Time synchronization method and device, first terminal, network equipment and storage medium

Abstract

The invention discloses a time synchronization method and device, a first terminal, network equipment and a storage medium, and the method comprises the steps: enabling the network equipment facing satellite transparent forwarding to carry out the TA pre-compensation based on first information through employing a satellite as an anchor point; wherein the first information represents ephemeris information of the satellite.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a time synchronization method, apparatus, first terminal, network equipment and storage medium. Background Art

[0002] In the related art, the satellite communication system uses the ground base station as the demarcation point, and the ground base station continuously switches the satellite used for transparent forwarding to realize satellite-to-ground communication. However, this solution is only applicable to the satellite staring beam projection in a fixed area, and there is a problem that the satellite staring beam has a small coverage area. Summary of the invention

[0003] To solve related technical problems, an embodiment of the present application provides a time synchronization method, apparatus, first terminal, network device and storage medium.

[0004] The technical solution of the embodiment of the present application is implemented as follows:

[0005] The embodiment of the present application provides a time synchronization method, which is applied to a network device for satellite transparent forwarding, and the method includes:

[0006] Taking the satellite as an anchor point, timing advance (TA) pre-compensation is performed based on first information; wherein the first information represents the ephemeris information of the satellite.

[0007] In the above solution, the method of taking the satellite as an anchor point and performing TA pre-compensation based on the first information includes:

[0008] Determining TA values ​​at different times in advance based on the first information;

[0009] Taking the satellite as an anchor point, TA pre-compensation is performed based on the determined TA value.

[0010] In the above scheme, the method further comprises:

[0011] Taking the satellite as an anchor point, fine time synchronization is performed with a first terminal on the satellite.

[0012] In the above solution, taking the satellite as an anchor point and performing fine time synchronization with the first terminal on the satellite includes:

[0013] Taking the satellite as an anchor point, fine adjustment of the TA is performed based on the second information; wherein the second information represents a TA adjustment value or a TA adjustment range.

[0014] In the above solution, the TA adjustment value represented by the second information includes the first TA adjustment value and / or the offset value; wherein,

[0015] The first TA adjustment value represents a TA adjustment value acquired by the network device when the first terminal accesses the network device, and the offset value represents a TA adjustment offset of the network device, and the offset value is less than or equal to the first TA adjustment value.

[0016] In the above solution, the first TA adjustment value is obtained during a random access process of the first terminal, or is obtained when the first terminal is in a connected state.

[0017] In the above scheme, the method further includes at least one of the following:

[0018] Sending a first message to the first terminal; wherein the first message carries third information, and the third information indicates periodically initiating random access for time fine synchronization;

[0019] Based on the third information, a second message is sent to the first terminal, where the second message indicates releasing a radio resource control (RRC, Radio Resource Control) connection.

[0020] In the above scheme, the method further includes:

[0021] In a case where the first TA adjustment value is greater than a set threshold, a third message is sent to the first terminal; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0022] In the above scheme, the method further includes at least one of the following:

[0023] Based on the second information, sending a second TA adjustment value to the first terminal;

[0024] Based on the second information, a third TA adjustment value is sent to a second terminal; wherein the second terminal represents a ground terminal that initiates random access to the network device.

[0025] In the above scheme, the method further includes:

[0026] A fourth message is sent to the second terminal; wherein the fourth message carries fourth information, and the fourth information indicates setting the satellite as an anchor point.

[0027] In the above scheme, the method further includes at least one of the following:

[0028] discarding the first data in the first subframe, and sending the second subframe to the satellite;

[0029] The first data in the first subframe is no longer scheduled; wherein,

[0030] The first data is located at the end of the first subframe, and a sending time of the first data overlaps with a sending time of at least part of the data in the second subframe.

[0031] In the above scheme, the number of symbols of the first data is determined based on the first time and the second time; wherein the first time represents the overlapping transmission time between the first subframe and the second subframe, and the second time represents the duration of each symbol.

[0032] The embodiment of the present application also provides a time synchronization method, which is applied to a first terminal on a satellite, and the method includes:

[0033] The satellite is used as an anchor point to perform precise time synchronization with network equipment that transparently forwards to the satellite.

[0034] In the above scheme, the method further includes:

[0035] Receiving a first message sent by the network device; wherein the first message carries third information, and the third information indicates periodically initiating random access for fine time synchronization;

[0036] Based on the third information, random access is initiated to the network device.

[0037] In the above scheme, the method further includes:

[0038] A third message sent by the network device is received; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0039] The embodiment of the present application also provides a time synchronization device, including:

[0040] The compensation unit is used to perform TA pre-compensation based on first information with the satellite as an anchor point; wherein the first information represents the ephemeris information of the satellite.

[0041] The embodiment of the present application also provides a time synchronization device, including:

[0042] The first synchronization unit is used to perform fine time synchronization with a network device oriented to satellite transparent forwarding by taking the satellite as an anchor point.

[0043] The embodiment of the present application further provides a network device, including a first processor and a first communication interface, wherein:

[0044] The first processor is used to perform TA pre-compensation based on first information with the satellite as an anchor point; wherein the first information represents the ephemeris information of the satellite.

[0045] The embodiment of the present application further provides a first terminal, including a second processor and a second communication interface, wherein:

[0046] The second processor is used to use the satellite as an anchor point to perform fine time synchronization with a network device that transparently forwards to the satellite.

[0047] The embodiment of the present application further provides a communication device, characterized in that it includes a processor and a memory for storing a computer program that can be run on the processor,

[0048] Wherein, when the processor is used to run the computer program, it executes the steps of any method on the network device side or the steps of any method on the first terminal side.

[0049] An embodiment of the present application also provides a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method described in any one of the above-mentioned network device sides are implemented, or the steps of the method described in any one of the above-mentioned first terminal sides are implemented.

