Open-loop uplink synchronization method, device, equipment and storage medium

Abstract

The embodiment of the invention discloses an open-loop uplink synchronization method and device, equipment and a storage medium. The method comprises the following steps: calculating an uplink frame number based on UTC time and a preset unified mapping rule, and calculating a starting moment of an uplink frame based on the uplink frame number; receiving a downlink broadcast message, obtaining feeder link public time delay and ephemeris data from the downlink broadcast message, and calculating the distance between a user terminal and a satellite based on the ephemeris data to calculate service link time delay; the feeder link public time delay and the service link time delay are both unidirectional time delays, obtaining a fine tuning value from the MAC CE command, and calculating an uplink lead in combination with the feeder link public time delay and the service link time delay; and determining an uplink moment according to the starting moment and the uplink advance, and sending an uplink frame at the uplink moment. According to the method, on the basis of not depending on downlink signal detection synchronization, through mapping of global time and estimation and compensation of one-way propagation time delay, synchronization of uplink signals is independently achieved, and decoupling of uplink and downlink networking of the heterogeneous wireless technology is achieved.

Description

Technical Field

[0001] This application relates to the field of satellite communication, and more particularly to an open-loop uplink synchronization method, apparatus, device, and storage medium. Background Technology

[0002] In the standard 3GPP (3rd Generation Partnership Project) 5G NR (New Radio) protocol (TS 38.211 / 38.213), the uplink synchronization mechanism relies on the downlink reference time. The UE (User Equipment) must first accurately detect the boundaries of the downlink frame, and then send the uplink signal in advance based on the TA (Timing Advance) value jointly determined by its own estimated latency and the base station's adjustment instructions.

[0003] However, in the asymmetric system of "DVB (Digital Video Broadcasting) downlink + NR uplink", since the UE's receiving module is a DVB receiver and the transmitting module is an NR transmitter, the uplink suffers from physical layer decoupling, resulting in no reference source, and thus problems such as uncertain processing delay and failure of traditional TA values. Summary of the Invention

[0004] This application provides an open-loop uplink synchronization method, apparatus, device, and storage medium. It first uses UTC time to determine the uplink frame number, then calculates the uplink advance based on the feeder link common delay, the service link delay, and the fine-tuning value, and then sends the uplink frame based on the start time of the corresponding uplink frame and the uplink advance. This solves the problems of physical layer decoupling leading to no reference source, uncertain processing delay, and failure of traditional TA in related technologies.

[0005] In a first aspect, embodiments of this application provide an open-loop uplink synchronization method, comprising:

[0006] Obtain the UTC time and a pre-defined unified mapping rule, calculate the uplink frame number based on the UTC time and the pre-defined unified mapping rule, and calculate the start time of the uplink frame based on the uplink frame number; Receive downlink broadcast messages, obtain feeder link common delay and ephemeris data based on the downlink broadcast messages, wherein the feeder link common delay is the one-way delay of data transmission between the gateway station and the satellite, calculate the distance between the user terminal and the satellite based on the ephemeris data, calculate the service link delay based on the distance, wherein the service link delay is the one-way delay of data transmission between the user terminal and the satellite; Obtain the fine-tuning value from the MAC CE command, and calculate the uplink advance based on the fine-tuning value, the feeder link common delay, and the service link delay; The uplink time is calculated based on the start time and the uplink advance, and the uplink time is earlier than the start time. The uplink frame is transmitted at the uplink time.

[0007] Furthermore, the calculation of the uplink frame number based on the UTC time and the pre-set unified mapping rule includes: The uplink frame number is calculated using the following unified mapping rule:

[0008]

[0009] in: Indicates the uplink frame number; Indicates the UTC time; Indicates the length of the uplink frame; This indicates the maximum value of the frame number; This indicates the floor function; This represents the modulo operation; and These are the preset first control parameter and the second control parameter, respectively.

[0010] Furthermore, the calculation of the distance between the user terminal and the satellite based on the ephemeris data includes: The coordinates of the satellite in the geocentric-geocentric coordinate system are obtained using the ephemeris data. Based on the longitude, latitude, and altitude of the user terminal, the coordinates of the user terminal in the geocentric coordinate system are calculated according to the ellipsoid model. The distance between the user terminal and the satellite is calculated based on the coordinates of the satellite and the user terminal in the geocentric coordinate system.

