminals of the Internet of Things have burstiness and low rate characteristics, and orthogonal allocation is difficult to dynamically adapt to traffic changes; when a large number of terminals simultaneously initiate access requests, the orthogonal resource pool may be quickly exhausted, resulting in a sharp increase in access failure rate. If all services are allocated resources without distinction, from the real-time demand point of view, time-sensitive users and non-time-sensitive users compete for the same resources, which is easy to cause the system packet loss rate to rise due to data packet collision for time-sensitive users; and for non-time-sensitive users, resources can be given priority to time-sensitive users, thus to some extent, causing the reduction of system resource use efficiency; if the influence of user modulation order and coding rate is not considered, the total amount of information transmitted by the system will be reduced.

[0086] In some embodiment scenarios, power domain non-orthogonal multiple access distinguishes signals on the same time-frequency resource block based on different powers of the transmitted signals of different user terminals received by the satellite, and realizes multiple access in the power domain through different power levels. However, pure power domain non-orthogonal multiple access has the following disadvantages: first, power domain non-orthogonal multiple access relies on power difference to distinguish users, and has high requirements for power control accuracy in the satellite scenario. In practice, dynamic changes in terminal positions and the like can cause insufficient power difference, and serial interference cancellation cannot effectively separate the signals. Second, the scheduling has strong dependence and needs to pre-pair users in terms of power, and relies on real-time calculation of an optimal power allocation scheme. The limited bandwidth of satellite communication consumes system capacity due to frequent scheduling signaling overhead. Third, the massive terminal support capability is limited, and when the number of terminals exceeds the level that can be distinguished in the power domain, the power difference is difficult to further expand, resulting in increased interference and saturated system capacity.

[0087] In some embodiment scenarios, code domain non-orthogonal multiple access realizes multiplexing of multiple users on the same time-frequency resource block through non-orthogonal coding, and then the satellite can distinguish user terminals by using the orthogonality of code words. However, in the satellite Internet of Things scenario, the following disadvantages exist: first, the number of code words is limited, and the size of the orthogonal code word set is limited by the spread spectrum gain. For a large number of terminals, the code word resources are quickly exhausted, resulting in an increased collision probability of non-orthogonal access. Second, the orthogonality degenerates. In actual channels, multipath fading and Doppler shift can destroy the orthogonality of code words, causing system performance to deteriorate. Third, the access success rate is low. When terminals randomly access, if the code word pool is full, new users need to wait or use non-orthogonal code words, resulting in a sharp increase in the collision probability.

[0088] Based on this, the satellite multiple access method provided by the embodiments of the present specification can be applied to the user terminal side. The user terminal can generate an access request based on the above satellite multiple access method and send it to the satellite. Figure 1 As shown, the satellite multiple access method provided by the embodiments of the present specification can include the following steps. Figure 1 As shown, the satellite multiple access method provided by the embodiments of the present specification can include the following steps.

[0089] S101: Receive a first downlink broadcast signal of a satellite, wherein the first downlink broadcast signal includes time-frequency resource information and first position information of the satellite.

[0090] S102: Obtain codebook mapping information corresponding to the satellite, and generate an access request based on the first position information, second position information of the user terminal, and the codebook mapping information.

[0091] S103: Send the access request to the satellite on a target time-frequency resource determined based on the time-frequency resource information.

[0092] The first downlink broadcast signal can be a signal broadcast by a satellite in a beam coverage area of the satellite, and thus when a user terminal is located in the beam coverage area of the satellite, the user terminal can receive the first downlink broadcast signal broadcast by the satellite. The first downlink broadcast signal broadcast by the satellite can include satellite time-frequency resource information and first location information.

[0093] The time-frequency resource information is a two-dimensional resource model including a time domain and a frequency domain currently available to the satellite, and the uplink data sent by the user terminal can be uploaded to the satellite based on the time-frequency resource information. Specifically, the time-frequency resource information can include a plurality of pre-divided time-frequency resource blocks or time-frequency resource sub-regions. Further, different time-frequency resource blocks or time-frequency resource sub-regions can correspond to different Internet of Things service types.

[0094] In some embodiments of the present specification, the Internet of Things service type can be obtained by classifying the Internet of Things service based on a priority of the Internet of Things service and an encoding rate. The Internet of Things service can include a service corresponding to the data to be uploaded by the user terminal (i.e., uplink data) and / or a service of uploading data by the user terminal. The service corresponding to the data to be uploaded by the user terminal can be understood as the service to which the uplink data itself belongs, and thus the Internet of Things service type corresponding to the uplink data can be determined based on the uplink data. The service of uploading data by the user terminal can be understood as a service corresponding to the action of uploading data by the user terminal, and thus the Internet of Things service type corresponding to the service of uploading data by the user terminal can be determined based on the attribute information of the user terminal itself. Further, the priority of the Internet of Things service can include a priority of the service corresponding to the uplink data and / or a priority of the user terminal, and the encoding rate can include an encoding rate required by the service corresponding to the uplink data and / or an encoding rate of the user terminal. The priority can represent a real-time requirement of the corresponding Internet of Things service.

[0095] The first location information can represent the location information of the satellite, for example, the location of the satellite on an orbit, the location of a subsatellite point of the satellite, the location of the satellite in an earth coordinate system, etc.

[0096] The codebook mapping information can include a codebook composed of all available code words of the satellite and a mapping relationship between the code words and the first position information and the second position information. The code words in the codebook mapping information can be superimposed on the uplink data transmitted by the user terminal, used to distinguish the data sent by different user terminals to the satellite, and thus a better demodulation performance can be obtained at the satellite side. Specifically, the mapping relationship between the code words and the first position information and the second position information can be represented as a mapping relationship between the distance between the code words and the first position information and the second position information, or a mapping relationship between the position sequence composed of the first position information and the second position information and the code words. Further, the distance between the first position information and the second position information can be represented by other parameters, such as a circle layer representing different distance intervals, power loss representing different distances, and the like. Thus, the mapping relationship between the code words and the first position information and the second position information can be represented by the mapping relationship between the code words and the corresponding parameters. The relative position between the user terminal and the satellite can further divide the time-frequency resource in the power domain. Based on the mapping relationship between the code words and the first position information and the second position information, the power domain can be further divided in the code domain. Thus, through the coupling of the time-frequency resource, the code domain and the power domain, the time-frequency resource level and the power domain level can be expanded, the time-frequency resource utilization efficiency and the spectrum efficiency can be improved, more user terminals can be supported to multiplex the same time-frequency resource, the system capacity can be improved, and the dependence on accurate power control and frequent scheduling can be reduced.

[0097] Specifically, based on the first position information, the second position information and the codebook mapping information, a target codebook required by data to be uploaded by the user terminal to the satellite can be determined. Before sending the uplink data to the satellite, the user terminal can generate an initial request for establishing a communication link between the user terminal and the satellite, and can superimpose the target codebook on the generated initial request to obtain an access request. Then, the access request can be sent to the satellite on the target time-frequency resource. Based on the positions of the user terminal and the satellite and the codebook mapping information, the user terminal can realize autonomous real-time random access without network interaction with the satellite, and can avoid satellite centralized scheduling signaling, which is suitable for scenarios of massive Internet of Things terminals accessing the satellite.