[0050] In the time synchronization method, device, first terminal, network device and storage medium provided in the embodiment of the present application, the network device for transparent forwarding to the satellite uses the satellite as an anchor point to perform TA pre-compensation based on the first information; wherein the first information represents the ephemeris information of the satellite; the first terminal on the satellite uses the satellite as an anchor point to perform fine time synchronization with the network device for transparent forwarding to the satellite. In the above scheme, the network device uses the satellite as an anchor point to perform TA pre-compensation, and the first terminal on the satellite uses the satellite as an anchor point to perform fine time synchronization with the network device, which can ensure that the signals sent to the same satellite by the network device at different times are time synchronized, that is, the sending time interval of any two signals is the same as the receiving time interval of the corresponding two signals received by the satellite, so that the new radio (NR) non-terrestrial network (NTN) beam scanning can be used to allow different synchronization signal blocks (SSB, SynchronizationSignal Block) to scan on different beams of the satellite, thereby expanding the coverage of the satellite. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 An example diagram of the architecture of a satellite communication system for related technologies;

[0052] Figure 2 This is an example diagram of the motion trajectory of a low-orbit satellite in related technology;

[0053] Figure 3 This is a related technology NR NTN SSB example diagram;

[0054] Figure 4 A schematic diagram of a time synchronization method implementation flow in an embodiment of the present application;

[0055] Figure 5 This is an example diagram of performing TA pre-compensation based on first information in an embodiment of the present application;

[0056] Figure 6 This is an example diagram of the transmission delay of network devices when a satellite is used as an anchor point in an embodiment of the present application;

[0057] Figure 7 This is an example diagram of the overlapping transmission time of part of the data in two subframes in an embodiment of the present application;

[0058] Figure 8 This is an example diagram of a first terminal periodically initiating random access in an embodiment of the present application;

[0059] Fig. 9 This is an example diagram of a network device instructing a first terminal to re-initiate random access according to an embodiment of the present application;

[0060] Fig.10 A schematic diagram of a time synchronization method implementation flow in an embodiment of the present application;

[0061] Fig.11 This is a schematic diagram of the structure of a time synchronization device according to an embodiment of the present application;

[0062] Fig.12 This is a schematic diagram of the structure of a time synchronization device according to an embodiment of the present application;

[0063] Fig.13 This is a schematic diagram of the network device structure of an embodiment of the present application;

[0064] Fig.14 This is a schematic diagram of the first terminal structure of an embodiment of the present application. DETAILED DESCRIPTION

[0065] like Figure 1 As shown in the figure, in the satellite communication system, the satellite (transparent forwarding satellite) is used as a relay device, and the anchor point is on the ground base station. The ground base station continuously switches satellites to realize satellite-to-ground communication. Since the distance between the low-orbit satellite and the ground is constantly changing, the time synchronization cannot be guaranteed on the satellite side after the signal sent by the ground base station reaches the satellite, that is, it cannot be guaranteed that the sending time interval of any two signals is the same as the receiving time interval of the corresponding two signals received by the satellite, so that the advantages of satellite beams and SSB beam sweeping in NRNTN cannot be fully utilized, and different SSBs in NR NTN cannot be used to scan on different beams to expand the satellite coverage, so that the satellite can only use fixed beams to forward data, and the satellite staring beam coverage area is small.

[0066] like Figure 2 As shown, the distance between the same satellite and the ground gateway is different at different times, that is, d1≠d2. In this way, if the ground base station is used as the anchor point, the time when the signal sent by the ground base station arrives at the satellite is not strictly synchronized. For example, at time t1, the time when the signal sent by the ground base station arrives at the satellite is t1+d1 / c, where c represents the speed of light; at time t2, the time when the signal sent by the ground base station arrives at the satellite is t2+d2 / c; the time interval between time t1 and time t2 is different from the time interval between (t1+d1 / c) and (t2+d2 / c). Figure 3 As shown in Figure 2, the SSB in NR NTN is based on symbol-level time synchronization in the air interface. Figure 2 In this case, the time when the signals sent by the ground base station at different times arrive at the satellite cannot be guaranteed to be strictly synchronized, and the satellite cannot perform symbol-level recognition of the received signals and perform beam adjustment based on SSB.

[0067] Based on this, in various embodiments of the present application, the network device for satellite transparent forwarding uses the satellite as an anchor point and performs TA pre-compensation based on the first information; wherein the first information represents the ephemeris information of the satellite; the first terminal on the satellite uses the satellite as an anchor point to perform fine time synchronization with the network device for satellite transparent forwarding. In the above scheme, the network device uses the satellite as an anchor point to perform TA pre-compensation, and the first terminal on the satellite uses the satellite as an anchor point to perform fine time synchronization with the network device, which can ensure that the signals sent by the network device to the same satellite at different times are time synchronized, that is, the sending time interval of any two signals is the same as the receiving time interval of the corresponding two signals received by the satellite, so that NRNTN beam scanning can be used to allow different SSBs to scan on different beams of the satellite, thereby expanding the coverage of the satellite.

[0068] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0069] The embodiment of the present application provides a time synchronization method, which is applied to a network device for satellite transparent forwarding. The network device for satellite transparent forwarding can be called a ground base station, and for the convenience of description, it is hereinafter referred to as a network device. Figure 4 As shown, the method includes:

[0070] Step 401: Taking the satellite as an anchor point, perform TA pre-compensation based on first information.

[0071] The first information represents the ephemeris information of the satellite.

[0072] Here, before the first uplink transmission moment arrives, the TA value of the first uplink transmission moment is determined based on the ephemeris information represented by the first information, and the satellite is used as an anchor point, and the uplink transmission delay is TA pre-compensated based on the TA value of the first uplink transmission moment to obtain the second uplink transmission moment, so that the network device can perform uplink transmission at the second uplink transmission moment. The first uplink transmission moment is any uplink transmission moment, and the uplink transmission moment can also be understood as the uplink transmission opportunity.

[0073] For example, the first uplink transmission time is t1, the TA value of t1 is TA1, the network device uses the satellite as the anchor point, and uses TA1 to perform TA pre-compensation on the uplink transmission delay, and the second uplink transmission time obtained is t1-TA1; the network device performs uplink transmission at the time corresponding to (t1-TA1).

