A method of determining timing advance, a communication device

Abstract

The embodiment of the application provides a method for determining timing advance, and a communication device, which are used for improving the precision of terminal calculating timing advance (TA) and solving the problem of inter-symbol interference (ISI). The method comprises the following steps: a first network device determines a first parameter according to a first time delay compensation value, wherein the first time delay compensation value is a time delay compensation made by the first network device for receiving a signal sent by a terminal, the first parameter is used for indicating a difference value between a round-trip time delay of a feeder link in a non-terrestrial network (NTN) and the first time delay compensation value, and the difference value is used for determining a 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 of the original application with the application number 202011105020.7 and the original filing date of October 15, 2020, and the entire contents of the original application are incorporated herein by reference.

[0002] This application claims priority to the Chinese patent application No. 202010093795.0 filed on February 14, 2020, entitled “A method for determining timing advance, and a communication device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

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

[0004] For non-terrestrial network (NTN) communication, when a terminal sends a preamble, the terminal can receive a common timing advance value broadcast by a network device, and use the common timing advance value for timing advance (TA) to reduce the influence of the round-trip time 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 practical applications, the network device often makes a part of delay compensation for the round-trip time delay between the terminal and the network device, so the terminal actually needs to compensate for only a part of the common timing advance value. However, in the prior art, the terminal can only obtain the common timing advance value broadcast by the network device, and cannot calculate the accurate TA, so there is still serious ISI in the random access preamble. SUMMARY

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

[0007] In a first aspect, embodiments of the present application provide a method for determining TA, comprising: a first network device determining a first parameter according to a first delay compensation value, wherein the first delay compensation value is a delay compensation made by the first network device for receiving a signal sent by a terminal, the first parameter is used to indicate a difference between a round-trip time 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 for sending a signal; and the first network device sending the first parameter.

[0008] In the embodiment, 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 receives the first parameter and determines the TA according to the first parameter, the terminal considers the case that the first network device has performed a part of delay compensation on the signal sent by the terminal, so that the accuracy of the TA calculated by the terminal can be improved, and the ISI problem can be better improved.

[0009] In a possible implementation, 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 that 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] The embodiment provides two possible implementation manners of the first parameter, and improves the flexibility of the scheme.

[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 can be the position coordinates of the compensation reference point, wherein the difference is determined according to 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 according to the position coordinates of the compensation reference point and the position coordinates of the second network device.

[0012] Through the embodiment, the terminal only needs to determine the difference according to the position coordinates of the compensation reference point and the position coordinates of the second network device, a novel indication manner of the difference is provided, and the implementation on the terminal side is simple.

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

[0014] Through the embodiment, the terminal device can determine whether the first parameter is the difference or the position coordinates of the compensation reference point according to the first indication information, and then calculate the TA used for the sending signal by using the corresponding algorithm, so that the flexibility of the scheme is improved, and the reliability of the scheme is ensured.

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

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

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

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

[0019] In a possible implementation, the first network device can further send a second parameter, where the second parameter is used to indicate a common round-trip time delay of a service link of a coverage beam or a cell of the second network device.

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

[0021] In a possible implementation, the second parameter is used to indicate the common round-trip time delay of the service link of the coverage beam or the cell of the second network device, and includes:

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

[0023] The implementation provides two possible implementation manners of the second parameter, thereby improving the flexibility of the scheme.

[0024] In a possible implementation, the second parameter is used to determine a common round trip time of a serving link of a second network device covering a beam or a cell, and the second parameter is a location coordinate of a serving link reference point; wherein the common round trip time of the serving link is determined according to a round trip time between the serving link reference point and the second network device, and the round trip time between the serving link reference point and the second network device is determined according to the location coordinate of the serving link reference point and a location coordinate of the second network device.

[0025] Through the implementation, the terminal can determine the round trip time between the serving link reference point and the second network device according to the location coordinate of the serving link reference point and the location coordinate of the second network device, the implementation provides a novel indication manner for the common round trip time of the serving link of the second network device covering the beam or the cell, and the terminal side is simple to implement.

[0026] In a possible implementation, the first network device can send third indication information, and the third indication information is used to indicate that the second parameter is the common round trip time of the serving link or the location coordinate of the serving link reference point.