[0011] Furthermore, the step of calculating the coordinates of the user terminal in the geocentric coordinate system based on the longitude, latitude, and altitude of the user terminal according to the ellipsoidal model includes: Calculate the radius of curvature of the circumpolar region based on the stated latitude:

[0012] Where N represents the radius of curvature of the primordial circle, and a represents the equatorial radius. The latitude of the user terminal is represented by , and e represents the first eccentricity. Calculate the coordinates of the user terminal in the geocentric coordinate system. :

[0013] in, H and H represent the longitude and altitude of the user terminal, respectively; , and These represent the X-axis, Y-axis, and Z-axis coordinates of the user terminal in the geocentric coordinate system.

[0014] Furthermore, the calculation of service link latency based on the distance includes: Divide the distance by the speed of light to obtain the service link delay.

[0015] Furthermore, the calculation of uplink advance based on the fine-tuning value, the feeder link common delay, and the service link delay includes: The uplink advance is calculated using the following formula:

[0016] in: This indicates the aforementioned advance amount; This indicates the fine-tuning value; This indicates the common delay of the feeder link; This indicates the service link latency; This represents the smallest unit of time in 5G NR.

[0017] Furthermore, the calculation of the uplink time based on the start time and the uplink advance includes: The uplink time is obtained by subtracting the uplink advance from the start time.

[0018] In a second aspect, embodiments of this application provide an open-loop uplink synchronization device, comprising: The acquisition module is used to obtain UTC time and pre-defined unified mapping rules; The calculation module is used to calculate the uplink frame number based on the UTC time and the pre-set unified mapping rule, and to calculate the start time of the uplink frame based on the uplink frame number; The receiving module is used to receive downlink broadcast messages; The acquisition module is also used to acquire feeder link common delay and ephemeris data based on the downlink broadcast message, wherein the feeder link common delay is the one-way delay of data transmission between the gateway station and the satellite; The calculation module is also used to calculate the distance between the user terminal and the satellite based on the ephemeris data, and to calculate the service link delay based on the distance, wherein the service link delay is the one-way delay of data transmission between the user terminal and the satellite; The acquisition module is also used to acquire fine-tuning values ​​from MAC CE commands; The calculation module is also used to calculate the uplink advance based on the fine-tuning value, the common delay of the feeder link, and the delay of the service link; and to calculate the uplink time based on the start time and the uplink advance, wherein the uplink time is earlier than the start time. A transmitting module is used to transmit the uplink frame at the uplink time.

[0019] In a third aspect, embodiments of this application provide an electronic device, including: a memory and one or more processors; The memory is used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the open-loop uplink synchronization method as described in the first aspect.

[0020] In a fourth aspect, embodiments of this application provide a storage medium for storing computer-executable instructions, which, when executed by a computer processor, are used to perform the open-loop uplink synchronization method as described in the first aspect.

[0021] This invention determines the uplink frame number using UTC time, then calculates the uplink advance based on the feeder link common delay and service link delay obtained from the downlink broadcast message, combined with the fine-tuning value obtained from the MAC CE command. Finally, the uplink frame is sent ahead of schedule based on the uplink advance and the start time of the uplink frame. Since it is no longer necessary to determine the uplink frame transmission time based on the boundary of the downlink frame received by the NR receiver, uplink and downlink hardware can be decoupled, allowing user terminals to achieve high-precision 5G NR uplink synchronization while using inexpensive DVB receiver chips. Because the uplink time is determined using UTC time received by the GNSS receiver, accurate time synchronization can be obtained, unaffected by unpredictable jitter in the DVB decoding link. Since the user terminal can calculate the accurate uplink advance based on the feeder link common delay, service link delay, and fine-tuning value before performing random access via PRACH (Physical Random Access Channel), it can send random access messages (e.g., preambles) based on UTC time and the uplink advance, improving the success rate of random access. This invention can independently achieve uplink signal synchronization without relying on downlink signal detection and synchronization, through global time mapping and estimation and compensation of one-way propagation delay, thus achieving decoupling of uplink and downlink networking in heterogeneous wireless technologies. Attached Figure Description

[0022] Figure 1 This is a flowchart of the open-loop uplink synchronization method provided in the embodiments of this application; Figure 2 This is a schematic diagram illustrating the principle of calculating uplink lead provided in an embodiment of this application; Figure 3 This is a schematic diagram of the transparent satellite architecture of NTN provided in the embodiments of this application; Figure 4 This is a schematic diagram of the open-loop uplink synchronization device provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but additional steps not included in the drawings may also be present. The above processes can correspond to methods, functions, procedures, subroutines, subroutines, etc.