[0074] Among them, the method for determining the TA value of the first uplink transmission time based on the ephemeris information represented by the first information is: based on the ephemeris information represented by the first information, determine the position information corresponding to the satellite at the first uplink transmission time; based on the position information of the network device and the position information corresponding to the satellite at the first uplink transmission time, determine the first distance at the first uplink transmission time, the first distance represents the distance between the network device and the satellite; based on the first distance at the first uplink transmission time and the speed of light, determine the TA value of the first uplink transmission time.

[0075] It should be noted that TA pre-compensation is actively performed by the network device. Time advance is also called timing advance or timing advance. The anchor point can also be understood as a reference point. In order to ensure that the signals sent to the satellite by the network device at different times can achieve time synchronization, the network device needs to consider TA pre-compensation when sending data to the satellite in each time slot, that is, the network device uses the TA value to perform TA pre-compensation and then sends data to the satellite. Specifically, when the network device needs to send data to the satellite, it determines the uplink transmission time corresponding to the current time slot; before the uplink transmission time corresponding to the current time slot arrives, it determines the first TA value of the uplink transmission time corresponding to the current time slot, and uses the first TA value to perform TA pre-compensation to obtain the uplink transmission time after TA pre-compensation, and sends data to the satellite at this uplink transmission time. In order to improve the efficiency of TA pre-compensation, the TA values ​​at different times can be determined in advance. Based on this, in one embodiment, the satellite is used as an anchor point and TA pre-compensation is performed based on the first information, including:

[0076] Determining TA values ​​at different times in advance based on the first information;

[0077] Taking the satellite as an anchor point, TA pre-compensation is performed based on the determined TA value.

[0078] Here, the network device determines the corresponding position information of the satellite at each moment in advance based on the ephemeris information represented by the first information; determines the first distance corresponding to each moment based on the position information of the network device and the position information of the satellite at each moment; determines the TA value at each moment based on the first distance corresponding to each moment and the speed of light; before the first uplink transmission moment, the TA value at the first uplink transmission moment is determined from the TA value at each moment; takes the satellite as an anchor point, and performs TA pre-compensation based on the TA value at the first uplink transmission moment. Among them, di represents the first distance at the i-th moment or the i-th uplink transmission moment, c represents the speed of light, and TAi represents the TA value at the i-th moment or the i-th uplink transmission moment.

[0079] Figure 5 An example diagram of TA pre-compensation based on the first information in an embodiment of the present application is given, such as Figure 5 As shown, when the first uplink transmission time is t1, the first distance at t1 is d1, and the TA value at t1 is When the network device uses the TA value at time t1 to perform TA pre-compensation, the second uplink transmission time obtained is Network equipment in That is, the data that should have been sent at time t1 is sent at When the first uplink transmission time is t2, the first distance at t2 is d2, and the TA value at t2 is When the network device uses the TA value at time t2 to perform TA pre-compensation, the second uplink transmission time obtained is Network equipment in That is, the data that should have been sent at time t2 is sent at Always send in advance.

[0080] Figure 6 An example of the transmission delay of network devices when the satellite is used as an anchor point in the embodiment of the present application is given, such as Figure 6 As shown, the network equipment The satellite sends data to the satellite at time t1, and the satellite receives the data at time t2. The satellite sends data to the network device at time t1, and the network device receives the data at time t3. The data is received at the moment.

[0081] Before and after the network device performs TA pre-compensation, the transmission time of some data in two adjacent subframes may overlap. Since the frame header of the subframe contains key information of the physical downlink control channel (PDCCH), in order to ensure that the data in the frame header of each subframe will not be overwritten and the key information of the PDCCH contained in the frame header will not be lost, the network device will discard the tail data of the previous subframe and give priority to sending the new subframe. Based on this, in one embodiment, the method also includes at least one of the following:

[0082] discarding the first data in the first subframe, and sending the second subframe to the satellite;

[0083] The first data in the first subframe is no longer scheduled; wherein,

[0084] The first data is located at the end of the first subframe, and a sending time of the first data overlaps with a sending time of at least part of the data in the second subframe.

[0085] Here, the first subframe is transmitted before the second subframe. Figure 7 An example of overlapping transmission times of some data in two subframes in an embodiment of the present application is given, such as Figure 7 As shown, the first subframe is a subframe sent by the network device after performing TA pre-compensation for the nth time, and the second subframe is a subframe sent by the network device after performing TA pre-compensation for the n+1th time. Performing TA pre-compensation can also be understood as timing adjustment.

[0086] In actual application, the network device may no longer schedule the first data in the first subframe, discard the first data in the first subframe, and send the second subframe to the satellite.

[0087] In order to accurately determine the first data that needs to be discarded, in one embodiment, the number of symbols of the first data is determined based on a first time and a second time; wherein the first time represents the overlapping transmission time between the first subframe and the second subframe, and the second time represents the duration of each symbol.

[0088] Here, the quotient of the first time and the second time (first time / second time) may be rounded up to obtain a maximum rounded-up value, and the maximum rounded-up value may be determined as the number of symbols of the first data.

[0089] In order to ensure that the time when the signals sent by the network device at different times arrive at the satellite can be synchronized, a NTN terminal, i.e., a first terminal, needs to be built into the satellite. The NTN terminal can be a standard NTN terminal or a lightweight (Redcap, reduced-capability) NTN terminal, so that the network device and the first terminal on the satellite can dynamically maintain time synchronization. Based on this, in one embodiment, the method further includes:

[0090] Taking the satellite as an anchor point, fine time synchronization is performed with a first terminal on the satellite.

[0091] Here, after the network device performs TA pre-compensation, there may still be a small deviation between the uplink TA pre-compensation value (the distance between the satellite and the ground network device calculated based on the ephemeris information) and the actual uplink propagation delay (the actual uplink propagation delay between the network device and the satellite). At this time, the network device uses the satellite as an anchor point and performs fine time synchronization with the first terminal on the satellite, so that symbol-level time synchronization is achieved between the network device and the satellite. Fine time synchronization can be understood as the network device actively pre-compensating for small deviations, which refers to the aforementioned small deviation obtained after the first terminal on the satellite accesses the network device for transparent forwarding to the satellite.

