Method for determining timing advance and communication device

Abstract

The embodiment of the invention provides a method for determining timing advance and a communication device, which are used for improving the accuracy of a terminal for calculating the timing advance (TA) and improving the problem of inter-symbol interference (ISI). The method comprises: a first network device determining a first parameter according to a first time delay compensation value, the first time delay compensation value being time delay compensation performed by the first network device for a signal sent by a receiving terminal, the first parameter is used for indicating a difference value between round-trip delay of a feed link in a non-terrestrial network NTN and the first delay compensation value, and the difference value is used for determining TA used by the terminal for sending a signal; and the first network device sends the first parameter.

Description

[0001] This application is a divisional application. The application number of the original application is 202011105020.7, and the original application date is October 15, 2020. The entire contents of the original application are incorporated into this application by reference.

[0002] This application claims the priority of the Chinese patent application filed with the China Patent Office on February 14, 2020, with application number 202010093795.0 and application name “A method for determining timing advance and communication device”, the entire contents of which are incorporated by reference in this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a method for determining timing advance and a communication device. Background Art

[0004] For non-terrestrial networks (NTN) communications, when sending a preamble, the terminal can receive a public timing advance value broadcast by a network device and use the public timing advance value for timing advance (TA) to reduce the impact of the round-trip delay between the terminal and the network device on the reception of the random access preamble and improve the problem of inter-symbol interference (ISI).

[0005] In actual applications, network devices often compensate for part of the round-trip delay between the terminal and the network device, so the delay that the terminal actually needs to compensate should only be a part of the public timing advance value. However, in the prior art, the terminal can only obtain the public timing advance value broadcast by the network device and cannot calculate the accurate TA, so the random access preamble still has serious ISI. Summary of the invention

[0006] The embodiments of the present application provide a method for determining a timing advance and a communication device, which are used to improve the accuracy of a terminal in calculating a TA and improve the accuracy of the TA.

[0007] In a first aspect, an embodiment of the present application provides a method for determining TA, including: a first network device determines a first parameter based on a first delay compensation value, wherein the first delay compensation value is the delay compensation made by the first network device for a signal sent by a receiving terminal, and the first parameter is used to indicate a difference between a round-trip delay of a feeder link in a non-terrestrial network NTN and the first delay compensation value, and the difference is used to determine the TA used by the terminal to send a signal; the first network device sends the first parameter.

[0008] In the embodiment of the present application, since the first parameter can indicate the difference between the round-trip delay of the feeder link and the first delay compensation value, when the terminal determines the TA according to the first parameter after receiving the first parameter, the situation that the first network device has made partial delay compensation for the signal sent by the terminal is taken into consideration. Therefore, the accuracy of the terminal's calculation of the TA can be improved, thereby better improving the ISI problem.

[0009] In a possible implementation manner, the first parameter is used to indicate the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value, including: the first parameter is the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value; or, the first parameter is used to determine the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value.

[0010] This implementation provides two possible implementations of the first parameter, thereby improving the flexibility of the solution.

[0011] In a possible implementation, the first parameter is used to determine the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value, and the first parameter may be the position coordinates of a compensation reference point; wherein the difference is determined based on the round-trip delay between the compensation reference point and the second network device, and the round-trip delay between the compensation reference point and the second network device is determined based on the position coordinates of the compensation reference point and the position coordinates of the second network device.

[0012] Through this implementation, the terminal can determine the difference only based on the position coordinates of the compensation reference point and the position coordinates of the second network device, which provides a novel indication method for the difference and is simple to implement on the terminal side.

[0013] In a possible implementation, in order to improve the flexibility of the solution, in a specific implementation, the first parameter can be either a difference value or the position coordinates of the compensation reference point. Further, the first network device can also send first indication information, and the first indication information is used to indicate that the first parameter is the difference value or the position coordinates of the compensation reference point.

[0014] Through this implementation, the terminal device can determine whether the first parameter is the difference or the position coordinates of the compensation reference point based on the first indication information, and then use the corresponding algorithm to calculate the TA used for sending the signal, thereby improving the flexibility of the solution while ensuring the reliability of the solution.

[0015] As an optional implementation, if the first parameter is the position coordinate of the compensation reference point, the first network device may also send second indication information, and the second indication information is used to indicate that the difference is a positive value or a negative value; wherein, the first delay compensation value is less than the round-trip delay of the feeder link or the compensation reference point is located on the feeder link, and the difference is a positive value; or, the first delay compensation value is greater than the round-trip delay of the feeder link or the compensation reference point is located on the service link in the NTN, and the difference is a negative value.

[0016] Through this implementation, the terminal can determine whether the difference is positive or negative according to the second indication information, and then calculate TA according to the difference, thereby further ensuring the accuracy of TA.

[0017] In a possible implementation, the TA is: the sum of the round-trip delay of the service link in the NTN and the difference; or the sum of the round-trip delay of the service link in the NTN, the difference and an offset; wherein the offset is related to a time division duplex TDD mode or a frequency division duplex FDD mode.

[0018] Through this implementation, multiple possible calculation methods of TA are provided, thereby improving the flexibility and applicability of the solution.

[0019] In a possible implementation manner, the first network device may also send a second parameter, where the second parameter is used to indicate a common round-trip delay of a service link of a beam or cell covered by the second network device.

[0020] Through this implementation, a terminal without positioning function can obtain the common round-trip delay of the service link covering the beam or cell of the second network device according to the second parameter, and then use the common round-trip delay of the service link as the round-trip delay of the service link between itself and the second network device, ensuring that the terminal without positioning function can also accurately calculate TA.

[0021] In a possible implementation manner, the second parameter is used to indicate a common round trip delay of a service link of a beam or a cell covered by the second network device, including:

[0022] The second parameter is the common round-trip delay of the service link of the beam or cell covered by the second network device, or the second parameter is used to determine the common round-trip delay of the service link of the beam or cell covered by the second network device.

[0023] This implementation provides two possible implementations of the second parameter, thereby improving the flexibility of the solution.

[0024] In one possible implementation, the second parameter is used to determine the common round-trip delay of the service link covering the beam or cell of the second network device, and the second parameter is the location coordinate of the service link reference point; wherein the common round-trip delay of the service link is determined based on the round-trip delay between the service link reference point and the second network device, and the round-trip delay between the service link reference point and the second network device is determined based on the location coordinates of the service link reference point and the location coordinates of the second network device.

[0025] Through this implementation, the terminal can determine the round-trip delay between the service link reference point and the second network device based on the location coordinates of the service link reference point and the location coordinates of the second network device. This implementation provides a novel indication method for the common round-trip delay of the service link covering the beam or cell of the second network device, and is simple to implement on the terminal side.

[0026] In a possible implementation manner, the first network device may send third indication information, where the third indication information is used to indicate that the second parameter is a common round-trip delay of the service link or a location coordinate of a reference point of the service link.

[0027] Through this implementation, the terminal device can determine whether the second parameter is the common round-trip delay of the service link or the location coordinates of the service link reference point based on the third indication information, and then use the corresponding algorithm to calculate the TA used for sending the signal, thereby improving the flexibility of the solution while ensuring the reliability of the solution.

[0028] In a possible implementation, the first network device may carry the first parameter in SIB1, OSI or MIB; the first network device may also carry the first parameter in RRC information, RRC reconfiguration message, DCI, group DCI, MAC element or TAC during the RRC connection phase; the first network device may also carry the first parameter in an RRC reconfiguration message or BWP-related signaling when the terminal performs cell / beam / BWP switching.

[0029] Through this implementation, multiple implementation methods for the first network device to send the first parameter are provided, thereby improving the flexibility of the solution.

[0030] In a second aspect, an embodiment of the present application provides a method for determining TA, including: a second network device determines the position coordinates of a compensation reference point based on a second delay compensation value, the second delay compensation value being a delay compensation value made by the second network device for a signal sent by a receiving terminal; wherein the second delay compensation value is used to determine the TA used by the terminal to send a signal, and the TA is equal to the round-trip delay of a service link in the NTN minus the second delay compensation value; the second network device sends the position coordinates of the compensation reference point.

[0031] In the embodiment of the present application, since the position coordinates of the compensation reference point are determined by the second network device based on the second delay compensation value, and the second delay compensation value is the delay compensation value made by the second network device for the signal sent by the receiving terminal, when the terminal determines TA based on the position coordinates of the compensation reference point after receiving the position coordinates of the compensation reference point, the situation in which the second network device has made partial delay compensation for the signal sent by the terminal is taken into account. Therefore, the accuracy of the terminal's calculation of TA can be improved, thereby better improving the ISI problem TA.

[0032] In a possible implementation manner, the second network device may also send a second parameter, where the second parameter is used to indicate a common round-trip delay of a service link of a beam or a cell covered by the second network device.

[0033] Through this implementation, a terminal without positioning function can obtain the common round-trip delay of the service link covering the beam or cell of the second network device according to the second parameter, and then use the common round-trip delay of the service link as the round-trip delay of the service link between itself and the second network device, ensuring that the terminal without positioning function can also accurately calculate TA.

[0034] In a possible implementation, the second parameter is used to indicate the common round-trip delay of the service link of the second network device covering the beam or cell, including: the second parameter is the common round-trip delay of the service link of the second network device covering the beam or cell, or the second parameter is used to determine the common round-trip delay of the service link of the second network device covering the beam or cell.

[0035] This implementation provides two possible implementations of the second parameter, which improves the flexibility of the solution. In one possible implementation, the second parameter is used to determine the common round-trip delay of the service link of the beam or cell covered by the second network device, and the second parameter is the position coordinates of the service link reference point; wherein the common round-trip delay of the service link is determined according to the round-trip delay between the service link reference point and the second network device, and the round-trip delay between the service link reference point and the second network device is determined according to the position coordinates of the service link reference point and the position coordinates of the second network device.

[0036] Through this implementation, the terminal can determine the round-trip delay between the service link reference point and the second network device based on the location coordinates of the service link reference point and the location coordinates of the second network device. This implementation provides a novel indication method for the common round-trip delay of the service link covering the beam or cell of the second network device, and is simple to implement on the terminal side.

[0037] In a possible implementation manner, the second network device may further send third indication information, where the third indication information is used to indicate that the second parameter is a common round-trip delay of the service link or a location coordinate of a reference point of the service link.

[0038] Through this implementation, the terminal device can determine whether the second parameter is the common round-trip delay of the service link or the location coordinates of the service link reference point based on the third indication information, and then use the corresponding algorithm to calculate the TA used for sending the signal, thereby improving the flexibility of the solution while ensuring the reliability of the solution.

[0039] In a possible implementation, the second network device may carry the position coordinates of the compensation reference point in SIB1, OSI or MIB and send it; the second network device may also carry the position coordinates of the compensation reference point in RRC information, RRC reconfiguration message, DCI, group DCI, MAC element or TAC and send it during the RRC connection phase; the second network device may also carry the position coordinates of the compensation reference point in RRC reconfiguration message or BWP-related signaling and send it when the terminal performs cell / beam / BWP switching.

[0040] Through this implementation, multiple implementation methods for the second network device to send the position coordinates of the compensation reference point are provided, thereby improving the flexibility of the solution.

[0041] In a third aspect, an embodiment of the present application also provides a method for determining TA, including: an ATG network device determines the location coordinates of an ATG reference point, wherein the location coordinates of the ATG reference point are used to determine the TA used by the terminal to send a signal to the ATG network device; the ATG network device sends the location coordinates of the ATG reference point.

[0042] In an embodiment of the present application, the ATG network device sends the location coordinates of the ATG reference point to the terminal, so that the terminal can calculate the TA used for sending the signal based on the location coordinates of the ATG reference point, which can improve the ISI problem during ATG communication; and, because the ATG network device tells the terminal the location coordinates of the ATG reference point instead of its own location coordinates, it can protect the location privacy of the ATG network device and improve the security of ATG communication.

[0043] In a fourth aspect, an embodiment of the present application provides a method for determining a TA, comprising: a terminal receives a first parameter, wherein the first parameter is used to indicate a difference between a round-trip delay of a feeder link in a non-terrestrial network NTN and a first delay compensation value, the first delay compensation value being a delay compensation made by the first network device for a signal sent by the receiving terminal, and the difference being used to determine the TA used by the terminal to send the signal; the terminal determines the TA used to send the signal based on the first parameter.

[0044] In a possible implementation manner, the first parameter is used to indicate the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value, including: the first parameter is the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value; or, the first parameter is used to determine the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value.

[0045] In a possible implementation, the first parameter is used to determine the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value, and the first parameter is the position coordinates of the compensation reference point, wherein the difference is determined based on the round-trip delay between the compensation reference point and the second network device, and the round-trip delay between the compensation reference point and the second network device is determined based on the position coordinates of the compensation reference point and the position coordinates of the second network device.

[0046] In a possible implementation, the method further includes: the terminal receives first indication information, the first indication information being used to indicate that the first parameter is the difference or the position coordinates of the compensation reference point; the terminal determines that the first parameter is the difference or the position coordinates of the compensation reference point based on the first indication information.

[0047] In a possible implementation, the method further includes: the terminal receives second indication information, the second indication information being used to indicate that the difference is a positive value or a negative value; the terminal determines, based on the second indication information, that the difference is a positive value or a negative value; wherein, if the difference is a positive value, the first delay compensation value is less than the round-trip delay of the feeder link or the compensation reference point is located on the feeder link; or, if the difference is a negative value, the first delay compensation value is greater than the round-trip delay of the feeder link or the compensation reference point is located on the service link in the NTN.

[0048] In a possible implementation, the TA is: the sum of the round-trip delay of the service link in the NTN and the difference; or the sum of the round-trip delay of the service link in the NTN, the difference and an offset; wherein the offset is related to a time division duplex TDD mode or a frequency division duplex FDD mode.

[0049] In a possible implementation manner, the method further includes: the terminal receiving a second parameter, wherein the second parameter is used to indicate a common round-trip delay of a service link of a beam or a cell covered by the second network device.

[0050] In a possible implementation, the second parameter is used to indicate the common round-trip delay of the service link of the second network device covering the beam or cell, including: the second parameter is the common round-trip delay of the service link of the second network device covering the beam or cell; or, the second parameter is used to determine the common round-trip delay of the service link of the second network device covering the beam or cell.

[0051] In one possible implementation, the second parameter is used to determine the common round-trip delay of the service link covering the beam or cell of the second network device, and the second parameter is the location coordinate of the service link reference point; wherein the common round-trip delay of the service link is determined based on the round-trip delay between the service link reference point and the second network device, and the round-trip delay between the service link reference point and the second network device is determined based on the location coordinates of the service link reference point and the location coordinates of the second network device.

[0052] In a possible implementation, the method also includes: the terminal receives third indication information, and the third indication information is used to indicate that the second parameter is the common round-trip delay of the service link or the location coordinates of the service link reference point; the terminal determines that the second parameter is the common round-trip delay of the service link or the location coordinates of the service link reference point based on the third indication information.

[0053] In a possible implementation, the first network device receives the first parameter, including: the terminal receives system information block SIB1, other system messages OSI or main system information block MIB, and the SIB1, the OSI or the MIB carries the first parameter; or, the terminal receives RRC information, RRC reconfiguration message, downlink control information DCI, group DCI, medium access control MAC element or timing advance command TAC in the radio resource control RRC connection phase, and the RRC information, the RRC reconfiguration message, the DCI, the group DCI, the MAC element or the TAC carries the first parameter; or, when the terminal performs cell / beam / partial bandwidth BWP switching, the first network device receives RRC reconfiguration message or BWP-related signaling, and the RRC reconfiguration message or the BWP-related signaling carries the first parameter.

[0054] In a fifth aspect, an embodiment of the present application provides a method for determining TA, including: a terminal receives the position coordinates of a compensation reference point, wherein the second delay compensation value is a delay compensation value made by the second network device for receiving a signal sent by the terminal, and the second delay compensation value is used to determine the TA used by the terminal to send the signal, and the TA is equal to the round-trip delay of the service link in the NTN minus the second delay compensation value; the terminal determines the TA used to send the signal based on the position coordinates of the compensation reference point.

[0055] In a possible implementation manner, the method further includes: the terminal receiving a second parameter, wherein the second parameter is used to indicate a common round-trip delay of a service link of a beam or a cell covered by the second network device.

[0056] In a possible implementation, the second parameter is used to indicate the common round-trip delay of the service link of the beam or cell covered by the second network device, including: the second parameter is the common round-trip delay of the service link of the beam or cell covered by the second network device; or, the second parameter is used to determine the common round-trip delay of the service link of the beam or cell covered by the second network device.

[0057] In one possible implementation, the second parameter is used to determine the common round-trip delay of the service link of the beam or cell covered by the second network device, and the second parameter is the location coordinate of the service link reference point; wherein the common round-trip delay of the service link is determined based on the round-trip delay between the service link reference point and the second network device, and the round-trip delay between the service link reference point and the second network device is determined based on the location coordinates of the service link reference point and the location coordinates of the second network device.

[0058] In a possible implementation, the method also includes: the terminal receives third indication information, and the third indication information is used to indicate that the second parameter is the common round-trip delay of the service link or the location coordinates of the service link reference point; the terminal determines that the second parameter is the common round-trip delay of the service link or the location coordinates of the service link reference point based on the third indication information.

[0059] In a possible implementation, the terminal sends the position coordinates of the compensation reference point, including: the terminal receives a system information block SIB1, other system messages OSI or a main system information block MIB, and the SIB1, the OSI or the MIB carries the position coordinates of the compensation reference point; or, the terminal receives RRC information, an RRC reconfiguration message, downlink control information DCI, a group DCI, a medium access control MAC element or a timing advance command TAC during the radio resource control RRC connection phase, and the RRC information, the RRC reconfiguration message, the DCI, the group DCI, the MAC element or the TAC carries the position coordinates of the compensation reference point; or, when performing cell / beam / partial bandwidth BWP switching, the terminal receives an RRC reconfiguration message or BWP-related signaling, and the RRC reconfiguration message or the BWP-related signaling carries the position coordinates of the compensation reference point.