[0024] In the standard 3GPP 5G NR protocol (TS38.211 / 38.213), the uplink synchronization mechanism relies on the "downlink reference time." That is:

[0025] The UE must first accurately detect the boundaries of the downlink frames. Then, based on the estimated latency and the TA value jointly determined by the base station's adjustment instructions, it sends the uplink signal in advance. This is a reference time for the downward movement.

[0026] However, in the asymmetric system of "DVB downlink + NR uplink", the following technical challenges exist: 1. Physical layer decoupling leads to no reference source: The UE's receiving module is a DVB receiver, and the transmitting module is an NR transmitter. The two may be implemented by different chips and distributed modules, and the frame structure of DVB is completely different from that of NR, so it cannot provide the nanosecond-level downlink frame boundary reference required by the NR system.

[0027] 2. Uncertain processing delay: DVB demodulation links typically undergo complex interleaving / deinterleaving and TS stream processing, resulting in millisecond-level processing delays with significant jitter, making them unsuitable as a precise time synchronization source for NR uplink.

[0028] 3. Traditional TA failure: The traditional TA mechanism that relies on closed-loop measurement cannot work in the initial access phase because the UE cannot determine the timing of the transmission of the Physical Random Access Channel (PRACH) under the condition of losing the traditional time reference, which causes relevant messages (such as preambles) to fail to be correctly transmitted to the receiving window on the base station side.

[0029] The core problem this invention aims to solve is: how user terminals can autonomously construct precise uplink transmission times in the absence of reliable 5G downlink reference signals, ensuring that the signal arrives at the satellite within the base station's receiving window.

[0030] The open-loop uplink synchronization method provided in this application can be applied to uplink devices in asymmetric systems of "DVB downlink + NR uplink", especially mobile phones, vehicle terminals, etc.

[0031] Figure 1 This is a flowchart of the open-loop uplink synchronization method provided in the embodiments of this application, see reference. Figure 1 The open-loop uplink synchronization method includes: Step S101: Obtain UTC (Coordinated Universal Time) and a pre-set unified mapping rule; calculate the uplink frame number based on the UTC time and the pre-set unified mapping rule; and calculate the start time of the uplink frame based on the uplink frame number.

[0032] UTC time is the world standard time, using a 24-hour format. The uplink frame length refers to the duration of the communication frame in the uplink direction in the time domain; in 5G NR, this duration is 10ms. The maximum frame number is 1023, and the frame number follows a cyclic counting rule.

[0033] Among them, the uplink frame number is a unique, network-wide synchronized time identifier assigned to each standard 10ms uplink wireless frame. It is the core number for the physical layer to perform timing identification, synchronization, and resource scheduling of uplink frames.

[0034] In one embodiment, UTC time can be obtained by the user terminal using a built-in GNSS (Global Navigation Satellite System) receiver module to obtain the UTC time through GNSS time synchronization.

[0035] In one embodiment, the base station and the user terminal use the same unified mapping rule to calculate the uplink frame number.

[0036] In one embodiment, calculating the start time of the uplink frame based on the uplink frame number includes: For uplink frame number The start time of its corresponding uplink frame . This is the start time of the uplink frame of frame 0. .

[0037] Since the base station and the user terminal use the same unified mapping rule to calculate the uplink frame number, and the uplink frame number cycles between 0 and 1023, the length of the uplink frame... Since it is fixed, after each cycle of uplink frame numbering ends, the start time of the uplink frame of the 0th frame in the next cycle is recorded. In subsequent communications, the user terminal and the base station can determine the start time of the uplink frame, i.e. the uplink boundary of the uplink frame, based on the same calculation rules. Therefore, by combining the start time of the uplink frame of the 0th frame in the current cycle with the number of the uplink frame, the start time of the uplink frame of the present invention can be determined.

[0038] Figure 2 This is a schematic diagram illustrating the principle of calculating uplink lead time according to an embodiment of this application. (Reference) Figure 2 Before sending uplink frames, the user terminal creates a virtual uplink frame sequence. Since the base station and user terminal use a unified mapping rule to calculate the uplink frame number, and the length of the uplink frame is fixed, uplink frames with the same frame number in both the virtual uplink frame sequence created by the user terminal and the actual uplink frame sequence received by the base station have the same start and end times. For example, for an uplink frame with frame number m, the start and transmission times in the virtual uplink frame created by the user terminal are the same as the start and transmission times of the uplink frame with frame number m in the actual uplink frame sequence received by the base station.