[0092] In order to ensure that the time when the signals sent by the network device at different times arrive at the satellite can be synchronized, in one embodiment, taking the satellite as an anchor point and performing fine time synchronization with the first terminal on the satellite includes:

[0093] Taking the satellite as an anchor point, fine adjustment of the TA is performed based on the second information; wherein the second information represents a TA adjustment value or a TA adjustment range.

[0094] Here, the network device obtains or determines the second information, and uses the satellite as an anchor point to perform TA fine adjustment on the second uplink transmission time based on the second information. The TA adjustment value represented by the second information can be determined by the network device during the communication with the first terminal, and the TA adjustment range can be a set range or can be determined based on the TA adjustment value represented by the second information.

[0095] That is, after the network device uses the TA value of the first uplink transmission time to perform TA pre-compensation and obtains the second uplink transmission time, it can also finely adjust the TA of the second uplink transmission time based on the offset value represented by the second information to obtain the third uplink transmission time, and send data to the satellite at the third uplink transmission time. Network devices can be Sending data to satellite all the time.

[0096] For example, in Figure 6In the example, the first uplink transmission time is t1, and the second uplink transmission time is The third uplink transmission time is obtained by finely adjusting the TA of the second uplink transmission time. Network devices can be The network device should send data to the satellite at time t1, and b is the TA adjustment value, or the TA adjustment value determined within the TA adjustment range. Always send in advance.

[0097] In one embodiment, the TA adjustment value represented by the second information includes a first TA adjustment value and / or an offset value; wherein,

[0098] The first TA adjustment value represents a TA adjustment value acquired by the network device when the first terminal accesses the network device, and the offset value represents a TA adjustment offset of the network device, and the offset value is less than or equal to the first TA adjustment value.

[0099] Here, the first TA adjustment value is measured during the communication between the network device and the first terminal, and the TA adjustment bias may be a set value, for example, set according to the first TA adjustment value measured in real time or a historical measurement value.

[0100] It should be noted that the TA adjustment range represented by the second information can be determined by the first TA adjustment value and the bias value; the minimum value of the TA adjustment range is greater than or equal to the bias value, and the maximum value of the TA adjustment range is less than or equal to the first TA adjustment value, that is, the TA adjustment range belongs to the range obtained by the first TA adjustment value and the bias value.

[0101] In an embodiment of the present application, the first terminal communicates with the network device so that the network device measures a first TA adjustment value or determines a bias value, thereby assisting the network device in fine-tuning the TA to ensure that the signals sent to the satellite by the network device at different times can achieve time synchronization.

[0102] In one embodiment, the first TA adjustment value is obtained during a random access process of the first terminal, or is obtained when the first terminal is in a connected state.

[0103] Here, the first terminal may initiate random access to the network device, or always maintain an RRC connection state to assist the network device in fine-tuning the TA.

[0104] The first terminal assists the network device in finely adjusting the TA by periodically initiating random access. In one embodiment, the method further includes at least one of the following:

[0105] Sending a first message to the first terminal; wherein the first message carries third information, and the third information indicates periodically initiating random access for time fine synchronization;

[0106] Based on the third information, a second message is sent to the first terminal, where the second message indicates releasing the RRC connection.

[0107] Here, before the network device performs TA fine adjustment based on the second information, the network device also sends a first message to the first terminal to instruct the first terminal to periodically initiate random access for time fine synchronization; the third information may include a random access timer, or a timing time; the first message may be an RRC reconfiguration message, and the third information may be carried in a first setting information element (IE, Information Element) in the RRC Reconfiguration message. The first setting IE is a newly added IE in the RRC Release message.

[0108] When the network device successfully establishes the RRC connection of the first terminal, the first terminal enters the RRC connection state, and the network device starts timing. When the timing time indicated by the third information is reached, a second message may be sent to the first terminal to instruct the first terminal to release the RRC connection, so that the first terminal switches from the RRC connection state to the RRC idle state. When the first terminal is in the RRC idle state, random access is initiated again. The second message may be an RRC Release message.

[0109] In actual application, the third information is the random access timer T Ramdom . Figure 8 An example diagram of a first terminal periodically initiating random access is given. Figure 8 As shown, the first terminal may initiate random access to the network device immediately upon receiving the RRC Reconfiguration message; or may start the random access timer T upon receiving the RRC Reconfiguration message. Ramdom , and in the random access timer T Ramdom When the timer expires, a random access is initiated to the network device; wherein, when the first terminal initiates random access to the network device, an RRC establishment request is sent to the network device, and the carried cause value represents the fine synchronization of time. When the network device successfully establishes the RRC connection of the first terminal, it sends an RRC connection establishment success (RRC Setup) message to the first terminal and starts the random access timer T on the network device side. Ramdom , in the random access timer T RamdomWhen the timer expires, an RRC Release message is sent to the first terminal, so that the first terminal switches from the RRC connected state to the RRC idle state, so as to initiate random access to the network device again.

[0110] In the case where the first terminal always maintains an RRC connection state to assist the network device in finely adjusting the TA, if the TA adjustment value in the connection state is too large, in order to improve the precision and accuracy of the TA fine adjustment, the network device needs to instruct the first terminal to re-initiate random access to assist the network device in finely adjusting the TA. Based on this, in one embodiment, the method further includes:

[0111] In a case where the first TA adjustment value is greater than a set threshold, a third message is sent to the first terminal; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0112] Here, the network device can configure periodic or non-periodic sounding reference signal (SRS) measurement through RRC reconfiguration message, or the first terminal can periodically send uplink data to the network device, for example, physical uplink control channel (PUCCH, Physical Uplink Control Channel), and / or physical uplink shared channel (PUSCH, Physical Uplink Shared Channel).

