Beam selection method, system and related apparatus in satellite communication system

Abstract

This application discloses a beam selection method, system, and related apparatus in a satellite communication system. A terminal sends a first user frame to a satellite network device. The first user frame carries an outbound link indication field, which in turn carries beam information for L downlink beams. The outbound link indication field instructs the satellite network device to select one of the L downlink beams to send the user frame to the terminal, where L is a positive integer. The terminal receives a second user frame sent by the satellite network device on the first of the L downlink beams. This allows for downlink beam selection by the satellite network device without additional signaling overhead, improving channel utilization.

Description

Technical Field

[0001] This application relates to the field of satellite communication technology, and in particular to a beam selection method, system and related apparatus in a satellite communication system. Background Technology

[0002] The BeiDou Navigation Satellite System (BDS) is a major infrastructure project independently developed by my country, integrating positioning, timing, and communication. One of the distinctive features of the BDS compared to other global navigation systems such as GPS, GLONASS, and Galileo is its short message service. The BDS short message service is particularly suitable for communication in areas such as oceans, deserts, grasslands, and uninhabited areas where mobile communication is unavailable, lacks coverage, or has been damaged. The short message system of the BeiDou-3 satellite has upgraded the short message technology, opening up some necessary resources of the BDS short message service communication system to civilian use. For civilian services and equipment, communication protocols need to be designed based on the characteristics of the BDS short message service communication system.

[0003] Currently, the communication system for the BeiDou-3 satellite area short message service is provided by three geostationary Earth orbit (GEO) satellites. Each GEO satellite has six available downlink beams and one optional beam. Given limited hardware resources, the maximum time for terminal 100 to search for a single beam on a single frequency point is 51 seconds. Incorrect beam selection will affect the speed at which terminal 100 accesses network device 200. Therefore, how BeiDou network device 200 selects the downlink beam to send data to terminal 100 is a problem that urgently needs to be solved in the BeiDou communication system. Summary of the Invention

[0004] This application provides a beam selection method, system, and related apparatus in a satellite communication system, which enables the selection of downlink beams for satellite network equipment without additional signaling overhead, thereby improving channel utilization.

[0005] In a first aspect, this application provides a beam selection method in a satellite communication system, comprising: a terminal sending a first user frame to a satellite network device, wherein the first user frame carries an outbound link indication field, the outbound link indication field carries beam information of L downlink beams, the outbound link indication field is used to instruct the satellite network device to select a beam from the L downlink beams to send the user frame to the terminal, where L is a positive integer; and the terminal receiving a second user frame sent to the terminal by the satellite network device on a first beam from the L downlink beams.

[0006] The beam selection method in a satellite communication system provided in this application enables the terminal to carry beam information of L downlink beams in the header of the incoming user frame, instructing the satellite network equipment to select the first beam from the L downlink beams to transmit the outgoing user frame. This allows the satellite network equipment to select the downlink beam without additional signaling overhead, thus improving channel utilization.

[0007] In one possible implementation, before the terminal sends the first user frame to the satellite network device, the method further includes: the terminal sequentially capturing pilot information in multiple satellite beams and obtaining the beam signal quality of each satellite beam in the multiple satellite beams; wherein, the pilot information includes the beam number and satellite number of the satellite beam; the terminal determines the L downlink beams from the multiple satellite beams based on the captured beam signal quality of the multiple satellite beams.

[0008] In one possible implementation, the beam information includes satellite number, beam number, and beam signal quality; the outbound link indication field includes L beam information fields, which include a satellite number field, a beam number field, and a beam level field; wherein, the satellite number field is used to indicate the satellite number of the downlink beam, the beam number field is used to indicate the beam number of the downlink beam, and the beam level field is used to indicate the level of beam signal quality of the downlink beam.

[0009] The signal quality of this beam includes any one of the following: carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal in the downlink beam.

[0010] In one possible implementation, the first user frame is a data request frame. The frame header of the data request frame includes an outbound link indication field and a subtype field. The subtype indication field indicates the frame type of the data request frame, which is a general data frame. The user information of the data request frame includes a service type field, which indicates the service type of the data request frame, either a mailbox overview query service or a mail download request service. This allows satellite network equipment to select the downlink beam when transmitting service data without additional signaling overhead, improving channel utilization.

[0011] In one possible implementation, the frame type of the second user frame is a general data frame; the second user frame is the first SLC PDU in the first application layer message generated by the satellite network device based on the data request frame, wherein the first application layer message is split into one or more SLC PDUs by the satellite network device, and the one or more SLC PDUs include the first SLC PDU.

[0012] In one possible implementation, the first user frame is an Acknowledgment (ACK) frame, and its header includes the outbound link indication field. Before the terminal sends the first user frame to the satellite network device, the method further includes: the terminal receiving a second SLC PDU transmitted by the satellite network device on a second beam, with the first user frame used to indicate the terminal's reception status of the second SLC PDU. In this way, without additional signaling overhead, the terminal can complete the selection of the downlink beam by the satellite network device when sending the next data frame by including the outbound link indication field in the ACK frame, thereby improving channel utilization.

[0013] In one possible implementation, the frame type of the second user frame is a general data frame; before the terminal sends the first user frame to the satellite network device, the method further includes: the terminal sending a data request frame to the satellite network device, the data request frame being used to request the satellite network device to generate a first application layer message; wherein the first application layer message is split into multiple SLC PDUs by the satellite network device, the multiple SLC PDUs including a first SLC PDU and the second SLC PDU, and the second user frame is the first SLC PDU.

[0014] In one possible implementation, before the terminal sends the first user frame to the satellite network device, the method further includes: the terminal splitting the second application layer message into one or more SLC PDUs, the one or more SLC PDUs including a third SLC PDU; wherein the frame type of the first user frame is a general data frame, the first user frame is the third SLC PDU, and the frame type of the second user frame is an ACK frame or a receipt frame; wherein, when the second user frame is an ACK frame, the second user frame is used to indicate the reception status of the third SLC PDU by the satellite network device; when the second user frame is a receipt frame, the second user frame is used to indicate the parsing status of the second application layer message by the satellite network device.

[0015] In one possible implementation, the frame type of the first user frame is a location reporting frame or an emergency rescue frame.

[0016] In one possible implementation, the terminal sequentially captures pilot information from multiple satellite beams, specifically including:

[0017] The terminal captures pilot information from multiple satellite beams sequentially based on a preset satellite beam acquisition order.

[0018] In one possible implementation, the terminal sequentially captures pilot information from multiple satellite beams, specifically including: the terminal acquiring its own location information; the terminal determining the satellite beam acquisition order of the multiple satellite beams based on its location information and a satellite beam coverage map, wherein the satellite beam coverage map includes beam coverage information for each satellite beam, including one or more of the following: beam center position, beam coverage radius, multiple signal strength intervals, and coverage edge coordinates of each of the multiple signal strength intervals; and the terminal sequentially capturing the pilot information from the multiple satellite beams based on the satellite beam acquisition order.

[0019] In one possible implementation, the terminal determines the satellite beam acquisition order of the multiple satellite beams based on its location information and satellite beam coverage map. Specifically, this includes: the terminal determining the distance between its location and the beam center of each of the multiple satellite beams based on its location information and satellite beam coverage map; and the terminal determining the satellite acquisition order of the multiple satellite beams based on the distance between its location and the beam center of the multiple satellite beams.

[0020] In one possible implementation, the terminal determines the satellite beam acquisition order of the multiple satellite beams based on its location information and satellite beam coverage map. Specifically, this includes: the terminal determining the signal strength range of its location under each of the multiple satellite beams based on its location information and satellite beam coverage map; and the terminal determining the satellite acquisition order of the multiple satellite beams based on the signal strength range of its location under each of the multiple satellite beams.

[0021] In one possible implementation, before the terminal determines the satellite beam acquisition order of the plurality of satellite beams based on the terminal's location information and the satellite beam coverage map, the method further includes: the terminal receiving a satellite beam coverage map sent by a satellite cloud server, wherein the satellite beam coverage map is generated by the satellite cloud server based on multiple measurement locations reported by n satellite terminals and beam signal strength information of the satellite beams at the multiple measurement locations, the beam signal strength information including the satellite number, beam number, and beam signal strength of the satellite beams.

[0022] Secondly, this application provides another beam selection method in a satellite communication system, comprising: a satellite network device receiving a first user frame sent by a terminal, wherein the first user frame carries an outbound link indication field, the outbound link indication field carries beam information of L downlink beams, the outbound link indication field is used to instruct the satellite network device to select a beam from the L downlink beams to send a user frame to the terminal, where L is a positive integer; the satellite network device selects the first beam from the L downlink beams to send a second user frame to the terminal.

[0023] In one possible implementation, the beam information includes satellite number, beam number, and beam signal quality; the outbound link indication field includes L beam information fields, which include a satellite number field, a beam number field, and a beam level field; wherein, the satellite number field is used to indicate the satellite number of the downlink beam, the beam number field is used to indicate the beam number of the downlink beam, and the beam level field is used to indicate the level of beam signal quality of the downlink beam.

[0024] The signal quality of this beam includes any one of the following: carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal in the downlink beam.

[0025] In one possible implementation, the first user frame is a data request frame, and the frame header of the data request frame includes an outbound link indication field and a subtype field. The subtype indication field is used to indicate the frame type of the data request frame, and the frame type of the data request frame is a general data frame.

[0026] The user information in the data request frame includes a service type field, which indicates the service type of the data request frame, namely, mailbox overview query service or mail download request service.

[0027] In one possible implementation, the frame type of the second user frame is a general data frame; before the satellite network device selects the first beam from the L downlink beams to send the second user frame to the terminal, the method further includes: the satellite network device generating a first application layer message based on the data request frame; the satellite network device splitting the first application layer message into one or more SLC PDUs, wherein the one or more SLC PDUs include the first SLC PDU.

[0028] In one possible implementation, the first user frame is an ACK frame, and the header of the first user frame includes the outbound link indication field. Before the satellite network device receives the first user frame sent by the terminal, the method further includes: the satellite network device sending a second SLC PDU to the terminal on a second beam, wherein the first user frame is used to indicate the terminal's reception status of the second SLC PDU.

[0029] In one possible implementation, the frame type of the second user frame is a general data frame; the method further includes: the satellite network device receiving a data request frame sent by the terminal; the satellite network device generating a first application layer message based on the data request frame; the satellite network device splitting the first application layer message into multiple SLC PDUs, the multiple SLC PDUs including a first SLC PDU and the second SLC PDU, and the second user frame being the first SLC PDU.

[0030] In one possible implementation, the first user frame is a general data frame, and the first user frame is the third SLC PDU among one or more SLC PDUs into which the second application layer message is split by the terminal; the second user frame is an ACK frame or a receipt frame; wherein, when the second user frame is an ACK frame, the second user frame is used to indicate the reception status of the third SLC PDU by the satellite network device; when the second user frame is a receipt frame, the second user frame is used to indicate the parsing status of the second application layer message by the satellite network device.

[0031] In one possible implementation, the frame type of the first user frame is a location reporting frame or an emergency rescue frame.

[0032] Thirdly, this application provides a satellite communication system, including: a first terminal and a satellite network device; wherein the first terminal can execute the method in any of the possible implementations of the first aspect described above. The satellite network device can execute the method in any of the possible implementations of the first aspect described above.

[0033] Fourthly, this application provides a communication device including one or more processors, one or more memories, and a transceiver. The transceiver, the one or more memories, and the one or more processors are coupled together. The one or more memories are used to store computer program code, which includes computer instructions. When the one or more processors execute the computer instructions, the communication device performs the method in any of the possible implementations of the first aspect described above.

[0034] The communication device can be a terminal or other product-type equipment.

[0035] Fifthly, this application provides a communication device including one or more processors, one or more memories, and a transceiver. The transceiver, the one or more memories, and the one or more processors are coupled together. The one or more memories are used to store computer program code, which includes computer instructions. When the one or more processors execute the computer instructions, the communication device performs the method in any of the possible implementations of the second aspect described above.

[0036] The communication device can be a satellite network device, or any network element or a combination of multiple network elements in a satellite network device.

[0037] In a sixth aspect, this application provides a computer storage medium including computer instructions that, when executed on a computer, cause the computer to perform the method in any possible implementation of the first aspect described above.

[0038] In a seventh aspect, this application provides a computer storage medium including computer instructions that, when executed on a computer, cause the computer to perform the method in any possible implementation of the second aspect described above.

[0039] Eighthly, this application provides a computer program product that, when run on a computer, causes the computer to perform the method in any possible implementation of the first aspect described above.

[0040] Ninthly, this application provides a computer program product that, when run on a computer, causes the computer to perform the method in any possible implementation of the second aspect described above.

[0041] In a tenth aspect, this application provides a chip or chip system for use in a terminal, including a processing circuit and an interface circuit. The interface circuit is used to receive code instructions and transmit them to the processing circuit, and the processing circuit is used to execute the code instructions to perform the method in any possible implementation of the first aspect described above.

[0042] For the beneficial effects of aspects two through six, please refer to the beneficial effects of aspect one, which will not be repeated here. Attached Figure Description

[0043] Figure 1 This application provides a schematic diagram of the architecture of a BeiDou communication system.

[0044] Figure 2A This application provides a schematic diagram of the data inbound transmission process in a BeiDou communication system, as illustrated in an embodiment of the present application.

[0045] Figure 2B This application provides a schematic diagram of the data outgoing transmission process in a BeiDou communication system, as illustrated in an embodiment of the present application.

[0046] Figure 3 This is a schematic diagram of the terminal structure provided in the embodiments of this application;

[0047] Figure 4 This is a schematic diagram of the protocol encapsulation architecture for inbound data of a Beidou communication system provided in this application embodiment;

[0048] Figure 5 This is a schematic diagram of the protocol parsing architecture for inbound data of a Beidou communication system provided in this application embodiment;

[0049] Figure 6 This is a schematic diagram of the protocol encapsulation architecture for outbound data of a Beidou communication system provided in this application embodiment;

[0050] Figure 7 This is a schematic diagram of the protocol parsing architecture for outbound data of a Beidou communication system provided in this application embodiment;

[0051] Figure 8 This is a flowchart illustrating a beam selection method in a BeiDou communication system provided in this application embodiment;

[0052] Figure 9A This is a schematic diagram of the frame format of a general inbound data frame provided in an embodiment of this application;

[0053] Figure 9B This is a schematic diagram of the frame header format of a general inbound data frame provided in an embodiment of this application;

[0054] Figure 9C This is a schematic diagram of the structure of an outbound link indication field provided in an embodiment of this application;

[0055] Figure 10 This is a flowchart illustrating a beam selection method in a BeiDou communication system provided in another embodiment of this application;

[0056] Figure 11A This is a schematic diagram of the frame format of an inbound ACK frame provided in an embodiment of this application;

[0057] Figure 11B This is a schematic diagram of the header format of an inbound ACK frame provided in an embodiment of this application;

[0058] Figure 11C This is a schematic diagram of the frame format of an inbound receipt frame provided in an embodiment of this application;

[0059] Figure 12 This is a flowchart illustrating a beam selection method in a BeiDou communication system provided in another embodiment of this application;

[0060] Figure 13 This is a schematic diagram of the frame format of a location reporting frame or emergency rescue frame provided in the embodiments of this application;

[0061] Figure 14 This is a partial schematic diagram of a satellite beam coverage map provided in an embodiment of this application;

[0062] Figure 15This is a schematic diagram of the architecture of another Beidou communication system provided in the embodiments of this application;

[0063] Figure 16 This is a schematic diagram illustrating a method for generating a satellite beam coverage map provided in an embodiment of this application;

[0064] Figure 17 This is a schematic diagram of another outbound link indication field provided in the embodiments of this application;

[0065] Figure 18 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0066] Figure 19 This is a schematic diagram of another communication device provided in an embodiment of this application;

[0067] Figure 20 This is a schematic diagram of another communication device provided in an embodiment of this application;

[0068] Figure 21 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0069] The technical solutions in the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; the word "and / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0070] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0071] The following describes a BeiDou communication system 10 provided in the embodiments of this application.

[0072] Figure 1 A schematic diagram of the architecture of a Beidou communication system 10 provided in an embodiment of this application is shown.

[0073] As above Figure 1As shown, the BeiDou communication system 10 may include a terminal 100, a BeiDou short message satellite 21, a BeiDou network device 200, a short message center 25, and a terminal 300. Optionally, the BeiDou communication system 10 may also include a national emergency rescue platform 26 and a national emergency rescue center 27.