[0027] Through the implementation, the terminal device can determine, according to the third indication information, whether the second parameter is the common round trip time of the serving link or the location coordinate of the serving link reference point, and then calculate the TA used by the sending signal by using a corresponding algorithm, thereby improving the flexibility of the scheme while ensuring the reliability of the scheme.

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

[0029] Through the implementation, multiple implementation manners of the first network device sending the first parameter are provided, and the flexibility of the scheme is improved.

[0030] In a second aspect, the embodiments of the present application provide a method for determining TA, comprising: determining, by a second network device, a position coordinate of a compensation reference point according to a second time delay compensation value, the second time delay compensation value being a time delay compensation value made by the second network device for a signal transmitted by a terminal; wherein the second time delay compensation value is used to determine TA used by the terminal for transmitting the signal, and the TA is equal to a round-trip time delay of a service link in an NTN minus the second time delay compensation value; and transmitting, by the second network device, the position coordinate of the compensation reference point.

[0031] In the embodiments of the present application, since the position coordinate of the compensation reference point is determined by the second network device according to the second time delay compensation value, and the second time delay compensation value is a time delay compensation value made by the second network device for a signal transmitted by a terminal, when the terminal receives the position coordinate of the compensation reference point and determines the TA according to the position coordinate of the compensation reference point, the situation that the second network device makes a part of time delay compensation for the signal transmitted by the terminal is considered, so that the accuracy of the TA calculated by the terminal can be improved, and the ISI problem TA can be better improved.

[0032] In a possible implementation, the second network device can further transmit a second parameter, wherein the second parameter is used to indicate a common round-trip time 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 time delay of the service link of the beam or the cell covered by the second network device according to the second parameter, and then take the common round-trip time delay of the service link as the round-trip time delay of the service link between the terminal and the second network device, so that the terminal without positioning function can also accurately calculate the TA.

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

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

[0036] Through the embodiment, the terminal can determine the round trip delay between the serving link reference point and the second network device according to the position coordinates of the serving link reference point and the position coordinates of the second network device, the embodiment provides a novel indication manner for the common round trip delay of the serving link of the second network device coverage beam or cell, and the terminal side is simple to implement.

[0037] In a possible implementation, the second network device can further send third indication information, where the third indication information is used to indicate that the second parameter is the common round trip delay of the serving link or the position coordinates of the serving link reference point.

[0038] Through the embodiment, the terminal device can determine whether the second parameter is the common round trip delay of the serving link or the position coordinates of the serving link reference point according to the third indication information, and then calculate the TA used for sending a signal, thereby improving the flexibility of the scheme while ensuring the reliability of the scheme.

[0039] In a possible implementation, the second network device can carry the position coordinates of the compensation reference point in SIB1, OSI or MIB for sending; the second network device can further carry the position coordinates of the compensation reference point in RRC information, an RRC reconfiguration message, DCI, group DCI, a MAC element or TAC for sending in an RRC connection stage; and the second network device can further carry the position coordinates of the compensation reference point in an RRC reconfiguration message or BWP related signaling for sending when the terminal performs cell / beam / BWP switching.

[0040] Through the embodiment, multiple implementation manners of the second network device sending the position coordinates of the compensation reference point are provided, thereby improving the flexibility of the scheme.

[0041] In a third aspect, the embodiments of the present application further provide a method for determining TA, comprising: an ATG network device determining position coordinates of an ATG reference point, where the position coordinates of the ATG reference point are used to determine TA used by a terminal for sending a signal to the ATG network device; and the ATG network device sending the position coordinates of the ATG reference point.

[0042] In the embodiments of the present application, the ATG network device issues the position coordinates of the ATG reference point to the terminal, so that the terminal can calculate the TA used for sending a signal according to the position coordinates of the ATG reference point, and the ISI problem in ATG communication can be improved; and since the ATG network device tells the terminal the position coordinates of the ATG reference point instead of its own position coordinates, the position privacy of the ATG network device can be protected, and the security of ATG communication can be improved.

[0043] In a fourth aspect, an embodiment of the present application provides a method for determining TA, comprising: receiving, by a terminal, 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 a first network device for a signal sent by the terminal, and the difference being used to determine a TA used by the terminal for sending a signal; and determining, by the terminal, the TA used for sending the signal according to the first parameter.