[0113] When the first terminal is in an RRC connected state, the network device measures a first TA adjustment value through SRS measurement and / or PUCCH and / or PUSCH; when the first TA adjustment value is greater than a set threshold, a third message is sent to the first terminal to instruct the first terminal to re-initiate random access; when the first terminal receives the third message, it switches from the RRC connected state to the RRC idle state and re-sends the random access to the network device. The first indication can be carried in the second setting IE carried by the third message.

[0114] Fig. 9 An example diagram of a network device instructing a first terminal to re-initiate random access is given. Fig. 9 As shown, the third message may be an RRC Release message, and the second setting IE is a newly added IE in the RRC Release message.

[0115] Considering that the first terminal and the ground terminal may initiate random access to the network device at the same time, in order to ensure that the signal sent by the network device to the satellite is time synchronized with the signal sent by the second terminal to the satellite, when the network device performs TA fine adjustment, the first terminal and / or the ground terminal may also need to perform TA adjustment. Based on this, in one embodiment, the method further includes at least one of the following:

[0116] Based on the second information, sending a second TA adjustment value to the first terminal;

[0117] Based on the second information, a third TA adjustment value is sent to a second terminal; wherein the second terminal represents a ground terminal that initiates random access to the network device.

[0118] Here, when the network device obtains the second information, it sends the second TA adjustment value to the first terminal based on the second information, and / or sends the third TA adjustment value to the second terminal based on the second information.

[0119] The second TA adjustment value is used for the first terminal to perform TA adjustment; the second TA adjustment value is determined based on the second information; the second TA adjustment value may be carried in a random access response (RAR) returned by the network device to the first terminal. The third TA adjustment value is used for the second terminal to perform TA adjustment with the satellite as an anchor point; the third TA adjustment value may be a TA adjustment value of the second terminal determined by the network device during the random access process of the second terminal, or may be determined by the second information and the TA adjustment value of the second terminal; the third TA adjustment value is carried in the RAR returned by the network device to the second terminal, and the number of the second terminal is at least one.

[0120] In actual application, when the TA adjustment value represented by the second information includes the first TA adjustment value and the bias value, the second TA adjustment value is the difference between the first TA adjustment value and the bias value, and the third TA adjustment value is the difference between the TA adjustment value of the second terminal and the bias value. For example, when the first TA adjustment value is a and the bias value is b, the second TA adjustment value = ab, and the third TA adjustment value = the TA adjustment value of the second terminal - b.

[0121] In order to ensure that the uplink and downlink data between the satellite and the second terminal are precisely synchronized in time, that is, the sending time interval of any two signals sent by the second terminal is the same as the receiving time interval of the corresponding two signals received by the satellite, and the sending time interval of any two signals sent by the satellite is the same as the receiving time interval of the corresponding two signals received by the second terminal, before sending the third TA adjustment value to the second terminal, it is necessary to tell the second terminal to perform TA adjustment with the satellite as the anchor point. Based on this, in one embodiment, the method further includes:

[0122] A fourth message is sent to the second terminal; wherein the fourth message carries fourth information, and the fourth information indicates setting the satellite as an anchor point.

[0123] Here, the fourth information is used to instruct the ground terminal to set the TA to the satellite as an anchor point, so that the ground terminal only needs to adjust the TA for the user link between the satellite and the ground terminal. The fourth message can be a system message or a cell broadcast message of the network device, for example, a system information block (SIB) 19. In actual application, the fourth information is carried in SIB19, for example, the network device writes the fourth information in the timing address information element (TA-Info-r17) in SIB19.

[0124] Correspondingly, the embodiment of the present application further provides a first terminal on a satellite, such as Fig.10 As shown, the method includes:

[0125] Step 1001: Using the satellite as an anchor point, perform fine time synchronization with a network device for satellite-oriented transparent forwarding.

[0126] Here, the first terminal uses the satellite as an anchor point to perform fine time synchronization with the network device, which can be understood as: the first terminal actively pre-compensates for the slight deviation between the uplink TA pre-compensation value and the actual uplink propagation delay. The uplink TA pre-compensation value is the distance between the satellite and the ground network device calculated based on the ephemeris information. The actual uplink propagation delay refers to the actual uplink propagation delay between the network device and the satellite.

[0127] In one embodiment, taking the satellite as an anchor point and performing fine time synchronization with a network device for satellite transparent forwarding includes:

[0128] A second TA adjustment value sent by the network device based on second information is received; wherein the second information represents the TA adjustment value or the TA adjustment range.

[0129] Here, the first terminal uses the satellite as an anchor point and performs TA adjustment based on the second TA adjustment value.

[0130] In one embodiment, the TA adjustment value represented by the second information includes a first TA adjustment value and / or an offset value; wherein,

[0131] The first TA adjustment value represents a TA adjustment value acquired by the network device when the first terminal accesses the network device, and the offset value represents a TA adjustment offset of the network device, and the offset value is less than or equal to the first TA adjustment value.

[0132] In one embodiment, the first TA adjustment value is obtained during a random access process of the first terminal, or is obtained when the first terminal is in a connected state.

[0133] In one embodiment, the method further comprises:

[0134] Receiving a first message sent by the network device; wherein the first message carries third information, and the third information indicates periodically initiating random access for fine time synchronization;

[0135] Based on the third information, random access is initiated to the network device.

[0136] Here, as described above, the third information may be a random access timer, and the first terminal may periodically initiate random access to the network device based on the random access timer. For example, upon receiving the first message, the first terminal may immediately initiate random access to the network device; the first terminal may also start the random access timer for timing when receiving the first message, and initiate random access to the network device when the random access timer expires.

[0137] When the first terminal receives the second message (for example, an RRC Release message) sent by the network device, the first terminal releases the RRC connection and switches from the RRC connected state to the RRC idle state; when entering the RRC idle state, the first terminal can immediately initiate random access to the network device again; when entering the RRC idle state, the first terminal can also start a random access timer to start timing, and when the random access timer expires, initiate random access to the network device again.

[0138] In this embodiment, the first terminal assists the network device in finely adjusting the TA by periodically initiating random access, thereby ensuring that the time when the signals sent by the network device at different times arrive at the satellite can achieve time synchronization.