[0074] Terminal 100 can send short message information to BeiDou short message satellite 21. BeiDou short message satellite 21 only acts as a relay, directly forwarding the short message information sent by terminal 100 to BeiDou network equipment 200 on the ground. BeiDou network equipment 200 can parse the short message information forwarded by the satellite according to the BeiDou communication protocol and forward the message content of the general message type parsed from the short message information to the short message service center (SMSC) 25. Short message service center 25 can forward the message content to terminal 300 through traditional cellular communication network. BeiDou network equipment 200 can also send emergency distress messages sent by terminal 100 to the National Emergency Rescue Center 27 through the National Emergency Rescue Platform 26.

[0075] Terminal 300 can also send short messages to Short Message Service (SMS) Center 25 via traditional cellular communication networks. SMS Center 25 can forward the short messages from Terminal 300 to BeiDou network device 200. BeiDou network device 200 can then relay the short messages from Terminal 300 to Terminal 100 via BeiDou short message satellite 21.

[0076] The aforementioned BeiDou network equipment 200 may include a BeiDou ground transceiver station 22, a BeiDou central station 23, and a BeiDou short message fusion communication platform 24. The BeiDou ground transceiver station 22 may include one or more devices with transmitting and receiving functions, or it may include one or more devices with both transmitting and receiving functions; this is not limited here. The BeiDou ground transceiver station 22 can be used by the BeiDou network equipment 200 for data processing at the physical layer protocol (PHY). The BeiDou central station 23 can be used by the BeiDou network equipment 200 for data processing at the satellite link control protocol (SLC) and message data convergence protocol (MDCP) layers. The BeiDou short message fusion communication platform 24 can be used for data processing at the application layer protocol (APP).

[0077] Because the BeiDou-10 communication system communicates via satellite links, its main characteristics are: long latency (approximately 270ms one-way) and high link loss. Currently, the BeiDou-10 communication system mainly supports bursty short message services and does not support connection state management, mobility management, broadcast control information, etc.

[0078] Terminal 100 can actively send data to BeiDou network equipment 200 via BeiDou short message satellite 21. However, due to the lack of air interface signaling, the ground central station cannot actively page the user. Because satellite communication has a long propagation distance, the BeiDou communication system 10 requires high transmission power from terminal 100. Limited by the current radio frequency (RF) devices on terminal 100, terminal 100 cannot continuously send signals to BeiDou short message satellite 21 for extended periods. To minimize damage to the RF devices on terminal 100, after continuous operation in the transmission state for a period, the RF devices of terminal 100 must stop working for a period before switching back to the transmission state. The duration of the transmission state on terminal 100 is determined by the underlying hardware capabilities of terminal 100. In the aforementioned BeiDou communication system 10, to ensure that the data received and transmitted by terminal 100 do not interfere with each other, terminal 100 does not support simultaneous data transmission and reception. Terminal 100 needs to send data first and then wait to receive data sent by BeiDou network equipment 200.

[0079] Among them, the Beidou network device 200 can operate in full-duplex mode, which can send and receive data simultaneously, and the Beidou network device 200 can send and receive data for a long time.

[0080] Figure 2A This application illustrates a data inbound transmission process in a BeiDou communication system provided by an embodiment of the present application.

[0081] like Figure 2A As shown, data inbound (also known as data uplink) refers to terminal 100 sending data to BeiDou network device 200. For example, terminal 100 can send data frames to BeiDou ground transceiver station 22. BeiDou ground transceiver station 22 can send the data frames to BeiDou central station 23. BeiDou central station 23 can aggregate the data frames into application layer messages and report them to BeiDou short message fusion communication platform 24. After receiving the data frames sent by terminal 100, BeiDou central station 23 can return an SLC layer acknowledgment character (ACK) to terminal 100. This ACK can be used to indicate whether BeiDou network device 200 has successfully received the data frames sent by terminal 100.

[0082] Figure 2B This illustration shows the data outgoing transmission process in a BeiDou communication system provided in an embodiment of this application.

[0083] like Figure 2B As shown, data outbound (also known as data downlink) refers to the BeiDou network device 200 sending data to the terminal 100. For example, the BeiDou short message fusion communication platform 24 in the BeiDou network device 200 can send application layer messages to the BeiDou central station 23; then the BeiDou central station 23 can split the application layer message into one or more data frames and send them to the BeiDou ground transceiver station 22, which is then relayed by the BeiDou short message satellite 21 and sent to the terminal 100. After receiving the data frame, the terminal 100 can return an SLC layer ACK to the BeiDou central station 23. This ACK can be used to determine whether the terminal 100 has successfully received the data frame sent by the BeiDou network device 200. Optionally, after receiving the data frame sent by the BeiDou central station 23, the terminal 100 may choose not to send an SLC layer ACK to the BeiDou central station 23.

[0084] Figure 3 A schematic diagram of the terminal 100 is shown.

[0085] The following description uses terminal 100 as an example to illustrate the embodiment. It should be understood that... Figure 3 The terminal 100 shown is merely an example, and terminal 100 can have more than... Figure 3 The more or fewer components shown can be combined into two or more components, or they can have different component configurations. Figure 3 The various components shown can be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0086] Terminal 100 may include: processor 110, external memory interface 120, internal memory 121, universal serial bus (USB) interface 130, charging management module 140, power management module 141, battery 142, antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, sensor module 180, button 190, motor 191, indicator 192, camera 193, display screen 194, and subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, a barometric pressure sensor 180C, a magnetic sensor 180D, an accelerometer sensor 180E, a distance sensor 180F, a proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0087] It is understood that the structure illustrated in the embodiments of the present invention does not constitute a specific limitation on the terminal 100. In other embodiments of this application, the terminal 100 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0088] Processor 110 may include one or more processing units, such as: application processor (AP), modem processor, graphics processing unit (GPU), image signal processor (ISP), controller, memory, video codec, digital signal processor (DSP), baseband processor, and / or neural network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0089] The controller can serve as the central nervous system and command center of the terminal 100. The controller can generate operation control signals based on the instruction opcode and timing signals to control the fetching and execution of instructions.

[0090] The processor 110 may also include a memory for storing instructions and data. In some embodiments, the memory in the processor 110 is a cache memory. This memory can store instructions or data that the processor 110 has just used or that are used repeatedly. If the processor 110 needs to use the instruction or data again, it can retrieve it directly from the memory. This avoids repeated accesses, reduces the waiting time of the processor 110, and thus improves the efficiency of the system.

[0091] In some embodiments, the processor 110 may include one or more interfaces. Interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0092] The I2C interface is a bidirectional synchronous serial bus, including a serial data line (SDA) and a serial clock line (SCL). In some embodiments, the processor 110 may include multiple I2C buses. The processor 110 can couple to the touch sensor 180K, charger, flash, camera 193, etc., through different I2C bus interfaces. For example, the processor 110 can couple to the touch sensor 180K through the I2C interface, enabling the processor 110 and the touch sensor 180K to communicate through the I2C bus interface, thereby realizing the touch function of the terminal 100.

[0093] The I2S interface can be used for audio communication. In some embodiments, the processor 110 may include multiple I2S buses. The processor 110 can be coupled to the audio module 170 via the I2S bus to enable communication between the processor 110 and the audio module 170. In some embodiments, the audio module 170 can transmit audio signals to the wireless communication module 160 via the I2S interface to enable the function of answering phone calls through a Bluetooth headset.

[0094] The PCM interface can also be used for audio communication, sampling, quantizing, and encoding analog signals. In some embodiments, the audio module 170 and the wireless communication module 160 can be coupled via the PCM bus interface. In some embodiments, the audio module 170 can also transmit audio signals to the wireless communication module 160 via the PCM interface, enabling the function of answering phone calls through a Bluetooth headset. Both the I2S interface and the PCM interface can be used for audio communication.

[0095] The UART interface is a universal serial data bus used for asynchronous communication. This bus can be a bidirectional communication bus. It converts the data to be transmitted between serial and parallel communication. In some embodiments, the UART interface is typically used to connect the processor 110 and the wireless communication module 160. For example, the processor 110 communicates with the Bluetooth module in the wireless communication module 160 via the UART interface to implement Bluetooth functionality. In some embodiments, the audio module 170 can transmit audio signals to the wireless communication module 160 via the UART interface to enable music playback through Bluetooth headphones.

[0096] The MIPI interface can be used to connect the processor 110 to peripheral devices such as the display screen 194 and the camera 193. The MIPI interface includes a camera serial interface (CSI) and a display serial interface (DSI). In some embodiments, the processor 110 and the camera 193 communicate via the CSI interface to enable the shooting function of the terminal 100. The processor 110 and the display screen 194 communicate via the DSI interface to enable the display function of the terminal 100.

[0097] The GPIO interface can be configured via software. It can be configured as a control signal or a data signal. In some embodiments, the GPIO interface can be used to connect the processor 110 to a camera 193, a display screen 194, a wireless communication module 160, an audio module 170, a sensor module 180, etc. The GPIO interface can also be configured as an I2C interface, an I2S interface, a UART interface, a MIPI interface, etc.

[0098] USB port 130 is a USB standard compliant interface, specifically a Mini USB port, Micro USB port, USB Type-C port, etc. USB port 130 can be used to connect a charger to charge terminal 100, and can also be used for data transfer between terminal 100 and peripheral devices. It can also be used to connect headphones for audio playback. This interface can also be used to connect other electronic devices, such as AR devices.

[0099] It is understood that the interface connection relationships between the modules illustrated in the embodiments of the present invention are merely illustrative and do not constitute a structural limitation on the terminal 100. In other embodiments of this application, the terminal 100 may also adopt different interface connection methods or a combination of multiple interface connection methods as described in the above embodiments.

[0100] The charging management module 140 receives charging input from a charger. The charger can be a wireless charger or a wired charger. In some wired charging embodiments, the charging management module 140 receives charging input from the wired charger via the USB interface 130. In some wireless charging embodiments, the charging management module 140 receives wireless charging input via the wireless charging coil of the terminal 100. While charging the battery 142, the charging management module 140 can also supply power to the electronic device via the power management module 141.

[0101] The power management module 141 connects the battery 142, the charging management module 140, and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140, providing power to the processor 110, internal memory 121, external memory, display screen 194, camera 193, and wireless communication module 160, etc. The power management module 141 can also monitor parameters such as battery capacity, battery cycle count, and battery health status (leakage current, impedance). In some other embodiments, the power management module 141 may also be located within the processor 110. In other embodiments, the power management module 141 and the charging management module 140 may be located in the same device.

[0102] The wireless communication function of terminal 100 can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem processor and baseband processor, etc.

[0103] Antennas 1 and 2 are used to transmit and receive electromagnetic wave signals. Each antenna in terminal 100 can be used to cover one or more communication frequency bands. Different antennas can also be multiplexed to improve antenna utilization. For example, antenna 1 can be multiplexed as a diversity antenna for a wireless local area network. In some other embodiments, the antennas can be used in conjunction with tuning switches.

[0104] The mobile communication module 150 can provide solutions for wireless communication applications including 2G / 3G / 4G / 5G on the terminal 100. The mobile communication module 150 may include at least one filter, switch, power amplifier, low-noise amplifier (LNA), etc. The mobile communication module 150 can receive electromagnetic waves via the antenna 1, and perform filtering, amplification, and other processing on the received electromagnetic waves before transmitting them to the modem processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modem processor and convert it into electromagnetic waves for radiation via the antenna 1. In some embodiments, at least some functional modules of the mobile communication module 150 may be housed in the processor 110. In some embodiments, at least some functional modules of the mobile communication module 150 and at least some modules of the processor 110 may be housed in the same device.

[0105] The modem processor may include a modulator and a demodulator. The modulator modulates the low-frequency baseband signal to be transmitted into a mid-to-high frequency signal. The demodulator demodulates the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing. After processing by the baseband processor, the low-frequency baseband signal is transmitted to the application processor. The application processor outputs sound signals through an audio device (not limited to speaker 170A, receiver 170B, etc.) or displays images or videos through the display screen 194. In some embodiments, the modem processor may be a separate device. In other embodiments, the modem processor may be independent of the processor 110 and may be housed in the same device as the mobile communication module 150 or other functional modules.

[0106] The wireless communication module 160 can provide solutions for wireless communication applications on the terminal 100, including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), satellite communication modules, frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies. The wireless communication module 160 can be one or more devices integrating at least one communication processing module. The wireless communication module 160 receives electromagnetic waves via antenna 2, performs frequency modulation and filtering of the electromagnetic wave signals, and sends the processed signal to processor 110. The wireless communication module 160 can also receive signals to be transmitted from processor 110, perform frequency modulation and amplification, and convert them into electromagnetic waves for radiation via antenna 2.

[0107] Among them, the satellite communication module can be used to communicate with satellite network equipment. For example, in the BeiDou communication system, the satellite communication module can communicate with BeiDou network equipment 200, and the satellite communication module can support short message transmission between BeiDou network equipment 200.

[0108] In some embodiments, antenna 1 of terminal 100 is coupled to mobile communication module 150, and antenna 2 is coupled to wireless communication module 160, enabling terminal 100 to communicate with networks and other devices via wireless communication technology. The wireless communication technology may include Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Time Division Code Division Multiple Access (TD-SCDMA), Long Term Evolution (LTE), BT, GNSS, WLAN, NFC, FM, and / or IR technologies, etc. The GNSS may include the Global Positioning System (GPS), the Global Navigation Satellite System (GLONASS), the BeiDou Navigation Satellite System (BDS), the Quasi-Zenith Satellite System (QZSS), and / or satellite-based augmentation systems (SBAS).

[0109] Terminal 100 implements display functions through a GPU, display screen 194, and application processor. The GPU is a microprocessor for image processing, connected to the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations and for graphics rendering. Processor 110 may include one or more GPUs, which execute program instructions to generate or modify display information.

[0110] Display screen 194 is used to display images, videos, etc. Display screen 194 includes a display panel. The display panel may be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a miniature LED, a microLED, a quantum dot light-emitting diode (QLED), etc. In some embodiments, terminal 100 may include one or N displays 194, where N is a positive integer greater than 1.

[0111] Terminal 100 can perform shooting functions through ISP, camera 193, video codec, GPU, display 194 and application processor.

[0112] The ISP (Image Signal Processor) is used to process data fed back from the camera 193. For example, when taking a picture, the shutter is opened, and light is transmitted through the lens to the camera's photosensitive element. The light signal is converted into an electrical signal, and the camera's photosensitive element transmits the electrical signal to the ISP for processing, transforming it into an image visible to the naked eye. The ISP can also perform algorithmic optimization of image noise, brightness, and skin tone. The ISP can also optimize parameters such as exposure and color temperature of the shooting scene. In some embodiments, the ISP can be set in the camera 193.

[0113] Camera 193 is used to capture still images or videos. An object is projected onto a photosensitive element by generating an optical image through the lens. The photosensitive element can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the light signal into an electrical signal, which is then passed to an ISP for conversion into a digital image signal. The ISP outputs the digital image signal to a DSP for processing. The DSP converts the digital image signal into image signals in standard RGB, YUV, or other formats. In some embodiments, terminal 100 may include one or N cameras 193, where N is a positive integer greater than 1.

[0114] A digital signal processor (DSP) is used to process digital signals. Besides digital image signals, it can also process other digital signals. For example, when terminal 100 selects a frequency point, the DSP can perform Fourier transforms on the frequency energy.

[0115] Video codecs are used to compress or decompress digital video. Terminal 100 may support one or more video codecs. Thus, terminal 100 can play or record videos in various encoding formats, such as Moving Picture Experts Group (MPEG) 1, MPEG 2, MPEG 3, MPEG 4, etc.

[0116] NPU stands for Neural Network (NN) Computing Processor. By borrowing the structure of biological neural networks, such as the transmission patterns between neurons in the human brain, it can rapidly process input information and continuously learn on its own. NPUs can enable intelligent cognitive applications in terminals, such as image recognition, facial recognition, speech recognition, and text understanding.

[0117] The external storage interface 120 can be used to connect an external storage card, such as a Micro SD card, to expand the storage capacity of the terminal 100. The external storage card communicates with the processor 110 through the external storage interface 120 to perform data storage functions. For example, music, video, and other files can be saved on the external storage card.

[0118] Internal memory 121 can be used to store computer executable program code, which includes instructions. Processor 110 executes various functional applications and data processing of terminal 100 by running the instructions stored in internal memory 121. Internal memory 121 may include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback, image playback, etc.), etc. The data storage area may store data created during the use of terminal 100 (such as audio data, phonebook, etc.). Furthermore, internal memory 121 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.

[0119] Terminal 100 can implement audio functions, such as music playback and recording, through audio module 170, speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, and application processor.

[0120] The audio module 170 is used to convert digital audio information into analog audio signals for output, and also to convert analog audio input into digital audio signals. The audio module 170 can also be used for encoding and decoding audio signals. In some embodiments, the audio module 170 may be located in the processor 110, or some functional modules of the audio module 170 may be located in the processor 110.