[0060] In a sixth aspect, an embodiment of the present application provides a method for determining a TA, including: a terminal receives the position coordinates of an air-to-ground ATG reference point; and the terminal determines the TA used to send a signal based on the position coordinates of the ATG reference point.

[0061] In a seventh aspect, an embodiment of the present application provides a communication device, which may be the first network device in the first aspect above, or a device in the first network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in combination with the first network device. The device may include a module that performs the method / operation / step / action described in the first aspect and any possible implementation of the first aspect, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0062] Exemplarily, the device may include: a processing unit, used to determine a first parameter based on a first delay compensation value, wherein the first delay compensation value is the delay compensation made by the first network device for a signal sent by a receiving terminal, and the first parameter is used to indicate the difference between the round-trip delay of a feeder link in a non-terrestrial network NTN and the first delay compensation value, and the difference is used to determine the TA used by the terminal to send the signal; a sending unit, used to send the first parameter.

[0063] In an eighth aspect, an embodiment of the present application provides a communication device, which may be the second network device in the second aspect above, or a device in the second network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in combination with the second network device. The device may include a module that performs the method / operation / step / action described in the second aspect and any possible implementation of the second aspect, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0064] Exemplarily, the device may include: a processing unit, used to determine the position coordinates of the compensation reference point according to a second delay compensation value, wherein the second delay compensation value is a delay compensation value made by the second network device for a signal sent by a receiving terminal; wherein the second delay compensation value is used to determine the TA used by the terminal to send the signal, and the TA is equal to the round-trip delay of the service link in the NTN minus the second delay compensation value; and a sending unit, used to send the position coordinates of the compensation reference point.

[0065] In a ninth aspect, an embodiment of the present application provides a communication device, which may be the ATG network device in the second aspect above, or a device in the ATG network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in combination with the ATG network device. The device may include a module that executes the method / operation / step / action described in the third aspect and any possible implementation of the third aspect, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0066] Exemplarily, the apparatus may include: a processing unit, used to determine the location coordinates of an ATG reference point, wherein the location coordinates of the ATG reference point are used to determine the TA used by the terminal to send a signal to the ATG network device; and a sending unit, used to send the location coordinates of the ATG reference point.

[0067] In the tenth aspect, an embodiment of the present application provides a communication device, which may be the middle terminal in the fourth aspect above, or a device in the terminal (for example, a chip, or a chip system, or a circuit), or a device that can be used with the terminal. The device may include a module corresponding to the method / operation / step / action described in the fourth aspect and any possible implementation of the fourth aspect, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0068] Exemplarily, the device may include: a receiving unit, configured to receive a first parameter, wherein the first parameter is used to indicate a difference between a round-trip delay of a feeder link in a non-terrestrial network NTN and a first delay compensation value, the first delay compensation value being a delay compensation made by the first network device for a signal sent by a receiving terminal, and the difference being used to determine a TA used by the terminal to send the signal; and a processing unit, configured to determine the TA used to send the signal based on the first parameter.

[0069] In the eleventh aspect, an embodiment of the present application provides a communication device, which may be the middle terminal in the fifth aspect above, or a device in the terminal (for example, a chip, or a chip system, or a circuit), or a device that can be used with the terminal. The device may include a module that corresponds to the method / operation / step / action described in the fifth aspect and any possible implementation of the fifth aspect, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0070] Exemplarily, the device may include: a receiving unit, configured to receive the position coordinates of a compensation reference point, wherein the second delay compensation value is a delay compensation value made by the second network device for receiving a signal sent by a terminal, and the second delay compensation value is used to determine the TA used by the terminal to send the signal, and the TA is equal to the round-trip delay of the service link in the NTN minus the second delay compensation value; and a processing unit, configured to determine the TA used to send the signal based on the position coordinates of the compensation reference point.

[0071] In the twelfth aspect, an embodiment of the present application provides a communication device, which may be the middle terminal in the sixth aspect, or a device in the terminal (for example, a chip, or a chip system, or a circuit), or a device that can be used with the terminal. The device may include a module corresponding to the method / operation / step / action described in the sixth aspect and any possible implementation of the sixth aspect, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0072] Exemplarily, the apparatus may include: a receiving unit, configured to receive the position coordinates of an air-to-ground ATG reference point; and a processing unit, configured to determine a TA used to send a signal according to the position coordinates of the ATG reference point.

[0073] In the thirteenth aspect, an embodiment of the present application provides a communication device, including a processor and a communication interface, wherein the communication interface is used to communicate with other communication devices; the processor is used to run a set of programs so that the method described in the above-mentioned first aspect, second aspect, third aspect, fourth aspect, fifth aspect or sixth aspect and any possible implementation manner of the above-mentioned first aspect, second aspect, third aspect, fourth aspect, fifth aspect or sixth aspect is implemented.

[0074] In the fourteenth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When the computer-readable instructions are executed on a communication device, the method described in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect or the sixth aspect and any possible implementation manner of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect or the sixth aspect is implemented.

[0075] In a fifteenth aspect, an embodiment of the present application provides a chip system, which includes a processor and may also include a memory, for implementing the method described in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or the sixth aspect and any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or the sixth aspect. The chip system may be composed of a chip, or may include a chip and other discrete devices.

[0076] In the sixteenth aspect, an embodiment of the present application provides a computer program product, comprising instructions, which, when executed on a computer, enables the computer to execute a method as described in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect or the sixth aspect above, and in any possible implementation manner of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect or the sixth aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 A schematic diagram of a possible network architecture of a land network communication system applicable to an embodiment of the present application;

[0078] Figure 2 A flowchart of a method for determining TA provided in an embodiment of the present application;

[0079] Figure 3A and Figure 3B Schematic diagram of compensation reference point;

[0080] Figure 4 Schematic diagram of the common round trip delay of the service link;

[0081] Figure 5A flowchart of another method for determining TA provided in an embodiment of the present application;

[0082] Figure 6 A schematic diagram for compensating for the round trip delay between a reference point and a second network device;

[0083] Figure 7 A flowchart of another method for determining TA provided in an embodiment of the present application;

[0084] Figure 8 A schematic diagram of a network architecture of an ATG communication system applicable to an embodiment of the present application;

[0085] Fig. 9 A flowchart of another method for determining TA provided in an embodiment of the present application;

[0086] Fig.10 A schematic diagram of an NTN network architecture applicable to an embodiment of the present application;

[0087] Fig.11 A flowchart of another method for determining TA provided in an embodiment of the present application;

[0088] Figures 12 to 16 This is a schematic diagram of the structure of the signaling sent by the network side to the terminal in an embodiment of the present application;

[0089] Fig.17 Schematic diagram of compensation reference point on feeder link;

[0090] Fig.18 Schematic diagram of compensation reference point on the service link;

[0091] Figure 19 to Figure 23 This is a schematic diagram of the structure of the signaling sent by the network side to the terminal in an embodiment of the present application;

[0092] Fig.24 Schematic diagram of the TA rate angle α of the service link and / or the TA rate angle β of the feeder link;

[0093] Fig.25 A schematic diagram of the structure of a communication device 2500 provided in an embodiment of the present application;

[0094] Fig.26 A schematic diagram of the structure of a communication device 2600 provided in an embodiment of the present application;

[0095] Fig. 27 A schematic diagram of the structure of a communication device 2700 provided in an embodiment of the present application;

[0096] Fig.28 A schematic diagram of the structure of a communication device 2800 provided in an embodiment of the present application;

[0097] Fig.29 A schematic diagram of the structure of a communication device 2900 provided in an embodiment of the present application;

[0098] Fig.30 A schematic diagram of the structure of a communication device 3000 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0099] In order to achieve global communication coverage of the fifth generation (5G) communication network, the 3rd generation partnership project (3GPP) organization is studying the adaptation of the new radio (NR) protocol to non-terrestrial networks (NTN). NTN communications include satellite communications, air to ground (ATG) communications, etc. Compared with terrestrial communications, NTN communications have different channel characteristics, such as large transmission delays, large doppler frequency deviations, etc. For example, the round-trip delay of geostationary earthorbit (GEO) satellite communications (regeneration mode) is 238 to 270ms. The round-trip delay of low earth orbit (LEO) satellite communications (orbit altitude 1200km, regeneration mode) is 8ms to 20ms. For ATG communication scenarios, the maximum round-trip delay will also reach 1ms.

[0100] A large round-trip delay will cause inter-symbol interference (ISI) of the uplink signal, affecting the decoding performance on the network side. The terminal will send a random access preamble (preamble) in the initial random access phase, and the network device will return a random access response (RAR). In order to improve the ISI problem, one possible solution is to require the random access preamble to have a longer cyclic prefix (not less than the round-trip delay) to ensure the orthogonality between the uplink signals of different terminals. However, the round-trip delay in the NTN communication scenario is too large, and it is difficult for CP to meet this requirement. Another possible solution is that when the network device returns a random access response (RAR) to the terminal, it can indicate the timing advance (TA) value in the RAR, so that the terminal uses the TA for timing advance, thereby reducing the timing difference between the network device and each terminal. However, the current TA adjustment value indicated by the network equipment in the RAR ranges from 0 to 2ms, and as the subcarrier spacing increases, the TA indication range in the RAR will also be reduced exponentially. For satellite communication scenarios, the maximum indication range of 2ms is not enough to indicate the round-trip delay in the NTN communication scenario. If the TA indication range in the RAR is extended, more signaling overhead will be occupied. For the ATG communication scenario, when the subcarrier spacing is greater than 30KHz, the TA indication range in the RAR will be less than 1ms, which is also insufficient to indicate the round-trip delay in the ATG communication scenario.

[0101] To this end, in the prior art, before the terminal sends a random access preamble, the network device can first inform the terminal of a common timing advance value, and the terminal uses the common timing advance value to send the random access preamble, thereby reducing the timing difference between the network device and each terminal, reducing the timing range of the uplink signal of each terminal reaching the network device, and thereby reducing the requirement for the length of the cyclic prefix of the preamble, and reducing the requirement for the TA indication range in the RAR.

[0102] Currently, there are two solutions for network devices to inform terminals of common timing advance values:

[0103] Solution 1: The network device broadcasts a public timing advance value, and the terminal directly uses the public timing advance value to send the random access preamble. In the transparent transmission mode (the satellite has no base station processing capability), the network device is a gateway station, and the public timing advance value can be calculated based on the round-trip delay from the reference point to the satellite and the gateway station; in the regeneration mode (the satellite has the base station processing capability), the network device is a satellite, and the public timing advance value can be calculated based on the round-trip delay from the reference point to the satellite.

[0104] This solution is simple to implement, and the terminal can use it directly after receiving the public timing advance value. However, in actual applications, network equipment often compensates for part of the delay of the signal sent by the terminal, and the terminal actually only needs to compensate for part of the public timing advance value. The terminal with positioning function can calculate the round-trip delay between the terminal and the satellite, but cannot obtain the uncompensated round-trip delay value between the satellite and the gateway. The terminal with positioning function cannot calculate the accurate TA based on the public timing advance value, and the terminal will still have the ISI problem after sending the signal.

[0105] Solution 2: The network device broadcasts two public timing advance values, one for the service link and the other for the feeder link. The terminal advances the timing of the service link according to the public timing advance value corresponding to the service link and advances the timing of the feeder link according to the public timing advance value corresponding to the feeder link.

[0106] This solution clarifies the two parts of the common timing advance of the service link and the feeder link. However, if the network equipment makes delay compensation for the signal sent by the terminal, and the delay compensation is the round-trip delay of the entire feeder link and part of the service link, the terminal with positioning function will also not be able to calculate the accurate TA.

[0107] The embodiment of the present application provides a method for determining TA, which is used to improve the accuracy of TA calculation by the terminal and improve the ISI problem. The method can be applied to the fourth generation (4G) communication system, and can also be applied to the fifth generation (5G) communication system, device-to-device (D2D) communication, machine communication, or to various future communication systems, such as the sixth generation (6G) communication system.

[0108] The method provided in the embodiment of the present application can be applied to a non-terrestrial network (NTN) communication system. Figure 1 The architecture of a possible land network communication system applicable to the embodiment of the present application is shown. The communication system may be composed of a terminal (or user terminal, user equipment), a first network device and a second network device. Among them, the communication link between the first network device and the second network device is a feedback link (or feeder link); the communication link between the second network device and the terminal is a service link.

[0109] The terminal may be a wireless terminal device capable of receiving network device scheduling and indication information. For example, a device for providing voice and / or data connectivity to users, or a handheld device with wireless connection function, or other processing equipment connected to a wireless modem. The wireless terminal device may communicate with one or more core networks or the Internet via a radio access network (e.g., radio access network, RAN). The wireless terminal device may be a mobile terminal device, such as a mobile phone (or "cellular" phone, mobile phone), a computer and a communication chip. For example, it may be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device, which may exchange language and / or data with a radio access network. The terminal may specifically be a personal communication service (PCS) phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a tablet computer (Pad), a computer with wireless transceiver function, and other devices. The terminal may also include a subscriber unit, a subscriber station, a mobile station, a mobile station (MS), a remote station, an access point (AP), a remote terminal device, an access terminal device, a user terminal device, a user agent, a subscriber station (SS), a customer premises equipment (CPE), a terminal, a mobile terminal (MT), etc. The wireless terminal device may also be a wearable device and a next generation communication system, for example, a terminal device in a 5G network or a terminal device in a future evolved public land mobile network (PLMN) network, a terminal device in an NR communication system, etc.

[0110] The first network device may be a gateway (also called a ground station, earth station, or a gateway), which may be used to connect the first network device and a core network.

[0111] The second network device can be a satellite (or satellite base station), a geostationary earth orbit (GEO) satellite, a non-geostationary earth orbit (NGEO) medium earth orbit (MEO) satellite and a low earth orbit (LEO) satellite, a high altitude platform station (HAPS), etc., without limitation here.

[0112] In the embodiment of the present application, the communication mode of the second network device may include a regenerative mode and a transparent mode.

[0113] When the communication mode of the second network device is the regeneration mode, the second network device can serve as a base station for wireless communication. For example, the second network device can use artificial satellites and high-altitude aircraft as base stations for wireless communication, such as an evolved base station (eNB) and a 5G base station (gNB). The first network device can transparently transmit signaling between the second network device and the core network.

[0114] When the communication mode of the second network device is the transparent transmission mode, the first network device acts as a base station for wireless communication, and the second network device can act as a relay of these base stations, and can transparently transmit signals between the first network device and the terminal.

[0115] It should be understood that Figure 1 Only one first network device and one second network device are shown. In actual use, the architecture of multiple first network devices and / or one second network device can be adopted as needed. Each second network device can provide services to one or more terminals, each second network device can correspond to one or more first network devices, and each first network device can correspond to one or more second network devices, which is not specifically limited in this application.

[0116] See also Figure 2 , which is a method for determining TA provided in an embodiment of the present application, and which can be applied to Figure 1 In the communication system shown, the communication mode of the second network device is a transparent transmission mode.

[0117] S201. A first network device determines a first parameter according to a first delay compensation value.

[0118] Among them, the first delay compensation value is the delay compensation made by the first network device for the signal sent by the receiving terminal, or in other words, the first delay compensation value is the delay compensation made by the first network device when receiving the signal sent by the terminal to compensate for the timing difference caused by the round-trip delay of the service link and the round-trip delay of the feeder link. The delay compensation here can be understood as the first network device performing a backward delay operation on the receiving window when receiving the signal sent by the terminal, and the size of the backward delay of the receiving window is the first delay compensation value. The sum of the round-trip delay of the service link and the round-trip delay of the feeder link should be greater than or equal to the first delay compensation value. The signal can be any signal sent by the terminal to the first network device, including but not limited to a random access preamble.

[0119] The first parameter is used to indicate the difference between the round-trip delay of the feeder link in the non-terrestrial network NTN and the first delay compensation value. One possible indication method is that the first parameter is the difference between the round-trip delay of the feeder link and the delay compensation value, and another possible indication method is that the first parameter is used to determine the difference between the round-trip delay of the feeder link in the NTN and the delay compensation value. The difference can be used to determine the TA used by the terminal to send a signal.

[0120] S202: The first network device sends a first parameter, and the terminal receives the first parameter.

[0121] Specifically, the first network device may first send the first parameter to the second network device, and then the second network device forwards the first parameter to the terminal.

[0122] S203. The terminal determines a TA used for sending a signal according to the first parameter.

[0123] If the first parameter is the difference, the terminal may directly determine the TA used for sending the signal based on the difference and the round-trip delay of the service link, such as using the value obtained by subtracting the difference from the round-trip delay of the service link as the TA used for sending the signal.

[0124] If the first parameter is used to determine the TA used by the terminal to send signals, the terminal needs to first determine the difference according to the first parameter, and then determine the TA used to send signals according to the determined difference and the round-trip delay of the service link.

[0125] As an optional implementation, when the first parameter is used to determine the difference between the round-trip delay of the feeder link in the NTN and the delay compensation value, the first parameter may be the position coordinates of the compensation reference point. The difference is equal to the round-trip delay between the compensation reference point and the second network device. The terminal device may determine the distance between the compensation reference point and the second network device based on the position coordinates of the compensation reference point and the position coordinates of the second network device, and further determine the round-trip delay between the compensation reference point and the second network device based on the distance between the compensation reference point and the second network device.

[0126] As an optional implementation, in order to improve the flexibility of the solution, in a specific implementation, the first parameter can be either a difference or the position coordinates of the compensation reference point. The first network device can send a first indication message to the terminal to indicate that the first parameter is a difference or the position coordinates of the compensation reference point.

[0127] In this way, the terminal device can determine whether the first parameter is the difference or the position coordinates of the compensation reference point based on the first indication information, and then use the corresponding algorithm to calculate the TA used for sending the signal.