[0139] In the case where the first terminal always maintains an RRC connection state to assist the network device in finely adjusting the TA, if the TA adjustment value in the connection state is too large, in order to improve the precision and accuracy of the TA fine adjustment, the network device needs to instruct the first terminal to re-initiate random access to assist the network device in finely adjusting the TA. Based on this, in one embodiment, the method further includes:

[0140] A third message sent by the network device is received; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0141] Here, upon receiving the third message, the first terminal re-initiates random access to the network device so that the network device re-determines the first TA adjustment value.

[0142] In order to implement the time synchronization method of the embodiment of the present application, the embodiment of the present application also provides a time synchronization device, which is arranged on a network device facing satellite transparent forwarding, such as Fig.11 As shown, the device comprises:

[0143] The compensation unit 1101 is used to perform TA pre-compensation based on first information with the satellite as an anchor point; wherein the first information represents the ephemeris information of the satellite.

[0144] In one embodiment, the compensation unit 1101 is specifically configured to determine in advance the TA values ​​at different times based on the first information; and perform TA pre-compensation based on the determined TA value with the satellite as an anchor point.

[0145] In one embodiment, the device further comprises:

[0146] The second synchronization unit is used to perform fine time synchronization with the first terminal on the satellite by taking the satellite as an anchor point.

[0147] In one embodiment, the second synchronization unit is specifically configured to use the satellite as an anchor point to perform TA fine adjustment based on second information; wherein the second information represents a TA adjustment value or a TA adjustment range.

[0148] In one embodiment, the TA adjustment value represented by the second information includes a first TA adjustment value and / or an offset value; wherein,

[0149] The first TA adjustment value represents a TA adjustment value acquired by the network device when the first terminal accesses the network device, and the offset value represents a TA adjustment offset of the network device, and the offset value is less than or equal to the first TA adjustment value.

[0150] In one embodiment, the first TA adjustment value is obtained during a random access process of the first terminal, or is obtained when the first terminal is in a connected state.

[0151] In one embodiment, the device further comprises:

[0152] A first sending unit is used to send a first message to the first terminal; and / or, based on the third information, send a second message to the first terminal; wherein the first message carries third information, and the third information indicates periodic initiation of random access for time fine synchronization; and the second message indicates the release of the RRC connection.

[0153] In one embodiment, the device further comprises:

[0154] The second sending unit is used to send a third message to the first terminal when the first TA adjustment value is greater than a set threshold; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0155] In one embodiment, the device further comprises:

[0156] A third sending unit is configured to send a second TA adjustment value to the first terminal based on the second information; and / or

[0157] Based on the second information, a third TA adjustment value is sent to a second terminal; wherein the second terminal represents a ground terminal that initiates random access to the network device.

[0158] In one embodiment, the device further comprises:

[0159] The fourth sending unit is used to send a fourth message to the second terminal; wherein the fourth message carries fourth information, and the fourth information indicates setting the satellite as an anchor point.

[0160] In one embodiment, the device further comprises at least one of the following:

[0161] a fifth sending unit, configured to discard the first data in the first subframe, and send a second subframe to the satellite;

[0162] A scheduling unit, configured to no longer schedule the first data in the first subframe; wherein,

[0163] The first data is located at the end of the first subframe, and a sending time of the first data overlaps with a sending time of at least part of the data in the second subframe.

[0164] In one embodiment, the number of symbols of the first data is determined based on a first time and a second time; wherein the first time represents the overlapping transmission time between the first subframe and the second subframe, and the second time represents the duration of each symbol.

[0165] In actual application, the compensation unit 1101 and the scheduling unit can be implemented by a processor in a time synchronization device, and the second synchronization unit, the first sending unit, the second sending unit, the third sending unit, the fourth sending unit and the fifth sending unit can be implemented by a processor in the time synchronization device combined with a communication interface.

[0166] In order to implement the time synchronization method of the embodiment of the present application, the embodiment of the present application also provides a time synchronization device, which is arranged on a first terminal on a satellite, such as Fig.12 As shown, the device comprises:

[0167] The first synchronization unit 1201 is used to perform fine time synchronization with a network device for satellite transparent forwarding by taking the satellite as an anchor point.

[0168] In one embodiment, the device further comprises:

[0169] A second receiving unit, configured to receive a first message sent by the network device; wherein the first message carries third information, and the third information indicates periodically initiating random access for time fine synchronization;

[0170] A random access unit is used to initiate random access to the network device based on the third information.

[0171] In one embodiment, the device further comprises:

[0172] A third receiving unit is used to receive a third message sent by the network device; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0173] In actual application, the second receiving unit and the third receiving unit can be implemented by the communication interface in the time synchronization device, the first synchronization unit 1201 can be implemented by the processor in the time synchronization device, and the random access unit can be implemented by the processor in the time synchronization device combined with the communication interface.

[0174] It should be noted that: the time synchronization device provided in the above embodiment only uses the division of the above program modules as an example when performing time synchronization. In actual applications, the above processing can be assigned to different program modules as needed, that is, the internal structure of the device is divided into different program modules to complete all or part of the processing described above. In addition, the time synchronization device provided in the above embodiment and the time synchronization method embodiment belong to the same concept. The specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0175] Based on the hardware implementation of the above program module, and in order to implement the method of the network device side of the satellite transparent forwarding in the embodiment of the present application, the embodiment of the present application also provides a network device, such as Fig.13 As shown, the network device 1300 includes:

[0176] The first communication interface 1301 is capable of exchanging information with other network nodes;

[0177] The first processor 1302 is connected to the first communication interface 1301 to implement information exchange with other network nodes, and is used to execute the method provided by one or more technical solutions of the network device side when running a computer program. The computer program is stored in the first memory 1303.

[0178] Specifically, the first processor 1302 is used to perform TA pre-compensation based on first information with the satellite as an anchor point; wherein the first information represents the ephemeris information of the satellite.