[0121] The speaker 170A, also known as a "loudspeaker," is used to convert audio electrical signals into sound signals. The terminal 100 can listen to music or make hands-free calls through the speaker 170A.

[0122] The receiver 170B, also known as the "earpiece," is used to convert audio electrical signals into sound signals. When the terminal 100 receives a phone call or voice message, the receiver 170B can be brought close to the listener's ear to hear the voice.

[0123] Microphone 170C, also known as a "microphone" or "voice transducer," is used to convert sound signals into electrical signals. When making a phone call or sending a voice message, the user can speak by bringing their mouth close to microphone 170C, inputting the sound signal into microphone 170C. Terminal 100 may have at least one microphone 170C. In some embodiments, terminal 100 may have two microphones 170C, which, in addition to collecting sound signals, can also perform noise reduction. In other embodiments, terminal 100 may have three, four, or more microphones 170C, which can collect sound signals, reduce noise, identify the sound source, and perform directional recording, etc.

[0124] The 170D headphone jack is used to connect wired headphones. The 170D headphone jack can be a USB 130 interface or a 3.5mm Open Mobile Terminal Platform (OMTP) standard interface, a CTIA (Cellular Telecommunications Industry Association of the USA) standard interface.

[0125] Pressure sensor 180A is used to sense pressure signals and convert them into electrical signals. In some embodiments, pressure sensor 180A can be disposed on display screen 194. There are many types of pressure sensors 180A, such as resistive pressure sensors, inductive pressure sensors, and capacitive pressure sensors. A capacitive pressure sensor may include at least two parallel plates with conductive material. When force is applied to pressure sensor 180A, the capacitance between the electrodes changes. Terminal 100 determines the pressure intensity based on the change in capacitance. When a touch operation is applied to display screen 194, terminal 100 detects the intensity of the touch operation based on pressure sensor 180A. Terminal 100 can also calculate the touch position based on the detection signal from pressure sensor 180A. In some embodiments, touch operations applied to the same touch position but with different touch operation intensities can correspond to different operation commands. For example: when a touch operation with an intensity less than a first pressure threshold is applied to the SMS application icon, a command to view an SMS is executed. When a touch operation with an intensity greater than or equal to the first pressure threshold is applied to the SMS application icon, a command to create a new SMS is executed.

[0126] The gyroscope sensor 180B can be used to determine the motion attitude of the terminal 100. In some embodiments, the gyroscope sensor 180B can determine the angular velocity of the terminal 100 around three axes (i.e., the x, y, and z axes). The gyroscope sensor 180B can be used for image stabilization. For example, when the shutter is pressed, the gyroscope sensor 180B detects the angle of the terminal 100's shake, calculates the distance that the lens module needs to compensate based on the angle, and allows the lens to counteract the shake of the terminal 100 through reverse movement, thus achieving image stabilization. The gyroscope sensor 180B can also be used in navigation and motion-sensing game scenarios.

[0127] The barometric pressure sensor 180C is used to measure air pressure. In some embodiments, the terminal 100 calculates altitude using the air pressure value measured by the barometric pressure sensor 180C to assist in positioning and navigation.

[0128] The magnetic sensor 180D includes a Hall sensor. The terminal 100 can use the magnetic sensor 180D to detect the opening and closing of the flip cover. In some embodiments, when the terminal 100 is a flip phone, the terminal 100 can detect the opening and closing of the flip cover using the magnetic sensor 180D. Then, based on the detected opening and closing state of the cover or the flip cover, features such as automatic flip unlocking can be set.

[0129] The 180E accelerometer can detect the magnitude of acceleration of terminal 100 in various directions (typically three axes). When terminal 100 is stationary, it can detect the magnitude and direction of gravity. It can also be used to identify the posture of electronic devices, and is applied to applications such as screen orientation switching and pedometers.

[0130] A distance sensor 180F is used to measure distance. The terminal 100 can measure distance via infrared or laser. In some embodiments, during a shooting scene, the terminal 100 can utilize the distance sensor 180F to measure distance for rapid focusing.

[0131] The proximity sensor 180G may include, for example, a light-emitting diode (LED) and a light detector, such as a photodiode. The LED may be an infrared LED. The terminal 100 emits infrared light outward through the LED. The terminal 100 uses the photodiode to detect infrared reflected light from nearby objects. When sufficient reflected light is detected, it can be determined that there is an object near the terminal 100. When insufficient reflected light is detected, the terminal 100 can determine that there is no object near the terminal 100. The terminal 100 may use the proximity sensor 180G to detect when a user holds the terminal 100 close to their ear for a call, so as to automatically turn off the screen to save power. The proximity sensor 180G can also be used in holster mode and pocket mode for automatic unlocking and screen locking.

[0132] The ambient light sensor 180L is used to sense the ambient light intensity. The terminal 100 can adaptively adjust the brightness of the display screen 194 based on the sensed ambient light intensity. The ambient light sensor 180L can also be used to automatically adjust the white balance when taking pictures. The ambient light sensor 180L can also work with the proximity sensor 180G to detect whether the terminal 100 is in a pocket to prevent accidental touches.

[0133] The fingerprint sensor 180H is used to collect fingerprints. The terminal 100 can use the characteristics of the collected fingerprints to unlock the device, access application locks, take photos with fingerprints, and answer calls with fingerprints.

[0134] Temperature sensor 180J is used to detect temperature. In some embodiments, terminal 100 uses the temperature detected by temperature sensor 180J to execute a temperature processing strategy. For example, when the temperature reported by temperature sensor 180J exceeds a threshold, terminal 100 reduces the performance of the processor located near temperature sensor 180J to reduce power consumption and implement thermal protection. In other embodiments, when the temperature is below another threshold, terminal 100 heats battery 142 to prevent abnormal shutdown of terminal 100 due to low temperature. In still other embodiments, when the temperature is below yet another threshold, terminal 100 boosts the output voltage of battery 142 to prevent abnormal shutdown due to low temperature.

[0135] Touch sensor 180K, also known as a "touch panel," can be located on display screen 194. The touch sensor 180K and display screen 194 together form a touchscreen, also known as a "touchscreen." Touch sensor 180K detects touch operations applied to or near it. The touch sensor can transmit the detected touch operation to the application processor to determine the type of touch event. Visual output related to the touch operation can be provided through display screen 194. In other embodiments, touch sensor 180K may also be located on the surface of terminal 100, in a different position than display screen 194.

[0136] The bone conduction sensor 180M can acquire vibration signals. In some embodiments, the bone conduction sensor 180M can acquire vibration signals from the vibrating bone segments of the human vocal cords. The bone conduction sensor 180M can also contact the human pulse to receive blood pressure signals. In some embodiments, the bone conduction sensor 180M can also be incorporated into headphones to form bone conduction headphones. The audio module 170 can parse the voice signals from the vibrating bone segments of the vocal cords acquired by the bone conduction sensor 180M to realize voice functionality. The application processor can parse heart rate information from the blood pressure signals acquired by the bone conduction sensor 180M to realize heart rate detection functionality.

[0137] Buttons 190 include a power button, volume buttons, etc. Buttons 190 can be mechanical buttons or touch-sensitive buttons. Terminal 100 can receive button input and generate key signal inputs related to user settings and function control of terminal 100.

[0138] Motor 191 can generate vibration alerts. Motor 191 can be used for incoming call vibration alerts or for touch vibration feedback. For example, different vibration feedback effects can correspond to touch operations performed on different applications (such as taking photos, playing audio, etc.). Motor 191 can also correspond to different vibration feedback effects for touch operations performed on different areas of the display screen 194. Different application scenarios (such as time reminders, receiving messages, alarm clocks, games, etc.) can also correspond to different vibration feedback effects. The touch vibration feedback effect can also be customized.

[0139] Indicator 192 can be an indicator light, used to indicate charging status, power changes, or to indicate messages, missed calls, notifications, etc.

[0140] The SIM card interface 195 is used to connect a SIM card. The SIM card can be inserted into or removed from the SIM card interface 195 to make contact with and separate from the terminal 100. The terminal 100 can support one or N SIM card interfaces, where N is a positive integer greater than 1. The SIM card interface 195 can support Nano SIM cards, Micro SIM cards, SIM cards, etc. Multiple cards can be inserted into the same SIM card interface 195 simultaneously. The multiple cards can be of the same or different types. The SIM card interface 195 is also compatible with different types of SIM cards. The SIM card interface 195 is also compatible with external memory cards. The terminal 100 interacts with the network through the SIM card to realize functions such as calls and data communication. In some embodiments, the terminal 100 uses an eSIM, i.e., an embedded SIM card. The eSIM card can be embedded in the terminal 100 and cannot be separated from the terminal 100.

[0141] The following describes a protocol encapsulation architecture for inbound data of a Beidou communication system 10 provided in the embodiments of this application.

[0142] Figure 4 This paper illustrates a schematic diagram of the protocol encapsulation architecture for inbound data of a Beidou communication system 10 provided in an embodiment of this application.

[0143] like Figure 4 As shown, the BeiDou message transmission protocol layer on terminal 100 can be divided into application layer protocol, message data convergence protocol (MDCP), satellite link control protocol (SLC) and physical layer protocol (PHY).

[0144] When terminal 100 sends data to BeiDou network device 200, the workflow of the BeiDou message transmission protocol on terminal 100 can be as follows:

[0145] At the APP layer, terminal 100 can compress the original data into compressed data using a compression algorithm, and add a compression indicator field to the front of the compressed data. This compression indicator field indicates the type of compression algorithm used to compress the data. Next, terminal 100 can encrypt the compressed data to obtain encrypted data, and add an encryption indicator field to the header of the encrypted data. This encryption indicator field indicates the type of encryption algorithm used to encrypt the encrypted data. Terminal 100 can then encapsulate the encrypted data, the compression indicator field, and the encryption indicator field into an application layer message and send it to the MDCP layer. This application layer message includes a header and message data. The header includes the compression indicator field, encryption indicator field, etc. The message data includes the aforementioned encrypted data.

[0146] Optionally, terminal 100 can also encrypt the compression instruction field together with the compressed data to obtain encrypted data.

[0147] At the MDCP layer, terminal 100 can obtain application layer messages sent by the APP layer through the inter-layer interface and treat the application layer messages as an MDCP SDU. Due to air interface limitations, terminal 100 can only send physical frames of a specified length at the physical layer each time, thus constraining the length of MDCP layer data to a specified length. Therefore, at the MDCP layer, terminal 100 can add padding data to the end of the MDCPSDU to a specified length and add a redundancy length indicator field to the header of the MDCP SDU. This redundancy length indicator field can be used to indicate the length of the padding data. Terminal 100 can split the padding data and the MDCP SDU with the added redundancy length indicator field into one or more fixed-length MDCP segment data (M_segment), and add a successor indicator field to the header of each MDCP segment data to obtain an MDCP PDU, that is, the MDCP PDU includes M_segment and the successor indicator field. The successor indication field can be used to indicate whether the current MDCPPDU is the first, middle, or last MDCPPDU among a series of consecutively sent MDCCP PDUs; or, it can be a single MDCCP PDU sent independently.

[0148] At the SLC layer, terminal 100 can obtain the MDCPPDU sent by the MDCP layer through the inter-layer interface, and use it as SLCSDU. At the SLC layer, terminal 100 can segment the SLCSDU into one or more (up to four) fixed-length SLC segment data (S_segment), and add frame header information to the header of each S_segment to obtain SLC PDU.

[0149] At the PHY layer, terminal 100 can obtain the SLC PDU issued by the SLC layer through the inter-layer interface, using it as a code block for the PHY layer. A synchronization header is added to the beginning of the code block, and a checksum field is added to the end. In the aforementioned BeiDou communication system 10, cyclic redundancy check (CRC) can be used to verify the code block; therefore, the checksum field can include the CRC code. Terminal 100 can encode the code block and checksum field (e.g., polar encoding) to obtain coded data, and then insert pilot signals into the coded data to obtain pilot coded data (pilot+data). Then, terminal 100 modulates the synchronization header and pilot coded data sequentially through the underlying hardware to obtain modulated data (modulated data). Terminal 100 can spread the modulated data to obtain spread-modulated data (spread+modulated data). Terminal 100 can send the spread-modulated data to BeiDou short message satellite 21, which then relays it to BeiDou network equipment 200.

[0150] The following describes a protocol parsing architecture for inbound data of a Beidou communication system 10 provided in an embodiment of this application.

[0151] Figure 5 This paper illustrates a schematic diagram of the protocol parsing architecture for inbound data of a Beidou communication system 10 provided in an embodiment of this application.

[0152] like Figure 5 As shown, the BeiDou short message transmission protocol layer of the BeiDou network equipment 200 can be divided into an application layer protocol, a message data convergence protocol (MDCP) layer, a satellite link control protocol (SLC) layer, and a physical layer protocol (PHY). The BeiDou network equipment 200 may include a BeiDou ground transceiver station 22, a BeiDou central station 23, and a BeiDou short message fusion communication platform 24. The BeiDou ground transceiver station 22 is responsible for protocol processing at the PHY layer. The BeiDou central station 23 is responsible for protocol processing at the SLC and MDCP layers. The BeiDou short message fusion communication platform 24 is responsible for protocol processing at the application layer protocol.

[0153] When BeiDou network device 200 receives data sent by terminal 100, the workflow of the BeiDou short message transmission protocol layer of BeiDou network device 200 can be as follows:

[0154] At the PHY layer, the BeiDou network device 200 can acquire the modulated and spread-spectrum pilot coded data sent by the terminal 100. The BeiDou network device 200 can despread the received spread-spectrum modulated data (spread+modulateddata) to obtain modulated data (modulateddata). Then, the BeiDou network device 200 can demodulate the modulated data to obtain pilot coded data (pilot+data). Next, the BeiDou network device 200 removes the pilot information from the pilot coded data to obtain coded data (codedata). Then, the BeiDou network device 200 can decode the coded data and verify the integrity of the codeblock through the checksum data in the check bit field. If complete, the BeiDou network device 200 can extract the codeblock and present it to the SLC layer through the inter-layer interface as the SLC PDU of the SLC layer.

[0155] At the SLC layer, the BeiDou network device 200 can combine SLC PDUs belonging to the same SLC SDU into a single SLC SDU based on the frame header information of the SLC PDU. The BeiDou network device 200 can then present the SLC SDU to the MDCP layer through the inter-layer interface, serving as the MDCP PDU for the MDCP layer.

[0156] At the MDCP layer, the BeiDou network device 200 can concatenate all MDCP PDUs belonging to the same MDCP SDU into a single MDCP SDU. The BeiDou network device 200 can then present the MDCP SDU to the APP layer through the inter-layer interface, serving as an application layer message received by the APP layer.

[0157] At the APP layer, the Beidou network device 200 can decrypt and decompress the application layer message based on the message header to obtain the original data.

[0158] In the embodiments of this application, the above protocol processing procedure is only an example for illustration, and this application does not limit the specific operation of protocol processing.

[0159] The following describes a protocol encapsulation architecture for outbound data of a Beidou communication system 10 provided in the embodiments of this application.

[0160] Figure 6 This paper illustrates a schematic diagram of the protocol encapsulation architecture for outbound data of a Beidou communication system 10 provided in an embodiment of this application.

[0161] like Figure 6 As shown, the BeiDou short message transmission protocol layer in the BeiDou network equipment 200 can be divided into an application layer protocol, a message data convergence protocol (MDCP) layer, a satellite link control protocol (SLC) layer, and a physical layer protocol (PHY). The BeiDou network equipment 200 may include a BeiDou ground transceiver station 22, a BeiDou central station 23, and a BeiDou short message fusion communication platform 24. The BeiDou ground transceiver station 22 is responsible for protocol processing at the PHY layer. The BeiDou central station 23 is responsible for protocol processing at the SLC and MDCP layers. The BeiDou short message fusion communication platform 24 is responsible for protocol processing at the APP layer.

[0162] When BeiDou network device 200 sends data to terminal 100, the workflow of the BeiDou short message transmission protocol in BeiDou network device 200 can be as follows:

[0163] At the APP layer, the BeiDou network device 200 can compress the raw data into compressed data using a compression algorithm, and add a compression indicator field to the front of the compressed data. This compression indicator field indicates the type of compression algorithm used. Next, the BeiDou network device 200 can encrypt the compressed data, obtaining encrypted data, and add an encryption algorithm field to the header of the encrypted data. This encryption algorithm field indicates the type of encryption algorithm used. The BeiDou network device 200 can then encapsulate the encrypted data, the compression indicator field, and the encryption indicator field into an application layer message and send it to the MDCP layer. This application layer message can include a message header and message data. The message header may include the compression indicator field and the encryption indicator field, etc. The message data includes the aforementioned encrypted data.