[0044] In a possible implementation, 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 being the difference between the round-trip delay of the feeder link in the NTN and the first delay compensation value; or the first parameter being 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 a position coordinate of a compensation reference point, wherein the difference is determined according to a round-trip delay between the compensation reference point and a second network device, and the round-trip delay between the compensation reference point and the second network device is determined according to the position coordinate of the compensation reference point and a position coordinate of the second network device.

[0046] In a possible implementation, the method further comprises: receiving, by the terminal, first indication information, the first indication information being used to indicate that the first parameter is the difference or the position coordinate of the compensation reference point; and determining, by the terminal, the first parameter according to the first indication information, the first parameter being the difference or the position coordinate of the compensation reference point.

[0047] In a possible implementation, the method further comprises: receiving, by the terminal, second indication information, the second indication information being used to indicate that the difference is a positive value or a negative value; and determining, by the terminal, the difference according to the second indication information, the difference being the positive value or the negative value; wherein, when the difference is the positive value, the first delay compensation value is smaller than the round-trip delay of the feeder link or the compensation reference point is located on the feeder link; or when the difference is the 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 a service link in the NTN.

[0048] In a possible implementation, the TA is: a sum of a round trip delay of a serving link in the NTN and the difference value; or a sum of a round trip delay of a serving link in the NTN, the difference value, 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, the method further includes: receiving, by the terminal, a second parameter, wherein the second parameter is used to indicate a common round trip delay of a serving link of a beam or a cell covered by a second network device.

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

[0051] In a possible implementation, the second parameter is used to determine a common round trip delay of a serving link of a beam or a cell covered by a second network device, and the second parameter is a position coordinate of a serving link reference point; wherein the common round trip delay of the serving link is determined according to a round trip delay between the serving link reference point and the second network device, and the round trip delay between the serving link reference point and the second network device is determined according to the position coordinate of the serving link reference point and a position coordinate of the second network device.

[0052] In a possible implementation, the method further includes: receiving, by the terminal, third indication information, wherein the third indication information is used to indicate that the second parameter is a common round trip delay of the serving link or a position coordinate of the serving link reference point; and determining, by the terminal according to the third indication information, that the second parameter is the common round trip delay of the serving link or the position coordinate of the serving link reference point.

[0053] In a possible implementation, the first network device receives the first parameter, including: the terminal receives a system information block (SIB1), other system information (OSI) or a master system information block (MIB), wherein the SIB1, the OSI or the MIB carries the first parameter; or the terminal receives a radio resource control (RRC) information, an RRC reconfiguration message, a downlink control information (DCI), a group DCI, a medium access control (MAC) element or a timing advance command (TAC) in an RRC connection phase, wherein the RRC information, the RRC reconfiguration message, the DCI, the group DCI, the MAC element or the TAC carries the first parameter; or the first network device receives an RRC reconfiguration message or a BWP-related signaling when the terminal performs cell / beam / part-bandwidth (BWP) switching, wherein 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 a TA, including: a terminal receiving a position coordinate of a compensation reference point, wherein the second time delay compensation value is a time delay compensation value made by a second network device for a signal sent by a receiving terminal, the second time delay compensation value is used to determine a TA used by the terminal for sending a signal, and the TA is equal to a round-trip time delay of a service link in an NTN minus the second time delay compensation value; and the terminal determining the TA used for sending a signal according to the position coordinate of the compensation reference point.

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

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

[0057] In a possible implementation, the second parameter is used to determine a common round-trip time delay of a service link of a second network device covering a beam or a cell, and the second parameter is a position coordinate of a service link reference point; wherein the common round-trip time delay of the service link is determined according to a round-trip time delay between the service link reference point and the second network device, and the round-trip time delay between the service link reference point and the second network device is determined according to the position coordinate of the service link reference point and a position coordinate of the second network device.

[0058] In a possible implementation, the method further includes: receiving, by the terminal, third indication information, the third indication information being used to indicate that the second parameter is a common round trip delay of the service link or a position coordinate of the service link reference point; and determining, by the terminal, according to the third indication information, that the second parameter is the common round trip delay of the service link or the position coordinate of the service link reference point.