[0179] In one embodiment, the first processor 1302 is specifically configured to determine in advance the TA values ​​at different times based on the first information; and perform TA pre-compensation based on the determined TA value with the satellite as an anchor point.

[0180] In one embodiment, the first processor 1302 is further configured to perform fine time synchronization with a first terminal on the satellite using the satellite as an anchor point.

[0181] In one embodiment, the first processor 1302 is specifically configured to perform TA fine adjustment based on the second information with the satellite as an anchor point; wherein the second information represents a TA adjustment value or a TA adjustment range.

[0182] In one embodiment, the TA adjustment value represented by the second information includes a first TA adjustment value and / or an offset value; wherein,

[0183] The first TA adjustment value represents a TA adjustment value acquired by the network device when the first terminal accesses the network device, and the offset value represents a TA adjustment offset of the network device, and the offset value is less than or equal to the first TA adjustment value.

[0184] In one embodiment, the first TA adjustment value is obtained during a random access process of the first terminal, or is obtained when the first terminal is in a connected state.

[0185] In one embodiment, the first communication interface 1301 is used to send a first message to the first terminal; and / or, based on the third information, send a second message to the first terminal; wherein the first message carries the third information, and the third information indicates the periodic initiation of random access for time fine synchronization; and the second message indicates the release of the RRC connection.

[0186] In one embodiment, the first communication interface 1301 is further used to send a third message to the first terminal when the first TA adjustment value is greater than a set threshold; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

[0187] In one embodiment, the first communication interface 1301 is further configured to send a second TA adjustment value to the first terminal based on the second information; and / or

[0188] Based on the second information, a third TA adjustment value is sent to a second terminal; wherein the second terminal represents a ground terminal that initiates random access to the network device.

[0189] In one embodiment, the first communication interface 1301 is further used to send a fourth message to the second terminal; wherein the fourth message carries fourth information, and the fourth information indicates setting the satellite as an anchor point.

[0190] In one embodiment, the first communication interface 1301 is further used to send data to the satellite based on the first TA value and / or the second information; and / or, based on the first TA value and / or the second information, receive data sent by the satellite; wherein,

[0191] The first TA value represents a TA value corresponding to a current time slot among the TA values ​​determined by the network device based on the first information.

[0192] In one embodiment, the first communication interface 1301 is further configured to discard the first data in the first subframe and send the second subframe to the satellite;

[0193] The first processor 1302 is further configured to no longer schedule the first data in the first subframe; wherein,

[0194] The first data is located at the end of the first subframe, and a sending time of the first data overlaps with a sending time of at least part of the data in the second subframe.

[0195] In one embodiment, the number of symbols of the first data is determined based on a first time and a second time; wherein the first time represents the overlapping transmission time between the first subframe and the second subframe, and the second time represents the duration of each symbol.

[0196] It should be noted that the specific processing process of the first processor 1302 and the first communication interface 1301 can be understood by referring to the above method.

[0197] Of course, in actual application, the various components in the network device 1300 are coupled together through the bus system 1304. It can be understood that the bus system 1304 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 1304 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Fig.13 Various buses are labeled as bus system 1304.

[0198] The first memory 1303 in the embodiment of the present application is used to store various types of data to support the operation of the network device 1300. Examples of such data include: any computer program used to operate on the network device 1300.

[0199] The method disclosed in the above embodiment of the present application can be applied to the first processor 1302, or implemented by the first processor 1302. The first processor 1302 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the first processor 1302. The above-mentioned first processor 1302 may be a general-purpose processor, a digital signal processor (DSP, Digital Signal Processor), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The first processor 1302 can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor, etc. In combination with the steps of the method disclosed in the embodiment of the present application, it can be directly embodied as a hardware decoding processor to execute, or it can be executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, which is located in the first memory 1303, and the first processor 1302 reads the information in the first memory 1303 and completes the steps of the above method in combination with its hardware.

[0200] In an exemplary embodiment, the network device 1300 may be implemented by one or more application specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components to execute the aforementioned method.

[0201] Based on the hardware implementation of the above program module, and in order to implement the method of the first terminal side on the satellite of the embodiment of the present application, the embodiment of the present application also provides a first terminal, such as Fig.14 As shown, the first terminal 1400 includes:

[0202] The second communication interface 1401 is capable of exchanging information with other network nodes;

[0203] The second processor 1402 is connected to the second communication interface 1401 to implement information exchange with other network nodes, and is used to execute the method provided by one or more technical solutions of the first terminal side when running a computer program. The computer program is stored in the second memory 1403.

[0204] Specifically, the second communication interface 1401 is used to perform fine time synchronization with a network device for satellite transparent forwarding, using the satellite as an anchor point.

[0205] In one embodiment, the second communication interface 1401 is further used to receive a first message sent by the network device; wherein the first message carries third information, and the third information indicates periodically initiating random access for time fine synchronization;

[0206] The second processor 1402 is configured to initiate random access to the network device based on the third information.

[0207] In one embodiment, the second communication interface 1401 is further used to receive a third message sent by the network device; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for fine time synchronization.

[0208] It should be noted that the specific processing process of the second processor 1402 and the second communication interface 1401 can be understood by referring to the above method.

[0209] Of course, in actual application, the various components in the first terminal 1400 are coupled together through the bus system 1404. It can be understood that the bus system 1404 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 1404 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, Fig.14 Various buses are labeled as bus system 1404.

[0210] The second memory 1403 in the embodiment of the present application is used to store various types of data to support the operation of the first terminal 1400. Examples of such data include: any computer program used to operate on the first terminal 1400.

[0211] The method disclosed in the above embodiment of the present application can be applied to the second processor 1402, or implemented by the second processor 1402. The second processor 1402 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the second processor 1402. The above-mentioned second processor 1402 may be a general-purpose processor, DSP, or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The second processor 1402 can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor, etc. In combination with the steps of the method disclosed in the embodiment of the present application, it can be directly embodied as a hardware decoding processor to execute, or it can be executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, which is located in the second memory 1403. The second processor 1402 reads the information in the second memory 1403 and completes the steps of the above method in combination with its hardware.