[0164] Optionally, the Beidou network device 200 can also encrypt the compression instruction field together with the compressed data to obtain encrypted data.

[0165] At the MDCP layer, the BeiDou network device 200 can obtain application layer messages sent from the APP layer through the inter-layer interface and treat each application layer message as an MDCP SDU. At the MDCP layer, the BeiDou network device 200 can split an MDCP SDU into one or more fixed-length MDCP segments (M_segement) and add a successor indication field to the header of each MDCP segment to obtain an MDCP PDU. That is, an MDCP PDU includes an M_segement and a successor indication field. The successor indication field can be used to indicate whether the current MDCP PDU is the starting, middle, or last MDCP PDU of a series of consecutively sent MDCP PDUs; or it can be a single, independently sent MDCP PDU.

[0166] At the SLC layer, the BeiDou network device 200 can obtain the MDCP PDU issued by the MDCP layer through the inter-layer interface, and use it as the SLC SDU. At the SLC layer, the BeiDou network device 200 can segment the SLC SDU into one or more (e.g., up to four) fixed-length SLC segment data (S_segement), and add frame header information to the header of each S_segement to obtain the SLCPDU.

[0167] Here, it's understandable that the SLC layer needs to segment the data to accommodate the frame length of the physical layer. However, the SLC layer is designed so that a single SLC SDU can only be divided into a maximum of four SLC PDUs; therefore, the MDCP layer also needs to segment the data.

[0168] At the PHY layer, the BeiDou network device 200 can obtain SLC PDUs from the SLC layer through the inter-layer interface. The BeiDou network device 200 can obtain SLC PDUs from one or more users from the SLC layer. The BeiDou network device 200 can concatenate the SLC PDUs from multiple users, add the frame header (e.g., version number) of the physical frame as a code block for the PHY layer, and add a check bit (e.g., cyclic redundancy check (CRC) code) to the end of the code block. The code block and CRC code are then encoded (e.g., polar encoding). The encoded physical frame, plus a reserved segment, can form the encoded data of a fixed-length physical time slot satellite-to-consumer data (S2C-d) channel (simply put, the data channel). The BeiDou network device 200 can also place multiple SLC PDUs from one user into different physical frames. Then, the BeiDou network device 200 combines the encoded data of the S2C-d channel branch with the pilot information of the satellite-to-consumer pilot (S2C-p) channel (hereinafter referred to as the pilot channel) to form pilot encoded data, i.e., outgoing data. The BeiDou network device 200 can send the outgoing data to the BeiDou short message satellite 21, which will then relay it to the terminal 100.

[0169] Understandably, the pilot information of the S2C_p channel branch is related to the satellite beam. When the satellite beam number is known, the pilot information of the S2C-p channel branch is also known and does not require decoding. The pilot information includes subcodes, where the data length of a subcode sequence can be 125 bits. When the transmission rate on the S2C-p channel branch is 1 kbps, the transmission duration of a subcode sequence is 125 ms. Therefore, the duration of a physical transmission slot on the S2C-d channel branch is also 125 ms.

[0170] The encoded data in the S2C_d channel branch needs to be decoded. The S2C-p channel and the S2C-d channel have the same center frequency and bandwidth, and the signals on the S2C-p channel are orthogonal to the signals on the S2C-d channel branch.

[0171] The following describes a protocol parsing architecture for outbound data of a Beidou communication system 10 provided in the embodiments of this application.

[0172] Figure 7 This paper illustrates a schematic diagram of the protocol parsing architecture for outbound data of a Beidou communication system 10 provided in an embodiment of this application.

[0173] like Figure 7 As shown, the BeiDou short message transmission protocol layer of terminal 100 can be divided into application layer protocol, message data convergence protocol (MDCP), satellite link control protocol (SLC) and physical layer protocol (PHY).

[0174] When terminal 100 receives data sent by BeiDou network equipment, the workflow of the BeiDou short message transmission protocol layer of terminal 100 can be as follows:

[0175] At the PHY layer, terminal 100 can obtain the modulated and spread-spectrum pilot coded data sent by BeiDou network device 200. Terminal 100 can despread the received spread-spectrum modulated data to obtain modulated data. Then, terminal 100 can demodulate the modulated data to obtain pilot coded data. Next, terminal 100 can remove the pilot information from the pilot coded data to obtain coded data. Then, terminal 100 can decode the coded data and verify the integrity of the code block through the check bit field. If complete, terminal 100 can extract the code block and present it to the SLC layer through the inter-layer interface as the SLC PDU of the SLC layer.

[0176] Here, the pilot coded data is the outgoing data sent by the Beidou network device 200 mentioned above. The outgoing data consists of the coded data of the S2C-d channel and the pilot information of the S2C-p channel.

[0177] At the SLC layer, terminal 100 can concatenate SLC PDUs belonging to the same SLC SDU into a single SLC SDU based on the frame header information of the SLC PDU. Terminal 100 can then present the SLC SDU to the MDCP layer through the inter-layer interface, serving as the MDCP PDU for the MDCP layer.

[0178] At the MDCP layer, terminal 100 can concatenate all MDCP PDUs belonging to the same MDCP SDU into a single MDCPSDU. Terminal 100 can then present the MDCP SDU to the APP layer through the inter-layer interface, serving as an application layer message received by the APP layer.

[0179] At the APP layer, terminal 100 can decrypt and decompress the application layer message based on the message header to obtain the original data.

[0180] In the embodiments of this application, the above protocol processing procedure is only an example for illustration, and this application does not limit the specific operation of protocol processing.

[0181] This application provides a beam selection method in a BeiDou communication system. Terminal 100 can acquire the satellite number, beam number, and beam signal quality of multiple satellite beams. Based on the acquired beam signal quality of the multiple satellite beams, terminal 100 can determine L downlink beams, where L is a positive integer. Terminal 100 carries beam information of the L satellite beams in a first user frame sent to BeiDou network device 200. This beam information includes the satellite number, beam number, and beam profile. The beam profile indicates the level of beam signal quality. After receiving the first user frame, BeiDou network device 200 can select a first beam from these L downlink beams and send a second user frame to terminal 100 on the first beam. In this way, the downlink beam selection of BeiDou network device 200 can be completed without additional signaling overhead, improving channel utilization.

[0182] The following describes a beam selection method in a BeiDou communication system provided in this application embodiment, with specific application scenarios as examples.

[0183] In some application scenarios, without connection state management and mobility management in the BeiDou communication system 10, the BeiDou network device 200 cannot actively page users. Therefore, before the terminal 100 receives service data from the BeiDou network device 200, the terminal 100 needs to actively send a data request frame to the BeiDou network device 200. The terminal 100 can capture multiple satellite beams and obtain the satellite number, beam number, and carrier-to-noise ratio of multiple satellite beams. The terminal 100 can select L downlink beams from the multiple satellite beams and carry the downlink beam information of the L downlink beams in the data request frame. This beam information is used to instruct the BeiDou network device 200 to select the first beam among these L downlink beams to send service data to the terminal 100. In this way, the selection of downlink beams by the BeiDou network device 200 can be completed without additional signaling overhead, improving channel utilization.

[0184] Figure 8 A flowchart illustrating a beam selection method in a BeiDou communication system provided in an embodiment of this application is shown.

[0185] like Figure 8 As shown, the method includes:

[0186] S801 and Beidou network equipment 200 transmit pilot information on each satellite beam. The pilot information includes the satellite number and beam number of the satellite beam.

[0187] Specifically, the 200 pairs of sub-codes for BeiDou network equipment can be encoded using pseudo-random sequence codes (such as Gold codes). Each set of pseudo-random sequence codes corresponds to the satellite number and beam number of a satellite beam.

[0188] The BeiDou short message satellite 21 in the BeiDou communication system 10 may include satellites C59, C60, and C61. Each satellite may have six satellite beams. In one possible implementation, the BeiDou short message satellite 21 may also support increasing the number of satellites; for example, it may also include satellites C62 and C63.

[0189] For example, the correspondence between Gold codes and satellite and beam numbers of satellite beams can be shown in Table 1 below:

[0190] Table 1

[0191]

[0192]

[0193] As shown in Table 1 above, the satellite beam number corresponding to pseudo-random sequence code 1 is "C59", and the beam number is "1". The satellite beam number corresponding to pseudo-random sequence code 2 is "C59", and the beam number is "2". The satellite beam number corresponding to pseudo-random sequence code 3 is "C59", and the beam number is "3". The satellite beam number corresponding to pseudo-random sequence code 4 is "C59", and the beam number is "4". The satellite beam number corresponding to pseudo-random sequence code 5 is "C59", and the beam number is "5". The satellite beam number corresponding to pseudo-random sequence code 6 is "C59", and the beam number is "6". The satellite beam number corresponding to pseudo-random sequence code 7 is "C60", and the beam number is "1". The satellite beam number corresponding to pseudo-random sequence code 8 is "C60", and the beam number is "2". The satellite beam number corresponding to pseudo-random sequence code 9 is "C60", and the beam number is "3". The satellite beam number corresponding to pseudo-random sequence code 10 is "C60", and the beam number is "4". The satellite beam number corresponding to pseudo-random sequence code 11 is "C60", and the beam number is "5". The satellite beam number corresponding to pseudo-random sequence code 12 is "C60", and the beam number is "6". The satellite beam number corresponding to pseudo-random sequence code 13 is "C61", and the beam number is "1". The satellite beam number corresponding to pseudo-random sequence code 14 is "C61", and the beam number is "2". The satellite beam number corresponding to pseudo-random sequence code 15 is "C61", and the beam number is "3". The satellite beam number corresponding to pseudo-random sequence code 16 is "C61", and the beam number is "4". The satellite beam number corresponding to pseudo-random sequence code 17 is "C61", and the beam number is "5". The satellite beam number corresponding to pseudo-random sequence code 18 is "C61", and the beam number is "6". The satellite beam corresponding to pseudo-random sequence code 19 has a satellite number of "C62" and a beam number of "1". The satellite beam corresponding to pseudo-random sequence code 20 has a satellite number of "C62" and a beam number of "2". The satellite beam corresponding to pseudo-random sequence code 21 has a satellite number of "C62" and a beam number of "3". The satellite beam corresponding to pseudo-random sequence code 22 has a satellite number of "C62" and a beam number of "4". The satellite beam corresponding to pseudo-random sequence code 23 has a satellite number of "C62" and a beam number of "5". The satellite beam corresponding to pseudo-random sequence code 24 has a satellite number of "C62" and a beam number of "6". The satellite beam corresponding to pseudo-random sequence code 25 has a satellite number of "C62" and a beam number of "1". The satellite beam corresponding to pseudo-random sequence code 26 has a satellite number of "C63" and a beam number of "2". The satellite beam corresponding to pseudo-random sequence code 27 has a satellite number of "C63" and a beam number of "3". The satellite number corresponding to pseudo-random sequence code 28 is "C63" and the beam number is "4". The satellite number corresponding to pseudo-random sequence code 29 is "C63" and the beam number is "5".The satellite number corresponding to the pseudo-random sequence code 30 is "C63", and the beam number is "6". Table 1 above is for illustrative purposes only and should not be construed as limiting the scope of this application.

[0194] S802 and terminal 100 acquire satellite beams according to the preset satellite beam acquisition sequence.

[0195] The terminal 100 can configure the parameters corresponding to the satellite beams for the tracking channel in the order of satellite beam acquisition. If the tracking channel successfully tracks the satellite beam, the terminal 100 records the satellite number and beam number corresponding to the acquired satellite beam.

[0196] For example, the preset satellite beam acquisition sequence can be: first from beam 1 to beam 6 in satellite C59, then from beam 1 to beam 6 in satellite C60, then from beam 1 to beam 6 in satellite C61, then from beam 1 to beam 6 in satellite C62, and finally from beam 1 to beam 6 in satellite C63. The above examples are merely for explaining this application and should not be construed as limiting it.

[0197] S803, Terminal 100 acquires the satellite number, beam number, and beam signal quality of multiple captured satellite beams.

[0198] During the process of acquiring a satellite beam, terminal 100 can match multiple locally stored pseudo-random sequence code templates with the pseudo-random sequence codes received on the satellite beam to determine the satellite number and beam number corresponding to the pseudo-random sequence codes in the satellite beam. Terminal 100 can also measure the signal quality of the satellite signals received on the satellite beam during the acquisition process.

[0199] Terminal 100 can also measure the beam signal strength and beam signal quality when pilot information is received on the satellite beam during the acquisition of the satellite beam. The beam signal quality can be measured using any one of the following parameters: carrier-to-noise ratio, signal-to-noise ratio, signal strength, etc. The beam signal strength information can specifically refer to any one of the following: the received power value of the satellite signal in the satellite beam, the path loss value of the satellite signal in the satellite beam, and the received signal strength value of the satellite signal in the satellite beam.

[0200] In one possible implementation, the satellite signal may refer to the radiodetermination satellite service (RDSS) signal transmitted under the satellite beam in the BeiDou short message satellite 21.

[0201] The path loss value of the satellite signal can be determined by the difference between the power of the satellite signal transmitted by the terminal 600 based on the BeiDou network device 200 and the received signal strength value of the satellite signal by the terminal 600. The power of the satellite signal transmitted by the BeiDou network device 200 can be preset in the terminal 600. Specifically, the power of the satellite signal transmitted by the BeiDou network device 200 can refer to the power of the satellite signal transmitted by the BeiDou central station 23.

[0202] S804, Terminal 100 determines L downlink beams based on the beam signal quality of multiple captured satellite beams. L is a positive integer.

[0203] Wherein, the L downlink beams can be the top L satellite beams from the multiple acquired satellite beams, ranked from highest to lowest beam signal quality. Here, L is a positive integer. In this embodiment, L is preferably described as being 2.

[0204] For example, the L downlink beams could be the top L satellite beams with the highest to lowest carrier-to-noise ratio. Alternatively, the L downlink beams could be the top L satellite beams with the highest to lowest signal-to-noise ratio. Or, the L downlink beams could be the top L satellite beams with the highest to lowest signal strength.

[0205] S805, Terminal 100 sends a data request frame to BeiDou network device 200. The header of the data request frame includes an outbound link indication field, which carries beam information for L downlink beams. The beam information includes the satellite number, beam number, and beam profile. The beam profile indicates the signal quality level of the downlink beam.

[0206] Specifically, in the BeiDou communication system 10, data request frames can include mailbox overview query frames and email download frames, etc. The format of the data request frame can be referenced... Figure 9A The frame format of the general data frame is shown.

[0207] like Figure 9A As shown, an inbound physical frame may include a synchronization header and a data segment. The synchronization header is used by the BeiDou network device 200 to synchronize inbound physical frames and identify the start position of the data segment. The duration of this synchronization header can be 40ms.

[0208] The data segment of the inbound physical frame may include the inbound user frame from the SLC layer and a check bit. In the BeiDou communication system 10, Cyclic Redundancy Check (CRC) can be used to check the data segment, and the check bit may include the CRC checksum.

[0209] The inbound user frame of the SLC layer can include frame header information (also known as frame format indication information) and user information. Specifically, when the frame type of the inbound user frame of the SLC layer is a general data frame, the frame header information of the general data frame can include a version number, subtype indication field, user ID field, outbound link indication field, acknowledgment mode enabled (AMenable) field, total frame count field, frame sequence number field, service data unit alternation indication field, and reserved (RSV) field.

[0210] The version number field can be used to indicate the protocol format version of the user frame. The data length of the version number field can be 3 bits.

[0211] The subtype indicator field indicates the subtype of the inbound user frame. The data length of the subtype indicator field can be 3 bits. Subtypes of inbound user frames can include general data frames (or information message frames), ACK frames, acknowledgment frames, location reporting frames, emergency rescue frames, etc. The subtype of a data request frame is a general data frame.

[0212] The User ID field can be used to indicate the device identifier of terminal 100. The data length of the User ID field can be 34 bits.

[0213] The AM enable field indicates whether the BeiDou network device 200 uses acknowledged or unacknowledged mode at the SLC layer. The AM enable field can have a data length of 1 bit.

[0214] The total number of frames field indicates the total number of general data frames included in the SLC session containing this general data frame. The total number of frames field can be 2 bits long. When the total number of frames field is 2 bits long, an SLC session can include a maximum of 4 general data frames.

[0215] The frame sequence number field can be used to indicate the sequence number of the general data frame within an SLC session. The length of this frame sequence number field can be 2 bits.

[0216] The SAI field indicates whether the general data frame is a new frame. It is compared with the SAI value of the previous general data frame in the SLC session; a flip indicates a new frame, otherwise it is a retransmission. The SAI field can be 1 bit long.