[0059] In a possible implementation, the terminal sending the position coordinate of the compensation reference point includes: receiving, by the terminal, a system information block (SIB) 1, other system information (OSI), or a master information block (MIB), wherein the SIB 1, the OSI, or the MIB carries the position coordinate of the compensation reference point; or receiving, by the terminal, radio resource control (RRC) information, an RRC reconfiguration message, downlink control information (DCI), group DCI, a medium access control (MAC) element, or a timing advance command (TAC) in an RRC connection phase, wherein the RRC information, the RRC reconfiguration message, the DCI, the group DCI, the MAC element, or the TAC carries the position coordinate of the compensation reference point; or receiving, by the terminal, an RRC reconfiguration message or a bandwidth part (BWP)-related signaling when performing cell / beam / BWP switching, wherein the RRC reconfiguration message or the BWP-related signaling carries the position coordinate of the compensation reference point.

[0060] In a sixth aspect, an embodiment of the present application provides a method for determining a TA, including: receiving, by a terminal, a position coordinate of an air-to-ground (ATG) reference point; and determining, by the terminal according to the position coordinate of the ATG reference point, a TA used for sending a signal.

[0061] In a seventh aspect, an embodiment of the present application provides a communication apparatus. The apparatus can be the first network device in the first aspect, or a device (for example, a chip, or a chip system, or a circuit) in the first network device, or an apparatus capable of being used in combination with the first network device. The apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the first aspect and any possible implementation of the first aspect, which can be a hardware circuit, software, or a combination of hardware circuit and software.

[0062] For example, the apparatus can include: a processing unit configured to determine a first parameter according to a first time delay compensation value, wherein the first time delay compensation value is a time 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 time delay compensation value, and the difference is used to determine a TA used by the terminal for sending a signal; and a sending unit configured to send the first parameter.

[0063] In an eighth aspect, an embodiment of the present application provides a communication apparatus. The apparatus can be the second network device in the second aspect, or a device (for example, a chip, or a chip system, or a circuit) in the second network device, or a device capable of being used in conjunction with the second network device. The apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the second aspect and any possible implementation manner of the second aspect. The module can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0064] For example, the apparatus can include a processing unit configured to determine a position coordinate of a compensation reference point according to a second time delay compensation value, the second time delay compensation value being a time delay compensation value made by the second network device for a signal transmitted by a terminal; wherein the second time delay compensation value is used to determine a TA used by the terminal for transmitting the signal, the TA being equal to a round-trip time delay of a service link in the NTN minus the second time delay compensation value; and a transmitting unit configured to transmit the position coordinate of the compensation reference point.

[0065] In a ninth aspect, an embodiment of the present application provides a communication apparatus. The apparatus can be the ATG network device in the second aspect, or a device (for example, a chip, or a chip system, or a circuit) in the ATG network device, or a device capable of being used in conjunction with the ATG network device. The apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the third aspect and any possible implementation manner of the third aspect. The module can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0066] For example, the apparatus can include a processing unit configured to determine a position coordinate of an ATG reference point, wherein the position coordinate of the ATG reference point is used to determine a TA used by a terminal for transmitting a signal to the ATG network device; and a transmitting unit configured to transmit the position coordinate of the ATG reference point.

[0067] In a tenth aspect, an embodiment of the present application provides a communication apparatus. The apparatus can be the terminal in the fourth aspect, or a device (for example, a chip, or a chip system, or a circuit) in the terminal, or a device capable of being used in conjunction with the terminal. The apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the fourth aspect and any possible implementation manner of the fourth aspect. The module can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0068] Exemplarily, the apparatus can comprise: 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 transmitted by a terminal, and the difference being used to determine a TA used by the terminal for transmitting the signal; and a processing unit configured to determine the TA used for transmitting the signal according to the first parameter.

[0069] In a eleventh aspect, an embodiment of the present application provides a communication apparatus. The apparatus can be the terminal in the fifth aspect, or a device (for example, a chip, or a chip system, or a circuit) in the terminal, or a device capable of being used in cooperation with the terminal. The apparatus can comprise a module corresponding to each of the steps in the method of the fifth aspect and any possible implementation manner of the fifth aspect. The module can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0070] Exemplarily, the apparatus can comprise: a receiving unit configured to receive a position coordinate of a compensation reference point, wherein the second delay compensation value is a delay compensation made by the second network device for a signal transmitted by a terminal, and the second delay compensation value is used to determine a TA used by the terminal for transmitting the signal, and the TA being equal to a round-trip delay of a service link in an NTN minus the second delay compensation value; and a processing unit configured to determine the TA used for transmitting the signal according to the position coordinate of the compensation reference point.