[0128] As an optional implementation manner, the first network device may further send second indication information to the terminal, where the second indication information is used to indicate whether the difference is a positive value or a negative value.

[0129] When the first parameter is a difference, the first network device sends a second indication information to indicate the positive or negative of the sent first parameter each time the first parameter is sent. Wherein, if the first delay compensation value is less than the round-trip delay of the feeder link, the difference is a positive value; or, if the first delay compensation value is greater than the round-trip delay of the feeder link, the difference is a negative value.

[0130] When the first parameter is the coordinate position of the compensation reference point, the first network device can also send a second indication information to indicate the positive or negative of the difference, or the positive or negative can be reflected by the positive or negative coordinates. Among them, when the first delay compensation value is less than the round-trip delay of the feeder link or the compensation reference point is located on the feeder link, the difference is a positive value; or, when the first delay compensation value is greater than the round-trip delay of the feeder link or the compensation reference point is located on the service link in the NTN, the difference is a negative value. When the first delay compensation value is equal to the round-trip delay of the feeder link or the compensation reference point is located on the second network device, the difference is 0, and this situation can be classified as a positive or negative difference.

[0131] For example, see Figure 3A , is a schematic diagram when the compensation reference point is located at the feeder link. A represents the round-trip delay value of the service link, D represents the first delay compensation value, and B represents the difference between the round-trip delay of the feeder link and the first delay compensation value. Figure 3A In the case shown, the difference is positive.

[0132] For example, see Figure 3B , is a schematic diagram when the compensation reference point is located in the service link. A represents the round-trip delay of the service link, the first delay compensation value D = D1 + D2, D1 represents the round-trip delay of the feeder link, and D2 represents the round-trip delay between the compensation reference point and the second network device. B represents the difference between the round-trip delay of the feeder link and the first delay compensation value. Figure 3A In the case shown, B = -D2 and the difference is negative.

[0133] As an optional implementation manner, the first indication information and the second indication information are included in the same indication information. For example, the first indication information and the second indication information are two different fields of the same indication information.

[0134] As an optional implementation, the first network device may not indicate the positive or negative value of the difference, but the terminal and the network device may pre-agree that the difference is equal to the round-trip delay of the feeder link minus the first delay compensation value or equal to the first delay compensation value minus the round-trip delay of the feeder link, and agree that the terminal shall perform addition or subtraction on the received difference after receiving the difference.

[0135] As an optional implementation, the calculation method of TA includes but is not limited to the following three methods: Method 1, TA is equal to the sum of the round-trip delay and the difference of the service link; Method 2, the sum of the round-trip delay and the offset of the service link in the NTN; Method 3, the sum of the round-trip delay, the difference and the offset of the service link in the NTN. Among them, the offset in Method 2 and Method 3 is related to the time division duplex (TDD) mode or the frequency division duplex (FDD) mode.

[0136] In the prior art, the timing advance used by the terminal is TA=(N TA +N TAoffset )*16*Ts / 2 μ T. Among them, N TA (also referred to as NTA in this article) is a TA adjustment value obtained by the terminal according to the parameter indicated by the first network device, for example, the TA calculated by the terminal according to the first parameter sent by the first network device in this application. TAoffset (This article can also be written as NTAoffset) represents the timing interval from uplink to downlink transmission, which is sent to the terminal through SIB information. For FDD mode, NTAoffset = 0; for TDD mode, NTAoffset = 624. This time interval allows the base station to have enough time to switch between receiving uplink signals and sending downlink signals. Ts represents 1 / (15e3*2048) seconds. μ is related to the subcarrier spacing, that is, the subcarrier spacing is 2 μ·15kHz. Therefore, in this solution, the TA calculated by the terminal according to the first parameter sent by the first network device can also be added to a fixed value (such as NTAoffset) and then used as the TA used by the terminal to send the signal.

[0137] In the embodiments of the present application, the terminal may be a terminal with a positioning function or a terminal without a positioning function, and the present application does not make any limitation thereto.

[0138] For terminals with positioning functions, such terminals can calculate the distance between themselves and the second network device based on the positioning function, and then calculate the round-trip delay between themselves and the second network device, and use it as the round-trip delay of the service link.

[0139] For terminals without positioning function, the network device can send down a second parameter, wherein the second parameter is used to indicate the common round-trip delay of the service link of the beam or cell covered by the second network device. In one possible indication method, the second parameter is the common round-trip delay of the service link of the beam or cell covered by the second network device; in another possible indication method, the second parameter is used to determine the common round-trip delay of the service link of the beam or cell covered by the second network device. Furthermore, this type of terminal can use the common round-trip delay of the service link as the round-trip delay of the service link between itself and the second network device. For example, see Figure 4 , the round-trip delay between a reference point in the coverage beam or cell of the second network device and the second network device that is closest to the second network device can be selected as the common round-trip delay of the service link.

[0140] As an optional implementation, when the second parameter is used to determine the common round-trip delay of the service link of the second network device covering the beam or cell, the second parameter is the position coordinates of the service link reference point. The common round-trip delay of the service link is determined according to the round-trip delay between the service link reference point and the second network device, and the round-trip delay between the service link reference point and the second network device is determined according to the position coordinates of the service link reference point and the position coordinates of the second network device.

[0141] In order to improve the flexibility of the scheme, in the specific implementation, the second parameter can be either the common round-trip delay of the service link or the position coordinates of the service link reference point. For example, in the non-staring mode of satellite communication, the coverage area of ​​the satellite's beam / cell moves with the movement of the satellite, and the service link reference point also moves with the satellite. In this case, the distance between the satellite and the service link reference point remains unchanged, and the round-trip delay remains unchanged. Sending the common round-trip delay of the service link to the UE can avoid frequent changes in the position coordinates of the sent service link reference point, which can reduce the complexity of the system. In the staring mode of satellite communication, the service link reference point remains unchanged during the time that the beam / cell continues to cover a certain area, so sending the position coordinates of the service link reference point to the UE is more conducive to reducing the complexity of system transmission signaling.

[0142] As an optional implementation, the first network device may send third indication information to the terminal, indicating whether the second parameter is the common round-trip delay of the service link or the position coordinates of the service link reference point. In this way, the terminal device can determine whether the second parameter is the common round-trip delay of the service link or the position coordinates of the service link reference point according to the third indication information, and then use an algorithm corresponding to the determined common round-trip delay of the service link or the position coordinates of the service link reference point to calculate the TA used for sending the signal.

[0143] As an optional implementation, the first indication information and / or the second indication information are included in the same indication information as the third indication information. For example, the first indication information, the second indication information, and the third indication information are three different fields of one indication information. In the embodiment of the present application, the first network device can send the above parameters (including the first parameter / the second parameter) and / or the indication information (including the first indication information / the second indication information / the third indication information) to the terminal in the following ways:

[0144] Method 1: carry the above parameters and indication information in system information block (SIB) 1, other system information (OSI) or main system information block (MIB) and other broadcast information, and send them to the terminal via unicast, broadcast or multicast.

[0145] Method 2: During the radio resource control (RRC) connection phase, the first network device carries the above-mentioned parameters and indication information in RRC information, RRC reconfiguration message, downlink control information (DCI), group DCI, medium access control (MAC) element or timing advance command (TAC) and sends it to the terminal, or sends it to the UE along with data transmission or in a separately allocated PDSCH bearer.

[0146] Method 3: When the terminal performs cell / beam / partial bandwidth (bandwidth part, BWP) switching, the first network device can send the above parameters and indication information in the RRC reconfiguration message or BWP-related signaling.

[0147] The above describes the technical solution when the second network device is in the transparent transmission mode. Next, the technical solution when the second network device is in the regeneration mode is described.

[0148] In the above scheme, since the first parameter is the difference between the round-trip delay of the feeder link and the delay compensation value, or the first parameter can be used to determine the difference between the round-trip delay of the feeder link and the delay compensation value, the terminal determines the TA used to send the signal based on the first parameter, taking into account the situation that the first network device performs partial delay compensation on the signal sent by the terminal. Therefore, the terminal can calculate a more accurate TA, which can improve the ISI problem.

[0149] See also Figure 5 , which is another method for determining TA provided in an embodiment of the present application, and which can be applied to Figure 1 In the communication system shown, the communication mode of the second network device is a regeneration mode.

[0150] S501. The second network device determines the position coordinates of a compensation reference point according to a second delay compensation value;

[0151] The second delay compensation value is the delay compensation value made by the second network device for the signal sent by the receiving terminal, which can be equal to the round-trip delay between the compensation reference point and the second network device; in other words, the second delay compensation value is the delay compensation made by the second network device when receiving the signal sent by the terminal to compensate for the timing difference caused by the round-trip delay of the service link. The delay compensation here can be understood as the second network device performing a backward delay operation on the receiving window when receiving the signal sent by the terminal, and the size of the backward delay of the receiving window is the second delay compensation value. The round-trip delay of the service link should be greater than or equal to the second delay compensation value. The signal can be any signal sent by the terminal to the second network device, including but not limited to a random access preamble.

[0152] S502: The second network device sends the position coordinates of the compensation reference point, and the terminal receives the position coordinates of the compensation reference point.

[0153] S503: The terminal determines the TA used for sending the signal according to the position coordinates of the compensation reference point.

[0154] Specifically, the terminal calculates the round-trip delay between the compensation reference point and the second network device according to the position coordinates of the compensation reference point, thereby obtaining a second delay compensation value; and then determines the TA used for sending the signal according to the round-trip delay of the service link and the second delay compensation value. Figure 6 , the position coordinates of the compensation reference point are located on the service link, and the round-trip delay B between the compensation reference point and the second network device represents the delay compensation value made by the second network device for the signal sent by the receiving terminal. Then the TA used by the terminal to send the signal can be equal to the round-trip delay of the service link minus the second delay compensation value, that is, AB.

[0155] Similar to the above-mentioned transparent transmission mode, in the regeneration mode, the terminal can be a terminal with a positioning function or a terminal without a positioning function, and this application does not limit it. For terminals with a positioning function, such terminals can calculate the distance between themselves and the second network device based on the positioning function, and then calculate the round-trip delay between themselves and the second network device, and use it as the round-trip delay of the service link. For terminals without a positioning function, the second network device can send down a second parameter, wherein the second parameter is the common round-trip delay of the service link of the beam or cell covered by the second network device, or the second parameter is used to determine the common round-trip delay of the service link of the beam or cell covered by the second network device. This type of terminal can use the common round-trip delay of the service link as the round-trip delay of the service link between itself and the second network device. The specific implementation method of the second parameter can refer to the specific implementation method of the second parameter in the above-mentioned transparent transmission mode, which will not be repeated here.

[0156] Similarly, in the regeneration mode, the second network device may also send third indication information to the terminal, where the third indication information is used to indicate that the second parameter is the common round-trip delay of the service link or the position coordinates of a reference point of the service link.

[0157] Similarly, in the regeneration mode, the second network device may send parameters or information in the three ways in the transparent transmission mode described above. For example, the second network device carries the position coordinates of the compensation reference point in SIB1, OSI or MIB and sends it to the terminal; or the second network device carries the position coordinates of the compensation reference point in RRC information, RRC reconfiguration message, DCI, group DCI, MAC element or TAC and sends it to the terminal during the RRC connection phase; or, when the terminal performs cell / beam / BWP switching, the second network device carries the position coordinates of the compensation reference point in RRC reconfiguration message or BWP-related signaling and sends it to the terminal.

[0158] In an alternative implementation, the second network device may directly send the second delay compensation value to the terminal, so that the terminal directly calculates the TA used for sending the signal according to the second delay compensation value.

[0159] In the above scheme, the second network device sends the position coordinates of the compensation reference point, so that the terminal can calculate the round-trip delay between the compensation reference point and the second network device according to the position coordinates of the compensation reference point, and then obtain the second delay compensation value. In this way, when the terminal calculates the TA according to the position coordinates of the compensation reference point, the terminal takes into account the situation that the network side has made partial delay compensation for the signal sent by the terminal, so the terminal can calculate a more accurate TA, thereby improving the ISI problem.

[0160] In the embodiment of the present application, for the terminal, it is not necessary to distinguish between the regeneration mode and the transparent transmission mode, or the terminal regards the first network device and the second network device as a whole (network side). After the terminal receives parameters (such as the position coordinates of the compensation reference point, the difference, the second delay compensation value, the first indication information or the second indication information, etc.) from the network side, the terminal directly determines the TA used for sending the signal based on the received parameters, that is, Figure 5 and Figure 2 The two solutions shown can be combined into one solution for implementation.

[0161] Exemplary, reference Figure 7 , which is another method for determining TA provided in an embodiment of the present application, and which can be applied to Figure 1 The communication system shown.

[0162] S701, the terminal receives a third parameter and a second indication information;

[0163] Exemplarily, the third parameter may be the position coordinates of the compensation reference point (regeneration mode or transparent transmission mode), may be a difference (transparent transmission mode), or may be a second delay compensation value (regeneration mode). The second indication information may be used to indicate the positive or negative of the third parameter (difference or second delay compensation value), or to indicate the positive or negative of the difference or second delay compensation value determined according to the third parameter.

[0164] S702. The terminal determines a TA used for sending a signal according to the third parameter and the second indication information.

[0165] Exemplarily, if the third parameter is a difference value, the difference value is positively or negatively calculated according to the second indication information, and the sum or difference is calculated with the round-trip delay of the service link to determine the TA used for sending the signal; if the third parameter is a second delay compensation value, the second delay compensation value is positively or negatively calculated according to the second indication information, and the sum or difference is calculated with the round-trip delay of the service link to determine the TA used for sending the signal; if the third parameter is the position coordinate of the compensation reference point, the difference value or the second delay compensation value is determined according to the position coordinate of the compensation reference point, and then the difference value or the second delay compensation value is positively or negatively calculated according to the second indication information, and finally the sum or difference is calculated with the round-trip delay of the service link to determine the TA used for sending the signal.

[0166] It should be understood that the above Figure 2 or Figure 5 Various possible implementations in the illustrated method embodiment can be referred to in the present method embodiment. For example, for a terminal without a positioning function, the position coordinates of a service link reference point can also be received from the network side, and then the round-trip delay between the service link reference point and the second network device is determined based on the position coordinates of the service link reference point and the position coordinates of the second network device, that is, the common round-trip delay of the service link. This type of terminal can use the common round-trip delay of the service link as the round-trip delay of the service link between itself and the second network device. For a terminal with a positioning function, the distance between itself and the second network device can be calculated based on the positioning function, and then the round-trip delay between itself and the second network device can be calculated, and it can be used as the round-trip delay of the service link. For specific methods, please refer to the relevant part of the previous text, which will not be repeated here.

[0167] In the embodiment of the present application, the terminal does not need to distinguish (or does not need to know) whether the second network device is in transparent transmission mode or regeneration mode, and the terminal can also calculate the accurate TA. That is, after receiving the parameters, the terminal directly calculates the parameters to determine the TA used for sending the signal, which reduces the difficulty of implementation on the terminal side.

[0168] In the prior art, the solution of network equipment broadcasting a common timing advance value is generally used in satellite communication systems. For the ATG communication system, since the coverage range of the ATG network equipment (generally 6-12km in height and about 100-300km in diameter) is large, the difference in round-trip delay between terminals at different locations within the coverage range of the ATG network equipment and the ATG network equipment is large. Therefore, the solution of broadcasting a common timing advance value is not suitable for ATG communication.

[0169] In view of this, an embodiment of the present application also provides a method for determining a TA, so as to enable a terminal in an ATG network to determine the TA used for sending a signal.

[0170] This solution can be applied to ATG communication system. For example, Figure 8 The network architecture diagram of an ATG communication system applicable to the embodiment of the present application is shown in FIG. The ATG communication system includes air-to-ground ATG network equipment and terminals, wherein the ATG network equipment includes ground base stations, and the terminals include high-altitude mobile terminals, such as high-altitude aircraft. Fig. 9 , the method comprising:

[0171] S901. The ATG network device determines the location coordinates of the ATG reference point.

[0172] The position coordinates of the ATG reference point can be understood as the virtual position coordinates of the ATG network device. The distance between the position coordinates of the ATG reference point and the position coordinates of the ATG network device satisfies a preset range, for example, is less than a preset distance value.

[0173] S902. The ATG network device sends the location coordinates of the ATG reference point to the terminal.

[0174] The specific implementation method of the ATG network device sending the ATG reference point here can refer to the specific implementation method of the first network device or the second network device sending the position coordinates of the compensation reference point or the service link reference point in the above text, which will not be repeated here.

[0175] S903. The terminal determines the TA used to send a signal to the ATG network device according to the location coordinates of the ATG reference point.

[0176] Specifically, the terminal calculates the round-trip delay between the ATG reference point and itself based on its own position coordinates and the position coordinates of the ATG reference point, and determines the round-trip delay as the TA used to send signals to the ATG network device, or adds an offset to the round-trip delay as the TA used to send signals to the ATG network device.

[0177] In the above scheme, the ATG network device sends the location coordinates of the ATG reference point to the terminal, so that the terminal can calculate the TA used to send the signal based on the location coordinates of the ATG reference point; and, because the ATG network device tells the terminal the location coordinates of the ATG reference point rather than its own location coordinates, the location privacy of the ATG network device can be protected and the security of ATG communication can be improved.

[0178] In specific implementation, both the ATG system and the satellite system belong to the NTN communication system, so the technical solutions in the ATG communication scenario and the technical solutions in the satellite communication scenario can be implemented in combination with each other.

[0179] See also Fig.10 , which is a schematic diagram of an NTN network architecture applicable to an embodiment of the present application. The communication system includes equipment in a satellite communication system (such as satellites, gateway stations, terminals, etc.) and equipment in an ATG communication system (such as base stations, terminals, etc.).

[0180] See also Fig.11 , which is another method for determining TA provided in an embodiment of the present application, and which can be applied to Fig.10 The communication system shown.