[0098] In the embodiments of the present specification, by using the first downlink broadcast signal and the codebook mapping information, the signaling overhead can be simplified. The satellite only needs to broadcast the first downlink broadcast signal, and the user terminal can perform local calculation based on the received first downlink broadcast information without network interaction with the satellite, so as to realize real-time and efficient access of the terminal. Moreover, based on the time-frequency resource information, the time-frequency resource utilization rate can be improved. Based on the codebook mapping information and the position of the user terminal, different code words or power levels can be used on the same time-frequency resource, the spectrum utilization rate is improved, the system capacity is improved, and access of a large number of terminals is realized.

[0099] Specifically, referring to Figure 2 In a satellite-based communication scenario, a satellite can broadcast a downlink broadcast signal including time-frequency resource information and location information of the satellite. A terminal device (or user terminal) of a user can receive the downlink broadcast signal, and generate an access request based on the location information of the satellite, the location information of the terminal device, and pre-stored codebook mapping information in the terminal device, and initiate random access on a target time-frequency resource determined based on the time-frequency resource information.

[0100] The satellite can be a low-orbit satellite, a medium-orbit satellite, a high-orbit satellite, or another type of satellite. This specification mainly takes a low-orbit satellite as an example for specific description. For other types of satellites, refer to the related embodiments of the low-orbit satellite. The low-orbit satellite (or low-orbit communication satellite) can be a satellite deployed and operated in a relatively low orbit (e.g., generally about several hundred kilometers to two thousand kilometers from the ground). Due to the low orbit height, the transmission delay is short, the path loss is small, and the low-orbit satellite has the characteristics of low latency and low cost.

[0101] Specifically, a plurality of low-orbit satellites can be combined to form a large low-orbit satellite system supporting real-time information processing. Furthermore, the low-orbit satellite, the user terminal, the ground base station, and the like can be combined to form a satellite Internet of Things system.

[0102] The user terminal can be a ground device supporting satellite communication. Specifically, the user terminal can be a mobile phone, an Internet of Things terminal, a satellite phone, a computer, or the like. It should be noted that the above-mentioned user terminals are only illustrative. In specific implementation, the user terminal can also include other types of electronic devices according to specific application scenarios and processing requirements. This specification does not limit the user terminal.

[0103] In some embodiments of this specification, the user terminal can also be in the coverage area of a plurality of satellites. Furthermore, the user terminal can determine a target satellite for multiple access from the plurality of satellites as a satellite in the satellite multiple access method of the embodiments of this specification based on a preset satellite selection strategy. For example, the user terminal can select a satellite with the highest signal strength from the plurality of satellites for access, or select a satellite with the longest service time from the plurality of satellites for access, and the like.

[0104] The serviceable duration of the satellite is a duration in which the satellite can serve the satellite terminal. The serviceable duration of the satellite can be determined based on satellite orbit data, a location of the satellite terminal, a relevant limit of the satellite (for example, a maximum off-axis angle of a beam of the satellite, which can be determined based on a phased array or an antenna of the satellite), and a receiving and transmitting limit of an antenna of the satellite terminal (for example, a minimum working elevation angle of the antenna of the satellite terminal). The satellite orbit data and the location of the satellite terminal are converted to the same coordinate system. Based on the converted satellite orbit data, a time period in which the satellite terminal satisfies a corresponding elevation angle threshold and the satellite satisfies a corresponding beam off-axis angle threshold is determined as a time period in which the satellite can serve the satellite terminal. Then, a duration corresponding to the time period is determined as the serviceable duration of the satellite.

[0105] In the communication process of the satellite Internet of Things system, the satellite terminal can access in real time and efficiently without network interaction with the satellite. In addition, by jointly designing the time-frequency domain-power domain-code domain in the satellite beam, the time-frequency resource utilization rate can be improved. Based on the positional relationship between the satellite terminal and the satellite, different power levels can be distinguished, and the same power level can be further divided based on codebook mapping information to provide different code words for the satellite terminal, so as to improve the spectrum utilization rate, increase the system capacity, and realize access of a large number of terminals.

[0106] In some embodiments of the present specification, the plurality of time-frequency resource blocks or time-frequency resource sub-regions in the time-frequency resource information are region units of fixed sizes. Then, when the satellite terminal uploads data to the satellite, one of the plurality of region units can be selected for data uploading. Further, different region units can be set to correspond to different Internet of Things service types of corresponding transmission data. Then, when the satellite terminal uploads data to the satellite, the selectable region units can be determined based on the Internet of Things service type of the data to be uploaded, and one of the selectable region units can be selected for sending uplink data.

[0107] In some embodiments of the present specification, the plurality of time-frequency resource sub-regions in the time-frequency resource information can be a plurality of time-frequency resource sub-regions of adaptive sizes. Different time-frequency resource sub-regions can correspond to different Internet of Things service types. Then, when the satellite terminal uploads data to the satellite, the Internet of Things service type corresponding to the current communication scenario can be determined based on the uploaded data and / or the satellite terminal. Then, one of the plurality of time-frequency resource sub-regions is selected as a target time-frequency resource sub-region, and a target time-frequency resource is determined based on the uploaded data in the target time-frequency resource sub-region, so as to send uplink data in the target time-frequency resource.

[0108] Specifically, the Internet of Things service type can include a high-rate high real-time type, a high-rate low real-time type, a low-rate high real-time type, and a low-rate low real-time type. Then, based on the transmission rate of the Internet of Things service, a plurality of high-rate areas and low-rate areas can be divided in the frequency domain of the time-frequency resource of the satellite, and based on the real-time of the Internet of Things service, the frequency bands of the high-rate area and the low-rate area can be further divided, and a low-priority area and a high-priority area can be divided for each partition, and then four time-frequency resource sub-areas can be obtained, each of which can correspond to a frequency band. For details, please refer to Figure 4 In some implementation scenarios, the user terminal of the Internet of Things service of different transmission rates of the user terminal can initiate random access on the time-frequency resource of the corresponding rate partition of the satellite. For the high-rate low real-time type and the low-rate low real-time type of the Internet of Things service, the user terminal can only initiate random access on the time-frequency resource of the low-priority area of the corresponding rate partition. For the high-rate high real-time type and the low-rate high real-time type of the Internet of Things service user terminal, random access can be initiated on the time-frequency resource of all priority areas of the corresponding rate partition.

[0109] Of course, it can be understood that in actual application scenarios, the division of multiple time-frequency resource sub-areas can be optimized and adjusted based on the real-time business distribution of the wave number coverage area of the satellite, for example, more or fewer time-frequency resource sub-areas can be divided, and for example, the frequency band corresponding to each time-frequency resource sub-area can be optimized and adjusted, and the present specification does not limit this.

[0110] Reference Figure 3 As shown in the figure, in some embodiments of the present specification, the target time-frequency resource can be determined in the following way:

[0111] S301: Determine the target service type of the Internet of Things service corresponding to the satellite accessed by the user terminal based on the attribute information of the user terminal and / or the uplink service data to be transmitted by the user terminal.

[0112] S302: Determine the target time-frequency resource in the time-frequency resource corresponding to each time-frequency resource sub-area based on the plurality of time-frequency resource sub-areas included in the time-frequency resource information, the Internet of Things service type corresponding to each time-frequency resource sub-area, and the target service type.

[0113] It can be understood that based on the attribute information of the user terminal, the first service type corresponding to the action of uploading data by the user terminal can be determined, based on the uplink service data, the second service type corresponding to the uplink service data can be determined, and the target service type can be determined based on the first service type and / or the second service type to select the time-frequency resource sub-area.

[0114] In some embodiments of this specification, the target time-frequency resource is located on at least one of the plurality of time-frequency resource sub-regions. It is understood that the determined target time-frequency resource may be located on one time-frequency resource sub-region, or it may be located on two or more time-frequency resource sub-regions.