[0071] In a twelfth aspect, an embodiment of the present application provides a communication apparatus. The apparatus can be the terminal in the sixth aspect, or a device (for example, a chip, or a chip system, or a circuit) in the terminal, or a device capable of being used in cooperation with the terminal. The apparatus can comprise a module corresponding to each of the steps in the method of the sixth aspect and any possible implementation manner of the sixth aspect. The module can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0072] Exemplarily, the apparatus can comprise: a receiving unit configured to receive a position coordinate of an air-to-ground (ATG) reference point; and a processing unit configured to determine a TA used for transmitting a signal according to the position coordinate of the ATG reference point.

[0073] In a thirteenth aspect, an embodiment of the present application provides a communication apparatus, comprising a processor and a communication interface, wherein the communication interface is configured to communicate with other communication apparatuses; and the processor is configured to run a set of programs to implement the method in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, the sixth aspect, or any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or the sixth aspect.

[0074] In a fourteenth aspect, an embodiment of the present application provides a computer readable storage medium, having stored computer readable instructions, which when run on a communication apparatus, cause the method in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, the sixth aspect, or any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or the sixth aspect to be implemented.

[0075] In a fifteenth aspect, an embodiment of the present application provides a chip system, comprising a processor, and further comprising a memory, to implement the method in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, the sixth aspect, or 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 can be composed of a chip, or can comprise a chip and other discrete devices.

[0076] In a sixteenth aspect, an embodiment of the present application provides a computer program product, comprising instructions, which when run on a computer, cause the computer to perform the method in the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, the sixth aspect, or any possible implementation of the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, or the sixth aspect. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0079] Figure 3A And Figure 3B A schematic diagram for compensating reference points;

[0080] Figure 4 A schematic diagram for a common round-trip delay of a service link;

[0081] Figure 5Flow chart of another method for determining TA provided by an embodiment of the present application

[0082] Figure 6 Diagram for compensating for the round-trip delay between the reference point and the second network device

[0083] Figure 7 Flow chart of another method for determining TA provided by an embodiment of the present application

[0084] Figure 8 Network architecture diagram of an ATG communication system applicable to an embodiment of the present application

[0085] Figure 9 Flow chart of another method for determining TA provided by an embodiment of the present application

[0086] Figure 10 Network architecture diagram of an NTN applicable to an embodiment of the present application

[0087] Figure 11 Flow chart of another method for determining TA provided by an embodiment of the present application

[0088] Figures 12 to 16 Structure diagram of signaling issued by the network side to the terminal in an embodiment of the present application

[0089] Figure 17 Diagram for compensating for the reference point on the feeder link

[0090] Figure 18 Diagram for compensating for the reference point on the service link

[0091] Figures 19~23 Structure diagram of signaling issued by the network side to the terminal in an embodiment of the present application

[0092] Figure 24 Diagram for TA rate angle of the service link and / or TA rate angle of the feeder link

[0093] Figure 25 Structure diagram of a communication device 2500 provided by an embodiment of the present application

[0094] Figure 26 Structure diagram of a communication device 2600 provided by an embodiment of the present application

[0095] Figure 27 Structure diagram of a communication device 2700 provided by an embodiment of the present application

[0096] Figure 28 ​A structural schematic diagram of a communication apparatus 2800 provided for an embodiment of the present application is shown in FIG. 28.

[0097] Figure 29 A structural schematic diagram of a communication apparatus 2900 provided for an embodiment of the present application is shown in FIG. 29.

[0098] Figure 30 A structural schematic diagram of a communication apparatus 3000 provided for an embodiment of the present application is shown in FIG. 30. DETAILED DESCRIPTION

[0099] In order to realize global communication coverage of the fifth generation (5th generation, 5G) communication network, the 3rd generation partnership project (3rd generation partnership project, 3GPP) organization is studying the adaptation of the new radio (new radio, NR) protocol into non-terrestrial networks (non-terrestrial networks, NTN). The NTN communication includes satellite communication, air to ground (air to ground, ATG) communication, etc. Compared with the terrestrial communication, the NTN communication has different channel characteristics, such as large transmission delay, large doppler frequency offset, etc. For example, the round-trip delay of geostationary earth orbit (geostationary earth orbit, GEO) satellite communication (regenerative mode) is 238-270 ms. The round-trip delay of low earth orbit (low earth orbit, LEO) satellite communication (orbital height 1200 km, regenerative mode) is 8 ms-20 ms. For the ATG communication scenario, the maximum round-trip delay will also reach 1 ms.