[0217] The outbound link indication field can be used to indicate the downlink beam selected by terminal 100 when suggesting that BeiDou network device 200 send inbound user frames to terminal 100. This outbound link indication field may include beam information for L downlink beams. The beam level can be used to indicate the level of beam signal quality within the downlink beam. In one possible implementation, beam signal quality can be measured using parameters such as carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal.

[0218] The Reserved (RSV) field can be reserved for future protocol extensions. The data length of this reserved field can be 3 bits.

[0219] User information may include all or part of the data in an application-layer message. This application-layer message may include a header and message data. The header may include a service type field, an encryption indicator field, and a compression indicator field. The service type indicates the service type of the application-layer message. The service type of the application-layer message may include mailbox overview query service, mail download service, or communication message service. The service type of this data request frame is either mailbox overview query service or mail download service.

[0220] When the service type of the application layer message is mailbox overview query service, the message data can carry the query information of terminal 100. The query information includes the number of messages sent to terminal 100 by the target terminal, etc.

[0221] When the service type of the application layer message is a letter download request service, the message data can carry a message ID, which is used to indicate the ID of the last successfully received letter by the terminal 100.

[0222] The data lengths and positional relationships of each field in the frame header information of the general data frame can be found by referring to... Figure 9B The header format of the general data frame is shown.

[0223] like Figure 9BAs shown, the version number field can be 3 bits long, specifically located in the frame header information, from bit 7 to bit 5 of byte 0. The subtype indicator field can be 3 bits long, specifically located in the frame header information, from bit 4 to bit 2 of byte 0. The user ID field can be 34 bits long, specifically located in the frame header information, from bit 1 to bit 0 of byte 4. The outbound link indicator field can be 16 bits long, specifically located in the frame header information, from bit 7 of byte 5 to bit 0 of byte 6. The AM enable field can be 16 bits long, specifically located in the frame header information, from bit 7 of byte 7. The total frame count field can be 2 bits long, specifically located in the frame header information, from bit 6 to bit 5 of byte 7. The frame sequence number field can be 2 bits long; specifically, it can be located in the frame header information, from bit 4 to bit 3 of byte 7. The SAI field can be 1 bit long; specifically, it can be located in the frame header information, from bit 2 of byte 7. The RSV field can be 2 bits long; specifically, it can be located in the frame header information, from bit 1 to bit 0 of byte 7.

[0224] The structure of the outbound link indication field can be found in the following reference. Figure 9C .

[0225] like Figure 9C As shown, the outbound link indication field can indicate the beam information of two downlink beams. The data length of the beam information for each downlink beam can be 8 bits. The beam information can include a satellite number field, a beam number field, and a beam position field.

[0226] The satellite number field carries the satellite number of the downlink beam, and the data length of the satellite number field can be 3 bits.

[0227] For example, the correspondence between the values ​​of the satellite number field and the satellite numbers of the downlink beam can be shown in Table 2 below:

[0228] Table 2

[0229] The value of the satellite number field Satellite 000 Indicates no recommended downlink beam. 001 C59 010 C60 011 C61 100 C62 101 C63 110 Reserved 111 Reserved

[0230] As shown in Table 2 above, a value of "000" in the satellite number field indicates that there is no proposed downlink beam. A value of "001" indicates that the satellite number is "C59". A value of "010" indicates that the satellite number is "C60". A value of "011" indicates that the satellite number is "C61". A value of "100" indicates that the satellite number is "C62". A value of "101" indicates that the satellite number is "C63". Values ​​"101" and "111" in the satellite number field are reserved values. Table 2 above is only used to explain this application and should not be construed as limiting it.

[0231] The beam number field carries the beam number of the downlink beam, and the data length of the beam number field can be 3 bits.

[0232] For example, the correspondence between the values ​​of the beam number field and the beam numbers of the downlink beams can be shown in Table 3 below:

[0233] Table 3

[0234] The value of the beam number field Beam 000 Indicates no recommended downlink beam. 001 1 010 2 011 3 100 4 101 5 110 6 111 Reserved

[0235] As shown in Table 3 above, a value of "000" in the beam number field indicates that no downlink beam is proposed. A value of "001" indicates that the beam number is "1". A value of "010" indicates that the beam number is "2". A value of "011" indicates that the beam number is "3". A value of "100" indicates that the beam number is "4". A value of "101" indicates that the beam number is "5". A value of "101" indicates that the beam number is "6". A value of "111" in the beam number field is a reserved value. Table 3 above is only used to explain this application and should not be construed as limiting it.

[0236] The beam position field can be used to indicate the beam signal quality level of the downlink beam. In this embodiment, the downlink beam signal quality level can have four levels, with higher levels indicating higher beam signal quality. When there are four beam signal quality levels, the data length of the beam position field can be 2 bits.

[0237] For example, the correspondence between the values ​​of the beam position field and the beam position of the downlink beam can be shown in Table 4 below:

[0238] Table 4

[0239] Beamstop field value Beamstop 00 0 01 1 10 2 11 3

[0240] As shown in Table 4 above, a value of "00" in the beam position field indicates a downlink beam signal quality level of 0. A value of "01" indicates a downlink beam signal quality level of 1. A value of "10" indicates a downlink beam signal quality level of 2. A value of "11" indicates a downlink beam signal quality level of 3. Level 0 represents the lowest beam signal quality, and level 3 represents the highest beam signal quality. Table 4 is for illustrative purposes only and should not be construed as limiting the scope of this application.

[0241] S806 and Beidou network equipment 200 respond to the data request frame and generate the first application layer message.

[0242] Specifically, after receiving a data request frame, the Beidou network device 200 can parse the application layer message from the data request frame and distinguish the service type of the data request frame from the service type indication field of the application layer service message.

[0243] If the service type of the data request frame is mailbox overview query service, the terminal 100 can generate a first application layer message based on the query information.

[0244] If the service type of the data request frame is a mail download request service, the terminal 100 parses the message ID carried in the message data of the data request frame. The Beidou network device 200 can determine the first message from the mailbox of the terminal 100 based on the message ID sent by the Beidou network device 200 requested by the terminal 100, and generate the first application layer message based on the first message.

[0245] S807 and Beidou network equipment 200 split the first application layer message into one or more SLC PDUs, and the one or more SLC PDUs include the first SLC PDU.

[0246] The first SLC PDU can be any one of the SLC PDUs in the first application layer message.

[0247] Specifically, regarding the process by which BeiDou network equipment 200 splits first application layer packets into one or more SLC PDUs, please refer to the aforementioned... Figure 6 The protocol encapsulation process for application layer messages in the illustrated embodiment will not be described in detail here.

[0248] The S808 and Beidou network equipment 200 select the first beam from L downlink beams.

[0249] The Beidou network equipment 200 can select the beam with the highest beam level from the L downlink beams indicated in the outbound link indication field and determine it as the first beam.

[0250] In one possible implementation, the BeiDou network device 200 can select any one of the L downlink beams and designate it as the first beam.

[0251] In one possible implementation, the BeiDou network device 200 can determine the first beam based on the beam size and load conditions of the L downlink beams. For example, when the data load on beam A, which has the largest beam size among the L downlink beams, exceeds a certain value, the BeiDou network device 200 can select beam B as the first beam from the L downlink beams. Specifically, beam size B is smaller than that of beam A, and the data load on beam B does not exceed a certain value.

[0252] S809, Beidou network equipment 200 sends the first SLC PDU to terminal 100 on the first beam.

[0253] Specifically, the BeiDou network device 200 can include the first SLC PDU as an outbound user frame in the first physical frame at the physical layer, and encode and modulate the first physical frame. The BeiDou network device 200 can transmit the pilot information corresponding to the first beam on the S2C-p branch of the first beam, and transmit the first physical frame on the S2C-d branch of the first beam.

[0254] Terminal 100 can synchronously receive physical frames from BeiDou network device 200 on the aforementioned L downlink beams, and attempt to parse user frames received on the aforementioned L downlink beams that are received by terminal 100.

[0255] In this case, after receiving the pilot information of the S2C-p branch and the first physical frame of the S2C-d branch in the first beam, the terminal 100 can decode the first SLC PDU from the first physical frame.

[0256] In one possible implementation, the BeiDou network device 200 can transmit the first SLC PDU to the terminal 100 in all L downlink beams. After receiving SLC PDUs destined for the terminal 100 in all L downlink beams, the terminal 100 can determine whether the same SLC PDU was transmitted in all L downlink beams by checking the total number of frames and the frame sequence number in the SLC PDU's frame header. If the terminal 100 receives the first SLC PDU destined for the terminal 100 in all L downlink beams, then the terminal 100 can retain only one first SLC PDU. This ensures a high success rate for data transmission from the BeiDou network device 200 to the terminal 100.

[0257] In one possible implementation, terminal 100 can instruct BeiDou network device 200 to reply with a first ACK frame after receiving the data request frame via the AM enable field in the data request frame. This first ACK frame can be used to indicate that BeiDou network device 200 has received the data request frame sent by terminal 100. Specifically, after receiving the data request frame, BeiDou network device 200 can select a first beam from the L downlink beams suggested in the outbound link indication field of the data request frame, and send the first ACK frame to terminal 100 in the first beam.

[0258] In some application scenarios, the BeiDou network device 200 can send general data frames to the terminal 100 using an acknowledgment mode. After receiving the general data frame sent by the BeiDou network device 200, the terminal 100 can return an ACK frame to the BeiDou network device 200. This ACK frame indicates the reception status of the general data frame. Therefore, when parsing the general data frame sent by the BeiDou network device 200, the terminal 100 can capture multiple satellite beams and obtain the satellite number, beam number, and carrier-to-noise ratio of multiple satellite beams. The terminal 100 can select L downlink beams from the multiple satellite beams and carry the beam information of the L downlink beams in the ACK frame. This beam information is used to instruct the BeiDou network device 200 to select the first beam among these L downlink beams to send service data to the terminal 100. In this way, the selection of downlink beams by the BeiDou network device 200 can be completed without additional signaling overhead, improving channel utilization.

[0259] Figure 10 A flowchart illustrating a beam selection method in a BeiDou communication system provided in an embodiment of this application is shown.

[0260] like Figure 10 As shown, the method includes:

[0261] S1001, Terminal 100 sends a data request frame to Beidou network device 200.

[0262] The data request frame header includes an outbound link indication field, which carries beam information for M downlink beams. This beam information includes the satellite number, beam number, and beam size. The beam size indicates the signal quality level of the downlink beam. M is a positive integer.

[0263] For a detailed description of the data request frame, please refer to the aforementioned... Figure 8 Step S805 in the illustrated embodiment.

[0264] S1002 and Beidou network equipment 200 respond to the data request frame and generate the first application layer message.

[0265] For details, please refer to the above. Figure 8 Step S806 in the illustrated embodiment will not be described again here.

[0266] S1003 and Beidou Network Equipment 200 split the first application layer message into multiple SLC PDUs, which include the first SLC PDU and the second SLC PDU.

[0267] The frame types of both the first SLC PDU and the second SLC PDU are general data frames in outbound user frames.

[0268] Specifically, regarding the process by which BeiDou network equipment 200 splits the first application layer message into multiple user frames, please refer to the aforementioned... Figure 6 The protocol encapsulation process for application layer messages during outbound transmission, as shown in the embodiment, will not be described in detail here.

[0269] S1004, Beidou network equipment 200 selects the second beam from M downlink beams.

[0270] The Beidou network equipment 200 can select the beam with the highest beam level from the M downlink beams indicated in the outbound link indication field and determine it as the second beam.

[0271] In one possible implementation, the BeiDou network device 200 can select any one of the M downlink beams and designate it as the second beam.

[0272] In one possible implementation, the BeiDou network device 200 can determine the second beam based on the beam size and load conditions of the M downlink beams. For example, when the data load on beam A, which has the largest beam size among the M downlink beams, exceeds a certain value, the BeiDou network device 200 can select beam B as the second beam from the M downlink beams. Specifically, beam B has a smaller beam size than beam A, and the data load on beam B does not exceed a certain value.

[0273] S1005 and Beidou network equipment 200 transmit pilot information on each satellite beam. The pilot information carries pseudo-random sequence codes, where each pseudo-random sequence code corresponds to the satellite number and beam number of a satellite beam.

[0274] For details, please refer to the above. Figure 8 Step S801 in the illustrated embodiment will not be described again here.

[0275] S1006, Beidou network equipment 200 sends the second SLC PDU to terminal 100 on the second beam.

[0276] Specifically, the BeiDou network device 200 can include the second SLC PDU as an outgoing user frame in the second physical frame and encode and modulate the second physical frame. The BeiDou network device 200 can transmit the pilot information corresponding to the second beam on the S2C-p branch of the second beam and transmit the second physical frame on the S2C-d branch of the second beam.

[0277] S1007 and Terminal 100 acquire satellite beams according to the preset satellite beam acquisition sequence.

[0278] For details, please refer to the above. Figure 8 Step S802 in the illustrated embodiment will not be described again here.

[0279] S1008, Terminal 100 acquires the satellite number, beam number, and beam signal quality of multiple captured satellite beams.

[0280] For details, please refer to the above. Figure 8 Step S803 in the illustrated embodiment will not be described again here.

[0281] S1009 and Terminal 100 determine L downlink beams based on the beam signal quality of the captured multiple satellite beams. L is a positive integer.

[0282] For details, please refer to the above. Figure 8 Step S804 in the illustrated embodiment will not be described again here.

[0283] After receiving the second SLC PDU, S1010 and terminal 100 send a second ACK frame to BeiDou network device 200. The second ACK frame indicates the reception status of the second user frame by terminal 100. The second ACK frame includes an outbound link indication field, which carries beam information for L downlink beams. The beam information includes satellite number, beam number, and beam profile. The beam profile indicates the beam signal quality level of the downlink beam.

[0284] The frame format of the second ACK frame can be found in [reference]. Figure 11A The frame format of the inbound ACK frame is shown.

[0285] like Figure 11A As shown, an inbound physical frame may include a synchronization header and a data segment. The synchronization header is used by the BeiDou network device 200 to synchronize inbound physical frames and identify the start position of the data segment. The duration of this synchronization header can be 40ms.

[0286] The data segment may include a user frame and a check bit. In the BeiDou communication system 10, Cyclic Redundancy Check (CRC) can be used to verify the data segment, and the check bit may include a CRC checksum. The user frame may include frame header information (also known as frame format indication information) and user information. Specifically, the header information of the inbound ACK frame may include a version number, a subtype indication field, a user ID field, an outbound link indication field, and a reserved (RSV) field.

[0287] The version number field can be used to indicate the protocol format version of the user frame. The data length of the version number field can be 3 bits.

[0288] The subtype indicator field indicates the subtype of a user frame. The data length of this field can be 3 bits. Subtypes of user frames can include general data frames (or information message frames), ACK frames, acknowledgment frames, location reporting frames, emergency rescue frames, etc. The subtype of an inbound ACK frame is an ACK frame.

[0289] The User ID field can be used to indicate the device identifier of terminal 100. The data length of the User ID field can be 34 bits.

[0290] The outbound link indication field can be used to indicate the downlink beam selected by terminal 100 when suggesting that BeiDou network device 200 send service data to terminal 100. This outbound link indication field may include beam information for L downlink beams. The beam information includes satellite number, beam number, and beam modulus. In one possible implementation, the beam modulus can be used to indicate the carrier-to-noise ratio (CNR) modulus of the satellite signal within the satellite beam.

[0291] The user information in an inbound ACK frame may include an ACK field and padding data. The ACK field can be 1 bit long, and the padding data can be used to fill the inbound ACK frame to a specified data length to meet the requirement that inbound physical frames have a fixed data length. Specifically, the ACK field can be used to indicate whether terminal 100 has received a general data frame (i.e., SLC PDU) sent to terminal 100 by BeiDou network device 200. For example, a value of "0" in the ACK field indicates that terminal 100 has not received the general data frame (i.e., SLC PDU) sent to terminal 100 by BeiDou network device 200. A value of "1" in the ACK field indicates that terminal 100 has received the general data frame (i.e., SLC PDU) sent to terminal 100 by BeiDou network device 200.

[0292] Optionally, when the BeiDou network device 200 continuously sends multiple general data frames to the terminal 100, the terminal 100 replies with an inbound ACK frame after receiving the multiple general data frames. In this case, the data length of the ACK field in the inbound ACK frame is not limited to 1 bit and can be longer. For example, the BeiDou network device 200 can support continuously sending four general data frames before receiving the ACK frame returned by the terminal 100. In this case, the data length of the ACK field in the inbound ACK frame can be 4 bits. One bit in the ACK field indicates the reception status of one of the four continuously sent general data frames.

[0293] The data lengths and positional relationships of each field in the header information of the inbound ACK frame can be found by referring to... Figure 11B The header format of the inbound ACK frame is shown.