[0115] Specifically, refer to Figure 4 As shown, different data packets correspond to different user terminals and / or different uplink data transmitted by user terminals. Assuming that data packet ① corresponds to a low-rate, high-real-time IoT service type, data packet ② corresponds to a high-rate, high-real-time IoT service type, data packet ③ corresponds to a low-rate, low-real-time IoT service type, and data packet ④ corresponds to a high-rate, low-real-time IoT service type, then data packet ① can be transmitted on the time-frequency resources of all sub-regions within the divided low-rate region. For example, in the diagram, of the three locations corresponding to data packet ①, one location is located in the high-priority region of the low-rate region, and two locations span the low-priority region of the low-rate region. The high-priority area and the high-priority area; data packet ② can be transmitted on the time-frequency resources of all sub-areas of the high-rate area, for example, the two positions corresponding to data packet ② in the figure, one position is located in the high-priority area of ​​the high-rate area, and the other position spans the low-priority area and the high-priority area of ​​the high-rate area; data packet ③ can be transmitted on the time-frequency resources of the low-priority area of ​​the low-rate area, for example, the two positions corresponding to data packet ③ in the figure, and both positions are located in the low-priority area of ​​the low-rate area; data packet ④ can be transmitted on the time-frequency resources of the low-priority area of ​​the high-rate area, for example, the two positions corresponding to data packet ④ in the figure, and both positions are located in the low-priority area of ​​the high-rate area.

[0116] The configuration process of time and frequency resource information will be further described below with reference to embodiments. The configuration process of time and frequency resource information may specifically include the following.

[0117] From the perspective of the characteristics of the Internet of Things service, the QoS (Quality of Service) requirements of typical Internet of Things services are analyzed, and the main communication performance indicators that affect differentiated services are found. Narrowband Internet of Things (NB-IoT) mainly realizes data collection and reporting transmission, network control instruction transmission, short message transmission, end-to-end data transmission, and positioning based on the base station. It can meet the requirements of low-power, long standby, deep coverage, and large capacity for low-rate connection services, and is more suitable for static and low-speed services, non-continuous mobility, real-time data transmission, and other service scenarios. The differences between various scenarios of the Internet of Things can be mainly distinguished from the transmission capabilities of uplink rate, downlink rate, latency, mobility, low-power requirements, voice broadcast, and other aspects, as well as the business models in two dimensions of single-user daily traffic, single transmission bandwidth, transmission frequency, and business occurrence time distribution. It can be mainly divided into the following categories:

[0118] (1) Autonomous event-triggered service type: such as smoke alarm detectors, device abnormal operation, etc., uplink small data volume (tens of bytes), period is mostly in years or months.

[0119] (2) Autonomous periodic reporting service type: such as remote meter reading of public utilities, environmental monitoring, etc., uplink small data volume (hundreds of bytes), period is mostly in days or hours.

[0120] (3) Remote control instruction service type: such as remote start / stop of devices, device triggered uplink reporting, downlink small data volume (tens of bytes), period is mostly in days or hours.

[0121] (4) Software remote update service type: such as software patch / update, uplink and downlink large data volume requirement (thousands of bytes), period is mostly in days or hours.

[0122] The above various services have different requirements for communication performance in terms of latency and bandwidth. Therefore, the business model is divided into four types according to two dimensions: rate (bandwidth) and real-time (latency) in the embodiments of the present specification: one is a service type with high latency requirement and low bandwidth requirement (i.e., low-rate high-real-time type), and specific services may be, for example, event-driven services, alarm messages, device triggering, etc.; two is a service type with high latency requirement and high bandwidth requirement (i.e., high-rate high-real-time type), and specific services may be, for example, image / video type services; three is a service type with low latency requirement and low bandwidth requirement (i.e., low-rate low-real-time type), and specific services may be, for example, periodic reporting type services, remote meter reading, environmental monitoring, etc.; four is a service type with low latency requirement and high bandwidth requirement (i.e., high-rate low-real-time type), and specific services may be, for example, software update services. The two-dimensional classification mechanism of the characteristics of the Internet of Things service can be specifically referred toFigure 5 as shown.

[0123] According to the above analysis results, the following will be further introduced in combination with the related standards of NB-IoT and the related configurations supported, the process of effective configuration of time-frequency resources based on the requirements of Internet of Things devices.

[0124] In the physical layer frame structure standard specified by NB-IoT, two subcarrier spacings are supported in the frequency domain: 3.75KHz and 15KHz, wherein the communication rate is high and the time delay is small under the 15KHz subcarrier spacing. The NB-IoT uplink physical layer supports two transmission modes: Single Tone and Multi Tone, wherein Single Tone refers to allocating one carrier to one user, and the transmission speed is low; Multi Tone refers to allocating multiple carriers <3, 6, 12> to one user, and the transmission speed is high, and this mode is only supported under the 15K subcarrier spacing. Two sizes of scheduling units (RU) are supported in the time domain, 8ms under the 15KHz subcarrier spacing and 32ms under the 3.75KHz subcarrier spacing (one radio frame 40ms=10 subframes). The above time-frequency resource configuration mode can be seen from Table 1.

[0125] Table 1

[0126]

[0127] The third RU specification is taken as an example for the design of the time-frequency resource configuration mode. One RU of this specification is a time-frequency resource block composed of 3 subcarriers and 8 time slots. According to the analysis of the four types of business requirements, the following resource division mode is considered.

[0128] The time-frequency resources are first divided into high-rate and low-rate areas, wherein the high-rate area adopts QPSK modulation mode, or higher coding rate; the low-rate area adopts BPSK modulation mode, or lower coding rate. In each area, two sub-areas are further divided, wherein the low-priority users are only allowed to randomly access the time-frequency resources in one of the sub-areas; the high-priority users are allowed to randomly access the time-frequency resources in both sub-areas. Specifically, for the above four types of business:

[0129] For type one-low rate, high real-time business, it is specified to use the time-frequency resources in the low-rate area for transmission; since the real-time requirement is high, the priority of this type of business is higher, and it can initiate random access on the time-frequency resources in the entire low-rate area.

[0130] For Type 2 - high-speed, high-real-time services, it is stipulated that they should be transmitted using the time-frequency resources of the high-speed zone. Due to their high real-time requirements, this type of service has a higher priority in this area and can initiate random access on the time-frequency resources of the entire high-speed zone.

[0131] For Type 3 – low-rate, low-real-time services, it is stipulated that they should be transmitted using time-frequency resources in the low-rate zone. Since their real-time requirements are low, this type of service has a lower priority in this area and can only initiate random access on the time-frequency resources of a sub-area in the low-rate zone.

[0132] For Type 4 services—high-rate, low-real-time services—it is stipulated that they should be transmitted using time-frequency resources in the high-rate zone. Because of their lower real-time requirements, this type of service has a lower priority in this area and can only initiate random access on time-frequency resources in a sub-area of ​​the high-rate zone.

[0133] Furthermore, if the user terminal's capabilities are limited, such as only being able to use a certain modulation or coding scheme, then its main transmission area is defined based on the data rate; and its sub-transmission areas are defined based on the real-time requirements of the terminal's services. The above-mentioned allocation of time and frequency resources can be referenced... Figure 4 As shown.

[0134] Of course, it should be noted that the allocation of time and frequency resources can be extended to other RU specifications, and the specific allocation of high and low rate main areas and high and low priority sub-areas can be intelligently optimized and adjusted according to the overall service distribution within a single beam area. The above selection of the third RU specification and... Figure 4 The partitioning method shown is for illustrative purposes only. In specific application scenarios, those skilled in the art can optimize and adjust the above time-frequency resource partitioning method for RUs of corresponding specifications, and this specification does not impose any limitations on this.