[0212] In an exemplary embodiment, the first terminal 1400 may be implemented by one or more ASICs, DSPs, PLDs, CPLDs, FPGAs, general purpose processors, controllers, MCUs, Microprocessors, or other electronic components to perform the aforementioned methods.

[0213] It can be understood that the memory (first memory 1303, second memory 1403) of the embodiment of the present application can be a volatile memory or a non-volatile memory, and can also include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a ferromagnetic random access memory, a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory can be a disk memory or a tape memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM, SyncLink Dynamic Random Access Memory), and direct RAM bus random access memory (DRRAM, Direct Rambus Random Access Memory).The memories described in the embodiments of the present application are intended to include, but are not limited to, these and any other suitable types of memories.

[0214] In an exemplary embodiment, the embodiment of the present application further provides a storage medium, namely a computer storage medium, specifically a computer-readable storage medium, for example, including a first memory 1303 storing a computer program, and the computer program can be executed by the first processor 1302 of the network device 1300 to complete the steps of the aforementioned network device side method. For another example, a second memory 1403 storing a computer program can be executed by the second processor 1402 of the first terminal 1400 to complete the steps of the aforementioned first terminal side method. The computer-readable storage medium can be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disk, or CD-ROM.

[0215] It should be noted that: "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0216] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0217] In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict.

[0218] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A time synchronization method, characterized in that: Applied to a network device for satellite transparent forwarding, the method comprises: Taking the satellite as an anchor point, time advance TA pre-compensation is performed based on first information; wherein the first information represents the ephemeris information of the satellite.

2. The method according to claim 1, characterized in that: The method of taking the satellite as an anchor point and performing TA pre-compensation based on the first information includes: Determining TA values ​​at different times in advance based on the first information; Taking the satellite as an anchor point, TA pre-compensation is performed based on the determined TA value.

3. The method according to claim 1, characterized in that: The method further comprises: Taking the satellite as an anchor point, fine time synchronization is performed with a first terminal on the satellite.

4. The method according to claim 3, characterized in that The step of taking the satellite as an anchor point and performing fine time synchronization with a first terminal on the satellite includes: Taking the satellite as an anchor point, fine adjustment of the TA is performed based on the second information; wherein the second information represents a TA adjustment value or a TA adjustment range.

5. The method according to claim 4, characterized in that The TA adjustment value represented by the second information includes a first TA adjustment value and / or an offset value; wherein, The first TA adjustment value represents a TA adjustment value acquired by the network device when the first terminal accesses the network device, and the offset value represents a TA adjustment offset of the network device, and the offset value is less than or equal to the first TA adjustment value.

6. The method according to claim 5, characterized in that The first TA adjustment value is obtained during a random access process of the first terminal, or is obtained when the first terminal is in a connected state.

7. The method according to claim 6, characterized in that The method further comprises at least one of the following: Sending a first message to the first terminal; wherein the first message carries third information, and the third information indicates periodically initiating random access for time fine synchronization; Based on the third information, a second message is sent to the first terminal, where the second message indicates releasing the radio resource control RRC connection.

8. The method according to claim 6, characterized in that The method further comprises: In a case where the first TA adjustment value is greater than a set threshold, a third message is sent to the first terminal; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

9. The method according to any one of claims 4 to 8, characterized in that: The method further comprises at least one of the following: Based on the second information, sending a second TA adjustment value to the first terminal; Based on the second information, a third TA adjustment value is sent to a second terminal; wherein the second terminal represents a ground terminal that initiates random access to the network device.

10. The method according to claim 9, characterized in that The method further comprises: A fourth message is sent to the second terminal, wherein the fourth message indicates setting the satellite as an anchor point.

11. The method according to any one of claims 1 to 8, characterized in that: The method further comprises at least one of the following: discarding the first data in the first subframe, and sending the second subframe to the satellite; The first data in the first subframe is no longer scheduled; wherein, The first data is located at the end of the first subframe, and a sending time of the first data overlaps with a sending time of at least part of the data in the second subframe.

12. The method according to claim 11, characterized in that The number of symbols of the first data is determined based on a first time and a second time; wherein the first time represents the overlapping transmission time between the first subframe and the second subframe, and the second time represents the duration of each symbol.

13. A time synchronization method, characterized in that: Applied to a first terminal on a satellite, the method comprises: The satellite is used as an anchor point to perform precise time synchronization with network equipment that transparently forwards to the satellite.

14. The method according to claim 13, characterized in that The method further comprises: Receiving a first message sent by the network device; wherein the first message carries third information, and the third information indicates periodically initiating random access for fine time synchronization; Based on the third information, random access is initiated to the network device.

15. The method according to claim 13 or 14, characterized in that The method further comprises: A third message sent by the network device is received; wherein the third message includes a first indication, and the first indication is used to indicate re-initiating random access for time fine synchronization.

16. A time synchronization device, characterized in that: include: The compensation unit is used to perform TA pre-compensation based on first information with the satellite as an anchor point; wherein the first information represents the ephemeris information of the satellite.

17. A time synchronization device, characterized in that: include: The first synchronization unit is used to perform fine time synchronization with a network device oriented to satellite transparent forwarding by taking the satellite as an anchor point.

18. A network device, characterized in that: comprising a first processor and a first communication interface, wherein: The first processor is used to perform TA active pre-compensation based on first information with the satellite as an anchor point; wherein the first information represents the ephemeris information of the satellite.

19. A first terminal, characterized in that: comprising a second processor and a second communication interface, wherein: The second processor is used to use the satellite as an anchor point to perform fine time synchronization with a network device that transparently forwards to the satellite.

20. A communication device, characterized in that: comprising a processor and a memory for storing a computer program capable of being executed on the processor, Wherein, when the processor is used to run the computer program, it executes the steps of the method described in any one of claims 1 to 12, or executes the steps of the method described in any one of claims 13 to 15.

21. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 12 are implemented, or the steps of the method according to any one of claims 13 to 15 are implemented.

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