[0039] For an uplink frame with frame number n, since the user terminal has already created a virtual uplink frame sequence before sending the uplink frame with frame number n, and the base station and user terminal use a unified mapping rule to calculate the uplink frame number and the length of the uplink frame is fixed, the user terminal can use the start time of the uplink frame with frame number n in the virtual uplink frame sequence as the uplink reception time of the uplink frame with frame number n actually received by the base station. After calculating the uplink advance, the uplink reception time can be subtracted from the uplink advance to obtain the uplink transmission time of the uplink frame with frame number n (i.e., ...). Figure 2 The start time of the nth frame in the sequence of uplink frames actually sent by the user terminal in the sequence.

[0040] This invention uses UTC time as the global time. Since the user terminal uses the same method as the base station to calculate the uplink frame number (i.e., it uses a unified mapping rule to map the global time to the uplink frame number), the user terminal and the base station can determine the uplink boundary without relying on the downlink reference time. The user terminal can determine the transmission time of the uplink frame in an asymmetric system of "DVB downlink + NR uplink". This differs from traditional methods of calculating uplink advance. Figure 2The uplink advance in this context refers to the offset between the uplink transmit and receive times, rather than the traditional offset between the uplink transmit and downlink receive times. Therefore... Figure 2 The uplink advance in the figure is the one-way transmission delay, not the return transmission time delay (RTD).

[0041] In one embodiment, calculating the uplink frame number based on the UTC time and the pre-defined unified mapping rule includes: The uplink frame number is calculated using the following unified mapping rule:

[0042]

[0043] in: Indicates the uplink frame number; This represents the UTC time, in seconds; The length of the uplink frame is 10ms, or 0.01s, in a 5G NR wireless system. This is the maximum value of the frame number; in a 5G NR wireless system, the uplink frame number cycles sequentially from 0 to 1023, therefore... It is 1023; This indicates the floor function; This represents the modulo operation; and These are the preset first and second control parameters, both of which are duration parameters.

[0044] The value range is 0~1.2288e7, that is... The value range is 0.00~0.01s; The value range is -32768 to 32767, that is... The value range is -327689 to 327670 ms.

[0045] Furthermore, for simplicity, it can be set , That is, the boundary of the uplink frame (receive time or transmit time) is aligned with whole seconds of UTC time.

[0046] Step S102: Receive downlink broadcast message, obtain feeder link common delay and ephemeris data based on the downlink broadcast message, the feeder link common delay is the one-way delay of data transmission between the gateway station and the satellite, calculate the distance between the user terminal and the satellite based on the ephemeris data, calculate the service link delay based on the distance, the service link delay is the one-way delay of data transmission between the user terminal and the satellite.

[0047] Among them, the downlink broadcast message can be an RRC message. RRC is short for Radio Resource Control, which is a core component of the 5G control plane protocol stack. It is responsible for radio resource management, configuration negotiation, state control and signaling interaction between the user terminal and the network side (base station gNB).

[0048] Ephemeris data is the core of satellite navigation systems, used to describe the orbital position and velocity of satellites at a specific time. Common types include broadcast ephemeris (good real-time performance, accuracy down to the meter level) and precise ephemeris (high latency, accuracy down to the centimeter level).

[0049] Figure 3 This is a schematic diagram of the transparent satellite architecture of NTN provided in this application embodiment. In the transparent satellite architecture, the base station is located at the gateway station, and the satellite signal propagates between the user terminal and the gateway station, being relayed via satellite along the way. The wireless link between the satellite and the gateway station is called the feeder link. Figure 3 In this context, the feeder link is denoted as FL, and the wireless link between the user terminal and the satellite is called the service link. Figure 3 In this context, the service link is SL.

[0050] A reference point can be defined on the feeder link. Figure 4 In this context, the RP (Reference Point) and the gateway station have a fixed propagation delay, defined as follows: .