[0135] The IoT service demand-driven high / low rate zone and high / low priority sub-region time-frequency resource allocation method in the embodiments of this specification is based on the IoT service characteristic bandwidth-latency two-dimensional classification mechanism, which divides IoT services into four categories according to rate requirements (high / low bandwidth) and real-time requirements (high / low latency), forming the basis for resource allocation. Based on the user terminal capability-driven time-frequency resource rate partitioning mechanism, according to the modulation and coding methods supported by the user terminal and the service's rate requirements, time-frequency resources are divided into high-rate zones (QPSK / high coding rate) and low-rate zones (BPSK / low coding rate). Based on the real-time requirement-driven time-frequency resource priority sub-region partitioning mechanism, differentiated access permissions are set according to the different latency requirements of the four types of services. Time-sensitive services can access the entire region, while non-time-sensitive services can only initiate access in low-priority sub-regions. Through the above embodiments, the system resource utilization efficiency can be improved, and the total amount of information transmitted by the system can be increased, adapting to the efficient access of massive numbers of satellite IoT terminals.

[0136] In some embodiments of this specification, the codebook mapping information may include the satellite's codebook library and codebook mapping matrix. The row index in the codebook mapping matrix may correspond to each position in the beam coverage area of ​​the satellite, and the column index in the codebook mapping matrix may correspond to the codewords of the spread spectrum codebook in the codebook library.

[0137] It is understood that the codebook library can include all scalable codewords for satellite and / or satellite communication scenarios. The codebook mapping matrix can characterize the mapping relationship between codewords and various locations in the satellite's beam coverage area. Based on the codebook mapping matrix, time and frequency resources can be multiplexed from both the power domain and the code domain, thereby improving system capacity.

[0138] Before introducing the specific process of determining the codebook mapping information, we will first introduce the division of the power layers with reference to the attached diagram.

[0139] Considering scenarios where the satellite beam is fixed to the ground, within the satellite's beam coverage area, the coverage area can be divided into several concentric circles (also called power concentric circles) based on the distance from different geographical locations to the nadir point. User terminals within the beam can then be assigned to different concentric circles based on their geographical location. Signals emitted by user terminals in different concentric circles travel different distances to reach the satellite, resulting in varying path losses and consequently, differences in the received power of the user signal at the satellite receiver. Therefore, power domain hierarchies can be achieved based on the division into power concentric circles.

[0140] Specifically, refer to Figure 7 As shown, the satellite's beam coverage diagram can be as follows: Figure 6 As shown. α, β, and γ represent the geocentric angle, the satellite's half-angle of view relative to the Earth, and the elevation angle of the observation point relative to the satellite, respectively. h, R ed1 and d2 represent the satellite altitude, Earth radius, and straight-line distance from the observation point to the satellite, respectively.

[0141] To ensure signal strength within the beam coverage area, the angle β of the satellite beam is controlled according to the satellite's onboard resource requirements. The satellite beam coverage area is the arc surface where the beam emitted by the satellite at angle β intersects with the Earth's surface. For low-Earth orbit satellites, this intersection can be approximated as a circle. A schematic diagram of the satellite's beam coverage area is shown below. Figure 7 As shown.

[0142] Assuming all user terminals within the beam coverage area have the same transmit power, the signal power reaching the satellite is primarily related to path loss, which is determined by the straight-line distance between the user terminal and the satellite. The path loss formula is as follows:

[0143] Formula (1)

[0144] Where PL represents path loss in dB; c represents the speed of light; and f represents the carrier frequency of the signal.

[0145] Based on the differences in the geographical location of the user terminal, Q concentric circles can be drawn within the coverage area of ​​the satellite beam, denoted as {C1, C2, ..., C...}. Q Within each concentric circle, the straight-line distance from user terminals to the satellite is approximately the same. The radius of each concentric circle boundary is 0 = r1. <r2<…<r Q =R, then for the q-th concentric circle, the distance d ∈ [r] between the user terminal and the nadir point. q ,r q+1 Assume that the power difference between the signals transmitted by user terminals within each concentric circle to the satellite is within P1dB, the straight-line distance between user terminals in different concentric circles to the satellite varies, and the power difference between concentric circles is greater than P2dB. Figure 8 This is a schematic diagram of the power coil division.

[0146] The beam coverage area partitioning method for the satellite communication system in this specification dynamically divides concentric rings based on the geometric distance from the user terminal to the satellite's nadir point. Path loss is calculated based on satellite altitude and beam coverage radius, dividing the beam coverage area into multiple continuously nested ring regions (i.e., power rings), with the ring boundaries expanding layer by layer from the inside out. By setting the maximum allowable power difference threshold within a ring and the minimum required power difference threshold between rings, constraint optimization determines the ring boundaries, thereby obtaining the number of ring parameters and boundary parameters. This ensures that terminals within a ring have negligible power differences due to their proximity, while terminals between rings exhibit significant power gradient differences. Through closed-loop optimization with geometric constraints, strict hierarchical control of the power domain is achieved, making interference within rings controllable and power differences between rings distinguishable, providing a foundation for non-orthogonal multiple access in the power domain.

[0147] On the basis of constructing the power circle layer of the user terminal, the user terminals between the circle layers have distinguishable characteristics in the power dimension, that is, the user terminals are distinguished from the power domain. Further, code domain non-orthogonality can be introduced to determine the codebook mapping information, so that each user terminal in the circle layer is distinguishable in the code word dimension. Through joint optimization of the power-code domain, more user access is achieved.

[0148] Reference Figure 9 As shown in the description, in some embodiments of the present application, the codebook mapping information can be determined in the following way:

[0149] S901: Construct an optimization model, which takes the maximum system transmission capacity in the beam coverage area of the satellite as the target, and takes the initial codebook of the satellite, the beam coverage area, and the received power of the signal sent by each position in the beam coverage area as the constraint condition.

[0150] S902: Optimize and solve the optimization model to obtain the codebook mapping information, which includes the target number of power circle layers, the boundary radius of each power circle layer, and the codebook set corresponding to each power circle layer.

[0151] In some embodiments of the present application, the difference in received power of the signal sent by the user terminal at each position in the same power circle layer to the satellite can meet the first power interval, and the difference in received power of the signal sent by the user terminal in different power circle layers to the satellite can meet the second power interval.

[0152] Specifically, the existing codebook to be optimized is denoted as W=[w1, w2, …, wn], where n is the number of code words in the initial codebook. N ] T where N is the number of available spreading codes (for example, the number of code words in the initial codebook), is the i-th spreading code, K is the length of the spreading code, and ||w i || 2 =1. It is assumed that when not optimized, the system can support at most N users using different spreading codes for non-orthogonal superposition, thereby multiplexing the same time-frequency resource. It is assumed that the i-th user uses the i-th spreading code to spread the modulation symbol sequence , and N s is the number of modulation symbols, then the received signal can be represented as:

[0153] Equation (2)

[0154] where, represents the additive white Gaussian noise with satellite received power .

[0155] For the codebook W, the code word correlation matrix is denoted as W, where the element in the ith row and jth column is the correlation between the mth and nth code words, i.e.

[0156] When optimizing the codebook, the correlation between code words can be considered to construct a codebook mapping matrix, so that the available code word set of users in different circle layers comes from the original codebook, while the orthogonality of the available code words in the circle layer is ensured to be strong, and the orthogonality between the circle layers is weakened with the increase of the distance between the circle layers.