[0181] S1101. The network side sends at least one parameter of the location coordinates of the service link reference point (referred to as the service link reference point location coordinates), the location coordinates of the compensation reference point (compensation reference point location coordinates), and the location coordinates of the ATG reference point (ATG reference point location coordinates) to the terminal, and the terminal receives the at least one parameter.

[0182] The network side may be any one or more network devices in the NTN system, such as a satellite, a gateway station or a base station, etc. The terminal may be a ground user terminal (such as a mobile phone, a computer, a vehicle-mounted device, etc.) or a high-altitude user terminal (such as a high-altitude aircraft, etc.).

[0183] Service link reference point: For terminals without positioning function, it is used to calculate the round-trip delay between the satellite and the service link reference point to obtain the common round-trip delay of the service link (or the timing advance adjustment value of the service link), which can be used as the round-trip delay of the service link. The service link reference point can be selected as a point within the coverage range of the beam / cell, and can be selected as a point on the horizontal plane or at a fixed height above the horizontal plane according to the needs, and can be determined according to the network layout requirements.

[0184] Compensation reference point: 1) When the compensation reference point is on the feeder link, the round-trip delay between the gateway station and the compensation reference point is the delay compensation value made by the network side for the uplink signal (i.e., the first delay compensation value mentioned above); 2) When the compensation reference point is on the service link, for the transparent transmission mode, the round-trip delay of the gateway station-satellite-compensation reference point is the delay compensation value made by the network side for the uplink signal (i.e., the first delay compensation value mentioned above); for the regeneration mode, the round-trip delay of the satellite-compensation reference point is the delay compensation value made by the network side for the uplink signal (i.e., the second delay compensation value mentioned above). The compensation reference point can be selected on the service link or the feeder link, and can be determined based on the delay compensation value of the signal sent by the network side to the terminal.

[0185] ATG reference point: The terminal obtains the TA used by the terminal based on the round-trip delay between the terminal location and the ATG reference point. The ATG reference point can be selected at any location in the ATG beam or cell coverage area (including the coordinates of the base station location) according to system requirements.

[0186] S1102. The terminal determines a TA used for sending a signal according to the at least one parameter.

[0187] In a possible implementation, a terminal (eg, an aircraft, a ground mobile terminal) may perform the following calculation based on the received reference point coordinates:

[0188] 1) Calculate the round trip delay value of the service link (or the timing advance adjustment value of the service link) according to the satellite position (obtained by ephemeris or satellite coordinates) and the service link reference point: A, where A is a positive number. For ease of description, A may be referred to as the common timing advance value of the service link in the following text.

[0189] 2) Calculate the round-trip delay value between the satellite and the compensation reference point according to the satellite position and the compensation reference point: B. If the compensation reference point is in the feeder link, B is a positive value; if the compensation reference point is in the service link, B is a negative value; the positive or negative value of the B value can be indicated to the UE through the second indication information above.

[0190] If the satellite is in transparent transmission mode, B is the difference between the round-trip delay of the feeder link and the delay compensation value made by the satellite for the signal sent by the terminal; if the satellite is in regeneration mode, B is the negative value of the delay compensation value made by the satellite for the signal sent by the terminal.

[0191] For the convenience of description, B may be referred to as a common compensation timing advance value hereinafter.

[0192] 3) Calculate the round-trip delay between the terminal and the ATG reference point based on the terminal position and the ATG reference point: C, where C is a positive number.

[0193] In another possible implementation, the network side may also directly send A, B or C, that is, at least one parameter may include A, B or C. For example, the network side sends B instead of the compensation reference point coordinates.

[0194] Furthermore, the terminal may select different parameters from A, B, and C according to different communication scenarios (such as ATG communication, satellite communication, etc.) to calculate the TA used when sending a signal (such as a random access preamble):

[0195] For example, when the terminal is in a satellite communication scenario:

[0196] 1) If the terminal has a positioning function, the terminal can calculate the timing advance TA_cal of the service link according to the ephemeris, and then calculate TA according to TA_cal and B, such as: TA=TA_cal+B.

[0197] 2) If the terminal does not have a positioning function, the terminal can calculate TA based on A and B, such as: TA=A+B.

[0198] For example, when the terminal is in the ATG communication scenario:

[0199] The terminal can calculate TA based on C, such as: TA=C.

[0200] The following is a detailed description through several specific embodiments. Fig.11 The specific implementation of the method shown.

[0201] Example 1

[0202] The base station can send the reference point coordinates to the terminal in a broadcast, multicast or unicast manner. Fig.12 , which is a schematic diagram of a possible reference point coordinate signaling provided in an embodiment of the present application.

[0203] The reference point coordinates may be in the same coordinate system as the satellite or may be relative coordinates. For example, the service link reference point coordinates and the compensation reference point coordinates may be coordinates relative to the satellite coordinate position, that is, the satellite is used as the coordinate origin.

[0204] The compensation reference point coordinate parameter may carry a positive or negative indicator to indicate whether the round-trip delay between the second network device and the compensation reference point is a positive or negative value when it is calculated. For example, the positive or negative indicator 0 indicates a negative value, and 1 indicates a positive value. If the round-trip delay is calculated as x seconds using the compensation reference point coordinates and the satellite coordinates, and the positive or negative indicator is 0, then B calculated in the solution is -x.

[0205] If it is a satellite communication scenario, the network side can further perform the following operations:

[0206] 1) The ATG reference point coordinates may be set to zero or not sent.

[0207] 2) Whether to send the compensation reference point coordinates can be selected based on whether the network side compensates for the signal sent by the terminal, or it can be set to zero. For example, if the network side does not perform delay compensation, the compensation reference point coordinates may not be sent, or the compensation reference point coordinates may be set to zero and sent.

[0208] 3) You can choose whether to send the compensation reference point coordinates based on whether the satellite communication is in transparent transmission mode or regeneration mode. For example, when the satellite is in transparent transmission mode, even if the network side does not make delay compensation for the signal sent by the terminal, it is necessary to send the compensation reference point coordinates to indicate the round-trip delay value of the feeder link to the terminal. At this time, the compensation reference point coordinates can be the location coordinates of the gateway station. The terminal can calculate the round-trip delay value of the feeder link based on the compensation reference point coordinates and the satellite coordinates. At the same time, the round-trip delay value of the combined service link can obtain the complete communication link round-trip delay, which is used as the timing advance adjustment value for the terminal to send the signal. When the satellite is working in regeneration mode, if the network side does not make delay compensation for the signal sent by the terminal, then the compensation reference point coordinates do not need to be sent.

[0209] If it is an ATG communication scenario, the network side can further perform the following operations:

[0210] 1) The service link reference point coordinates and the compensation reference point coordinates may be set to zero, or the service link reference point coordinates and the compensation reference point coordinates may not be sent.

[0211] 2) If in the ATG communication scenario, the network side performs delay compensation on the signal sent by the terminal, then it is necessary to send a compensation reference point to inform the terminal of the delay compensation value made by the network side on the signal sent by the terminal. At this time, the service link reference point coordinates are set to zero, or the service link reference point coordinates are not sent.

[0212] Of course, the satellite communication scenario and the ATG communication scenario can exist at the same time. If both the satellite communication scenario and the ATG communication scenario exist, the network side and the terminal can simultaneously perform the operations performed by the network side and the terminal in the above-mentioned ATG communication scenario and the ATG communication scenario. The specific implementation methods can refer to the above-mentioned satellite communication scenario and the ATG communication scenario respectively, which will not be repeated here.

[0213] In one possible design, the minimum coordinate granularity or coordinate unit of the service link reference point coordinates, compensation reference point coordinates and ATG reference point coordinates is based on m as the basic unit. In another possible design, a combination of several length units can be used together, for example, a combination of km and m can be used to save signaling overhead. If only a single length unit is used to represent the three-dimensional coordinates of the service link reference point as (10300m, 9600m, 10070m), then the three numbers 10030, 9600, and 10070 need to be represented, requiring 42 bits. If the length unit combination of km and m is used, it can be expressed as (10km+300m, 9km+600m, 10km+70m), and the numbers 10,300, 9,600, 10,70 need to be transmitted, occupying 39 bits. Signaling overhead can be saved by using multiple length unit combinations.

[0214] In order to further save signaling overhead, in a possible design, the reference point coordinates can be transmitted with the satellite orbit height H as the reference length. For example, the reference point coordinates sent by the network side to the terminal are (a, b, c), and the terminal can calculate the reference point coordinates to be used based on (a+H, b+H, c+H). In a possible design, the reference point coordinates can be sent with the satellite coordinates as the reference point. For example, the coordinates of the satellite are (x, y, z), and the reference point coordinates sent by the network side to the terminal are (a, b, c). Then the terminal can calculate the reference point coordinates to be used based on (x+a, y+b, z+c).

[0215] The reference point coordinate signaling format provided in this embodiment is compatible with satellite communication and ATG communication scenarios, and supports both terminals with positioning functions and terminals without positioning functions to determine TA, thereby saving signaling bits.

[0216] Example 2

[0217] See also Fig.13 , is a schematic diagram of another possible reference point coordinate signaling provided in an embodiment of the present application. The difference from embodiment 1 is that: Fig.13 A satellite communication / ATG communication scenario indication bit is added to the signaling shown to indicate which scenario the reference point coordinates sent by the network side are applicable to. For example, the signaling indicating to the terminal that the transmission is the service link reference point coordinates, the compensation reference point coordinates, or the ATG reference point coordinates, or other combinations.

[0218] Through this embodiment, satellite communication and ATG communication can reuse the same coordinate signaling bits, thereby reducing signaling overhead.

[0219] Example 3

[0220] Different from the above embodiment 1 or embodiment 2, this embodiment replaces a certain reference point coordinate with a common timing advance value, that is, the common timing advance and the reference point coordinate are used jointly. (For the convenience of description, the service link common timing advance value, the common compensation timing advance value and the ATG common timing advance value may be collectively referred to as the common timing advance value, and the service link reference point, the compensation reference point coordinates and the coordinates ATG reference point coordinates may be referred to as reference point coordinates.)

[0221] For example, see Fig.14A , Fig. 14B , the network side replaces the service link reference point coordinates with the service link common timing advance value (i.e., the round-trip delay of the service link).

[0222] For example, see Fig.14A , 14C , the coordinates of the compensation reference point are replaced by the common compensation timing advance value (i.e., the round-trip delay between the compensation reference point and the satellite).

[0223] For example, see Fig.14D , the ATG reference point coordinates are replaced by the ATG common timing advance value (i.e., the common round-trip delay in the ATG service area).

[0224] The relationship between the common compensation timing advance value and the compensation reference point can be: the common compensation timing advance value is equal to the round-trip delay between the satellite position and the compensation reference point position. 1) When the compensation reference point is on the feeder link, the common compensation timing advance value is used as a positive value, corresponding to Fig.14D 2) When the compensation reference point is on the service link, the common compensation timing advance value is negative and used, corresponding to Fig.14D The positive and negative indicator in is negative.

[0225] It should be noted that if the compensation reference point has always been on the feeder link or the network side's compensation for the signal delay sent to the terminal is not greater than the round-trip delay of the feeder link, then the round-trip delay or the public compensation timing advance value calculated by the compensation reference point used will always be a positive value, so the positive and negative indication bits of the compensation reference point or the public compensation timing advance value can also be omitted, that is, the default is a positive value. Alternatively, if the compensation reference point has always been on the service link or the network side's compensation for the signal delay sent to the terminal is not less than the round-trip delay of the feeder link, then the network side and the terminal have agreed that the round-trip delay or the public compensation timing advance value calculated by the compensation reference point used by the terminal is always a negative value, so the positive and negative indication bits of the compensation reference point or the public compensation timing advance value can also be omitted, that is, the default is a negative value. The method of this embodiment is applicable to all embodiments in this article.

[0226] In an optional implementation, for a scenario where the ATG reference point does not need to be transmitted, the service link common timing advance value / service link reference point coordinates and the common compensation timing advance value / compensation reference point coordinates may be used in combination.

[0227] See also Fig.14E In non-staring communication, the combination of the service link common timing advance value and the common compensation timing advance value / compensation reference point coordinates is more conducive to reducing the complexity of system transmission signaling. In staring mode, the use of service link reference point coordinates in combination with the common compensation timing advance value / compensation reference point coordinates is more conducive to reducing the complexity of system transmission signaling. This is because in staring mode, during the period of time when the beam / cell continuously covers a certain area, the service link reference point remains unchanged, and the service link reference point coordinates sent by the network side to the terminal do not need to be changed. The choice of using the common compensation timing advance value or the compensation reference point coordinates depends on whether the network side compensates for the signal delay sent by the terminal and whether the compensation value is fixed, which will not be elaborated here.

[0228] In summary, the reasonable combination of the service link common timing advance value / service link reference point coordinates and the common compensation timing advance value / compensation reference point coordinates can reduce the complexity of signaling sent by the system.

[0229] In an optional implementation, if it is a satellite communication scenario, the ATG reference point coordinates / ATG common timing advance value may be set to zero or not sent. If it is an ATG communication scenario, the service link common timing advance value / service link reference point coordinates and / or the common compensation timing advance value / compensation reference point coordinates may be set to zero or not sent.

[0230] In an optional implementation, if the network side does not transmit the compensation reference point coordinates / service link reference point coordinates, it can be assumed to fall back to the default coordinates, for example, the default coordinates are the satellite coordinates, that is, the public compensation timing advance value is 0.

[0231] In an optional implementation, the service link common timing advance value and the common compensation timing advance value can be represented by a combination of different time units. For example, assuming that the service link common timing advance value is 20.77ms, when only the ms unit dimension is used, 12 bits are required to represent it. If the frame length (10 milliseconds) and subframe length (1 millisecond) dimensions are used to jointly represent it: 2*frame length+0.77*subframe length. Only 9 bits are required on the network side to represent it, which can save signaling overhead. Similarly, the basic time unit Ts of LTE and multiples of Ts can be used to jointly represent it, for example: a*Ts+b*Ts*10^3, and only a and b need to be sent to the terminal.

[0232] In this embodiment, the terminal uses a common timing advance value to replace the reference point coordinates. For some scenarios, using a common timing advance value to replace the reference point coordinates can reduce the complexity of sending signaling and updates. For example, in the non-staring mode of satellite communication, the coverage area of ​​the beam / cell moves with the movement of the satellite, and the service link reference point also moves with the satellite. In this case, the distance between the satellite and the reference point remains unchanged, and the round-trip delay remains unchanged. In this case, the service link common timing advance value is used to replace the service link reference point coordinates and send them to the terminal, which can avoid frequent changes in the sent service link reference point coordinates and reduce system complexity.

[0233] Example 4

[0234] This embodiment is based on Embodiment 3, and adds a satellite communication / ATG communication scenario indicator bit to indicate the scenario to which the reference point coordinates sent by the network side are applicable.

[0235] For example, see Fig.15A , Fig. 15B The communication scenario indicator bit indicates to the terminal that the transmitted signaling is the service link reference point coordinates, the common compensation timing advance value, or the ATG reference point coordinates, or other combinations.

[0236] Through this embodiment, satellite communication and ATG communication can reuse the same signaling bits, which can reduce the signaling overhead of the entire NTN system.

[0237] Example 5

[0238] See also Fig. 15C In this embodiment, based on Embodiment 3, an indication bit can be added to the service link common timing advance value / reference point coordinate signaling to indicate whether the signaling represents the service link common timing advance value or the service link reference point coordinate value. In this way, the system can decide whether to inform the terminal in the form of a common timing advance value or a reference point coordinate according to whether the satellite is in the staring mode and whether the network side performs delay compensation for the signal sent by the terminal, thereby improving the flexibility of the system.

[0239] Similarly, an indication bit may be added to the common compensation timing advance value / compensation reference point coordinate signaling to indicate whether the signaling represents the common compensation timing advance value or the compensation reference point coordinate value, thereby providing flexibility for the network side to configure the signaling.

[0240] See also Fig.15D For scenarios where the ATG reference point does not need to be transmitted, the service link common timing advance value / service link reference point coordinates and the common compensation timing advance value / compensation reference point coordinates combination can be sent separately.

[0241] Example 6

[0242] Based on Example 5, this embodiment adds a satellite communication / ATG communication scenario indicator bit to indicate the scenario to which the reference point coordinates sent by the network side are applicable.

[0243] For example, see Fig.16 The communication scenario indicator bit indicates to the terminal that the transmitted signaling may be a service link common timing advance value / service link reference point coordinates, a common compensation timing advance value / compensation reference point coordinates, or an ATG reference point coordinates, or other combinations.

[0244] Through this embodiment, satellite communication and ATG communication scenarios can reuse the same signaling bits, which can reduce signaling overhead.

[0245] Example 7

[0246] This embodiment provides that the network side indicates to the terminal the positive or negative value of the common compensation timing advance value / compensation reference point coordinates by implicit indication (ie, used to indicate whether the partial value is a positive value or a negative value when used).

[0247] In an optional implementation, the compensation reference point coordinates are expressed as relative coordinates. For example, the compensation reference point coordinates are expressed as coordinates relative to the satellite position, that is, the satellite is used as the origin of the coordinate system. If the compensation reference point coordinates are above the satellite, it represents a positive value, and if they are below the satellite, it represents a negative value.

[0248] In another optional implementation, the positive or negative value of a dimension in the three-dimensional coordinates of the compensation reference point indicates whether the round-trip delay calculated using the compensation reference point is positive or negative. For example, the coordinates of the compensation reference point sent by the network side to the terminal are (-501km, 580km, 520km), and the network side and the terminal agree that the positive or negative value of the first dimension of the coordinate point indicates whether the calculated round-trip delay is positive or negative. Then the round-trip delay calculated by the terminal based on the reference point coordinates (-501km, 580km, 520km) is a negative value.