[0100] Large round-trip delay can cause inter-symbol interference (ISI) of uplink signals, affecting the decoding performance of the network side. The terminal sends a random access preamble in the initial random access stage, and the network device returns a random access response (RAR). 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, but the round-trip delay in the NTN communication scenario is too large, and the CP cannot meet this requirement. Another possible solution is that the network device can indicate the timing advance (TA) value in the RAR when returning the random access response (RAR) to the terminal, so that the terminal uses the TA to perform timing advance, thereby reducing the timing difference between the network device and each terminal. However, the TA adjustment value currently indicated by the network device in the RAR ranges from 0 to 2 ms, and as the subcarrier spacing increases, the indication range of TA in the RAR will also be reduced by a factor of two. For the satellite communication scenario, the maximum 2ms indication range is not enough to indicate the length of the round-trip delay in the NTN communication scenario. If the TA indication range in the RAR is expanded, it will occupy more signaling overhead. 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 not enough to indicate the round-trip delay in the ATG communication scenario.

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

[0102] Currently, the scheme for the network device to inform the terminal of the common timing advance value includes the following two schemes:

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

[0104] The scheme is simple to implement, and the terminal can directly use the common timing advance value after receiving it. However, in actual application, the network device often compensates for a part of the time delay of the signal sent by the terminal, and the terminal actually only needs to compensate for a part of the time delay of the common timing advance value. The terminal with the positioning function can calculate the round-trip time delay between the terminal and the satellite, but cannot obtain the un-compensated part of the round-trip time delay value between the satellite and the gateway. The terminal with the positioning function cannot calculate the accurate TA according to the common timing advance value, and the terminal still has the ISI problem after sending the signal.

[0105] Scheme 2: The network device broadcasts two common timing advance values, one of which is the common timing advance value corresponding to the service link, and the other of which is the common timing advance value corresponding to the feeder link. The terminal performs timing advance on the service link according to the common timing advance value corresponding to the service link, and performs timing advance on the feeder link according to the common timing advance value corresponding to the feeder link.

[0106] This scheme clearly defines the two-part common timing advance of the service link and the feeder link, but if the network device compensates for the time delay of the signal sent by the terminal, and the time delay compensation is for the round-trip time delay of all feeder links and part of the service links, the terminal with the positioning function cannot calculate the accurate TA.

[0107] Embodiments of the present application provide a method for determining TA to improve the accuracy of the terminal calculating TA and improve the ISI problem. The method can be applied to a fourth generation (4th Generation, 4G) communication system, and can also be applied to a fifth generation (5th generation, 5G) communication system, device-to-device (Device-to-Device, D2D) communication, machine communication, or various communication systems in the future, such as a sixth generation (6th generation, 6G) communication system.

[0108] The method provided by the embodiments of the present application can be applied to a non-terrestrial network (NTN) communication system. Figure 1 A possible architecture of a terrestrial network communication system to which embodiments of the present application are applicable is shown. The communication system can be composed of a terminal (or user terminal, user equipment), a first network device, and a second network device. The communication link between the first network device and the second network device is a feeder link, and the communication link between the second network device and the terminal is a service link.

[0109] The terminal can be a wireless terminal device capable of receiving network device scheduling and indication information. It can be a device for providing voice and / or data connectivity to users, or a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. The wireless terminal device can communicate with one or more core networks or the Internet through a radio access network (RAN), and the wireless terminal device can be a mobile terminal device, such as a mobile phone (or called "cellular" phone, mobile phone), computer and communication chip, for example, it can be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that can exchange language and / or data with the radio access network. The terminal can 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 Pad, a computer with wireless transceiver function, and the like. The terminal can 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, an access terminal, a user terminal, a user agent, a subscriber station (SS), a customer premises equipment (CPE), a terminal, a mobile terminal (MT), and the like. The wireless terminal device can 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, and the like.