[0051] For ease of calculation, it can be set to =0, meaning the RP overlaps with the gateway station. The time offset of RTT between the satellite payload and the reference point (RP) can be expressed as Common TA, which is usually a quadratic function with time as the independent variable. Its parameters are derived by the base station through curve fitting and provided to the user terminal through downlink broadcast messages (such as SIB19, which is a type of RRC message). In DVB, the satellite can be a GSO satellite. Since the GSO satellite is stationary relative to the Earth, Common TA can degenerate into a constant.

[0052] The time offset of RTT between the satellite and the user terminal can be expressed as Service Link RTT, which is obtained by the user terminal through distance derivation using the received satellite ephemeris and its own GNSS navigation and positioning.

[0053] For satellites, since the feeder link delay is essentially constant, the reference point RP can be set as the gateway station. =0 and CommonTA contains only values ​​of order 0.

[0054] In one embodiment, obtaining the feeder link common delay based on the downlink broadcast message includes: The formula for calculating the common delay of the feeder link is as follows:

[0055] in, This indicates the common delay of the feeder link. This refers to the parameter ta-Common in the RRC message. ta-Common is determined based on the distance between the satellite and the reference point (which overlaps with the gateway station).

[0056] In another embodiment, if the delay in satellite signal relay cannot be ignored, then additional processing delay should be added:

[0057] This indicates the processing delay.

[0058] In one embodiment, the feeder link delay is the propagation time required to transmit data from the gateway station to the satellite; The processing delay is the time consumed by the satellite after receiving data sent by the gateway station, processing the data, and forwarding it.

[0059] Furthermore, since DVB is generally used for transparent satellite transmission, the processing latency in a transparent transmission architecture roughly includes: RF amplification delay: The time it takes for the satellite to amplify the RF signal received from the feeder link through a high-power amplifier, which is related to the amplifier's response speed; Frequency conversion delay: The time it takes to convert the received uplink RF frequency to the downlink RF frequency, which is determined by the circuit response speed of the mixer and local oscillator module; Forwarding scheduling delay: If the satellite supports multi-beam switching, the time it takes to schedule the signal to the target downlink beam. Therefore, the processing delay is the sum of the RF amplification delay, the frequency conversion delay, and the forwarding scheduling delay.

[0060] In one embodiment, calculating the distance between the user terminal and the satellite based on ephemeris data includes: The coordinates of the satellite in the geocentric-geocentric coordinate system are obtained using the ephemeris data. Based on the longitude, latitude, and altitude of the user terminal, the coordinates of the user terminal in the geocentric coordinate system are calculated according to the ellipsoid model. The distance between the user terminal and the satellite is calculated based on the coordinates of the satellite and the user terminal in the geocentric coordinate system.

[0061] Furthermore, obtaining the satellite's coordinates in the geocentric coordinate system using the ephemeris data includes: The coordinates of the satellite in the Earth-centered Earth-fixed coordinate system are obtained using the ephemeris data. :

[0062] , and These are the x-axis, y-axis, and z-axis coordinates of the satellite in the Earth-centered, Earth-fixed coordinate system, respectively.

[0063] Furthermore, the step of calculating the coordinates of the user terminal in the geocentric coordinate system based on the longitude, latitude, and altitude of the user terminal according to the ellipsoidal model includes: Calculate the radius of curvature of the circumpolar region based on the stated latitude:

[0064] Where N represents the radius of curvature of the primordial circle, and a represents the equatorial radius. The latitude of the user terminal is represented by , and e represents the first eccentricity. The semi-major axis of WGS84 is the equatorial radius. The square of the first eccentricity; GNSS positioning provides the longitude, latitude, and altitude of the user terminal's location, and calculates the user terminal's coordinates in the geocentric coordinate system based on an ellipsoidal model. :

[0065] in, H and H represent the longitude and altitude of the user terminal, respectively; , and These represent the X-axis, Y-axis, and Z-axis coordinates of the user terminal in the geocentric coordinate system.

[0066] Furthermore, calculating the distance between the user terminal and the satellite based on their coordinates in the geocentric coordinate system includes: Calculate the vector of the satellite-to-ground propagation path : .

[0067] Calculate the distance between the user terminal and the satellite. : .

[0068] In one embodiment, the distance-based service link latency calculation includes: Divide the distance by the speed of light to obtain the service link delay.

[0069] Furthermore, the service link latency is calculated using the following formula. :

[0070] The service link latency is the length of the satellite-to-ground propagation path and the speed of light. The ratio between them.