[0294] like Figure 11B As shown, the version number field can be 3 bits long, specifically located in the frame header information, from bit 7 to bit 5 of byte 0. The subtype indicator field can be 3 bits long, specifically located in the frame header information, from bit 4 to bit 2 of byte 0. The user ID field can be 34 bits long, specifically located in the frame header information, from bit 1 to bit 0 of byte 4. The outbound link indicator field can be 16 bits long, specifically located in the frame header information, from bit 7 of byte 5 to bit 0 of byte 6. The RSV field can be 8 bits long, specifically located in the frame header information, from bit 7 of byte 7 to bit 0 of byte 7.

[0295] In this embodiment, the outbound link indication field can indicate the beam information of two downlink beams. The data length of the beam information for each downlink beam can be 8 bits. The beam information can include a satellite number field, a beam number field, and a beam position field. The satellite number field carries the satellite number of the downlink beam, and the data length of the satellite number field can be 3 bits. The beam number field carries the beam number of the downlink beam, and the data length of the beam number field can be 3 bits. The beam position field can be used to indicate the carrier-to-noise ratio (CNR) level of the downlink beam. In this embodiment, the CNR level of the downlink beam can have 4 levels; the higher the level, the higher the CNR of the downlink beam. When the CNR level of the downlink beam includes 4 levels, the data length of the beam position field can be 2 bits. For a detailed description of the outbound link indication field, please refer to the foregoing. Figure 9C The embodiments shown are not described in detail here.

[0296] S1011, Beidou network equipment 200 selects the first beam from L downlink beams.

[0297] For details, please refer to the above. Figure 8 Step S808 in the illustrated embodiment will not be described again here.

[0298] S1012, Beidou network equipment 200 sends the first SLC PDU to terminal 100 on the first beam.

[0299] For details, please refer to the above. Figure 8 Step S809 in the illustrated embodiment will not be described again here.

[0300] In one possible implementation, the BeiDou network device 200 sends the last SLC PDU in the first application layer message to the terminal 100. After receiving the last SLC PDU, the terminal 100 does not send an ACK frame to the BeiDou network device 200. Instead, it waits for the terminal 100 to assemble the received SLC PDU into an application layer message and complete the parsing of the application layer message before sending a receipt frame to the BeiDou network device 200. This receipt frame indicates the status of the application layer message parsing by the terminal 100. Therefore, the terminal 100 can capture multiple satellite beams and obtain the satellite number, beam number, and beam signal quality of the multiple satellite beams during or after receiving the last SLC PDU. The terminal 100 can select L downlink beams from the multiple satellite beams and carry the beam information of the L downlink beams in the outbound link indication field of the receipt frame. This beam information is used to instruct the BeiDou network device 200 to select the first beam among these L downlink beams to send service data to the terminal 100. In this way, the downlink beam selection of the BeiDou network equipment 200 can be completed without additional signaling overhead, thereby improving channel utilization.

[0301] For example, after terminal 100 sends a message download request to BeiDou network device 200, BeiDou network device 200 can generate multiple application layer messages based on the message download request sent by terminal 100. These multiple application layer messages include a first application layer message and a second application layer message. BeiDou network device 200 can first send the first application layer message to terminal 100. After receiving the first application layer message sent by BeiDou network device 200, terminal 100 can return a receipt frame to BeiDou network device 200. This receipt frame can be used to indicate the parsing status of the first application layer message by terminal 100. The receipt frame includes the aforementioned outbound link indication field, which carries beam information for L downlink beams. If the BeiDou network device 200 determines that the terminal 100 has successfully parsed the first application layer message based on the receipt frame, the BeiDou network device 200 can select the first beam from the above L downlink beams and send part or all of the SLC PDU in the second application layer message to the terminal 100 on the first beam.

[0302] The frame format of the receipt frame can be found in [reference]. Figure 11C The frame format of the inbound receipt frame is shown.

[0303] like Figure 11C As shown, an inbound physical frame may include a synchronization header and a data segment. The synchronization header is used by the BeiDou network device 200 to synchronize inbound physical frames and identify the start position of the data segment. The duration of this synchronization header can be 40ms.

[0304] The data segment may include a user frame and a check bit. In the BeiDou communication system 10, Cyclic Redundancy Check (CRC) can be used to verify the data segment, and the check bit may include a CRC checksum. The user frame may include frame header information (also known as frame format indication information) and user information. Specifically, the frame header information of the inbound receipt frame may include a version number, a subtype indication field, a user ID field, an outbound link indication field, and a reserved (RSV) field.

[0305] The version number field can be used to indicate the protocol format version of the user frame. The data length of the version number field can be 3 bits.

[0306] The subtype indicator field indicates the subtype of a user frame. The data length of this field can be 3 bits. Subtypes of user frames can include general data frames (or information message frames), ACK frames, receipt frames, location reporting frames, emergency rescue frames, etc. The subtype of an inbound receipt frame is a receipt frame.

[0307] The User ID field can be used to indicate the device identifier of terminal 100. The data length of the User ID field can be 34 bits.

[0308] The outbound link indication field can be used to indicate the downlink beam selected by terminal 100 when suggesting that BeiDou network device 200 send service data to terminal 100. This outbound link indication field may include beam information for L downlink beams. The beam information includes satellite number, beam number, and beam level. The beam level can be used to indicate the level of beam signal quality in the downlink beam. In one possible implementation, beam signal quality can be measured using parameters such as carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal.

[0309] The user information in the inbound receipt frame can include a receipt information field and padding data. The receipt information field can be 4 bits long, and the padding data can be used to fill the inbound receipt frame to a specified data length to meet the requirement that the inbound physical frame has a fixed data length.

[0310] The receipt information field can be used to indicate the status of terminal 100's parsing of application layer messages. For example, when the value in the receipt information field is "0000", it can indicate that terminal 100 has successfully parsed the application layer message; when the error code value is "0001", it can indicate that terminal 100 has failed to parsing the application layer message, and the reason for the failure is a decryption error; when the error code value is "0010", it can indicate that terminal 100 has failed to parsing the application layer message, and the reason for the failure is a decoding error; and so on.

[0311] The position of each field in the header of the receipt frame can be referred to the above. Figure 11B The header format of the inbound ACK frame shown will not be described again here.

[0312] In some application scenarios, terminal 100 can proactively send service data to BeiDou network device 200. Upon receiving the service data, BeiDou network device 200 can return an ACK to terminal 100, which serves as feedback on the reception status of the service data. Therefore, before sending user frames for communication services to BeiDou network device 200, terminal 100 can capture multiple satellite beams and obtain the satellite number, beam number, and carrier-to-noise ratio of these beams. Terminal 100 can select L downlink beams from these multiple satellite beams and carry the beam information of these L downlink beams in the user frames of the communication message service. After receiving the user frames for general data services sent by terminal 100, BeiDou network device 200 can select the first beam from these L downlink beams and send an ACK frame to terminal 100. In this way, the selection of downlink beams by BeiDou network device 200 can be completed without additional signaling overhead, improving channel utilization.

[0313] Figure 12A flowchart illustrating a beam selection method in a BeiDou communication system provided in an embodiment of this application is shown.

[0314] like Figure 12 As shown, the method includes:

[0315] S1201, Terminal 100 splits the second application layer message into one or more user frames. These one or more user frames include a third SLC PDU.

[0316] Specifically, for the process by which terminal 100 splits a second application layer packet into one or more SLC PDUs, please refer to the aforementioned... Figure 4 The protocol encapsulation process for inbound application layer messages in the illustrated embodiment will not be described in detail here.

[0317] S1202, Terminal 100 acquires satellite beams according to the preset satellite beam acquisition sequence.

[0318] For details, please refer to the above. Figure 8 Step S802 in the illustrated embodiment will not be described again here.

[0319] S1203, Terminal 100 acquires the satellite number, beam number, and beam signal quality of multiple captured satellite beams.

[0320] For details, please refer to the above. Figure 8 Step S803 in the illustrated embodiment will not be described again here.

[0321] S1204, Terminal 100 determines L downlink beams based on the beam signal quality of multiple captured satellite beams.

[0322] For details, please refer to the above. Figure 8 Step S804 in the illustrated embodiment will not be described again here.

[0323] S1205, Terminal 100 sends a third SLC PDU to BeiDou network equipment 200, wherein the third SLC PDU carries beam information for L downlink beams. The beam information includes the satellite number, beam number, and beam profile. The beam profile can be used to indicate the carrier-to-noise ratio (CNR) level of the downlink beam.

[0324] The third SLC PDU can be a general data frame within an inbound user frame. The frame format of the third SLC PDU can be found in the preceding description. Figures 9A-9C The embodiments shown are not described in detail here.

[0325] After receiving the third SLC PDU, S1206 and Beidou network equipment 200 select the first beam from the L downlink beams indicated in the third SLC PDU.

[0326] For details on the process of selecting the first beam from L downlink beams, please refer to the aforementioned... Figure 8 Step S808 in the illustrated embodiment will not be described again here.

[0327] S1207, Beidou network equipment 200 sends a third ACK frame to terminal 100 on the first beam. The third ACK is used to indicate the reception status of the third SLC PDU.

[0328] In one possible implementation, the BeiDou network device 200 can send a third ACK to the terminal 100 in all L downlink beams. After receiving the third ACK from the terminal 100 in all L downlink beams, the terminal 100 can retain only one third ACK. This ensures a high success rate for the BeiDou network device 200 in sending ACKs to the terminal 100.

[0329] In one possible implementation, terminal 100 can continuously send N SLCPDUs (SLCPDUs) from the second application layer message to BeiDou network device 200, where N is a positive integer. Each of these N SLCPDUs carries beam information for L downlink beams. After receiving M SLCPDUs from these N SLCPDUs, BeiDou network device 200 can select a first beam from the L downlink beams and send an ACK frame on the first beam to terminal 100, where M ≤ N and M is a positive integer. This ACK frame can be used to indicate the reception status of these N SLCPDUs, for example, the frame sequence number of the SLCPDU that BeiDou network device 200 has not received.

[0330] In some application scenarios, terminal 100 can proactively send location reporting frames or emergency rescue frames to BeiDou network device 200. Upon receiving the location reporting frame or emergency rescue frame from terminal 100, BeiDou network device 200 can send a user frame in return. Therefore, before sending the location reporting frame or emergency rescue frame, the terminal can capture multiple satellite beams and obtain their satellite numbers, beam numbers, and carrier-to-noise ratios. Terminal 100 can select L downlink beams from these multiple satellite beams and include their beam information in the location reporting frame or emergency rescue frame. After receiving the location reporting frame or emergency rescue frame from terminal 100, BeiDou network device 200 can select the first beam from these L downlink beams and send an ACK frame to terminal 100. This allows for downlink beam selection by BeiDou network device 200 without additional signaling overhead, improving channel utilization.

[0331] The frame format for location reporting frames or emergency rescue frames can be found in the following references. Figure 13 .

[0332] like Figure 13 As shown, an inbound physical frame may include a synchronization header and a data segment. The synchronization header is used by the BeiDou network device 200 to synchronize inbound physical frames and identify the start position of the data segment. The duration of this synchronization header can be 40ms.

[0333] The data segment may include a user frame and a check bit. In the BeiDou communication system 10, Cyclic Redundancy Check (CRC) can be used to verify the data segment, and the check bit may include a CRC checksum. The user frame may include frame header information (also known as frame format indication information) and user information. The frame header information of a general data frame may include a version number, subtype indication field, user ID field, outbound link indication field, Acknowledgment mode enable (AM enable) field, total number of frames field, frame sequence number field, service data unit alternation indication field, and reserved (RSV) field.

[0334] The version number field can be used to indicate the protocol format version of the user frame. The data length of the version number field can be 3 bits.

[0335] The subtype indicator field indicates the subtype of a user frame. The data length of this field can be 3 bits. Subtypes of user frames can include general data frames (or information message frames), ACK frames, acknowledgment frames, location reporting frames, emergency rescue frames, etc. The subtype of a location reporting frame is a location reporting frame, and the subtype of an emergency rescue frame is an emergency rescue frame.

[0336] The User ID field can be used to indicate the device identifier of terminal 100. The data length of the User ID field can be 34 bits.

[0337] The AM enable field indicates whether the BeiDou network device 200 uses acknowledged or unacknowledged mode at the SLC layer. The AM enable field can have a data length of 1 bit.

[0338] The total number of frames field indicates the total number of location reporting frames / emergency rescue frames included in the SLC session containing this location reporting frame / emergency rescue frame. The total number of frames field can be 2 bits long. When the total number of frames field is 2 bits long, an SLC SDU can include a maximum of 4 location reporting frames.

[0339] The frame sequence number field can be used to indicate the frame sequence number of a reported frame or emergency rescue frame within an SLC session. The length of this frame sequence number field can be 2 bits.

[0340] The SAI field indicates whether the location reporting frame or emergency rescue frame is a new frame. It is compared with the SAI value of the previous frame in the SLC session; a flip indicates a new frame, otherwise it is a retransmission. The SAI field can be 1 bit long.

[0341] The outbound link indication field can be used to indicate the downlink beam selected by terminal 100 when suggesting that BeiDou network device 200 send user frames to terminal 100. This outbound link indication field may include beam information for L downlink beams. The beam level can be used to indicate the signal quality level of the downlink beams. The data length of this outbound link indication field can be 16 bits. In one possible implementation, beam signal quality can be measured using parameters such as carrier-to-noise ratio, signal-to-noise ratio, and signal strength. A description of the outbound link indication field can be found above. Figure 9C The embodiments shown are not described in detail here.

[0342] The Reserved (RSV) field can be reserved for future protocol extensions. The data length of this reserved field can be 3 bits.

[0343] In some embodiments, the order in which the terminal 100 acquires satellite beams is not limited to the preset fixed acquisition order described above. The terminal 100 may have a pre-set satellite beam coverage map of the BeiDou communication system 10. This satellite beam coverage map may include beam coverage information for each satellite beam. The beam coverage information may include one or more of the following: beam center position, beam coverage radius, multiple signal strength intervals, coverage edge coordinates of each signal strength interval, etc. The terminal 100 can determine the satellite beam acquisition order through the following steps:

[0344] 1. Terminal 100 can obtain the location information of Terminal 100.

[0345] Terminal 100 can obtain its location information through GNSS technology. GNSS technology includes, but is not limited to: BDS positioning technology, GPS positioning technology, GNONASS positioning technology, GALILEO positioning technology, QZSS positioning technology, SBAS positioning technology, etc.

[0346] When the satellite communication module and the cellular communication module on the terminal 100 are both turned on, the terminal 100 can also locate the base station through the cellular communication module.

[0347] When the satellite communication module and the Wi-Fi communication module on the terminal 100 are both turned on, the terminal 100 can also perform Wi-Fi positioning through the Wi-Fi communication module.

[0348] 2. Terminal 100 can determine the satellite beam acquisition order based on the preset satellite beam coverage map of Beidou communication system 10 and the location information of terminal 100.

[0349] Terminal 100 can calculate the distance between its location and the center point of each satellite beam in the satellite beam coverage map. Terminal 100 can then sort the satellite beam acquisition order from smallest to largest distance between itself and the beam center point. The smaller the distance between the center point of a satellite beam and terminal 100, the more likely terminal 100 is to acquire that satellite beam.

[0350] For example, Figure 14 This illustration shows a portion of the satellite beam coverage map provided in an embodiment of this application. For example... Figure 14 As shown, terminal 100 can calculate that the distance between its location 1403 and the center point 1401 of satellite beam C60-3 (i.e., satellite beam number C60, beam number 3) is 300 km. Terminal 100 can calculate that the distance between its location 1403 and the center point 1402 of satellite beam C59-1 (i.e., satellite beam number C59, beam number 1) is 860 km. Therefore, in the satellite beam acquisition order, satellite beam C60-3 precedes satellite beam C59-1. The above examples are merely for explaining this application and should not be construed as limiting the scope of the application.

[0351] In one possible implementation, terminal 100 can also calculate the signal strength range of each satellite beam at its location. Terminal 100 can sort the satellite beam acquisition order by ranking the signal strength range values ​​of each satellite beam at its location from largest to smallest. At terminal 100's location, the larger the signal strength range value of a satellite beam, the more likely terminal 100 is to acquire that satellite beam. Specifically, terminal 100 can determine the signal strength range of the satellite beam at its location by calculating the distance between its location and the edge coordinates of each signal strength range.

[0352] For example, such as Figure 14 As shown, the location 1403 of terminal 100 is within the signal strength range 2 (e.g., -130dBm to -120dBm) of satellite beam C60-3, and the location 1403 of terminal 100 is also within the signal strength range D (e.g., -160dBm to -150dBm) of satellite beam C59-1. The value of signal strength range 2 is greater than the value of signal strength range D. Therefore, in the acquisition order of satellite beams by terminal 100, satellite beam C60-3 precedes satellite beam C59-1. The above example is merely for explaining this application and should not be construed as limiting it.