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

[0111] The second network device can be a satellite (or satellite base station), a geostationary earth orbit (GEO) satellite, a medium earth orbit (MEO) satellite of a non-geostationary earth orbit (NGEO), a low earth orbit (LEO) satellite, a high altitude platform station (HAPS), etc., which is not limited herein.

[0112] In the embodiments of the present application, the communication mode of the second network device can include two modes of regenerative mode and transparent mode.

[0113] When the communication mode of the second network device is the regenerative mode, the second network device can serve as a base station for wireless communication, for example, the second network device can be an artificial satellite and a high-altitude aircraft, etc., as a base station for wireless communication, for example, as an evolved base station (eNB) and a 5G base station (gNB), etc., and 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 mode, the first network device serves as a base station for wireless communication, and the second network device can serve as a relay for 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, and in actual use, multiple first network devices and / or one second network device architecture can be taken according to needs. 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 the present application.

[0116] Referring to Figure 2 A method for determining TA is provided in the embodiments of the present application, which can be applied to Figure 1 The communication system shown, wherein the communication mode of the second network device is the transparent mode.

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

[0118] The first time delay compensation value is time delay compensation made by the first network device for a signal sent by the terminal, or in other words, the first time delay compensation value is time delay compensation made by the first network device when receiving the signal sent by the terminal, in order to compensate for the timing difference caused by the service link round-trip time delay and the feeder link round-trip time delay. The time delay compensation here can be understood as a backward time delay operation on a receiving window by the first network device when receiving the signal sent by the terminal, and the size of the backward time delay of the receiving window is the first time delay compensation value. The sum of the round-trip time delay of the service link and the round-trip time delay of the feeder link should be greater than or equal to the first time 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 time delay of the feeder link in the non-terrestrial network (NTN) and the first time delay compensation value. One possible indication method is that the first parameter is the difference between the round-trip time delay of the feeder link and the time delay compensation value, and another possible indication method is that the first parameter is used to determine the difference between the round-trip time delay of the feeder link in the NTN and the time 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 the first parameter, and the terminal receives the first parameter.

[0121] Specifically, the first network device can 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 the TA used to send a signal according to the first parameter.

[0123] If the first parameter is the difference, the terminal can directly determine the TA used to send a signal according to the difference and the round-trip time delay of the service link, such as using the value obtained by subtracting the difference from the round-trip time delay of the service link as the TA used to send a signal.

[0124] If the first parameter is used to determine the TA used by the terminal to send a signal, the terminal needs to first determine the difference according to the first parameter, and then determine the TA used to send a signal according to the determined difference and the round-trip time 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 can be the position coordinates of the compensation reference point. Wherein, the difference is equal to the round trip delay between the compensation reference point and the second network device. The terminal device can determine the distance between the compensation reference point and the second network device according to the position coordinates of the compensation reference point and the position coordinates of the second network device, and then determine the round trip delay between the compensation reference point and the second network device according to 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 scheme, in specific implementation, the first parameter can be both the difference and the position coordinates of the compensation reference point. The first network device can send first indication information to the terminal, which is used to indicate whether the first parameter is the 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 according to the first indication information, and then use the corresponding algorithm to calculate the TA used by the sending signal.

[0128] As an optional implementation, the first network device can also send second indication information to the terminal, which is used to indicate whether the difference is positive or negative.

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

[0130] When the first parameter is the coordinates 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 represented by the positive or negative of the coordinates. Wherein, 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 positive; 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 negative. 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, which can be classified as the difference being positive or negative.

[0131] For example, referring to Figure 3A , a schematic diagram for the compensation reference point located on the feeder link. Wherein 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. InFigure 3A In the case shown, the difference value is positive.

[0132] For example, see Figure 3B , a schematic diagram for compensating the case where the reference point is located in the service link. Where 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. In Figure 3A In the case shown, B = -D2, and the difference value is negative.

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

[0134] As an optional implementation, the first network device can also not indicate the positive or negative of the difference value, but the terminal and the network device can be previously agreed that the difference value 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 agreed that the terminal receives the difference value and performs addition calculation or subtraction calculation on the received difference value.