[0071] In determining , and Then, the upward lead time can be determined. The uplink advance is the duration of the uplink transmission advance relative to the uplink reception time, which is related to global time.

[0072] Step S103: Obtain the fine-tuning value from the MAC CE (MAC Control Element) command, and calculate the uplink advance based on the fine-tuning value, the feeder link common delay, and the service link delay.

[0073] Among them, the MAC CE command is a control information block embedded in the MAC PDU (Protocol Data Unit). It is specifically used for transmitting fine-grained, low-latency MAC layer control instructions between the base station and the terminal. It does not carry actual service data. It is the dedicated carrier for realizing core MAC layer functions such as wireless resource scheduling, uplink synchronization, and power control. It is also a key Layer 2 signaling for adapting to large latency and Doppler frequency offset in satellite fusion scenarios.

[0074] The fine-tuning value is a timing advance specific to the user terminal (e.g., a specific timing advance TA in the MAC CE command), used to compensate for the propagation delay difference between the user terminal and the beam reference point based on the common delay of the feeder link, thereby achieving accurate calibration of uplink synchronization.

[0075] Uplink lead time refers to the time interval between the time the user terminal sends the uplink frame and the time the base station receives the uplink frame.

[0076] In one embodiment, calculating the uplink advance based on the fine-tuning value, the feeder link common delay, and the service link delay includes: The uplink advance is calculated using the following formula:

[0077] in: This indicates the aforementioned advance amount; This indicates the fine-tuning value; This indicates the common delay of the feeder link; This indicates the service link latency; This represents the smallest unit of time in 5G NR.

[0078] After calculating the uplink advance, the start time of the uplink frame to be sent can be further determined based on the frame number of the current uplink frame.

[0079] Step S104: Calculate the uplink time based on the start time and the uplink advance, wherein the uplink time is earlier than the start time, and send the uplink frame at the uplink time.

[0080] The start time of the uplink frame is the time when the base station begins to receive uplink frames.

[0081] Since the start time and the uplink advance are already known, the user terminal only needs to send the uplink frame in advance based on the start time to ensure that the uplink frame falls within the receiving window of the base station.

[0082] In one embodiment, calculating the uplink time based on the start time and the uplink advance includes: The uplink time is obtained by subtracting the uplink advance from the start time.

[0083] As described above, the open-loop uplink synchronization method of this application no longer requires determining the transmission time of the uplink frame based on the boundary of the downlink frame received by the NR receiver. Therefore, it decouples the uplink and downlink hardware, enabling user terminals to achieve high-precision 5G NR uplink synchronization while using inexpensive DVB receiver chips. This application determines the uplink time using the UTC time received by the GNSS receiver, achieving accurate time synchronization without being affected by unpredictable jitter in the DVB decoding link. Before performing random access via PRACH (Physical Random Access Channel), the user terminal of this application can calculate an accurate uplink advance based on the line link common delay, serving link delay, and fine-tuning value. It can then transmit random access messages (e.g., preambles) based on UTC time and uplink advance, improving the success rate of random access.

[0084] Figure 4 This is a schematic diagram of the open-loop uplink synchronization device provided in an embodiment of this application. (Reference) Figure 4 The open-loop uplink synchronization device includes: Module 21 is used to obtain UTC time and pre-defined unified mapping rules; Calculation module 22 is used to calculate the uplink frame number based on the UTC time and the pre-set unified mapping rule; Receiver module 23 is used to receive downlink broadcast messages; The acquisition module 21 is further configured to acquire feeder link common delay and ephemeris data based on the downlink broadcast message; the feeder link common delay is the one-way delay of data transmission between the gateway station and the satellite; The calculation module 22 is also used to calculate the distance between the user terminal and the satellite based on the ephemeris data, and to calculate the service link delay based on the distance, wherein the service link delay is the one-way delay of data transmission between the user terminal and the satellite; The acquisition module 21 is also used to acquire fine-tuning values ​​from MAC CE commands; The calculation module 22 is also used to calculate the uplink advance based on the fine-tuning value, the common delay of the feeder link, and the service link delay; and to calculate the uplink time based on the start time and the uplink advance, wherein the uplink time is earlier than the start time. The sending module 24 is used to send the uplink frame at the uplink time.

[0085] It is worth noting that in the above embodiments of the open-loop uplink synchronization device, the modules included are divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the protection scope of the embodiments of this application.