[0157] Since the Signal to Interference plus Noise Ratio (SINR) of the extended symbol determines the demodulation quality of the data symbol, the final purpose of the codebook mapping matrix design optimization is to make the transmission signal of the user terminal using the code word allocation mode for symbol transmission obtain the optimal demodulation performance at the satellite.

[0158] Therefore, in the embodiments of the present specification, the system transmission and capacity maximization in the beam coverage area are taken as the optimization target, and under the constraints of the code word correlation matrix corresponding to the codebook, the beam coverage area and the power distribution, the circle layer division strategy and the available code word set of each circle layer with the maximum capacity are obtained through low complexity calculation, and an optimization model is constructed. The optimization target variable of the optimization model is the number of power circle layers, the boundary radius of each power circle layer and the codebook mapping matrix.

[0159] In some embodiments of the present specification, the optimization model can be represented by the following formula:

[0160] Formula (3)

[0161] Wherein, Q represents the target number, N represents the number of code words of the initial codebook, represents the average received power corresponding to the qth power circle layer, N q represents the number of user terminals in the qth power circle layer, r q represents the boundary radius of the qth power circle layer, PL(d) represents the path loss of the signal transmitted by the user terminal with a distance of d from the subsatellite point of the satellite to the satellite, P1 represents a first power threshold corresponding to the difference in received power of the signals transmitted by the user terminal at different positions in the same power circle layer to the satellite, and P2 represents a second power threshold corresponding to the difference in received power of the signals transmitted by the user terminal in different power circle layers to the satellite. represents the distance from the center point of the qth power circle layer to the subsatellite point of the satellite, represents the distance from the center point of the qth power circle layer to the subsatellite point of the satellite, A​​q,m denotes the m-th codeword index corresponding to the q-th power ring layer, and R denotes the radius of the beam coverage area, denotes the noise power, denotes the codebook set cross-correlation strength in the q-th power ring layer. Specifically, the q-th power ring layer corresponds to the codeword index set The noise power can represent an additive white Gaussian noise.

[0162] Specifically, the number of user terminals N q in the q-th power ring layer in the above formula (3) can be represented by the following formula:

[0163] Formula (4)

[0164] Specifically, the average received power corresponding to the q-th power ring layer in the above formula (3) can be represented by the following formula:

[0165] Formula (5)

[0166] where P t may represent the transmit power of the user terminal, G can represent the antenna gain of the satellite, and H can represent the height of the satellite.

[0167] Specifically, the codebook set cross-correlation strength in the q-th power ring layer in the above formula (3) can be represented by the following formula:

[0168] Formula (6)

[0169] In some embodiments of the present specification, since the above-mentioned constructed optimization model is a mixed integer nonlinear programming model, directly optimizing and solving the optimization model has low efficiency and low calculation accuracy, therefore the solution of the above-mentioned optimization model can be converted into the solution of a continuous action space optimization problem. Further, the optimization model can be converted into a deep reinforcement model, and the deep reinforcement model is optimized and solved.

[0170] Specifically, optimizing and solving the optimization model to obtain the codebook mapping information can include:

[0171] Step S1, constructing a deep reinforcement model, determining the state space, action space, policy network, value network and optimization target of the deep reinforcement model based on the optimization model, the policy network is provided with a policy function of codebook allocation, and the value network is provided with a reward function.

[0172] ​In step S2, parameters in the policy network and the value network are optimized based on the optimization target, the policy function and the reward function until system and capacity converge or a preset training number is reached, to obtain the codebook mapping information.

[0173] In some embodiments of the present specification, a state vector in a state space can include system key parameters, such as a power ring layer radius, a received power corresponding to a power ring layer, a cross-correlation strength of a codebook set in a ring layer, and the like. Specifically, the state vector can be represented by the following formula:

[0174] Formula (7)

[0175] wherein r q represents a boundary radius of the qth power ring layer. q

[0176] In some embodiments of the present specification, an action vector in an action space can include a ring boundary adjustment amount and a code word allocation weight, which are used to control a power ring layer boundary and a codebook allocation. Specifically, the action vector can be represented by the following formula:

[0177] Formula (8)

[0178] wherein a q represents the ring boundary adjustment amount, a q represents the code word allocation weight.

[0179] In some embodiments of the present specification, the policy function can be represented by the following formula:

[0180] Formula (9)

[0181] wherein τ q represents a preset adaptive threshold value corresponding to the qth power ring layer, z q represents a weight of the mth code word corresponding to the power ring layer, and A q represents the mth code word corresponding to the qth power ring layer. q m q,m That is, a power ring layer close to the center of a beam coverage area automatically obtains a lower threshold value, thereby allocating more code words; and a power ring layer close to the edge of the beam coverage area obtains a higher threshold value, thereby allocating fewer code words.

[0182] In some embodiments of the present specification, the reward function can be represented by the following formula:

[0183] Formula (10)

[0184] ​​​​​​ Formula (11)

[0185] Formula (12)

[0186] Formula (13)

[0187] Where r(s,a) represents the reward, Viol intra Indicates the first penalty item, Viol inter C represents the second penalty item. sum Let λ1 and λ2 represent the weighting coefficients of the first and second penalty terms, respectively, and PL represent the system's sum and capacity. max,q PL represents the maximum power loss of the transmitted signal at each position in the q-th power layer. min,q This represents the minimum power loss of the transmitted signal at each position in the q-th power layer. This indicates the constraint on the difference in received power of signals transmitted by the user terminal in different power layers before reaching the satellite. This represents the constraint on the difference in received power of signals transmitted by the user terminal at different locations within the same power layer when they reach the satellite. Specifically, the first penalty term is a constraint within the power layer, and the second penalty term is a constraint between power layers.

[0188] In some embodiments of this specification, the optimization objective can be expressed by the following formula:

[0189] Formula (14)

[0190] in It can represent an Actor network (policy function). This can represent the Critic network (value function), ρ β It can represent the state distribution of behavioral strategies.

[0191] In some embodiments of this specification, the structure of the above-described deep enhancement model can be referred to Figure 10 As shown, it mainly consists of an Actor network and a Critic network. The Actor network is used to learn the optimal solution for the state transition policy, while the Critic network is used to minimize the error between the estimated Q-value and the true Q-value, providing direction for the Actor network's updates. The policy gradient update function and loss function within the network are as follows:

[0192] Formula (15)

[0193] Formula (16)

[0194] in, .

[0195] For the Actor network, the input is the state space S, and the output is an action in the action space A, that is, the adjustment strategy for the codebook mapping matrix and the circle layer division; for the Critic network, the input is the state space S and the action in the action space A, and the output is the evaluation of the value of the action, which is used to guide the update of the Actor network. The specific optimization process is as follows:

[0196] Step S1: initialize the parameters of the Actor network and its target network , the parameters of the Critic network and its target network ;

[0197] Step S2: generate an action a from the Actor network according to the current state s ;

[0198] Step S3: execute the action a (t) , the environment changes according to the action, and obtains a new state s (t+1) and a reward r (t) ;

[0199] Step S4: store (s (t) , a (t) , r (t) , s (t+1) ) to the experience replay pool;

[0200] Step S5: obtain Q(s (t) , a (t) | θ c ) from the Critic network;

[0201] Step S6: randomly sample a batch of data from the experience replay pool, update the Critic network parameter θ Q by minimizing the loss function L(θ c ); update the Actor network parameter θ a based on the policy gradient descent, and gradually optimize the power circle layer division and the code word usage strategy;

[0202] Step S7: update the parameters of the Actor target network and the Critic target network and ;

[0203] Step S8: repeat steps S1 to S7 until the system and capacity converge or reach the preset training times.