[0249] Through this embodiment, the network side does not need to add additional signaling to indicate the positive or negative value of the common compensation timing advance value / compensation reference point coordinates, which can save signaling overhead.

[0250] Example 8

[0251] For a terminal with a positioning function in the NTN system, the signaling sent by the network side to the terminal may not include the service link common compensation timing advance value / service link reference point coordinates to save unnecessary signaling overhead.

[0252] For example, the signaling sent by the network side to the terminal only needs to have the common compensation timing advance value / compensation reference point coordinate parameters (including positive and negative indication bits). Alternatively, the signaling sent by the network side to the terminal only needs to have the common compensation timing advance value / compensation reference point coordinate parameters (including positive and negative indication bits) and the ATG reference point coordinates.

[0253] Because the terminal with positioning function can calculate the round-trip delay of the service link based on its own position and the position of the satellite (the terminal can obtain the position of the satellite from the ephemeris information), there is no need for the common round-trip delay value of the service link indicated by the service link common timing advance value / service link reference point coordinates. However, the terminal or satellite with positioning function cannot obtain the round-trip delay of the feeder link based on the ephemeris information. If the network side performs propagation delay compensation on the signal sent by the terminal, the terminal cannot obtain the delay compensation value on the network side. Therefore, the terminal with positioning function cannot obtain complete propagation delay information, such as the feeder link propagation delay and the network side propagation delay compensation value, only through its own position information and the satellite's position information.

[0254] like Fig.17 As shown, if the compensation value of the propagation delay compensation made by the network side for the signal sent by the terminal is less than the round-trip delay of the feeder link or the compensation reference point is on the feeder link, then the public compensation timing advance value can be used to represent the remaining propagation delay value after deducting the delay compensated by the network side in the feeder link. For example, if the propagation round-trip delay of the feeder link is a (that is, the round-trip delay of the signal propagation between the satellite and the gateway station is a), and the propagation delay compensation value of the feeder link by the network side is b (that is, the round-trip delay between the gateway station and the compensation reference point is b), then the public compensation timing advance value sent by the network side to the terminal is equal to ab (that is, the round-trip delay between the satellite and the compensation reference point is ab). Optionally, the network side can send a public compensation timing advance value of (ab) / 2 to the terminal (which can save signaling overhead), that is, the propagation delay value remaining after deducting the one-way delay compensated by the network side from the one-way propagation delay of the feeder link. When the terminal receives the public compensation timing advance value of (ab) / 2, it is multiplied by 2 before use. At this time, the positive and negative indicator bits of the common compensation timing advance value indicate a positive sign, which means that the subsequent operation is an addition operation. Then, the terminal adds the common compensation timing advance value (i.e., the value equal to ab) to the service link round-trip delay value calculated by the terminal to obtain the TA for timing advance adjustment of the signal sent by the terminal. Similarly, the network side can send the coordinates of the compensation reference point, and the positive and negative indicator bits indicate a positive sign. The terminal calculates the round-trip delay between the two based on the satellite position and the reference point position, and then adds the calculated service link round-trip delay value to the common compensation timing advance value according to the positive sign indicated by the positive and negative indicator bits to obtain the TA that the terminal can use.

[0255] like Fig.18As shown, when the compensation value of the propagation delay compensation made by the network side for the signal sent by the terminal is greater than the round-trip delay of the feeder link or the compensation reference point is on the service link, that is, the network side compensates for the propagation round-trip delay of the feeder link and part of the propagation round-trip delay of the service link (the round-trip delay of the gateway station-satellite-compensation reference point), then the public compensation timing advance value can be used to indicate that the network side compensates for the partial propagation round-trip delay of the service link (that is, the signal propagation round-trip delay value between the satellite and the compensation reference point). For example, assuming that the round-trip delay between the satellite and the compensation reference point is d, that is, the public compensation timing advance value is d. Or in order to save signaling overhead, the public compensation timing advance value is set to d / 2, and the terminal multiplies it by 2 after receiving d / 2 and then performs subsequent operations. At this time, the positive and negative indicator bit of the public compensation timing advance value indicates a negative sign, indicating that the subsequent operation is a subtraction operation. Then, the terminal subtracts the calculated service link round-trip delay value from the public compensation timing advance value (that is, a value equal to d) to obtain the TA for timing advance adjustment of the signal sent by the terminal. Similarly, the network side can send the coordinates of the compensation reference point, and the positive and negative indicator bits indicate a negative sign. The terminal calculates the round-trip delay between the satellite position and the reference point position, and then subtracts the calculated service link round-trip delay value from the public compensation timing advance value according to the negative sign indicated by the positive and negative indicator bit to obtain the TA that the terminal can use.

[0256] Example 9

[0257] As described in Examples 2, 4, and 6, when the network side uses an indicator bit to indicate that the information contained in the signaling is the service link reference point coordinates or the service link common timing advance value or the compensation reference point coordinates or the common compensation timing advance value or the ATG reference point coordinates, the network side can use a table lookup to inform the terminal of the reference point coordinates and the composition of the timing advance signaling.

[0258] As an example, Table 1 shows different reference point coordinates and timing advance signaling compositions corresponding to different index numbers. The network side can send an index number to the terminal, and the terminal uses the index number to query the reference point coordinates and the composition of the timing advance signaling, and decodes the signaling to obtain the corresponding data. For example, when the terminal receives the index number 2, it means that the signaling received by the terminal includes the common timing advance value of the service link, the compensation reference point coordinate value, and the ATG reference point coordinate value. For example, when the terminal receives the index number 14, it means that the signaling received by the terminal includes the common timing advance value of the service link and the compensation reference point coordinates.

[0259] Table 1 Reference point coordinates, timing advance signaling composition Table 1

[0260]

[0261] As an example, referring to Table 2, for the case where the terminal does not need the ATG reference point coordinates, the table can be further reduced to save the signaling overhead of the transmission index number. For example, when the terminal receives the index number 3, it means that the signaling received by the terminal includes the service link reference point coordinates and the common compensation timing advance value.

[0262] Table 2 Reference point coordinates, timing advance signaling composition Table 2

[0263]

[0264] It should be noted that if the compensation reference point has always been on the feeder link or the network side's compensation for the signal delay sent to the terminal is not greater than the round-trip delay of the feeder link, then the round-trip delay or public compensation timing advance value calculated by the compensation reference point used will always be a positive value, so the positive and negative indication bits of the compensation reference point or the public compensation timing advance value can also be omitted, that is, the default is a positive value. Alternatively, if the compensation reference point has always been on the service link or the network side's compensation for the signal delay sent to the terminal is not less than the round-trip delay of the feeder link, then the network side and the terminal have agreed that the round-trip delay or public compensation timing advance value calculated by the compensation reference point used by the terminal is always a negative value. Therefore, the positive and negative indication bits of the compensation reference point or the public compensation timing advance value can also be omitted, that is, the default is a negative value.

[0265] As described in Example 8, for a terminal with a positioning function, it is only necessary to send a common compensation timing advance value or a compensation reference point coordinate parameter to it. Correspondingly, referring to Table 3, if the terminal receives an index number 1, it means that the signaling received by the terminal is the compensation reference point coordinate.

[0266] Table 3 Reference point coordinates, timing advance signaling composition Table 3

[0267] Index Number Compensation reference point coordinates Public compensation timing advance value 1 √ × 2 × √

[0268] As an optional implementation, the index number in the above Table 1, Table 2 or Table 3 can be sent to the terminal via SIB signaling or RRC signaling, that is, the reference point or timing advance value composition can be configured to the terminal via SIB signaling or RRC signaling.

[0269] In this implementation manner, the network side can use a table lookup method to inform the terminal of the reference point coordinates and the composition of the timing advance signaling, which can save signaling overhead.

[0270] Example 10

[0271] This embodiment introduces the type of signaling that carries the parameters involved in the above embodiments 1 to 9 (such as reference point coordinates, common timing advance values, etc.).

[0272] Method 1: The network equipment can carry parameters such as the service link common timing advance value / service link reference point coordinates, common compensation timing advance value / compensation reference point coordinates, ATG reference point coordinates of the target cell / beam in the broadcast information of SIB1, OSI, MIB, etc., and send it to the terminal by unicast, broadcast or multicast by the network equipment.

[0273] Method 2: If sent during the RRC connection phase, the network device may carry these parameters in at least one of the following information: RRC information, RRCReconfiguration message, DCI, group DCI, MAC element, TAC, or send these parameters to the terminal along with data transmission or in a separately allocated PDSCH bearer.

[0274] Method 2: When the terminal switches the cell / beam / BWP, the network device can send these parameters to the terminal in the RRC Reconfiguration message and BWP-related signaling.

[0275] For example, when switching between beams or BWPs occurs:

[0276] If it is in the initial BWP stage, the parameters are sent in the RRC signaling corresponding to the initial BWP. The signaling format can be as follows:

[0277]

[0278]

[0279] The "ReferencePointCoordinateGroup" field may be used for parameters involved in embodiments 1 to 9, including reference point coordinates, common timing advance values, etc. The "ReferencePointCoordinateGroupList" field indicates specific values ​​of reference point coordinates, common timing advance values, etc.

[0280] If in other non-initial BWP phases, the parameters are sent in BWP downlink common (BWP-DownlinkCommon) signaling or BWP uplink common (BWP-UplinkCommon) signaling, and the signaling format sent in the non-initial BWP phase can be as follows:

[0281]

[0282] The "ReferencePointCoordinateGroup" field may be used for parameters involved in embodiments 1 to 9, including reference point coordinates, common timing advance values, etc. The "ReferencePointCoordinateGroupList" field indicates specific values ​​of reference point coordinates, common timing advance values, etc.

[0283] The specific format of the "ReferencePointCoordinateGroupList" field involved in the above signaling is as follows (it should be understood that the following is only an example and not a limitation. According to the different signaling combinations listed in the embodiments of the present application, other different field formats may also appear):

[0284]

[0285] The "ServiceLinkReferencePoint" field indicates the service link reference point coordinate value, and the "CompensatedReferencePoint" field indicates the compensated reference point coordinate value.

[0286] or,

[0287]

[0288] Among them, the "ATGReferencePoint" field indicates the coordinate value of the ATG reference point.

[0289] or,

[0290]

[0291] The "ServiceLinkCommonTimingAdvance" field indicates the service link common timing advance value.

[0292] or,

[0293] ReferencePointCoordinateGroupList::=SEQUENCE{

[0294] ServiceLinkTimingValue BITSTRING(SIZE(n)),

[0295] CompensatedTimingValue BITSTRING(SIZE(n)),}

[0296] Among them, the "ServiceLinkTimingValue" field indicates the timing advance value or the reference point coordinates, and there is a 1-bit indicator in the "ServiceLinkTimingValue" to indicate whether the parameter is a service link common timing advance value or a service link reference point coordinate value, and at the same time carries the corresponding service link common timing advance value / service link reference point coordinates. Similarly, the "CompensatedTimingValue" field indicates a common compensated timing advance value or a compensated reference point coordinate, and there is a 1-bit indicator in the "CompensatedTimingValue" to indicate whether the parameter is a common compensated timing advance value or a compensated reference point coordinate value, and at the same time carries the corresponding common compensated timing advance value / compensated reference point coordinates.

[0297] It should be understood that different beams or cells can be distinguished in the protocol according to BWP, transmission configuration indicator (TCI) or synchronization signal block (SSB); or in other words, the beam or cell can be indicated according to BWP, TCI or SSB. For example, the switching of the beam or cell can be indicated by the switching of BWP, TCI or SSB between the terminal and the network device, so that for the terminal and / or the network device, the actual switching may be BWP, TCI or SSB. In addition, the beam or cell described in the present application may also be replaced by BWP, TCI or SSB.

[0298] Embodiment 11

[0299] This embodiment introduces a switching scenario between different beams or BWPs, in which the service link common timing advance value / service link reference point coordinate value, common compensation timing advance value / compensation reference point coordinate value, and ATG reference point coordinate value of the target cell / beam are sent to the terminal through BWP downlink dedicated (BWP-DownlinkDedicated) signaling and BWP uplink dedicated (BWP-UplinkDedicated) signaling.

[0300] The signaling format can be as follows:

[0301]

[0302] The "ReferencePointCoordinateGroup" field may be used for parameters involved in embodiments 1 to 9, including reference point coordinates, common timing advance values, etc. The "ReferencePointCoordinateGroupList" field indicates specific values ​​of reference point coordinates, common timing advance values, etc.

[0303] Example 12

[0304] Before initiating a BWP or beam or cell handover, a measurement process may be triggered. Therefore, in this embodiment, the network-side delay compensation value of the target BWP or beam or cell is sent down through the neighboring cell measurement configuration and the corresponding RRC signaling in the handover.

[0305] For example, the network side sends the network side delay compensation value of the target BWP or beam or cell through the measurement signaling "MeasConfig" in RRC. The signaling format can be as follows:

[0306]

[0307]

[0308] The "ReferencePointCoordinateGroup" field may be used for parameters involved in embodiments 1 to 9, including reference point coordinates, common timing advance values, etc. The "ReferencePointCoordinateGroupList" field indicates specific values ​​of reference point coordinates, common timing advance values, etc.

[0309] According to the handover signaling process, the service link common timing advance value / service link reference point coordinate value, common compensation timing advance value / compensation reference point coordinate value, and ATG reference point coordinate value of the target BWP or beam or cell are sent in the service BWP or beam or cell through the RRC registration message (RRCReconfiguration). The specific signaling format is as follows:

[0310]

[0311] The "rrcReconfiguration" field indicates RRC registration signaling. The specific format of the "RRCReconfiguration-IEs" field may be as follows:

[0312]

[0313] Example 13

[0314] This embodiment describes that when the ATG reference point coordinates need to be sent, the ATG reference point coordinates can replace the satellite position coordinates (or part of the ephemeris information) and be sent to the terminal, which can save signaling overhead.

[0315] In NTN's satellite communication, the network side sends satellite position coordinates or ephemeris information to the terminal. Therefore, when the terminal switches to the ATG communication scenario, the ATG reference point coordinates can replace the satellite position coordinates or ephemeris information.

[0316] like Fig.19 As shown, the ATG reference point coordinates / satellite position coordinates occupy the same or partially the same signaling bits, and can be sent together or separately with other reference point coordinates, common timing advance values ​​(service link reference point coordinates or service link common timing advance values ​​or compensation reference point coordinates or common compensation timing advance values), etc.

[0317] In this way, the terminal with positioning function can still use the ATG reference point coordinates and its own position coordinates to calculate the round-trip delay between the terminal and the base station and determine the timing advance adjustment value.

[0318] Furthermore, 1 bit can be used to indicate to the terminal whether the network side sends the ATG reference point coordinate information or the satellite position coordinate / ephemeris information to the terminal, such as Fig. 20 shown.

[0319] Embodiment 14

[0320] This embodiment describes a method for calculating TA.

[0321] In the prior art, the timing advance used by the terminal is TA=(N TA +N TAoffset )*16*Ts / 2 μ Among them, N TA It is the TA adjustment value obtained by the terminal according to the parameters indicated by the network side, for example, the TA adjustment value calculated by the terminal according to the common timing advance value and / or reference point coordinates and / or terminal location information sent by the network side in the patent of this invention. TAoffset Indicates the timing interval from uplink to downlink transmission, which is sent to the terminal through SIB information. For FDD mode, NT Aoffset =0; TDD mode, N TAoffset =624. This time interval allows the base station to have enough time to switch between receiving uplink signals and sending downlink signals. Ts represents 1 / (15e3*2048) seconds. μ is related to the subcarrier spacing, that is, the subcarrier spacing is 2 μ 15kHz.

[0322] In this embodiment, the TA adjustment value calculated by the terminal according to the common timing advance value and / or the reference point coordinates and / or the terminal location information sent by the network side can be equal to a fixed value (for example, N TAoffset ) are added together to obtain the timing advance that can be used by the terminal.

[0323] In the embodiments of the present application, the fixed value includes but is not limited to the following three implementations:

[0324] Method 1: The fixed value is the offset.

[0325] The offset may be related to one or more of the following factors:

[0326] 1) Duplex mode, including time division duplex (TDD) mode and frequency division duplex (FDD) mode;

[0327] 2) Position error or positioning error of a second network device (such as a satellite, etc.);

[0328] It should be understood that positioning error and position error are merely different terms and have the same meaning.

[0329] 3) Terminal position error or positioning error.

[0330] Of course, the above three factors are only examples and not limitations, and may be related to other factors in practical applications.

[0331] In one possible design, the network side may send an offset (e.g., a time offset) to the UE to indicate the quotient of the position error or positioning error of the second network device and the speed of light, i.e., positioning error / speed of light, or the quotient of the position error or positioning error of the second network device and the speed of light with an offset of 2 times, i.e., 2*positioning error / speed of light.

[0332] It should be understood that the speed of light refers to the speed at which light waves propagate in the air or outer space. For example, the speed of light is often used = 3*10 8 .

[0333] Optionally, the offset can be a positive value, a negative value or 0, that is, the offset sent by the network side to the terminal can be: +(positioning error / speed of light), or -(positioning error / speed of light), or +(2*positioning error / speed of light), or -(2*positioning error / speed of light).

[0334] When it is necessary to avoid the TA value obtained by the terminal being too large and causing ISI, the offset can use a negative value; when it is necessary to avoid the TA value being too small and causing the terminal signal to reach the network device too late, the offset can use a positive value. Alternatively, the network side can agree with the terminal that the offset sent is a positive value, and when the terminal receives the offset, it uses a negative value for the offset.

[0335] The unit of offset can be nanosecond (ns), microsecond (us), millisecond (ms), 16*Ts / 2 μ Etc., the embodiments of the present application are not limited thereto.

[0336] It is understandable that the position error or positioning error of the second network device can be understood as the deviation distance between the position coordinates of the second network device (the position coordinates can be represented by ephemeris information or three-dimensional coordinates) and the actual position of the second network device due to the perturbation. The position error or positioning error can be the maximum possible deviation distance between the position coordinates of the second network device and the actual position of the second network device. The position error or positioning error can also be called ephemeris error.