[0353] The following describes a BeiDou communication system 20 provided in the embodiments of this application.

[0354] Figure 15 A schematic diagram of the architecture of a Beidou communication system 20 provided in an embodiment of this application is shown.

[0355] like Figure 15 As shown, the BeiDou communication system 20 may include a terminal 100, a BeiDou short message satellite 21, BeiDou network equipment 200, a BeiDou cloud server 28, and n terminals 600, where n is a positive integer. Optionally, the BeiDou communication system 20 may also include a national emergency rescue platform (…). Figure 15 (not shown in the image), Short Message Center (SMS) Figure 15 (not shown in the image), National Emergency Center ( Figure 15 (Not shown in the image). Optionally, the n terminals 600 may also include terminal 100.

[0356] Among them, terminal 100 and terminal 600 can access Beidou cloud server 28 through cellular network / Wi-Fi network.

[0357] The BeiDou network equipment 200 may include a BeiDou ground transceiver station 22, a BeiDou central station 23, and a BeiDou short message fusion communication platform 24. The BeiDou ground transceiver station 22 may include one or more devices with transmitting capabilities and one or more devices with receiving capabilities, or it may include one or more devices with both transmitting and receiving capabilities; this is not limited here. For specific details regarding the BeiDou network equipment 200 and the BeiDou short message satellite 21, please refer to the aforementioned... Figure 1 The text in the illustrated embodiment will not be repeated here.

[0358] The Beidou cloud server 28 can communicate with the Beidou network device 200. Specifically, the Beidou cloud server 28 can communicate with the Beidou short message fusion communication platform 24 in the Beidou network device 200.

[0359] Based on the above Figure 15 The BeiDou communication system 20 shown in this application introduces a method for generating a satellite beam coverage map provided in the embodiment of this application.

[0360] Figure 16 This illustrates a method for generating a satellite beam coverage map provided in an embodiment of this application.

[0361] like Figure 16 As shown, the generation of this satellite beam coverage map may include the following steps:

[0362] S1601 and Beidou network equipment 200 transmit pilot information on each satellite beam. The pilot information includes the satellite number and beam number of the satellite beam.

[0363] For details, please refer to the above. Figure 8 Step S801 in the illustrated embodiment will not be described again here.

[0364] S1602 and terminal 600 can capture satellite beams according to a preset satellite beam acquisition sequence.

[0365] For details, please refer to the above. Figure 8 Step S802 in the illustrated embodiment will not be described again here.

[0366] S1603, Terminal 600 acquires the satellite number, beam number, beam signal quality, and beam signal strength information of the captured multiple satellite beams.

[0367] During the process of acquiring a satellite beam, the terminal 600 can receive pilot information transmitted in the satellite beam. The terminal 600 can parse the satellite number and beam number of the satellite beam from the pilot information transmitted in the satellite beam.

[0368] Terminal 600 can also measure the beam signal strength and quality when pilot information is received on the satellite beam during the acquisition process. The beam signal quality can be measured using any one of the following parameters: carrier-to-noise ratio, signal-to-noise ratio, signal strength, etc. The beam signal strength information can specifically refer to any one of the following: the received power value of the satellite signal in the satellite beam, the path loss value of the satellite signal in the satellite beam, and the received signal strength value of the satellite signal in the satellite beam.

[0369] In one possible implementation, the satellite signal may refer to the radiodetermination satellite service (RDSS) signal transmitted under the satellite beam in the BeiDou short message satellite 21.

[0370] The path loss value of the satellite signal can be determined by the difference between the power of the satellite signal transmitted by the terminal 600 based on the BeiDou network device 200 and the received signal strength value of the satellite signal by the terminal 600. The power of the satellite signal transmitted by the BeiDou network device 200 can be preset in the terminal 600. Specifically, the power of the satellite signal transmitted by the BeiDou network device 200 can refer to the power of the satellite signal transmitted by the BeiDou central station 23.

[0371] S1604 and Terminal 600 determine M downlink beams based on the beam signal quality of multiple captured satellite beams.

[0372] The M downlink beams can be the top M satellite beams with the highest to lowest beam signal quality among the acquired satellite beams. M is a positive integer. In this embodiment, M is preferably set to 1.

[0373] For example, the M downlink beams could be the top M satellite beams with the highest to lowest carrier-to-noise ratio. Alternatively, the M downlink beams could be the top M satellite beams with the highest to lowest signal-to-noise ratio. Or, the M downlink beams could be the top M satellite beams with the highest to lowest signal strength.

[0374] S1605, Terminal 600 sends a location reporting frame or an emergency rescue frame. The location reporting frame or emergency rescue frame carries the location information of Terminal 600 and the beam signal strength information of M downlink beams.

[0375] The frame format for location reporting frames or emergency rescue frames can be referenced above. Figure 13 The illustrated embodiment.

[0376] The outbound link indication field in location reporting frames or emergency rescue frames can carry beam signal strength information for M downlink beams. The structure of the outbound link indication field can be found in [reference needed]. Figure 17 .

[0377] like Figure 17 As shown, the outbound link indication field can indicate the beam information and beam signal strength information of one downlink beam. Specifically, the outbound link indication field can include a beam information field and a beam signal strength information field. The data length of both the beam information field and the beam signal strength information field can be 8 bits. The beam information field can include a satellite number field, a beam number field, and a beam position field.

[0378] The satellite number field carries the satellite number of the downlink beam, and its data length can be 2 bits. The beam number field carries the beam number of the downlink beam, and its data length can be 3 bits. The beam size field indicates the level of beam signal quality for the downlink beam, and its data length can be 2 bits. In one possible implementation, beam signal quality can be measured using parameters such as the carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal.

[0379] The beam signal strength information field indicates the satellite signal strength level of the downlink beam. This field can be 8 bits long and can represent 256 signal levels.

[0380] The location reporting frame or emergency rescue frame may include the location information of the terminal 600. The location of the location information field in the location reporting frame or emergency rescue frame can be referred to the aforementioned. Figure 13 The embodiments shown are not described in detail here.

[0381] Terminal 600 can measure its current location information (e.g., latitude and longitude) via a GNSS positioning module. In one possible implementation, terminal 600 can also obtain its location information via other positioning methods such as Wi-Fi positioning.

[0382] After S1606 and Beidou network equipment 200 parse the location information of terminal 600 and the beam signal strength information of M downlink beams from the location reporting frame or emergency rescue frame, they send the location information of terminal 600 and the beam signal strength information of M downlink beams to Beidou cloud server 28.

[0383] S1607 and Beidou Cloud Server 28 generate a satellite beam coverage map based on the location information and beam signal strength information reported by n terminals 600.

[0384] S1608 and Beidou Cloud Server 28 send the satellite beam coverage map to Terminal 100.

[0385] Specifically, after connecting to a cellular network or Wi-Fi network, terminal 100 can actively send an acquisition request to BeiDou cloud server 28 to obtain a satellite beam coverage map. Alternatively, after terminal 100 connects to BeiDou cloud server 28 via a cellular network or Wi-Fi network, BeiDou cloud server 28 can actively send a satellite beam coverage map to terminal 100.

[0386] After acquiring the satellite beam coverage map, before sending the inbound user frame to the BeiDou network device 200, terminal 100 can determine the satellite beam acquisition order based on the satellite beam coverage map and its location information. Terminal 100 can then acquire the satellite beams sequentially according to the determined acquisition order, obtaining the satellite number, beam number, and beam signal quality of multiple satellite beams. Based on the signal quality of the acquired satellite beams, terminal 100 determines L downlink beams and carries the beam information of these L downlink beams in the inbound user frame. The specific frame format of the inbound user frame can be found in the aforementioned embodiments and will not be repeated here.

[0387] In one possible implementation, if the terminal 600 is in a cellular network or a Wi-Fi network, after obtaining the location information of the terminal 600 and the beam signal strength information of the M downlink beams, the terminal 600 can report the location information of the terminal 600 and the beam signal strength information of the M downlink beams at the location of the terminal 600 to the Beidou cloud server 28 through the cellular network or Wi-Fi network.

[0388] In one possible implementation, terminal 600 can record the location information of each location and the beam signal strength information of M downlink beams. After terminal 600 connects to a cellular network or Wi-Fi network, terminal 600 can report the recorded location information of each location and the beam signal strength information of the M downlink beams to Beidou cloud server 28 via the cellular network or Wi-Fi network.

[0389] The beam selection method in the BeiDou communication system provided in this application embodiment enables terminal 100 to send a first user frame to BeiDou network equipment. The first user frame carries an outbound link indication field, which contains beam information for L downlink beams. This outbound link indication field instructs BeiDou network equipment 200 to select one of the L downlink beams to send the user frame to terminal 100, where L is a positive integer. Terminal 100 can receive a second user frame sent by BeiDou network equipment 200 on the first of the L downlink beams. This allows for downlink beam selection by BeiDou network equipment without additional signaling overhead, improving channel utilization.

[0390] The first user frame can be Figure 8 The data request frame in the illustrated embodiment, the second user frame can be as described above. Figure 8 The first SLC PDU in the illustrated embodiment. For details, please refer to the foregoing. Figure 8 The embodiments shown are not described in detail here.

[0391] In one possible implementation, the first user frame can be as described above. Figure 10 The second ACK frame in the illustrated embodiment, the second user frame can be as described above. Figure 10 The first SLC PDU in the illustrated embodiment. For details, please refer to the foregoing. Figure 10 The embodiments shown are not described in detail here.

[0392] In one possible implementation, the first user frame can be as described above. Figure 12 In the illustrated embodiment, the third SLCPDU and the second user frame can be as described above. Figure 12 The third ACK frame in the illustrated embodiment. For details, please refer to the foregoing. Figure 12The embodiments shown are not described in detail here.

[0393] The foregoing details the method provided in this application. In order to facilitate better implementation of the above-described solutions in the embodiments of this application, the embodiments of this application also provide corresponding devices or equipment.

[0394] This application embodiment can divide the terminal 100 into functional modules according to the above method example. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0395] The following will combine Figures 18 to 21 The communication device of the embodiments of this application is described in detail.

[0396] In the case of using integrated units, see Figure 18 , Figure 18 This is a schematic diagram of the structure of the communication device 1800 provided in an embodiment of this application. The communication device 1800 can be the terminal 100 in the above embodiments. Optionally, the communication device 1800 can be a chip / chip system, such as a Beidou communication chip. Figure 18 As shown, the communication device 1800 may include a transceiver unit 1810 and a processing unit 1820.

[0397] In one design, the processing unit 1820 can be used to generate a first user frame.

[0398] The transceiver unit 1810 can be used to send a first user frame to the BeiDou network equipment. The first user frame carries an outbound link indication field, which carries beam information of L downlink beams. The outbound link indication field is used to instruct the BeiDou network equipment to select a beam from the L downlink beams to send the user frame to the terminal, where L is a positive integer.

[0399] The transceiver unit 1810 is also used to receive the second user frame sent to the terminal by the Beidou network device on the first beam of the L downlink beams.

[0400] The first user frame can be Figure 8 The data request frame in the illustrated embodiment, the second user frame can be as described above. Figure 8 The first SLC PDU in the illustrated embodiment. For details, please refer to the foregoing. Figure 8 The embodiments shown are not described in detail here.

[0401] In one possible implementation, the first user frame can be as described above. Figure 10 The second ACK frame in the illustrated embodiment, the second user frame can be as described above. Figure 10 The first SLC PDU in the illustrated embodiment. For details, please refer to the foregoing. Figure 10 The embodiments shown are not described in detail here.

[0402] In one possible implementation, the first user frame can be as described above. Figure 12 In the illustrated embodiment, the third SLCPDU and the second user frame can be as described above. Figure 12 The third ACK frame in the illustrated embodiment. For details, please refer to the foregoing. Figure 12 The embodiments shown are not described in detail here.

[0403] Optionally, the transceiver unit 1810 can also be used to perform the above-mentioned tasks. Figure 8 , Figure 10 or Figure 12 The method embodiments shown above illustrate the functional steps related to sending and receiving performed by terminal 100.

[0404] Optionally, the processing unit 1820 can also be used to perform the above. Figure 8 , Figure 10 or Figure 12 In the method embodiment shown, the terminal 100 performs functional steps such as user frame generation and parsing, beam capture, and beam signal quality measurement.

[0405] It should be understood that the communication device 1800 in this design can perform the method steps executed by the terminal 100 in the aforementioned embodiment, and for the sake of brevity, it will not be described again here.

[0406] In the case of using integrated units, see Figure 19 , Figure 19 This is a schematic diagram of the communication device 1900 provided in an embodiment of this application. The communication device 1900 can be the BeiDou network device 200 in the above embodiments. Optionally, the communication device 1900 can be a specific network element in the BeiDou network device 200, such as one or a combination of multiple network elements from the BeiDou ground transceiver station 22, the BeiDou central station 23, and the BeiDou short message fusion communication platform 24. Figure 19 As shown, the communication device 1900 may include a transceiver unit 1910 and a processing unit 1920.

[0407] In one design, the transceiver unit 1910 can be used to receive a first user frame sent by a terminal. The first user frame carries an outbound link indication field, which carries beam information of L downlink beams. The outbound link indication field is used to instruct the BeiDou network device to select a beam from the L downlink beams to send the user frame to the terminal, where L is a positive integer.

[0408] The processing unit 1920 can be used to select the first beam from L downlink beams.

[0409] The transceiver unit 1910 is also used to transmit a second user frame to the terminal in the first beam.

[0410] The first user frame can be Figure 8 The data request frame in the illustrated embodiment, the second user frame can be as described above. Figure 8 The first SLC PDU in the illustrated embodiment. For details, please refer to the foregoing. Figure 8 The embodiments shown are not described in detail here.

[0411] In one possible implementation, the first user frame can be as described above. Figure 10 The second ACK frame in the illustrated embodiment, the second user frame can be as described above. Figure 10 The first SLC PDU in the illustrated embodiment. For details, please refer to the foregoing. Figure 10 The embodiments shown are not described in detail here.

[0412] In one possible implementation, the first user frame can be as described above. Figure 12 In the illustrated embodiment, the third SLCPDU and the second user frame can be as described above. Figure 12 The third ACK frame in the illustrated embodiment. For details, please refer to the foregoing. Figure 12 The embodiments shown are not described in detail here.

[0413] Optionally, the transceiver unit 1910 can also be used to perform the above-mentioned tasks. Figure 8 , Figure 10 or Figure 12 The method embodiment shown illustrates the functional steps related to sending and receiving performed by the BeiDou network device 200.

[0414] Optionally, the processing unit 1920 can also be used to perform the above. Figure 8 , Figure 10 or Figure 12 The illustrated method embodiment shows the functional steps related to beam selection and user frame generation performed by the BeiDou network device 200.

[0415] It should be understood that the communication device 1900 in this design can perform the method steps executed by the Beidou network device 200 in the aforementioned embodiment, and for the sake of brevity, it will not be described again here.

[0416] The terminal 100 and Beidou network device 200 of this application embodiment have been described above. It should be understood that any device possessing the above-described... Figure 18 Any product of the aforementioned terminal 100 functions, as long as it possesses the above-mentioned features. Figure 19 Any form of product that incorporates the functions of the Beidou network device 200 falls within the protection scope of the embodiments of this application.

[0417] As a possible product form, the terminal 100 described in this application embodiment can be implemented using a general bus architecture.

[0418] See Figure 20 , Figure 20 This is a schematic diagram of the structure of the communication device 2000 provided in an embodiment of this application. The communication device 2000 may be a terminal 100, or a device therein. Figure 20 As shown, the communication device 2000 includes a processor 2001 and a transceiver 2002 internally connected and communicating with the processor. The processor 2001 can be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit (CPU) for satellite communication. The baseband processor can process satellite communication protocols and data, while the CPU can control the communication device (e.g., baseband chip, terminal, terminal chip), execute computer programs, and process data from these programs. The transceiver 2002, also known as a transceiver unit, transceiver, or transceiver circuit, is used to implement transceiver functions. The transceiver 2002 may include a receiver and a transmitter. The receiver, also known as a receiver circuit, is used to implement a receiving function; the transmitter, also known as a transmitter or transmitting circuit, is used to implement a transmitting function. Optionally, the communication device 2000 may also include an antenna 2003 and / or a radio frequency unit (not shown in the figure). The antenna 2003 and / or radio frequency unit may be located inside the communication device 2000 or separate from the communication device 2000, that is, the antenna 2003 and / or radio frequency unit may be deployed remotely or in a distributed manner.