[0204] After training, the following to-be-optimized items can be obtained: optimal circle layer division , codebook mapping matrix and power difference index and i.e. to obtain the ring layer partition strategy (including the target number of power rings and the boundary radius) and the code word selection strategy (including the codebook mapping matrix) with the maximum system capacity.

[0205] The hierarchical codebook mapping method for power domain and code domain joint optimization in the embodiments of the present specification constructs a codebook mapping matrix for codebook-ring layer mapping by predefining a spreading codebook and an orthogonality evaluation matrix between code words, the matrix row represents the ring layer index, the column represents the code word index, and the matrix element identifies whether the code word is allowed to be used by the user terminal of the corresponding ring layer; in the optimization process, a hierarchical orthogonality allocation strategy is executed, including an adjacent ring layer isolation strategy, i.e. allocating a completely mutually exclusive subset of code words to adjacent ring layers to ensure that the orthogonality level of the code words is the highest, and a non-adjacent ring layer multiplexing strategy, i.e. allowing non-adjacent ring layers to multiplex the same code word, and the greater the distance between the ring layers, the lower the allowed orthogonality level of the multiplexed code word. Further, based on a deep reinforcement model, the ring layer partition and codebook allocation are jointly optimized, a state space, an action space, a policy function and a reward function are designed, and the maximum system capacity is taken as the target to generate the final codebook mapping matrix. Through codebook-ring layer coupling mapping, the inner ring layer users obtain high-orthogonal code words to suppress strong interference, and the outer ring layer users multiplex low-orthogonal code words but achieve separability through power difference, which significantly improves the system capacity.

[0206] The embodiments of the present specification expand the power domain level by introducing code domain differentiation, support more user multiplexing of the same time-frequency resource, and reduce the dependence on accurate power control and frequent scheduling; and by jointly optimizing the power-code domain, the code word with weak orthogonality is allowed to be allocated to the user terminal with large power difference, the available code word set is expanded by several times compared to the original size, and the system capacity is improved.

[0207] It can be understood that the determination process of the codebook mapping information can be implemented at the user terminal side, and then the user terminal can directly prestore the determined codebook mapping information. The determination process of the codebook mapping information can also be implemented at the satellite side or other servers, satellite communication platforms and the like, and then before implementing the satellite multiple access method in the embodiments of the present specification, the user terminal can obtain the codebook mapping information, and then realize the local low signaling overhead terminal access at the user terminal side.

[0208] Referring to Figure 11 In some embodiments of the present specification, based on the first position information, the second position information of the user terminal and the codebook mapping information, the access request can include:

[0209] S1101: Determine a target position of the user terminal in a beam coverage area of the satellite based on the first position information and the second position information;

[0210] S1102: Determine a target code word corresponding to the user terminal based on the target position and the code book mapping information;

[0211] S1103: Generate the access request based on the target code word.

[0212] Specifically, the first position information is a sub-satellite point position information of the satellite, and determining the target position of the user terminal in the beam coverage area of the satellite based on the first position information and the second position information can include: determining a distance from the user terminal to the sub-satellite point of the satellite based on the second position information and the sub-satellite point position information; determining a target circle layer of the user terminal in a plurality of power circle layers corresponding to the satellite as the target position based on the distance, the plurality of power circle layers being divided based on powers of signals emitted by positions in the beam coverage area received by the satellite.

[0213] Specifically, determining the target code word corresponding to the user terminal based on the target position and the code book mapping information can include: determining a target code book set corresponding to the target circle layer in the code book mapping information, the target code book set including a plurality of candidate code words; and randomly selecting one candidate code word from the plurality of candidate code words as the target code word.

[0214] In some embodiments of the present specification, generating the access request based on the target code word can include: generating a first request, and expanding a symbol in the first request based on the target code word to obtain the access request.

[0215] In a specific implementation scenario, an optimized circle layer division and code word map (i.e., code book mapping matrix) can be given, and the access of the user terminal adopts a lightweight mechanism of “autonomous calculation + random selection”. Specifically, the user terminal pre-stores a code book map and a code book library, when the user terminal needs to access the satellite network, first acquires its position information, and receives real-time sub-satellite point coordinates broadcast by the satellite, calculates the plane distance d from the user terminal to the sub-satellite point. Further, power circle layer matching and code word selection are performed. Specifically, the circle layer boundary sequence , the distance d of the user terminal from the sub-satellite point is mapped to the corresponding circle layer index q (for example , q = 3). The q-th row of the code book map A is queried according to the circle layer index q, and the available code word index set A q is obtained. A code word w mThe above circle layer matching and code word selection process can be completely completed by the user terminal without interaction with the satellite, and the scheduling and calculation overheads are low, and the satellite Internet of Things scenario can be adapted.

[0216] The low signaling overhead terminal access method in the embodiments of the present specification can broadcast the current subsatellite point position information and time-frequency resource information of the satellite at the beginning of the beam residence period, and prestore the spread spectrum codebook library and the circle layer-codebook mapping matrix in the user terminal device, so that the user terminal can calculate the distance from the subsatellite point according to the self-positioning information and the received subsatellite point information of the satellite, and then determine the circle layer index based on the prestored circle layer boundary parameters, and query the codebook map based on the circle layer index to obtain the codebook number set allowed to be used by the power circle layer where the user terminal is located. Further, a code word can be randomly selected from the codebook set corresponding to the available codebook number set as a target code word for spreading the symbols in the data to be transmitted. Further, the user terminal can initiate random access on the available time-frequency resource corresponding thereto based on the device attributes thereof and the services provided thereby.

[0217] The above access design in the embodiments of the present specification can realize signaling overhead simplification, that is, the satellite only needs to broadcast the subsatellite point position and does not need to dynamically issue the codebook allocation table; the user terminal can perform local calculation by pre-storing the codebook map to realize real-time access without network interaction; and the user terminal can randomly select a codebook in the codebook set corresponding to the circle layer where the user terminal is located, so that the centralized scheduling signaling on the satellite side can be avoided; and by means of differentiated time-frequency resource occupation authority, the differentiated service requirements can be maximally adapted, the massive Internet of Things terminal access scenario can be adapted, and the resource utilization efficiency is high.

[0218] Based on the above satellite multiple access method applied to the user terminal, the embodiments of the present specification further provide a satellite multiple access device applied to the user terminal. Figure 12 As shown in the figure, the satellite multiple access device provided by the embodiments of the present specification can include: Figure 12 As shown in the figure, the satellite multiple access device can include:

[0219] The receiving module 1201 is configured to receive a first downlink broadcast signal of a satellite, wherein the first downlink broadcast signal comprises time-frequency resource information and first position information of the satellite;

[0220] The generating module 1202 is configured to obtain codebook mapping information corresponding to the satellite, and generate an access request based on the first position information, second position information of the user terminal, and the codebook mapping information;

[0221] The sending module 1203 is configured to send the access request to the satellite on a target time-frequency resource determined based on the time-frequency resource information.

[0222] The description and functions of the above modules can be understood with reference to the content of the satellite multiple access method part in Figure 1 , which will not be repeated here.