[0086] This application also provides an electronic device that can integrate the open-loop uplink synchronization device provided in this application. Figure 5 This is a schematic diagram of the structure of the electronic device provided in an embodiment of this application. (Reference) Figure 5 The electronic device includes: an input device 43, an output device 44, a memory 42, and one or more processors 41; the memory 42 is used to store one or more programs; when one or more programs are executed by one or more processors 41, the one or more processors 41 implement the open-loop uplink synchronization method provided in the above embodiments. The input device 43, output device 44, memory 42, and processors 41 can be connected via a bus or other means. Figure 5 Taking the example of a connection between China and Israel via a bus.

[0087] The memory 42, as a computing device-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as program instructions / modules corresponding to the open-loop uplink synchronization method provided in any embodiment of this application (e.g., the acquisition module 21, calculation module 22, receiving module 23, and sending module 24 in the open-loop uplink synchronization device). The memory 42 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the device, etc. Furthermore, the memory 42 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, or other non-volatile solid-state storage device. In some instances, the memory 42 may further include memory remotely located relative to the processor 41, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0088] Input device 43 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the device. Output device 44 may include display devices such as a display screen.

[0089] The processor 41 executes various functional applications and data processing of the device by running software programs, instructions and modules stored in the memory 42, thereby realizing the above-mentioned open-loop uplink synchronization method.

[0090] The open-loop uplink synchronization device, equipment, and computer provided above can be used to execute the open-loop uplink synchronization method provided in any of the above embodiments, and have corresponding functions and beneficial effects.

[0091] This application embodiment also provides a storage medium storing computer-executable instructions, which, when executed by a computer processor, are used to perform the open-loop uplink synchronization method provided in the above embodiment. The open-loop uplink synchronization method includes: Obtain the UTC time and a pre-defined unified mapping rule, calculate the uplink frame number based on the UTC time and the pre-defined unified mapping rule, and calculate the start time of the uplink frame based on the uplink frame number; Receive downlink broadcast messages, obtain feeder link common delay and ephemeris data based on the downlink broadcast messages, wherein the feeder link common delay is the one-way delay of data transmission between the gateway station and the satellite, calculate the distance between the user terminal and the satellite based on the ephemeris data, calculate the service link delay based on the distance, wherein the service link delay is the one-way delay of data transmission between the user terminal and the satellite; Obtain the fine-tuning value from the MAC CE command, and calculate the uplink advance based on the fine-tuning value, the feeder link common delay, and the service link delay; The uplink time is calculated based on the start time and the uplink advance, and the uplink time is earlier than the start time. The uplink frame is transmitted at the uplink time.

[0092] Storage medium – any type of memory device or storage device. The term “storage medium” is intended to include: mounting media, such as CD-ROMs, floppy disks, or magnetic tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (e.g., hard disks or optical storage); registers or other similar types of memory elements, etc. Storage media may also include other types of memory or combinations thereof. Furthermore, storage media may reside in a first computer system in which a program is executed, or may reside in a different second computer system connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term “storage medium” can include two or more storage media that may reside in different locations (e.g., in different computer systems connected via a network). Storage media may store program instructions (e.g., specifically implemented as a computer program) executable by one or more processors.

[0093] Of course, the computer-executable instructions stored in the storage medium provided in the embodiments of this application are not limited to the open-loop uplink synchronization method provided above, but can also execute related operations in the open-loop uplink synchronization method provided in any embodiment of this application.

[0094] The open-loop uplink synchronization device, equipment, and storage medium provided in the above embodiments can execute the open-loop uplink synchronization method provided in any embodiment of this application. For technical details not described in detail in the above embodiments, please refer to the open-loop uplink synchronization method provided in any embodiment of this application.

[0095] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments provided herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the claims.

Claims

1. An open loop uplink synchronization method, characterized by, The method comprises the following steps: UTC time and a pre-set uniform mapping rule are acquired, an uplink frame number is calculated based on the UTC time and the pre-set uniform mapping rule, and a starting time of an uplink frame is calculated based on the uplink frame number; A downlink broadcast message is received, feeder link common time delay and ephemeris data are acquired based on the downlink broadcast message, the feeder link common time delay is a one-way time delay of data transmission between a gateway station and a satellite, a distance between a user terminal and the satellite is calculated based on the ephemeris data, and service link time delay is calculated based on the distance, the service link time delay being a one-way time delay of data transmission between the user terminal and the satellite; A fine adjustment value is acquired from a MAC CE command, and uplink advance is calculated based on the fine adjustment value, the feeder link common time delay and the service link time delay; The uplink time is calculated based on the starting time and the uplink advance, the uplink time being earlier than the starting time, and the uplink frame is sent at the uplink time.