[0337] It can be understood that the position error or positioning error of the above terminal refers to the position deviation that occurs when the terminal uses a positioning system or positioning method to locate its own position, that is, the deviation distance or possible maximum deviation distance between the terminal position coordinates obtained by positioning and the actual position coordinates.

[0338] It can be understood that the network side and the terminal can agree that the network side sends a positive offset to the terminal, and the terminal subtracts the calculated TA adjustment value from the offset to obtain the timing advance that the terminal can use; which is equivalent to the network side sending a negative offset to the terminal, and the terminal adds the calculated TA adjustment value to the offset to obtain the timing advance that the terminal can use.

[0339] In summary, the fixed value may be an offset, and the network side may send / configure the offset to the terminal, and the terminal may add or subtract the calculated TA adjustment value from the offset to obtain a timing advance that the terminal may use. The TA adjustment value calculated by the terminal may be the sum of the round-trip delay of the service link and the common compensation timing advance value (or difference).

[0340] In another possible design, the network side may send to the UE a value of a position error or positioning error that can determine an offset.

[0341] The position error or positioning error value here can be the position error or value of the second network device (such as a satellite, etc.) and / or the position error of the terminal. Below, position_err is used to represent the position error or positioning error value. The unit of position_err can be meters. Position_err is used to indicate the possible position error of the second network device.

[0342] After receiving position_err, the terminal calculates the above offset based on position_err.

[0343] For example, the terminal device may calculate the offset value to be used by the terminal in any of the following ways:

[0344] 1) -2*position_err / speed of light, that is, the quotient of -2*position_err and the speed of light;

[0345] 2) +2*position_err / speed of light, +2*position_err and the quotient of the speed of light;

[0346] 3) position_err / speed of light, i.e. the quotient of position_err and the speed of light;

[0347] 4) -position_err / speed of light, that is, the quotient of -position_err and the speed of light.

[0348] Similarly, if you need to avoid ISI, you can use a negative value, and if you need to avoid the TA value being too small, you can use a positive value. Finally, the terminal can add or subtract the calculated TA adjustment value from the offset (e.g. -2*position_err / speed of light) to obtain the timing advance that the terminal can use. The TA adjustment value calculated by the terminal can be the sum of the round-trip delay of the service link and the common compensation timing advance value (or the above difference).

[0349] It should be noted that the offset may include one or more of the TDD mode or FDD mode related part, the position error part of the second network device, and the position error part of the terminal. If the offset includes both the TDD mode or FDD mode related part and the position error part of the second network device and / or the position error part of the terminal, the network side may merge these parts (for example, add / subtract) and send them to the terminal or send these parts separately to the terminal. Accordingly, the terminal can directly use the merged offset after receiving it; or after the terminal receives the above parts, it merges the above parts (add / subtract) and uses them as the final offset. The numerical value of the offset can be agreed upon by the protocol, or sent / configured to the terminal by the network side.

[0350] Method 2: The fixed value is a numerical offset.

[0351] As described above (e.g., Example 3), the common compensation timing advance value (i.e., the round-trip delay value between the satellite and the compensation reference point) sent by the network side to the terminal replaces the position coordinates of the compensation reference point. When the compensation reference point is on the feeder link, the common compensation timing advance value needs to be used as a positive value, and when the compensation reference point is on the service link, the common compensation timing advance value needs to be used as a negative value.

[0352] In order to improve the flexibility of the solution, in the embodiment of the present application, the terminal side may not know whether the compensation reference point is in the feeder link or the service link, but the network side sends a common timing parameter to the terminal for the terminal to determine the common compensation timing advance value. The network side can send / configure a numerical offset to the terminal. After receiving the common timing parameter, the terminal subtracts or adds it from the numerical offset to obtain the common compensation timing advance value used by the terminal, that is:

[0353] Common compensation timing advance value = common timing parameter + numerical offset; or,

[0354] Common compensation timing advance value = common timing parameter - numerical offset.

[0355] Here, the common compensation timing advance value calculated by the common timing parameter + / - numerical offset may be positive or negative.

[0356] Correspondingly, the terminal can add the round-trip delay of the service link in the NTN, the common timing parameter, and the ± numerical offset to obtain the TA to be used. Among them, ± represents + or -. That is:

[0357] TA = round trip delay of the service link (or the timing advance adjustment value of the service link)

[0358] + Public compensation timing advance value

[0359] =Round trip delay of service link + common timing parameter ± numerical offset.

[0360] For example, when the numerical offset is a positive value, the public compensation timing advance value = public timing parameter - numerical offset can be used to calculate the public compensation timing advance value used by the terminal. The numerical value of the numerical offset can be agreed upon by the protocol, or sent / configured to the terminal by the network side. For example, the public timing parameter range sent by the transmitter is 0 to 10. After receiving the public timing parameter, the receiving end subtracts it from a numerical offset (assuming it is 5), and the obtained public compensation timing advance value has a representation range of -5 to 5. This method is equivalent to shifting the public timing parameter sent by the transmitter at the receiving end by a numerical offset length, thereby obtaining the representation range of the public compensation timing advance value to be used.

[0361] It is understandable that this method can also be used to send other numerical parameters, so that the sender can send positive or negative values, and the receiver can shift the numerical range, so as to achieve the effect of using positive / negative values ​​to represent the range. This can improve the flexibility of the solution and simplify the complexity of the sender.

[0362] Method 3: The fixed value includes two parts: offset and numerical offset.

[0363] The network side sends an offset to the terminal and agrees on a numerical offset value with the terminal (or the network side sends a numerical offset value to the terminal). The terminal side can add the round-trip delay of the service link in the NTN, the common timing parameter, the ± numerical offset, and the ± offset to obtain the TA to be used, that is:

[0364] TA = round trip delay of service link + common compensation timing advance value ± offset

[0365] =Round trip delay of service link + common timing parameter ± numerical offset ± offset.

[0366] It should be understood that the above three methods are merely examples of fixed values ​​and are not limitations. In practical applications, the possibility of other implementation methods is not excluded.

[0367] Furthermore, fixed values ​​such as offsets, common timing parameters or numerical offsets can be carried in at least one broadcast information in system information block (SIB) 1, other system information (OSI), master system information block (MIB), etc., and broadcast or multicast by the network device to the terminal. In addition, if the offset, common timing parameters, numerical offset, etc. are sent during the radio resource control (RRC) connection phase, the network side can carry this information in at least one information in RRC information, RRCReconfiguration message, downlink control information (DCI), group DCI, media access control (MAC) control element (CE), timing advance command (TAC), or send it to the UE along with data transmission or in a separately allocated PDSCH bearer.

[0368] The following is a specific example of signaling design such as offset, common timing parameters, and numerical offset.

[0369] Example 1: The network side can add a new variable field such as T-offset to the random access generic configuration (RACH-ConfigGeneric) parameter to indicate the offset, wherein the RACH-ConfigGeneric parameter is usually sent to the UE in a broadcast message or an RRC message to provide the UE with generic parameters used in the random access process. For example:

[0370]

[0371] Optionally, the network side can determine the range of T-offset based on the possible maximum distance value of the ephemeris error or satellite position error or satellite positioning error. For example, taking the maximum value of the ephemeris error or satellite position error as 10km, T-offset is 16*Ts / 2 μ It is a dimensionless unit. The T-offset range is 0 to 511 and requires 9 bits of signaling to represent it.

[0372] It can be understood that if different maximum satellite positioning error ranges and time dimension units are assumed, T-offset can have different representation ranges. For example, after the terminal receives T-offset, the TA adjustment value obtained by the terminal is subtracted from the T-offset value to finally obtain the timing advance TA value used by the terminal, that is, TA = (N TA -T-offset)*16*Ts / 2 μ ; or use the TA adjustment value obtained by the terminal minus the T-offset value and the timing interval N TAoffset Finally, the timing advance TA value used by the terminal is obtained, that is, TA=(N TA +N TAoffset -T-offset)*16*Ts / 2 μ Among them, N TA It is a TA adjustment value obtained by the terminal according to the parameters indicated by the network side. For example, in an embodiment of the present application, the terminal calculates the TA adjustment value according to at least one of the common timing advance value, the common compensation timing advance value, the reference point coordinates, and the terminal's location information sent by the network side.

[0373] Optionally, the RACH-ConfigGeneric parameter can be transmitted in messages such as SIB1, RRC setup signaling (RRCSetup), RRC reconfiguration signaling (RRCReconfiguration), and RRC recovery signaling (RRCResume), which can ensure that the terminal can receive values ​​such as offset, common timing parameters, and numerical offset during the initial access phase and connection state switching, and establish accurate uplink time synchronization.

[0374] Example 2: The network side may send a distance value of an ephemeris error, position error, or positioning error that can determine an offset to the terminal through a random access generic configuration (RACH-ConfigGeneric) parameter, where D-offset is used to represent the distance value of the ephemeris error, position error, or positioning error of the offset.

[0375]

[0376] This example adds a new variable field, D-offset, to the RACH-ConfigGeneric parameter to indicate the distance value of the ephemeris error, position error, or positioning error that can determine the offset.

[0377] In this example, the network side can determine the representation range of D-offset based on the possible maximum distance value of the ephemeris error or satellite position error or satellite positioning error. For example, taking the maximum value of the ephemeris error or satellite position error as 10km, D-offset is measured in meters, and the D-offset representation range is 0 to 1000, which requires 10 bits of signaling to represent. 10 bits can represent the range of 0 to 1023, of which 1001 to 1023 are set as reserved, and can also be reserved for other indication purposes.

[0378] It can be understood that if different maximum satellite positioning error ranges and distance dimension units are assumed, D-offset may have different representation ranges.

[0379] For example, after receiving D-offset, the terminal can use the TA adjustment value obtained by the terminal to subtract D-offset / light speed, or use the TA adjustment value to subtract Then the timing advance TA value used by the terminal is obtained. Indicates rounding up. That is:

[0380] TA=N TA *16*Ts / 2 μ - D-offset / speed of light; or,

[0381]

[0382] Where Tc represents the time unit T c =1 / (Δf max ·N f ), Δf max =480×10 3 Hz,N f =4096. From the above definition of Ts, we know that κ = Ts / T c =64, that is, Ts = 1 / (Δf ref ·N f,ref ),Δf ref =15·10 3 Hz,N f,ref =2048.

[0383] Example 3: In order for the terminal to obtain a more accurate TA value to apply for access to the communication system, the network side may send a common compensation timing advance value to the terminal through a random access common configuration (RACH-ConfigGeneric) parameter. Here, TA-common is used to represent the common compensation timing advance value:

[0384]

[0385] In this example, the network side adds a new variable field such as TA-common in the RACH-ConfigGeneric parameter to indicate a parameter value used to determine a common compensation timing advance value or a common timing advance value.

[0386] Optionally, the network side may determine the representation range of TA-common according to the maximum possible orbital altitude and the possible minimum communication elevation angle of the satellite.

[0387] For example, assuming the orbit altitude is a GEO orbit and the minimum communication angle is 10 degrees, at 16·64·T c / 2 u For dimension units, the range of TA-common is required to be -4155513 to +4155513, which requires 23 bits of signaling to represent. The range that 23 bits can represent is: -4194303 to +4194303. Among them, the ranges of -4194303 to -4155513 and 4194303 to 4155513 are reserved and can also be used for other indication purposes. It can be understood that if different satellite orbit altitudes, minimum elevation angles and time dimension units are assumed, the indication range of TA-common can be different.

[0388] After receiving TA-common, the terminal can calculate the round-trip delay of the service link according to the terminal position and the satellite position, and add it to the time length represented by TA-common to obtain the TA adjustment value.

[0389] It should be understood that TA-common may represent either a common compensation timing advance value or a common propagation delay that the terminal needs to compensate for.

[0390] It should be understood that TA-common can represent a positive value, a negative value, and zero. A positive value represents sending an uplink signal in advance, and a negative value represents sending an uplink signal in a delayed manner.

[0391] Example 4: In order to save signaling bits, the network side can combine the common compensation timing advance signaling according to the orbit height range.

[0392] For example:

[0393]

[0394] In this example, the network side adds two new variable fields in the RACH-ConfigGeneric parameter, namely the low-orbit common timing advance TA-common-LEO and the common timing advance complement TA-common-complement, which are used to determine the common compensation timing advance value or the common propagation delay that the terminal needs to compensate. Among them, TA-common-complement is optional, that is, the network side can choose to send or not send the TA-common-complement parameter. The network side can decide whether to send the TA-common-complement parameter based on the orbital height of the second network device. Please refer to the following example for details.

[0395] Optionally, the network side may determine the representation range and number of bits of TA-common-LEO and TA-common-complement according to the orbital altitude range of the satellite and the possible minimum communication elevation angle.

[0396] For example, for scenarios where the orbital altitude is not higher than 1200km, the network side can only send TA-common-LEO signaling (20 bits), that is, TA-common-complement is not sent. At this time, only 20 bits of signaling need to be sent to indicate the common compensation timing advance value, which is in the range of -320609 to +320609. The 20 bits can indicate the range of -524287 to +524287, of which the ranges of -524287 to -320609 and 320609 to 524287 are reserved and can also be used for other indication purposes.

[0397] For example, for scenarios where the orbital altitude is greater than 1200km, the network side can send TA-common-LEO and TA-common-complement signaling (3 bits) to the UE, where TA-common-LEO represents the high-order bits and TA-common-complement represents the low-order bits. TA-common-LEO and TA-common-complement together constitute 23-bit signaling, representing the range of -4155513 to 4155513. The range that 23 bits can represent is: -4194303 to +4194303. Among them, the ranges of -4194303 to -4155513 and 4194303 to 4155513 are reserved and can also be used for other indication purposes.

[0398] After receiving the common compensation timing advance value represented by TA-common-LEO and TA-common-complement, the terminal can calculate the round-trip delay of the service link according to the terminal position and the satellite position, and add it to the time length represented by the common compensation timing advance value to obtain the TA adjustment value. This signaling transmission method provides flexibility and saves some signaling bits in scenarios with low orbital altitudes.

[0399] Example 5: In order to save signaling bits in different orbit height scenarios, the network side can indicate the common compensation timing advance signaling separately according to the orbit height range. For example:

[0400]

[0401] In this example, the network side adds three new variable fields in the RACH-ConfigGeneric parameter, namely, TA-common-LEO-600 common timing advance for low orbit 600, TA-common-LEO-1200 common timing advance for low orbit 1200, and TA-common-GEO common timing advance for synchronous orbit, which represent the parameter values ​​used to determine the common compensation timing advance value or the common propagation delay that the terminal needs to compensate. Among them, A-common-LEO-600, TA-common-LEO-1200 and TA-common-GEO are all optional, that is, the network side can choose to send only one of the three parameters, only two of them, or all of them.

[0402] Optionally, the network side can determine the representation range and number of bits of TA-common-LEO-600, TA-common-LEO-1200 and TA-common-GEO according to the orbital altitude range of the satellite and the possible minimum communication elevation angle. Among them, TA-common-LEO-600 represents the common compensation timing advance value related parameters with an orbital altitude not exceeding 600km, TA-common-LEO-1200 represents the common compensation timing advance value related parameters with an orbital altitude not exceeding 1200km, and TA-common-GEO represents the common compensation timing advance value related parameters with an orbital altitude not exceeding 36000km.

[0403] For example, for scenarios where the orbital altitude is not higher than 600km, the network side can send TA-common-LEO-600 signaling (19 bits), that is, TA-common-LEO-1200 and TA-common-GEO are not sent. At this time, only 19 bits of signaling need to be sent for the terminal to determine the common compensation timing advance value, which is represented by a range of -197800…+197800. The 19 bits can indicate a range of: -262143~+262143, of which -262143~-197800 and 197800~262143 are reserved and can also be used for other indication purposes.

[0404] For example, for the scenario where the orbit altitude is greater than 600km and not greater than 1200km, the network side can send TA-common-LEO-1200 signaling (20 bits) to the UE, that is, TA-common-LEO-600 and TA-common-GEO are not sent. At this time, only 20 bits of signaling need to be sent for the terminal to determine the common compensation timing advance value, and the range used to indicate it is -320609…320609. The range that 20 bits can indicate is: -524287~+524287, of which -524287~-320609 and 320609~524287 are reserved, and can also be reserved for other indication purposes.

[0405] For example, for scenarios where the orbital altitude is higher than 1200km, the network side needs to send TA-common-GEO signaling (23 bits), that is, TA-common-LEO-600 and TA-common-LEO-1200 are not sent. At this time, 23 bits of signaling need to be sent for the terminal to determine the common compensation timing advance value, which is expressed in the range of -4155513 to +4155513. The range that 23 bits can represent is: -4194303 to +4194303. Among them, the ranges of -4194303 to -4155513 and 4194303 to 4155513 are reserved and can also be used for other indication purposes.

[0406] After the terminal receives the common compensation timing advance value represented by any one or more of TA-common-LEO-600, TA-common-LEO-1200 or TA-common-GEO, it can calculate the round-trip delay of the service link according to the terminal position and the satellite position, and add it to the time length represented by the common compensation timing advance value to obtain the TA adjustment value.

[0407] Example 6: The network side may send a parameter value (i.e., a common timing parameter, where TA-common-timing is used to represent the common timing parameter) for determining a common compensation timing advance value or a common timing advance value to the terminal through a random access generic configuration (RACH-ConfigGeneric) parameter:

[0408]

[0409] In this example, the network side adds a new variable field common timing parameter, namely TA-common-timing, to the RACH-ConfigGeneric parameter to indicate the parameter value used to determine the common compensation timing advance value or the common timing advance value.

[0410] Optionally, the network side may determine the representation range of TA-common-timing according to the maximum possible orbital altitude and the possible minimum communication elevation angle of the satellite.