[0223] Based on the foregoing satellite multiple access method, the embodiments of the present specification further provide a satellite multiple access method applied to a satellite. Figure 13 As shown in the satellite multiple access method provided by the embodiments of the present specification, the satellite multiple access method can include: Figure 13 As shown in the satellite multiple access method provided by the embodiments of the present specification, the satellite multiple access method can include:

[0224] S1301: sending a first downlink broadcast signal to a user terminal, wherein the first downlink broadcast signal includes time-frequency resource information of the satellite and first position information;

[0225] S1302: receiving an access request sent by the user terminal, wherein the access request is generated by the user terminal based on the first position information, second position information of the user terminal, and codebook mapping information corresponding to the satellite obtained by the user terminal after receiving the first downlink broadcast signal.

[0226] The description and specific implementation methods of the above steps can be understood with reference to the content of the satellite multiple access method part in Figure 1 , which will not be repeated here.

[0227] Based on the foregoing satellite multiple access method applied to a satellite, the embodiments of the present specification further provide a satellite multiple access device applied to a satellite. Figure 14 As shown in the satellite multiple access device provided by the embodiments of the present specification, the satellite multiple access device can include: Figure 14 As shown in the satellite multiple access device provided by the embodiments of the present specification, the satellite multiple access device can include:

[0228] The sending module 1401 is configured to send a first downlink broadcast signal to a user terminal, wherein the first downlink broadcast signal includes time-frequency resource information of the satellite and first position information;

[0229] The receiving module 1402 is configured to receive an access request sent by the user terminal, wherein the access request is generated by the user terminal based on the first position information, second position information of the user terminal, and codebook mapping information corresponding to the satellite obtained by the user terminal after receiving the first downlink broadcast signal.

[0230] The description and functions of the above modules can be understood with reference to the content of the satellite multiple access method part in Figure 1 , which will not be repeated here.

[0231] Based on the foregoing satellite multiple access method, the embodiments of the present specification further provide a satellite multiple access method. Figure 15An example of a satellite multiple access method is shown. As shown in Figure 15 The satellite multiple access method can include the following steps.

[0232] S1501: The satellite sends a first downlink broadcast signal to a user terminal.

[0233] The first downlink broadcast signal includes time-frequency resource information and first location information of the satellite.

[0234] S1502: The user terminal receives the first downlink broadcast signal of the satellite.

[0235] S1503: The user terminal obtains codebook mapping information corresponding to the satellite, and generates an access request based on the first location information, second location information of the user terminal, and the codebook mapping information.

[0236] S1504: The user terminal sends the access request to the satellite on a target time-frequency resource determined based on the time-frequency resource information.

[0237] The above steps and their specific implementation methods can be understood by referring to the content of the satellite multiple access method in Figure 1 , which will not be repeated here.

[0238] An embodiment of the present application further provides an electronic device, as shown in Figure 16 The electronic device can be a satellite or a user terminal. The electronic device 1601 can include one or more processors 1602, such as one or more central processing units (CPUs), each of which can implement one or more hardware threads. The electronic device 1601 can also include any memory 1603 for storing any kind of information such as code, settings, data, etc. Without limitation, for example, the memory 1603 can include any one or a combination of the following: any type of RAM, any type of ROM, a flash memory device, a hard disk, an optical disk, etc. More generally, any memory can store information using any technology. Further, any memory can provide volatile or non-volatile retention of information. Further, any memory can represent a fixed or removable component of the electronic device 1601. In one case, the electronic device 1601 can perform any operation of the associated instructions when the processor 1602 executes the associated instructions stored in any memory or combination of memories. The electronic device 1601 also includes one or more drive mechanisms 1604, such as a hard disk drive mechanism, an optical disk drive mechanism, etc., for interacting with any memory.

[0239] The electronic device 1601 can also include one or more network interfaces 1605 for exchanging data with other devices via one or more communication links 1606. The one or more communication buses 1607 couple the various components in the electronic device 1601.

[0240] The communication links 1606 can be any type of connection for example, local area network, wide area network, e.g., the Internet, peer-to-peer connections, direct connections, etc., or any combination thereof. The communication links 1606 can include any combination of hardwired links, wireless links, routers, gateway functionality, name servers, etc. governed by any protocol or combination of protocols.

[0241] The present application also provides a computer readable storage medium, having stored thereon a computer program, which, when executed by a processor, performs the steps of the above method.

[0242] The present application also provides a computer readable instruction, wherein when the processor executes the instruction, the program therein causes the processor to perform the method of any of the preceding embodiments.

[0243] It should be understood that the size of the sequence number of each process described above in various embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0244] It should also be understood that in the embodiments of the present application, the term "and / or" is only to describe the association relationship of the associated objects, which means that there can be three relationships. For example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0245] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present application can be realized in electronic hardware, computer software or a combination of both. In order to clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been described in general terms in the above description. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0246] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0247] In several embodiments provided by the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiments are merely schematic. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electric, mechanical or in other forms.

[0248] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0249] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0250] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part of the prior art that contributes to the present application, 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 a number of instructions for causing an electronic device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0251] The principles and implementation manners of the present application are described in the specific embodiments. The above embodiment descriptions are only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges can be changed. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A satellite multiple access method, characterized in that, Applied to user terminals, including: Receive a first downlink broadcast signal from a satellite, the first downlink broadcast signal including the satellite's time and frequency resource information and first location information; The codebook mapping information corresponding to the satellite is obtained, and an access request is generated based on the first location information, the second location information of the user terminal, and the codebook mapping information. The codebook mapping information includes the satellite's codebook library and codebook location mapping information. The codebook location mapping information is used to characterize the mapping relationship between each location in the satellite's beam coverage area and the codewords in the spread spectrum codebook in the codebook library. The codebook location mapping information is used to multiplex time-frequency resources from the code domain and the power domain. The access request is sent to the satellite on the target time-frequency resource determined based on the time-frequency resource information.

2. The satellite multiple access method according to claim 1, characterized in that, The codebook mapping information is stored in the user terminal.

3. The satellite multiple access method according to claim 1, characterized in that, The codebook location mapping information is represented by a codebook mapping matrix. The row index in the codebook mapping matrix corresponds to each position in the beam coverage area of ​​the satellite, and the column index in the codebook mapping matrix corresponds to the codewords of the spread spectrum codebook in the codebook library.

4. The satellite multiple access method according to claim 1, characterized in that, Based on the first location information, the second location information of the user terminal, and the codebook mapping information, an access request is generated, including: Based on the first location information and the second location information, the target location of the user terminal in the beam coverage area of ​​the satellite is determined; Based on the target location and the codebook mapping information, the target codeword corresponding to the user terminal is determined; The access request is generated based on the target codeword.

5. The satellite multiple access method according to claim 4, characterized in that, The first location information is the sub-satellite point location information of the satellite. Based on the first location information and the second location information, determining the target location of the user terminal within the beam coverage area of ​​the satellite includes: Based on the second location information and the nadir point location information, the distance from the user terminal to the nadir point of the satellite is determined; Based on the distance, the target position of the user terminal is determined in one of the multiple power layers corresponding to the satellite. The multiple power layers are divided based on the power of signals emitted from each location within the beam coverage area received by the satellite.

6. The satellite multiple access method according to claim 5, characterized in that, Based on the target location and the codebook mapping information, determining the target codeword corresponding to the user terminal includes: The target codebook set corresponding to the target layer is determined from the codebook mapping information, and the target codebook set includes multiple candidate codewords; Randomly select one candidate codeword from the plurality of candidate codewords as the target codeword.

7. The satellite multiple access method according to claim 4, characterized in that, Generating the access request based on the target codeword includes: A first request is generated, and the symbols in the first request are expanded based on the target codeword to obtain the access request.