[0419] Optionally, the communication device 2000 may include one or more memories 2004, which may store instructions, which may be computer programs, that can be executed on the communication device 2000 to cause the communication device 2000 to perform the methods described in the above method embodiments. Optionally, the memory 2004 may also store data. The communication device 2000 and the memory 2004 may be provided separately or integrated together.

[0420] The processor 2001, transceiver 2002, and memory 2004 can be connected via a communication bus.

[0421] In one design, the communication device 2000 can be used to perform the functions of the terminal 100 in the aforementioned embodiments; the processor 2001 can be used to perform the aforementioned... Figure 8 , Figure 10 or Figure 12 In the method embodiment shown, terminal 100 performs functional steps such as user frame generation and parsing, beam acquisition, and beam signal quality measurement, and / or other processes used in the technology described herein; transceiver 2002 can be used to perform the above-mentioned... Figure 8 , Figure 10 or Figure 12 The functional steps related to sending and receiving and / or other processes used in the techniques described herein are performed by terminal 100 in the method embodiments shown.

[0422] In any of the above designs, the processor 2001 may include a transceiver for implementing receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0423] In any of the above designs, the processor 2001 may store instructions, which may be computer programs. These computer programs, running on the processor 2001, cause the communication device 2000 to execute the method steps performed by the terminal 100 in the above method embodiments. The computer program may be embedded in the processor 2001; in this case, the processor 2001 may be implemented in hardware.

[0424] In one implementation, the communication device 2000 may include circuitry capable of performing the functions of transmitting, receiving, or communicating as described in the foregoing method embodiments. The processor and transceiver described in this application can be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal-oxide-semiconductor (CMOS), n-metal-oxide-semiconductor (NMOS), positive-channel metal-oxide-semiconductor (PMOS), bipolar junction transistors (BJTs), bipolar CMOS (BiCMOS), silicon-germanium (SiGe), gallium arsenide (GaAs), etc.

[0425] The scope of the communication device described in this application is not limited thereto, and the structure of the communication device may vary. Figure 20 The communication device 2000 may be a standalone device or part of a larger device. For example, the communication device 2000 may be:

[0426] (1) Independent integrated circuit IC, or chip, or chip system or subsystem;

[0427] (2) A collection of one or more ICs, optionally including storage components for storing data and computer programs;

[0428] (3) ASIC, such as modem;

[0429] (4) Modules that can be embedded in other devices;

[0430] (5) Receivers, terminals, smart terminals, cellular phones, wireless devices, handheld devices, mobile units, vehicle-mounted devices, network devices, cloud devices, artificial intelligence devices, etc.

[0431] (6) Others, etc.

[0432] As a possible product form, any network element in the BeiDou network device 200 described in this application embodiment (e.g., BeiDou ground transceiver station 22, BeiDou central station 23, BeiDou short message fusion communication platform 24) can be implemented by a general bus architecture.

[0433] See Figure 21 , Figure 21 This is a schematic diagram of the structure of the communication device 2100 provided in an embodiment of this application. The communication device 2100 may be a BeiDou network device 200, or a device thereof. Figure 21 As shown, the communication device 2100 includes a processor 2101 and a transceiver 2102 internally connected and communicating with the processor. The processor 2101 can be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit (CPU) for satellite communication. The baseband processor can process satellite communication protocols and data, while the CPU can control the communication device (e.g., a baseband chip), execute computer programs, and process data from those programs. The transceiver 2102, also known as a transceiver unit, transceiver, or transceiver circuit, is used to implement transceiver functions. The transceiver 2102 may include a receiver and a transmitter. The receiver, also known as a receiver circuit, is used to implement a receiving function; the transmitter, also known as a transmitter or transmitting circuit, is used to implement a transmitting function. Optionally, the communication device 2100 may also include an antenna 2103 and / or a radio frequency unit (not shown in the figure). The antenna 2103 and / or radio frequency unit may be located inside the communication device 2100 or separate from the communication device 2100, that is, the antenna 2103 and / or radio frequency unit may be deployed remotely or in a distributed manner.

[0434] Optionally, the communication device 2100 may include one or more memories 2104, which may store instructions, which may be computer programs, that can be executed on the communication device 2100 to cause the communication device 2100 to perform the methods described in the above method embodiments. Optionally, the memory 2104 may also store data. The communication device 2100 and the memory 2104 may be provided separately or integrated together.

[0435] The processor 2101, transceiver 2102, and memory 2104 can be connected via a communication bus.

[0436] In one design, the communication device 2100 can be used to perform the functions of the BeiDou network device 200 in the aforementioned embodiments: the processor 2101 can be used to perform the above-mentioned functions. Figure 8 , Figure 10 or Figure 12The method embodiment shown illustrates the functional steps related to beam selection, user frame generation, and / or other processes used in the techniques described herein performed by the BeiDou network device 200; the transceiver 2102 can be used to perform the above-mentioned... Figure 8 , Figure 10 or Figure 12 The method embodiments shown include the functional steps related to sending and receiving performed by the BeiDou network device 200 and / or other processes used in the techniques described herein.

[0437] In any of the above designs, the processor 2101 may include a transceiver for implementing receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0438] In any of the above designs, the processor 2101 may store instructions, which may be computer programs. These computer programs, running on the processor 2101, cause the communication device 2100 to execute the method steps executed by the terminal 100 in the above method embodiments. The computer program may be embedded in the processor 2101; in this case, the processor 2101 may be implemented in hardware.

[0439] This application also provides a computer-readable storage medium storing computer program code. When the processor executes the computer program code, the processor performs the method in any of the foregoing embodiments.

[0440] This application also provides a computer program product that, when run on a computer, causes the computer to perform the methods in any of the foregoing embodiments.

[0441] This application also provides a communication device, which can exist in the form of a chip. The device includes a processor and an interface circuit. The processor is used to communicate with other devices through a receiving circuit, so that the device can execute the method in any of the foregoing embodiments.

[0442] This application also provides a BeiDou communication system, including a terminal 100 and a BeiDou network device 200, which can perform the methods in any of the foregoing embodiments.

[0443] This application fully describes the short message communication function in the BeiDou communication system. It is understood that other satellite systems may also support short message communication functions. Therefore, it is not limited to the BeiDou communication system. If other satellite systems also support short message communication functions, the method described in this application is also applicable to the communication of other satellite systems.

[0444] The steps of the methods or algorithms described in this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a core network interface device. Of course, the processor and storage medium can also exist as discrete components in the core network interface device.

[0445] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this application can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer-readable storage media and communication media, wherein communication media include any medium that facilitates the transmission of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0446] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A beam selection method in a satellite communication system, characterized in that, include: The terminal sends a first user frame to the satellite network device, wherein the first user frame carries an outbound link indication field, the outbound link indication field carries beam information of L downlink beams, the outbound link indication field is used to instruct the satellite network device to select a beam from the L downlink beams to send the user frame to the terminal, where L is a positive integer; The terminal receives the second user frame sent to it by the satellite network device on the first of the L downlink beams.

2. The method according to claim 1, characterized in that, Before the terminal sends the first user frame to the satellite network equipment, the method further includes: The terminal sequentially captures pilot information from multiple satellite beams and obtains the beam signal quality of each satellite beam; wherein, the pilot information includes the beam number and satellite number of the satellite beam; The terminal determines the L downlink beams from the multiple satellite beams based on the beam signal quality of the captured satellite beams.

3. The method according to claim 1, characterized in that, The beam information includes satellite number, beam number, and beam signal quality; the outbound link indication field includes L beam information fields, which include a satellite number field, a beam number field, and a beam level field; wherein, the satellite number field is used to indicate the satellite number of the downlink beam, the beam number field is used to indicate the beam number of the downlink beam, and the beam level field is used to indicate the level of beam signal quality of the downlink beam.

4. The method according to claim 3, characterized in that, The beam signal quality includes any one of the following: carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal in the downlink beam.

5. The method according to any one of claims 1-4, characterized in that, The first user frame is a data request frame. The frame header of the data request frame includes the outbound link indication field and the subtype indication field. The subtype indication field is used to indicate the frame type of the data request frame. The frame type of the data request frame is a general data frame. The user information in the data request frame includes a service type field, wherein the service type field is used to indicate the service type of the data request frame, and the service type of the data request frame is either mailbox overview query service or letter download request service.

6. The method according to claim 5, characterized in that, The second user frame is a general data frame; the second user frame is a first satellite link control layer protocol data unit (SLC PDU) in a first application layer message generated by the satellite network device based on the data request frame, wherein the first application layer message is split into one or more SLC PDUs by the satellite network device, and the one or more SLC PDUs include the first SLC PDU.

7. The method according to any one of claims 1-4, characterized in that, The first user frame is an Acknowledgment (ACK) frame, and the frame header of the first user frame includes the outbound link indication field. Before the terminal sends the first user frame to the satellite network equipment, the method further includes: The terminal receives a second SLC PDU transmitted by the satellite network equipment on the second beam, and the first user frame is used to indicate the terminal's reception status of the second SLC PDU.

8. The method according to claim 7, characterized in that, The second user frame is a general data frame; before the terminal sends the first user frame to the satellite network equipment, the method further includes: The terminal sends a data request frame to the satellite network device, the data request frame being used to request the satellite network device to generate a first application layer message; wherein, the first application layer message is split into multiple SLC PDUs by the satellite network device, the multiple SLC PDUs including a first SLC PDU and a second SLC PDU, and the second user frame is the first SLC PDU.

9. The method according to any one of claims 1-4, characterized in that, Before the terminal sends the first user frame to the satellite network equipment, the method further includes: The terminal splits the second application layer message into one or more SLC PDUs, and the one or more SLC PDUs include a third SLC PDU; Wherein, the frame type of the first user frame is a general data frame, and the first user frame is the third SLC PDU; the frame type of the second user frame is an ACK frame or a receipt frame; wherein, when the second user frame is an ACK frame, the second user frame is used to indicate the reception status of the third SLC PDU by the satellite network device; when the second user frame is a receipt frame, the second user frame is used to indicate the parsing status of the second application layer message by the satellite network device.

10. The method according to any one of claims 1-4, characterized in that, The first user frame is either a location reporting frame or an emergency rescue frame.

11. The method according to claim 2, characterized in that, The terminal sequentially captures pilot information from multiple satellite beams, specifically including: The terminal sequentially captures pilot information from the multiple satellite beams based on a preset satellite beam acquisition order.

12. The method according to claim 2, characterized in that, The terminal sequentially captures pilot information from multiple satellite beams, specifically including: The terminal obtains the location information of the terminal; The terminal determines the satellite beam acquisition order of the multiple satellite beams based on the terminal's location information and the satellite beam coverage map. The satellite beam coverage map includes beam coverage information for each satellite beam, and the beam coverage information includes one or more of the following: beam center position, beam coverage radius, multiple signal strength intervals, and coverage edge coordinates of each of the multiple signal strength intervals. The terminal sequentially captures pilot information from the multiple satellite beams based on the satellite beam acquisition order.

13. The method according to claim 12, characterized in that, The terminal determines the satellite beam acquisition order of the multiple satellite beams based on its location information and satellite beam coverage map, specifically including: Based on its location information and satellite beam coverage map, the terminal determines the distance between its location and the beam center of each of the multiple satellite beams. The terminal determines the satellite acquisition order of the multiple satellite beams based on the distance between the terminal's location and the beam center locations of the multiple satellite beams.

14. The method according to claim 12, characterized in that, The terminal determines the satellite beam acquisition order of the multiple satellite beams based on its location information and satellite beam coverage map, specifically including: Based on the terminal's location information and the satellite beam coverage map, the terminal determines the signal strength range of the terminal's location under each of the multiple satellite beams; The terminal determines the satellite acquisition order of the multiple satellite beams based on the signal strength range of each satellite beam in the multiple satellite beams according to the location of the terminal.

15. The method according to any one of claims 12-14, characterized in that, Before the terminal determines the satellite beam acquisition order of the plurality of satellite beams based on the terminal's location information and the satellite beam coverage map, the method further includes: The terminal receives a satellite beam coverage map sent by the satellite cloud server. The satellite beam coverage map is generated by the satellite cloud server based on multiple measurement locations reported by n satellite terminals and the beam signal strength information of the satellite beams at the multiple measurement locations. The beam signal strength information includes the satellite number, beam number, and beam signal strength of the satellite beams.

16. A beam selection method in a satellite communication system, characterized in that, include: The satellite network device receives a first user frame sent by the terminal, wherein the first user frame carries an outbound link indication field, the outbound link indication field carries beam information of L downlink beams, the outbound link indication field is used to instruct the satellite network device to select a beam from the L downlink beams to send the user frame to the terminal, where L is a positive integer; The satellite network equipment selects a first beam from the L downlink beams to send a second user frame to the terminal.

17. The method according to claim 16, characterized in that, The beam information includes satellite number, beam number, and beam signal quality; the outbound link indication field includes L beam information fields, which include a satellite number field, a beam number field, and a beam level field; wherein, the satellite number field is used to indicate the satellite number of the downlink beam, the beam number field is used to indicate the beam number of the downlink beam, and the beam level field is used to indicate the level of beam signal quality of the downlink beam.

18. The method according to claim 17, characterized in that, The beam signal quality includes any one of the following: carrier-to-noise ratio, signal-to-noise ratio, and signal strength of the satellite signal in the downlink beam.

19. The method according to any one of claims 16-18, characterized in that, The first user frame is a data request frame. The frame header of the data request frame includes the outbound link indication field and the subtype indication field. The subtype indication field is used to indicate the frame type of the data request frame. The frame type of the data request frame is a general data frame. The user information in the data request frame includes a service type field, wherein the service type field is used to indicate the service type of the data request frame, and the service type of the data request frame is either mailbox overview query service or letter download request service.

20. The method according to claim 19, characterized in that, The frame type of the second user frame is a general data frame; Before the satellite network device selects the first beam from the L downlink beams to send the second user frame to the terminal, the method further includes: The satellite network device generates a first application layer message based on the data request frame; The satellite network device splits the first application layer message into one or more SLC PDUs, wherein the one or more SLC PDUs include the first SLC PDU.

21. The method according to any one of claims 16-18, characterized in that, The first user frame is an ACK frame, and the frame header of the first user frame includes the outbound link indication field. Before the satellite network device receives the first user frame sent by the terminal, the method further includes: The satellite network equipment transmits a second SLC PDU to the terminal on the second beam, wherein the first user frame is used to indicate the terminal's reception status of the second SLC PDU.

22. The method according to claim 21, characterized in that, The second user frame is a general data frame; the method further includes: The satellite network device receives a data request frame sent by the terminal; The satellite network device generates a first application layer message based on the data request frame; The satellite network device splits the first application layer message into multiple SLC PDUs, the multiple SLC PDUs including a first SLC PDU and a second SLC PDU, and the second user frame is the first SLC PDU.

23. The method according to any one of claims 16-18, characterized in that, The first user frame is a general data frame, and the first user frame is the third SLC PDU among one or more SLCPDUs into which the second application layer message is split by the terminal. The second user frame is of type ACK or acknowledgment frame; wherein, when the second user frame is ACK, the second user frame is used to indicate the satellite network device's reception status of the third SLC PDU; when the second user frame is acknowledgment frame, the second user frame is used to indicate the satellite network device's parsing status of the second application layer message.

24. The method according to any one of claims 16-18, characterized in that, The first user frame is either a location reporting frame or an emergency rescue frame.

25. A satellite communication system, characterized in that, This includes terminals and satellite network equipment; among which, The terminal is used to execute the method according to any one of claims 1-15; The satellite network equipment is used to perform the method described in any one of claims 16-24.

26. A communication device, characterized in that, The device includes one or more processors, one or more memories, and a transceiver; wherein the transceiver, the one or more memories, and the one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program code, the computer program code including computer instructions, which, when executed by the one or more processors, cause the communication device to perform the method as described in any one of claims 1-15.

27. The communication device according to claim 26, characterized in that, The communication device is a terminal.

28. A communication device, characterized in that, The device includes one or more processors, one or more memories, and a transceiver; wherein the transceiver, the one or more memories, and the one or more memories are coupled to the one or more processors, and the one or more memories are used to store computer program code, the computer program code including computer instructions, which, when the one or more processors execute the computer instructions, cause the communication device to perform the method as described in any one of claims 16-24.

29. The communication device according to claim 28, characterized in that, The communication device is a satellite network equipment.

30. A computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-15.

31. A computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 16-24.

32. A chip system applied in a terminal, characterized in that, It includes a processing circuit and an interface circuit, the interface circuit being used to receive code instructions and transmit them to the processing circuit, the processing circuit being used to execute the code instructions to perform the method as described in any one of claims 1-15.

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