[0411] For example, assuming the orbit altitude is a GEO orbit and the minimum communication angle is 10 degrees, at 16·64·T c / 2 u As a unit of measure, the range of TA-common-timing is 0 to 8311026, and 23 bits of signaling are required to represent it. The range that 23 bits can represent is: 0 to 8388607, of which the range of 8311027 to 8388607 is reserved and can also be used for other indication purposes.

[0412] It is understandable that if different satellite orbit altitudes, minimum elevation angles and time dimension units are assumed, the indication range of TA-common-timing may be different.

[0413] After receiving the common timing parameter TA-common-timing, the terminal subtracts the common timing parameter TA-common-timing from the numerical offset to obtain a common compensation timing advance value or a common timing advance value.

[0414] For example, assuming that the numerical offset is 4155513 (the numerical offset can be agreed upon by the protocol or the numerical offset can be configured by the network to the UE), after the terminal receives TA-common-timing, it obtains the common compensation timing advance value through TA-common-timing-4155513, and the representation range of the common compensation timing advance value is -4155513 to +4155513. This method is equivalent to performing an offset operation on the received TA-common-timing value, that is, TA-common-timing-numerical offset. Here, the numerical offset equals 4155513 as an example, and is not limited to this value in actual use. For another example, after the terminal receives TA-common-timing, it can calculate the common compensation timing advance value, and then calculate the round-trip delay of the service link based on the terminal position and the satellite position, and add it to the time length represented by the common compensation timing advance value to obtain the TA adjustment value.

[0415] Furthermore, the above-mentioned exemplary transmission signaling methods may be used in combination.

[0416] For example, the network side can add three new variable domains in the RACH-ConfigGeneric parameter: TA-common-timing-LEO-600 common timing parameter, TA-common-timing-LEO-1200 common timing parameter, and TA-common-timing-GEO common timing parameter, to indicate the common timing parameter value used to determine the common compensation timing advance value or the common propagation delay that the terminal needs to compensate:

[0417]

[0418] Optionally, the representation range and number of bits of TA-common-timing-LEO-600, TA-common-timing-LEO-1200 and TA-common-timing-GEO can be determined according to the orbital altitude range of the satellite and the possible minimum communication elevation angle. Among them, TA-common-timing-LEO-600 represents the common timing parameters related to the common compensation timing advance value with an orbital altitude not greater than 600km, TA-common-timing-LEO-1200 represents the common timing parameters related to the common compensation timing advance value with an orbital altitude not greater than 1200km, and TA-common-timing-GEO represents the common timing parameters related to the common compensation timing advance value with an orbital altitude not greater than 36000km. Among them, TA-common-timing-LEO-600, TA-common-timing-LEO-1200 and TA-common-timing-GEO are all optional, that is, the network side can choose not to send one of the three parameters.

[0419] For example, for a scenario with an orbit altitude of no more than 600 km, the minimum communication angle is 10 degrees, with 16·64·T c / 2 u As a unit of measure, the network side can send TA-common-timing-LEO-600 signaling (19 bits), that is, TA-common-timing-LEO-1200 and TA-common-timing-GEO are not sent. At this time, only 19 bits of common timing parameter signaling need to be sent for the terminal to determine the common compensation timing advance value, which is used to represent the range of 0 to 395600. The 19 bits can indicate the range of: 0 to 524287, of which the range of 395601 to 524287 is reserved (reserved) and can also be used for other indication purposes. Similarly, TA-common-timing-LEO-1200 and TA-common-timing-GEO signaling use 20 bits and 23 bits of signaling to represent the range of 0 to 641218 and 0 to 8311026 respectively.

[0420] For example, assuming that the common timing parameters for different orbit parameter ranges have different numerical offsets, the numerical offset value corresponding to TA-common-timing-LEO-600 is 197800, the numerical offset value corresponding to TA-common-timing-LEO-1200 is 320609, and the numerical offset value corresponding to TA-common-timing-GEO is 4155513. After receiving TA-common-timing-LEO-600, the terminal obtains the common compensation timing advance value through TA-common-timing-LEO-600-197800, and the representation range of the common compensation timing advance value is -197800 to 197800.

[0421] For another example, for different satellite orbit altitudes, minimum elevation angles and time dimension units, the indication ranges of TA-common-timing-LEO-600, TA-common-timing-LEO-1200 or TA-common-timing-GEO may be different. After receiving the common timing parameters TA-common-timing-LEO-600, TA-common-timing-LEO-1200 or TA-common-timing-GEO, the terminal subtracts it from the corresponding numerical offset to obtain the common compensation timing advance value or the common timing advance value. The terminal can calculate the round-trip delay of the service link based on the terminal position and the satellite position, and add it to the time length represented by the common compensation timing advance value to obtain the TA adjustment value.

[0422] Several detailed examples are given below to describe how the terminal calculates the TA value to be used based on the terminal position, satellite position, common compensation timing advance value, etc.

[0423] Assuming 16·64·T c / 2 u As a unit of measure, the round trip delay of the service link is quantified as follows:

[0424] for

[0425] Where RTD service It represents the round-trip delay between the terminal and the satellite, which is equal to the quotient of twice the distance between the terminal and the satellite and the speed of light. Indicates rounding down.

[0426] The common compensation timing advance value obtained by the terminal is NT common , then the TA amount used by the terminal to send the random access preamble or uplink data is:

[0427] TA=(NTservice +NT common )*16*64T c / 2 u (2)

[0428] If the offset T-offset, common timing parameters and numerical offset are taken into account, the amount of TA used by the terminal is:

[0429] TA=(NT service +NT common -T -offset )*16*64T c / 2 u (3)

[0430] If the position error D-offset, common timing parameters and numerical offset are taken into account, the amount of TA used by the terminal is:

[0431]

[0432] It can be seen that formula (4) is Partially replace T-offset in formula (3), which means subtracting the timing uncertainty caused by the satellite positioning error from the timing advance value to be used by the terminal, that is, the timing uncertainty is twice the possible satellite positioning error divided by the speed of light, and then (16·64·T c / 2 u ) The time unit is quantized by rounding up.

[0433] The amount of TA used by the terminal can also be:

[0434] TA=(NT service +TA-common-timing-value offset)*16*64T c / 2 u (5)

[0435] The common compensation timing advance value is NT, which is replaced by TA-common-timing-value offset. common .

[0436] The amount of TA used by the terminal can also be:

[0437] TA=(NT service +TA-common-timing-value offset-T-offset)*16*64T c / 2 u (6)

[0438] The amount of TA used by the terminal can also be:

[0439]

[0440] It should be understood that if the TA is calculated using other time units, then it is only necessary to replace (16·64·T c / 2 u ) time unit. For example, use 64·T c / 2 u As a unit of dimension, then replace (16·64·T in the above formulas (1) to (7) c / 2 u ) The time unit is replaced by 64·T c / 2 u Time unit is OK.

[0441] If NT is calculated service At 64·T c / 2 u The common compensation timing advance value NT is obtained as a time unit. common , common timing parameters and numerical offsets are based on 16·64·T c / 2 u is the time unit. Then Then the amount of TA used by the terminal is:

[0442] TA=(NT service / 16·+NT common )*16*64T c / 2 u (8)

[0443] If the offset T-offset or position error D-offset is considered, the common timing parameters and the numerical offset, then the TA amount used by the terminal is:

[0444] TA=(NT service / 16·+NT common -T-offset)*16*64T c / 2 u (9)

[0445] or,

[0446]

[0447] Similarly, formula (10) is Partially replace T-offset in formula (9), which means subtracting the timing uncertainty caused by the satellite positioning error from the timing advance value to be used by the terminal, that is, the timing uncertainty is twice the possible satellite positioning error divided by the speed of light, and then (16·64·T c / 2u ) The time unit is quantized by rounding up.

[0448] The amount of TA used by the terminal can also be:

[0449] TA=(NT service / 16·+TA-common-timing-value offset)*16*64T c / 2 u (11)

[0450] The common compensation timing advance value is replaced by (TA-common-timing-value offset) as NT common .

[0451] The amount of TA used by the terminal can also be:

[0452] TA=(NT service / 16·+TA-common-timing-

[0453] Numeric offset - T-offset)*16*64T c / 2 u (12)

[0454] The amount of TA used by the terminal can also be:

[0455]

[0456] The following introduces the impact of cell handover, beam switch, gateway switch and satellite switch on the public compensation timing advance or public timing advance.

[0457] 1. Cell handover:

[0458] 1) In the Cell handover process, the UE measures and reports the channel quality of the neighboring cell according to the instructions of the network side, and then the gNB where the source cell is located (referred to as the source gNB, which is the same as or different from the gNB where the target cell is located) sends RRCReconfiguration signaling to the UE. As can be seen from the above signaling, the public compensation timing advance or public timing advance signaling exists in RRCReconfiguration, so the public compensation timing advance or public timing advance of the target cell can be carried in RRCReconfiguration. For non-random access handover (RACHless handover), the source gNB will also send RRCReconfiguration signaling to the UE, and the public compensation timing advance value or public timing advance value of the target gNB can also be sent to the UE.

[0459] 2) The UE receives the SIB1 of the target cell and can also obtain the common compensation timing advance or common timing advance of the target cell.

[0460] 2. Satellite switch: Please refer to the cell handover process, which will not be repeated here.

[0461] 3. Beam switch: When the source beam and the target beam belong to the same cell. The common compensation timing advance or common timing advance is broadcast in SIB1 and is cell-level signaling. Therefore, when doing a beam switch, the two beams use the same common compensation timing advance or common timing advance, and there will be no timing jump. (If the common compensation timing advance or common timing advance is at the beam level, the network side may compensate different beams with different delay values, which will lead to timing jumps. Therefore, it is necessary to carry the common compensation timing advance value or common timing advance value in the BWP switching signaling, such as in the BWP-UplinkDedicated signaling.)

[0462] 4. Gateway switch:

[0463] When a soft gateway switch occurs, that is, the UE can establish connections with two gateways at the same time and can receive messages from both gateways, the gateway switch scenario can be equivalent to a cell handover process, that is, the common compensation timing advance value or the common timing advance value of the target gateway can be sent to the UE in the RRC Reconfiguration signaling.

[0464] When a hard gateway switch occurs, that is, the UE can only establish a connection with one gateway at a time. When the UE disconnects from a gateway and establishes a connection with another gateway at the same time, that is, when a hard switch occurs, the delay of the feeder link part will change. Before the gateway switch, the gNB can send the UE the common compensation timing advance value or common timing advance value used in the target gateway or the difference between the common compensation timing advance value or common timing advance value currently used. For example, the UEs of the entire beam or cell need to update the common compensation timing advance value or common timing advance value, so the RRCReconfiguration signaling can be used to carry the above parameters to update them.

[0465] Furthermore, when a soft handover of a gateway station or a hard handover of a gateway station occurs, the gNB uses MAC CE signaling to send the common compensation timing advance value or the common timing advance value of the target gateway or the difference between the common compensation timing advance value or the common timing advance value currently used and the UE.

[0466] In some special scenarios, sending the common compensation timing advance value difference or the common timing advance value difference also needs to use the same number of bits as sending the complete common compensation timing advance value or the common timing advance value. For example, when the network side performs timing compensation on the uplink signal before switching, and does not perform timing compensation on the uplink signal after switching, then it is necessary to represent the complete round-trip delay of the feeder link part. At this time, the number of bits required for the common compensation timing advance value difference is the same as that for representing the complete common compensation timing advance value. If the protocol does not support these special scenarios, sending the common compensation timing advance value difference can save signaling overhead compared to sending the complete common compensation timing advance value.

[0467] The effectiveness of the common compensation timing advance value or the common timing advance value is described below.

[0468] If the common compensation timing advance value or common timing advance value is carried by SIB1, the SIB1 update period determines the maximum error of the common compensation timing advance value or common timing advance value. The error comes from the relative motion between the satellite and the gateway.

[0469] System messages (including SIB1) are updated only in the start frame of the modification period, and the start frame of the modification period meets the following conditions:

[0470] SFN mod m = 0;

[0471] Wherein, m represents the number of system frames included in the change period length, SFN represents the system frame number, and mod represents the remainder;

[0472] m = modificationPeriodCoeff * defaultPagingCycle, unit: frame;

[0473] modificationPeriodCoeff=2 / 4 / 8 / 16;

[0474] defaultPagingCycle=32 / 64 / 128 / 256.

[0475] Among them, modificationPeriodCoeff and defaultPagingCycle can be configured through SIB1.

[0476] It can be seen that the minimum change period is 64frame=640ms.

[0477] Assume that the common compensation timing advance value indicates the difference between the round-trip delay of the feeder link and the timing compensation value of the uplink data on the network side. If the distance between the satellite and the gateway is getting closer and closer, the value of the common compensation timing advance indication may be larger, and the preamble or uplink data may arrive early, causing inter-symbol interference (ISI).

[0478] In order to avoid ISI, the public compensation timing advance value or public timing advance value corresponding to the start time of the next update period can be sent at the start time of a certain update period. In this way, the public compensation timing advance value or public timing advance value sent is small, and the preamble or uplink data sent by the UE will arrive at the network side later, thereby avoiding ISI. For example, if the update period is 640ms, the late arrival time does not exceed 33.28us.

[0479] Embodiment 15

[0480] The concept of the technical solution of the present invention can also be applied to the transmission of a timing advance rate (TA rate) reference point, a Doppler pre-compensation reference point / a Doppler post-compensation reference point.

[0481] Specifically, the TA rate reference point can be divided into a service link TA rate reference point and a feeder link TA rate reference point. The service link TA rate mentioned here and in the following text refers to the service link common TA rate.

[0482] Service link timing advance change rate (TA rate) reference point: The terminal can calculate the service link common timing advance change rate of the beam or cell based on the relative movement speed or distance change rate between the satellite (the terminal can obtain the satellite's position and speed information through the ephemeris information) and the service link TA rate reference point. For example, based on the satellite's movement direction, the satellite's position and the position of the reference point, the terminal can calculate the relative speed V between the satellite and the reference point (when the satellite and the reference point move towards each other, V takes a negative value; when the satellite and the reference point move in the opposite direction, V takes a positive value.), TA rate is equal to 2*V / c, c is the speed of light 3*10 8 m / s. In this way, the change value of TA after a period of time △T can be calculated based on the TA rate, which is △T*2*V / c. The corrected TA is TA_original+△T*2*V / c, where TA_original is the TA used before. Therefore, the terminal can use the common timing advance change rate to correct the timing advance of the signal sent by the sending terminal (if there is a common timing advance change rate of the feeder link, the service link common timing advance change rate and the feeder link common timing advance change rate, that is, the sum of the two, can be used to calculate the final TA change rate, so as to correct the uplink timing advance adjustment value).

[0483] Feeder link timing advance change rate (TA rate) reference point: The terminal can calculate the feeder link common timing advance change rate of the beam or cell based on the relative movement speed or distance change rate between the satellite (the terminal can obtain the satellite's position and speed information through the ephemeris information) and the feeder link TA rate reference point (same as the above description). The terminal uses the common timing advance change rate to correct the timing advance adjustment value of the signal sent by the sending terminal (if there is a service link common timing advance change rate, the service link common timing advance change rate and the feeder link common timing advance change rate, that is, the sum of the two, can be used to calculate the final TA change rate, so as to correct the uplink timing advance adjustment value). The feeder link timing advance change rate reference point can be the location coordinates of the gateway station.

[0484] Doppler pre / post compensation reference point: The terminal can calculate the Doppler pre / post compensation value of the beam or cell based on the relative motion speed between the satellite (the terminal can obtain the satellite's position and speed information through the ephemeris information) and the Doppler pre / post compensation reference point. The Doppler pre / post compensation value can represent the Doppler post compensation value made by the satellite for the signal sent by the terminal received in the corresponding beam / cell, and the Doppler pre compensation value made by the satellite for the downlink signal sent in the corresponding beam / cell. Alternatively, the Doppler pre / post compensation value can represent the Doppler pre compensation value that the terminal needs to make for the signal when sending the signal sent by the terminal, and the Doppler post compensation value that the terminal makes for the signal when receiving the downlink signal. The Doppler pre / post compensation reference point can be selected at any position covered by the beam / cell according to system requirements, such as the center point of the beam / cell.

[0485] If the Doppler value calculated based on the Doppler pre / post compensation reference point and the satellite position and movement direction represents the Doppler pre-compensation value made by the network side for the downlink signal, then the terminal with the global navigation satellite system (GNSS) function can calculate the frequency deviation of the crystal oscillator based on the Doppler pre-compensation value and the frequency deviation value of the downlink signal. At the same time, the terminal with the GNSS function can calculate the Doppler frequency deviation value caused by the uplink channel based on its own position, the position of the satellite, and the direction of movement of the satellite. The pre-compensation value made by the terminal with the GNSS function for the signal sent by the terminal can be obtained by subtracting the Doppler post-compensation value made by the satellite side for the signal sent by the terminal from the Doppler frequency deviation value of the uplink channel.

[0486] For one possible design, see Fig.21A , a reference point group can be defined, including the service link reference point coordinates, compensation reference point coordinates, ATG reference point coordinates, service link TArate reference point coordinates, feeder link TA rate reference point coordinates, and Doppler pre / post compensation reference point coordinates. In another possible design, see Fig.21B The network side can send the service link TA rate reference point coordinates, feeder link TA rate reference point coordinates, and Doppler pre / post compensation reference point coordinates separately.

[0487] It should be understood that the multiple reference points mentioned above (such as the service link TA rate reference point, the feeder link TA rate reference point coordinates, and the Doppler pre / post compensation reference point) may be the same reference point, or the multiple reference points are located at the same position. For example, if two or three of the service link reference point coordinates, the service link TA rate reference point coordinates, and the Doppler pre / post compensation reference point coordinates are the same reference coordinates, then the system only needs to transmit one reference coordinate and agree with the terminal in advance on how to use the reference point. For example, if the service link TA rate reference point coordinates and the service link reference point coordinates are the same reference point, then the system and the terminal agree that when the terminal receives the reference point, the service link common timing advance change rate of the beam or cell can be calculated based on the relative motion speed or distance change rate between the satellite (the terminal can obtain the satellite's position and speed information through the ephemeris information) and the reference point, and the terminal obtains the common timing advance adjustment value of the service link based on the round-trip delay between the satellite's position and the reference point.