8. The satellite multiple access method according to claim 1, characterized in that, The time-frequency resource information includes multiple time-frequency resource sub-regions and the corresponding IoT service types for each time-frequency resource sub-region.

9. The satellite multiple access method according to claim 8, characterized in that, The IoT service type is obtained by classifying IoT services based on their priority and encoding rate.

10. The satellite multiple access method according to claim 1, characterized in that, The target time-frequency resources are determined in the following way: Based on the attribute information of the user terminal and / or the uplink service data to be transmitted by the user terminal, determine the target service type of the Internet of Things service corresponding to the satellite accessed by the user terminal; Based on the multiple time-frequency resource sub-regions included in the time-frequency resource information, the IoT service types corresponding to each time-frequency resource sub-region, and the target service type, the target time-frequency resource is determined from the time-frequency resources corresponding to the multiple time-frequency resource sub-regions.

11. The satellite multiple access method according to claim 10, characterized in that, The target time-frequency resource is located on at least one of the plurality of time-frequency resource sub-regions.

12. The satellite multiple access method according to claim 1, characterized in that, The codebook mapping information is determined in the following way: An optimization model is constructed, which aims to maximize the system transmission capacity within the beam coverage area of ​​the satellite, and uses the initial codebook of the satellite, the beam coverage area, and the received power corresponding to the transmitted signal at each location within the beam coverage area as constraints. The optimization model is optimized and solved to obtain the codebook mapping information, which includes the target number of power layers, the boundary radius of each power layer, and the codebook set corresponding to each power layer.

13. The satellite multiple access method according to claim 12, characterized in that, The difference in received power of signals transmitted by the user terminal at different positions within the same power sphere when they reach the satellite satisfies a first power range, and the difference in received power of signals transmitted by the user terminal within different power spheres when they reach the satellite satisfies a second power range.

14. The satellite multiple access method according to claim 12, characterized in that, The optimization model is expressed by the following formula: ； in, Q Indicates the target quantity. N This indicates the number of codewords in the initial codebook. Indicates the first q The average received power within each power layer N q Indicates the first q Number of user terminals within each power zone r q Indicates the first q The boundary radius of each power layer, PL(d), represents the path loss of the signal transmitted from the user terminal to the satellite at a distance d from the satellite's nadir point. P 1 This represents a first power threshold corresponding to the difference in received power of signals transmitted by the user terminal at different positions within the same power ring reaching the satellite. P 2 This represents the second power threshold corresponding to the difference in the received power of signals transmitted by the user terminal within different power layers reaching the satellite; Indicates the first q The distance from the center point of each power concentric circle to the sub-satellite point of the satellite. Indicates the first q+ The distance from the center point of one power concentric circle to the sub-satellite point of the satellite. A q,m Let R represent the index of the m-th codeword corresponding to the q-th power coil, and let R represent the radius of the beam coverage area. Indicates noise power. Indicates the first q The cross-correlation strength of the codebook set within each power sphere; SINR q Indicates the first q The signal-to-interference-plus-noise ratio of the signal transmitted within each power layer.

15. The satellite multiple access method according to any one of claims 12, 13 or 14, characterized in that, The optimization model is optimized and solved to obtain the codebook mapping information, including: A deep reinforcement model is constructed, and the state space, action space, policy network, value network, and optimization objective of the deep reinforcement model are determined based on the optimization model. The policy network includes a policy function for codebook allocation, and the value network includes a reward function. Based on the optimization objective, the policy function, and the reward function, the parameters in the policy network and the value network are optimized until the system and capacity converge or the preset number of training iterations are reached, thereby obtaining the codebook mapping information.

16. The satellite multiple access method according to claim 15, characterized in that, The policy function is expressed by the following formula: ； in, τ q Indicates the first q Each power coil corresponds to a preset adaptive threshold. z m Indicates the power coil corresponding to the first m The weight of each codeword, A q,m Indicates the first q The power coil corresponding to the first m Individual codeword index.

17. The satellite multiple access method according to claim 15, characterized in that, The reward function is expressed by the following formula: ； ； ； ； in, r ( s,a Let ) represent the reward, s represent the state vector, a represent the action vector, and Viol represent the reward. intra Indicates the first penalty item, Viol inter This indicates the second penalty item. C sum Indicates the system's sum and capacity. λ 1 and λ 2 represents the weighting coefficients of the first and second penalty terms, respectively. max,q Indicates the first q The maximum power loss corresponding to the transmitted signal at each position of each power layer, PL min,q Indicates the first q The minimum power loss corresponding to the signal transmitted at each position in each power layer. This indicates the constraint on the difference in received power of signals transmitted by the user terminal in different power layers before reaching the satellite. This indicates the constraint on the difference in received power of signals transmitted by the user terminal at different positions within the same power ring when they reach the satellite. Q Indicates the target quantity. N q Indicates the first q Number of user terminals within each power zone; SINR q Indicates the first q The signal-to-interference-plus-noise ratio of the signal transmitted within each power layer.

18. A satellite multiple access method, characterized in that, Applied to satellites, including: A first downlink broadcast signal is sent to the user terminal, the first downlink broadcast signal including the satellite's time and frequency resource information and first location information; The system receives an access request sent by the user terminal. The access request is generated by the user terminal upon receiving the first downlink broadcast signal, based on the first location information, the second location information of the user terminal, and the obtained codebook mapping information corresponding to the satellite. The codebook mapping information includes the satellite's codebook library and codebook location mapping information. The codebook location mapping information is used to characterize the mapping relationship between each location in the satellite's beam coverage area and the codewords in the spread spectrum codebook in the codebook library. The codebook location mapping information is used to multiplex time-frequency resources from the code domain and the power domain.

19. A satellite multiple access device, characterized in that, Applied to user terminals, including: The receiving module is used to receive the first downlink broadcast signal of the satellite, wherein the first downlink broadcast signal includes the satellite's time and frequency resource information and first location information; A generation module is used to obtain codebook mapping information corresponding to the satellite, and generate an access request based on the first location information, the second location information of the user terminal, and the codebook mapping information; the codebook mapping information includes the satellite's codebook library and codebook location mapping information, the codebook location mapping information is used to characterize the mapping relationship between each location in the satellite's beam coverage area and the codewords in the spread spectrum codebook in the codebook library; the codebook location mapping information is used to multiplex time-frequency resources from the code domain and the power domain; The sending module is used to send the access request to the satellite on the target time-frequency resource determined based on the time-frequency resource information.

20. A satellite multiple access device, characterized in that, Applied to satellites, including: The transmitting module is used to transmit a first downlink broadcast signal to a user terminal, wherein the first downlink broadcast signal includes the satellite's time and frequency resource information and first location information; The receiving module is configured to receive an access request sent by the user terminal. The access request is generated by the user terminal receiving the first downlink broadcast signal and based on the first location information, the second location information of the user terminal, and the obtained codebook mapping information corresponding to the satellite. The codebook mapping information includes the satellite's codebook library and codebook location mapping information. The codebook location mapping information is used to characterize the mapping relationship between each location in the beam coverage area of ​​the satellite and the codewords in the spread spectrum codebook in the codebook library. The codebook location mapping information is used to multiplex time-frequency resources from the code domain and the power domain.

21. An electronic device, characterized in that, It includes a processor and a memory for storing processor-executable instructions, wherein the processor, when executing the instructions, implements the steps of the method according to any one of claims 1 to 18.

22. A computer storage medium, characterized in that, The computer storage medium stores computer program instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 18.

23. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 18.

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