2. The open-loop uplink synchronization method of claim 1, wherein, The uplink frame number is calculated based on the UTC time and the pre-set uniform mapping rule, which comprises the following steps: The uplink frame number is calculated using the following uniform mapping rule: Wherein: denotes the uplink frame number; represents the UTC time; represents the length of the uplink frame; represents the maximum value of the frame number; denotes a floor operation; represents a modulo operation; and are respectively preset first and second control parameters.

3. The open-loop uplink synchronization method of claim 1, wherein, The distance between the user terminal and the satellite is calculated based on the ephemeris data, which comprises the following steps: The coordinates of the satellite in the Earth-Centered Earth-Fixed coordinate system are acquired through the ephemeris data; The coordinates of the user terminal in the Earth-Centered Earth-Fixed coordinate system are calculated according to an ellipsoid model based on the longitude, latitude and height of the user terminal; The distance between the user terminal and the satellite is calculated according to the coordinates of the satellite and the user terminal in the Earth-Centered Earth-Fixed coordinate system.

4. The open-loop uplink synchronization method of claim 3, wherein, The coordinates of the user terminal in the Earth-Centered Earth-Fixed coordinate system are calculated according to an ellipsoid model based on the longitude, latitude and height of the user terminal, which comprises the following steps: The meridian curvature radius is calculated based on the latitude: wherein N represents the colatitude radius of curvature, a represents the equatorial radius, represents the latitude of the user terminal, e represents the first eccentricity; calculating coordinates of the user terminal in the geocentric geodetic coordinate system : wherein, and H represent the longitude and altitude of the user terminal, respectively; , and denote the X, Y and Z coordinates of the user terminal in the geocentric geodetic coordinate system, respectively.

5. The open-loop uplink synchronization method of claim 3, wherein, The service link time delay is calculated based on the distance, which comprises the following steps: The distance is divided by the speed of light to obtain the service link time delay.

6. The open-loop uplink synchronization method of claim 1, wherein, The uplink advance is calculated based on the fine adjustment value, the feeder link common time delay and the service link time delay, which comprises the following steps: The uplink advance is calculated using the following formula: Wherein: denotes the uplink timing advance; denotes the fine tuning value; represents the feeder link common delay; representing the service link latency; indicates the minimum time unit in 5G NR.

7. The open-loop uplink synchronization method of claim 1, wherein, The uplink time is calculated based on the starting time and the uplink advance, which comprises the following steps: The uplink time is obtained by subtracting the uplink advance from the starting time.

8. An open loop uplink synchronization apparatus, characterized by, The method comprises the following steps: An acquisition module is configured to acquire UTC time and a pre-set uniform mapping rule; A calculation module is configured to calculate an uplink frame number based on the UTC time and the pre-set uniform mapping rule, and calculate a starting time of an uplink frame based on the uplink frame number; A receiving module is configured to receive a downlink broadcast message; The acquisition module is further configured to acquire feeder link common time delay and ephemeris data based on the downlink broadcast message, the feeder link common time delay being a one-way time delay of data transmission between a gateway station and a satellite; The calculation module is further configured to calculate a distance between a user terminal and a satellite based on the ephemeris data, and calculate service link time delay based on the distance, the service link time delay being a one-way time delay of data transmission between the user terminal and the satellite; The acquisition module is further configured to acquire a fine adjustment value from a MAC CE command; The computing module is further configured to calculate an uplink advance based on the fine tuning value, a feeder link common delay, and a service link delay; and calculate an uplink time based on the start time and the uplink advance, the uplink time being earlier than the start time. A sending module configured to send the uplink frame at the uplink time.

9. An electronic device, comprising: Comprising: a memory and one or more processors; the memory configured to store one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the open-loop uplink synchronization method according to any one of claims 1-7.

10. A storage medium storing computer-executable instructions, wherein: The computer-executable instructions, when executed by a computer processor, perform the open-loop uplink synchronization method according to any one of claims 1-7. The computer-executable instructions, when executed by a computer processor, perform the open-loop uplink synchronization method according to any one of claims 1-7.

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