[0488] The above-mentioned reference point group may use the signaling transmission position used in the aforementioned embodiments.

[0489] In a possible implementation manner, the service link TA rate reference point coordinates, the feeder link TA rate reference point coordinates, and the Doppler pre / post compensation reference point coordinates may be replaced by the service link TA rate value (with a positive or negative sign indication), the feeder link TA rate value (with a positive or negative sign indication), and the Doppler pre / post compensation value (with a positive or negative sign indication), respectively. Similar to the third embodiment, the reference point coordinates and the TA rate value and the Doppler pre / post compensation value may be used in combination. For example Fig. 22 As shown, the service link TArate reference point coordinates can be used in combination with the feeder link TA rate value and Doppler pre / post compensation value.

[0490] In another possible implementation, Fig.23 As shown, each signaling can add an indication bit to indicate that the transmitted signaling is the service link TA rate reference point coordinate or service link TA rate value (with positive and negative signs), the feeder link TA rate reference point coordinate or feeder link TA rate value (with positive and negative signs), or the Doppler pre / post compensation reference point coordinate or Doppler pre / post compensation value. For non-staring mode, the service link common TArate of a certain beam / cell does not change, so sending signaling to the terminal in the form of service link TA rate value (with positive and negative signs) can reduce the frequency of signaling changes and reduce system complexity. Therefore, as Fig.23 The flexible signaling transmission method shown can reduce the complexity of signaling sent by the system.

[0491] When the network side does not send the TArate reference point coordinates or the Doppler compensation reference point coordinates to the terminal or sends an invalid coordinate point (for example, a coordinate value of all zeros), the terminal can use the default reference point coordinate value, for example, the default reference point coordinate value can be the coordinate value of the gateway station. That is, when the network side does not send the TA rate reference point coordinates or the Doppler compensation reference point coordinates to the terminal or sends an invalid coordinate point (for example, a coordinate value of all zeros), the TA rate reference point coordinates or the Doppler compensation reference point fall back to the default reference point.

[0492] Example 16

[0493] This embodiment is based on Embodiment 14, and the service link / feeder link TA rate reference point coordinates and / or the service link / feeder link TA rate value are replaced with the service link / feeder link TA rate angle.

[0494] See also Fig.24 , assuming that the network side sends the TA rate angle α of the service link and / or the TA rate angle β of the feeder link to the terminal, and the speed of the satellite along the direction of movement is A. When the terminal receives the TA rate angle, the corresponding TA rate value of the service link can be calculated according to the formula [-2*cos(α)*A / c], and the corresponding TA rate value of the feeder link can be calculated according to the formula [-2*cos(β)*A / c]. Then, the change value of TA after a period of time △T can be calculated according to the TA rate, which is [-2*cos(α)*A / c]+[-2*cos(β)*A / c]. The corrected TA is TA_original+[-2*cos(α)*A / c]+[-2*cos(β)*A / c], where TA_original is the TA used before. If the network side only sends the TArate angle α of the service link or the TA rate angle β of the feeder link to the terminal, the terminal only needs to calculate the updated TA based on TA_original+[-2*cos(α)*A / c] or TA_original+[-2*cos(β)*A / c].

[0495] Embodiment 17

[0496] In this embodiment, the parameters sent to the terminal, such as link reference point coordinates, compensation reference point coordinates, TA rate reference point coordinates, etc., can also send the corresponding validity period of the parameters to the terminal at the same time. This is because the LEO satellite is moving all the time, and the positional relationship between the terminal and the satellite is constantly changing. The public timing advance value or reference point coordinates sent by the network to the terminal has a validity period, and is no longer applicable after the validity period.

[0497] For example, when the network sends the compensation reference point coordinates to the terminal, the validity period of the reference point coordinates sent to the terminal is △T. △T can be a value in time slots or in Ts. If the time slot is used as a unit, the terminal will receive the reference point coordinates for △T / 2 seconds after receiving them. μ If the unit is Ts, then the compensation reference point will no longer be applicable after △T*Ts seconds after the terminal receives the coordinates of the reference point.

[0498] If the network side sends the link reference point coordinates, compensation reference point coordinates, TA rate reference point coordinates, etc. to the terminal in a periodic broadcast mode, then when the parameter expires, the terminal can obtain a new parameter value by re-receiving the parameter and decoding it. If the network side sends the link reference point coordinates, compensation reference point coordinates, TA rate reference point coordinates, etc. to the terminal in a non-periodic broadcast mode, then when the parameter expires, the terminal can obtain a new parameter value by re-applying for the parameter from the network side.

[0499] In this embodiment, the parameters sent by the network side to the terminal are configured with corresponding validity periods, which can further improve the reliability of communication.

[0500] It should be noted that in the embodiment of the present application, the satellite communication scenario and the ATG communication scenario can exist at the same time. If both the satellite communication scenario and the ATG communication scenario exist, the network side and the terminal can simultaneously perform the operations performed by the network side and the terminal in the above-mentioned ATG communication scenario and the ATG communication scenario. The specific implementation method in this case can refer to the satellite communication scenario and the ATG communication scenario respectively, and will not be repeated here.

[0501] The above embodiments can be combined with each other to achieve different technical effects.

[0502] In the embodiments provided by the present application above, the method provided by the embodiment of the present application is introduced from the perspective of interaction between network equipment (such as satellites, gateway stations, ATG network equipment, etc.) and terminals. In order to implement the various functions in the methods provided by the embodiments of the present application above, the terminal and the network equipment may include hardware structures and / or software modules to implement the above functions in the form of hardware structures, software modules, or hardware structures plus software modules. Whether one of the above functions is executed in the form of hardware structures, software modules, or hardware structures plus software modules depends on the specific application and design constraints of the technical solution. The following introduces the communication device of the embodiment of the present application.

[0503] The embodiment of the present application also provides a communication device 2500, which can be the first network device in the above method embodiment, or a device in the first network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in combination with the first network device. The device 2500 may include a module corresponding to the method / operation / step / action performed by the first network device in the execution method embodiment, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0504] For example, see Fig.25 , the device 2500 comprises:

[0505] A processing unit 2501 is configured to determine a first parameter according to a first delay compensation value, wherein the first delay compensation value is a delay compensation performed by the first network device for a signal sent by a receiving terminal, and the first parameter is used to indicate a difference between a round-trip delay of a feeder link in a non-terrestrial network NTN and the first delay compensation value, and the difference is used to determine a TA used by the terminal to send a signal;

[0506] The sending unit 2502 is used to send the first parameter.

[0507] The specific implementation of the operations performed by the above units can refer to the specific implementation of the operations performed by the first network device in the above method embodiment, which will not be repeated here.

[0508] The embodiment of the present application also provides a communication device 2600, which can be the second network device in the above method embodiment, or a device in the second network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in combination with the first network device. The device 2500 may include a module that corresponds to the method / operation / step / action performed by the second network device in the execution method embodiment, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0509] For example, see Fig.26 , the device 2600 comprises:

[0510] A processing unit 2601 is configured to determine the position coordinates of a compensation reference point according to a second delay compensation value, where the second delay compensation value is a delay compensation value made by the second network device for receiving a signal sent by a terminal; wherein the second delay compensation value is used to determine a TA used by the terminal to send a signal, and the TA is equal to a round-trip delay of a service link in the NTN minus the second delay compensation value;

[0511] The sending unit 2602 is used to send the position coordinates of the compensation reference point.

[0512] The specific implementation of the operations performed by the above units can refer to the specific implementation of the operations performed by the second network device in the above method embodiment, which will not be repeated here.

[0513] The embodiment of the present application also provides a communication device 2700, which can be the ATG network device in the above method embodiment, or a device in the ATG network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in combination with the ATG network device. The device 2700 may include a module corresponding to the method / operation / step / action performed by the ATG network device in the execution method embodiment, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0514] For example, see Fig. 27 , the device 2700 comprises:

[0515] The processing unit 2701 is configured to determine the position coordinates of an ATG reference point, wherein the position coordinates of the ATG reference point are used to determine a TA used by a terminal to send a signal to the ATG network device;

[0516] The sending unit 2702 is used to send the position coordinates of the ATG reference point.

[0517] The specific implementation of the operations performed by the above units can refer to the specific implementation of the operations performed by the ATG network device in the above method embodiment, which will not be repeated here.

[0518] The embodiment of the present application also provides a communication device 2800, which can be a terminal in the above method embodiment, or a terminal in the ATG network device (for example, a chip, or a chip system, or a circuit), or a device that can be used in conjunction with the terminal. The device 2800 may include a module that corresponds to the method / operation / step / action performed by the terminal in the execution method embodiment, and the module may be a hardware circuit, or software, or a combination of a hardware circuit and software.

[0519] For example, see Fig.28 , the device 2800 comprises:

[0520] A receiving unit 2801 is configured to receive a first parameter, wherein the first parameter is used to indicate a difference between a round-trip delay of a feeder link in a non-terrestrial network NTN and a first delay compensation value, the first delay compensation value is a delay compensation performed by the first network device for a signal sent by a receiving terminal, and the difference is used to determine a TA used by the terminal to send a signal;

[0521] The processing unit 2802 is used to determine the TA value used for sending the signal according to the first parameter.

[0522] or,

[0523] A receiving unit 2801 is configured to receive the position coordinates of a compensation reference point, wherein the second delay compensation value is a delay compensation value made by the second network device for receiving a signal sent by the terminal, and the second delay compensation value is used to determine a TA used by the terminal to send a signal, and the TA is equal to a round-trip delay of a service link in the NTN minus the second delay compensation value;

[0524] The processing unit 2802 is used to determine the TA used for sending the signal according to the position coordinates of the compensation reference point.

[0525] or,

[0526] The receiving unit 2801 is used to receive the position coordinates of the air-to-ground ATG reference point;

[0527] The processing unit 2802 is used to determine the TA used for sending the signal according to the position coordinates of the ATG reference point.

[0528] The specific implementation of the operations performed by the above units can refer to the specific implementation of the operations performed by the terminal in the above method embodiment, which will not be repeated here.

[0529] The above describes the communication device in the embodiment of the present application, and the following describes possible product forms of the communication device. It should be understood that any product having the above Figure 25 to Figure 28 Any form of product with the functions of the communication device described above falls within the protection scope of the embodiments of the present application. It should also be understood that the following description is only an example and does not limit the product form of the communication device of the embodiments of the present application to this.

[0530] Fig.29 A communication device 2900 provided in an embodiment of the present application can be used to execute the method executed by the above-mentioned first network device, second network device, ATG device or terminal. The device 2900 may include a processor 2901 and a communication interface, the communication interface is used to communicate with other communication devices; the processor 2901 is used to run a set of programs so that the device can implement the method steps in the above-mentioned method embodiment.

[0531] Among them, the processor 2901 can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and can implement or execute the methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor 2901 can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware processor for execution, or can be executed by a combination of hardware and software modules in the processor.

[0532] The communication interface 2902 may be a transceiver, circuit, bus, module or other type of communication interface for communicating with other devices through a transmission medium. Exemplarily, when the device is a terminal, the other device may be a satellite, a gateway station or an ATG network device. When the device is a satellite, a gateway station or an ATG network device, the other device may be a terminal.

[0533] Optionally, the device 2900 may further include a memory 2903 for storing program instructions and / or data. Wherein, the memory 2903 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), etc., or a volatile memory (volatile memory), such as a random access memory 2903 (RAM). The memory is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present application may also be a circuit or any other device that can realize a storage function, for storing program instructions and / or data.

[0534] The memory 2903 may be coupled to the processor 2901. The coupling in the embodiment of the present application is an indirect coupling or communication connection between devices, units or modules, which may be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. The processor 2901 may operate in coordination with the memory 2903. The processor 2901 may execute program instructions stored in the memory 2903. At least one of the at least one memory 2903 may be included in the processor 2901.

[0535] It should be understood that the specific connection medium between the communication interface 2902, the processor 2901 and the memory 2903 is not limited in the embodiment of the present application. Fig.29 The memory 2903, the communication interface 2902 and the processor 2901 are connected via a bus. Fig.29The connections between the other components are shown in bold lines, which are only for illustration and are not intended to be limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.29 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0536] Fig.30 An apparatus 3000 provided in an embodiment of the present application can be used to execute the method executed by the first network device, the second network device, the ATG device or the terminal. The apparatus 3000 can be a communication device or a chip in the communication device. Fig.30 As shown, the device 3000 includes: at least one input interface (Input(s)) 3001, a logic circuit 3002, and at least one output interface (Output(s)) 3003.

[0537] Optionally, the above-mentioned logic circuit 3002 can be a chip, an encoder, an encoding circuit or other integrated circuit that can implement the method of the present application.

[0538] Since the specific methods and embodiments have been introduced above, the functions of the input interface 3001, the logic circuit 3002 or the output interface 3003 can refer to the relevant parts of the corresponding embodiments and will not be repeated here.

[0539] An embodiment of the present application provides a computer-readable storage medium, in which computer-readable instructions are stored. When the computer-readable instructions are executed on a communication device, the communication device executes the method executed by the above-mentioned first network device, second network device, ATG device or terminal.

[0540] An embodiment of the present application provides a computer program product, including instructions, which, when executed on a computer, enables the computer to execute the method executed by the above-mentioned first network device, second network device, ATG device or terminal.

[0541] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0542] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0543] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A communication method, It is characterized in that include: Acquire a common timing parameter, a first fixed value, and a second fixed value, wherein the first fixed value is acquired according to at least one of a timing advance command TAC or a media access control element MAC CE, and the second fixed value is acquired according to a radio resource control RRC message, or the second fixed value is a value agreed upon by a protocol; The timing advance TA is determined according to the common timing parameter, the first fixed value, the second fixed value and the round trip delay of the service link.

2. The method according to claim 1, It is characterized in that The timing advance is the sum of the round-trip delay of the service link, the common timing parameter, the first fixed value, and the second fixed value.

3. The method according to claim 2, It is characterized in that The round trip delay of the service link, the common timing parameter, the first fixed value and the second fixed value have the same time unit.

4. The method according to any one of claims 1 to 3, It is characterized in that The common timing parameters are carried in a radio resource control RRC message.

5. The method according to any one of claims 1 to 4, It is characterized in that The common timing parameter is obtained according to the system message SIB.

6. The method according to any one of claims 1 to 5, It is characterized in that The value of the second fixed value is related to the duplex mode.

7. The method according to any one of claims 1 to 6, It is characterized in that The round trip delay of the service link is determined according to the location of the terminal and the location of the satellite.

8. The method according to claim 7, It is characterized in that Also includes: The round trip delay of the service link is determined according to the position of the terminal and the position of the satellite.

9. The method according to any one of claims 1 to 8, It is characterized in that The TA is corrected based on the timing advance change rate TArate.

10. The method according to claim 9, It is characterized in that The TA is the sum of the timing advance before correction and the timing advance change rate TA rate*ΔT, where ΔT represents a time interval.

11. The method according to claim 9 or 10, It is characterized in that The TA rate is carried in a radio resource control RRC message.

12. The method according to any one of claims 1 to 11, It is characterized in that The terminal receives a validity period of the common timing parameter, and the common timing parameter is no longer applicable after the validity period.

13. A communication method, It is characterized in that include: determining a common timing parameter, a first fixed value and a second fixed value; sending the common timing parameter, the first fixed value, and the second fixed value; The first fixed value is carried in at least one of a timing advance command TAC or a media access control element MAC CE, and the second fixed value is carried in a radio resource control RRC message; the common timing parameter, the first fixed value, and the second fixed value are used to determine the timing advance TA.

14. The method according to claim 13, It is characterized in that The timing advance is the sum of the round trip delay of the service link, the common timing parameter, the first fixed value and the second fixed value.

15. The method according to claim 14, It is characterized in that The round trip delay of the service link, the common timing parameter, the first fixed value and the second fixed value have the same time unit.

16. The method according to any one of claims 13 to 15, It is characterized in that The common timing parameters are carried in a radio resource control RRC message.

17. The method according to any one of claims 13 to 16, It is characterized in that The common timing parameters are carried in the system message SIB.

18. The method according to any one of claims 13 to 17, It is characterized in that Also includes: The sending timing advance change rate TA rate is used to correct the TA.

19. The method according to claim 18, It is characterized in that The TA rate is carried in a radio resource control RRC message.

20. The method according to any one of claims 13 to 19, It is characterized in that Also includes: The validity period of the common timing parameters is sent, and the common timing parameters are no longer applicable after the validity period.

21. A communication device, It is characterized in that The method comprises a unit or a module for executing the method according to any one of claims 1 to 12.

22. A communication device, It is characterized in that The method comprises a unit or a module for executing the method according to any one of claims 13 to 20.

23. A communication device, It is characterized in that The device comprises a processor coupled to a memory storing a computer program, wherein the processor is configured to run the computer program so that the communication device executes the method according to any one of claims 1 to 12.

24. A communication device, It is characterized in that The device comprises a processor coupled to a memory storing a computer program, wherein the processor is configured to run the computer program so that the communication device executes the method according to any one of claims 13 to 20.

25. A computer-readable storage medium, It is characterized in that The computer storage medium stores computer-readable instructions, and when the computer-readable instructions are executed on a computer, the method described in any one of claims 1 to 12 is executed; or, the method described in any one of claims 13 to 20 is executed.

26. A computer program product comprising instructions, It is characterized in that When it is run on a computer, the method described in any one of claims 1 to 12 is executed; or, the method described in any one of claims 13 to 20 is executed.

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