[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 of the service link and the difference value; method 2, the sum of the round-trip delay of the service link in the NTN and the offset; method 3, the sum of the round-trip delay of the service link in the NTN, the difference value and the offset. 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 T. Among them, (NTA) is the TA adjustment value obtained by the terminal according to the parameters 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. (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 can allow the base station to have enough time to switch between receiving uplink signals and transmitting downlink signals. Ts represents 1 / (15e3 2048) seconds. μ is related to the subcarrier spacing, that is, the subcarrier spacing is kHz. Therefore, the TA calculated by the terminal according to the first parameter sent by the first network device in this solution can be added with a fixed value (for example, NTAoffset) and then used as the TA of the terminal for sending signals.

[0137] In the embodiments of the present application, the terminal can be a terminal with positioning function or a terminal without positioning function, which is not limited in the present application.

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

[0139] For the terminal without positioning function, the network device can issue a second parameter, wherein the second parameter is used to indicate the common round-trip delay of the service link of the second network device coverage beam or cell. In one possible indication manner, the second parameter is the common round-trip delay of the service link of the second network device coverage beam or cell. In another possible indication manner, the second parameter is used to determine the common round-trip delay of the service link of the second network device coverage beam or cell. Further, the terminal can take the common round-trip delay of the service link as the round-trip delay of the service link between the terminal and the second network device. For example, see Figure 4 The round-trip delay between the reference point closest to the second network device in the second network device coverage beam or cell and 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 coverage 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] To improve the flexibility of the scheme, in implementation, the second parameter can be either the common round-trip delay of the service link or the location coordinate of the service link reference point. For example, in the non-staring mode of satellite communication, the coverage area of the beam / cell of the satellite moves with 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 is constant, and the round-trip delay is constant. Sending the common round-trip delay of the service link to the UE can avoid frequent conversion of the location coordinate of the service link reference point sent, and can reduce the complexity of the system. In the staring mode of satellite communication, the service link reference point is constant during the time when the beam / cell continuously covers a certain area, so sending the location coordinate 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 can send third indication information to the terminal, for indicating whether the second parameter is the common round-trip delay of the service link or the location coordinate of the service link reference point. In this way, the terminal device can determine, according to the third indication information, whether the second parameter is the common round-trip delay of the service link or the location coordinate of the service link reference point, and then calculate the TA used for sending the signal by using the algorithm corresponding to the determined common round-trip delay of the service link or the location coordinate of the service link reference point.

[0143] As an optional implementation, the first indication information and / or the second indication information are contained 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 embodiments of the present application, the first network device can send the above-mentioned parameters (including the first parameter / second parameter) and / or indication information (including the first indication information / second indication information / third indication information) to the terminal by the following ways:

[0144] Way 1: The above-mentioned parameters and indication information are carried in broadcast information such as system information block (SIB) 1, other system information (OSI), or master information block (MIB), and are sent to the terminal by unicast, broadcast, or groupcast.

[0145] Manner 2: The first network device carries the above-mentioned parameters and indication information in the RRC information, RRC reconfiguration message, DCI, group DCI, MAC element or TAC in the RRC connection stage and sends them to the terminal, or sends them to the UE with data transmission or in a separately allocated PDSCH bearer.

[0146] Manner 3: The first network device can send the above-mentioned parameters and indication information in the RRC reconfiguration message or BWP related signaling when the terminal performs cell / beams / BWP switching.

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

[0148] In the above-mentioned solution, 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, so the terminal determines the TA used for sending the signal according to the first parameter, which takes into account the case that the first network device has made a part of delay compensation for the signal sent by the terminal, so the terminal can calculate a more accurate TA, which can improve the ISI problem.

[0149] Referring to Figure 5 Another method for determining TA provided by the embodiments of the present application can be applied to Figure 1 The communication system shown in FIG. 1, wherein the communication mode of the second network device is the regeneration mode.

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

[0151] The second time delay compensation value is a time delay compensation value made by the second network device for a signal sent by the terminal, and can be equal to a round-trip time delay between the compensation reference point and the second network device. In other words, the second time delay compensation value is a time delay compensation made by the second network device when receiving the signal sent by the terminal, in order to compensate for the timing difference caused by the round-trip time delay of the service link. The time delay compensation here can be understood as a backward time delay operation made by the second network device on a receiving window when receiving the signal sent by the terminal, and the size of the backward time delay of the receiving window is the second time delay compensation value. The round-trip time delay of the service link should be greater than or equal to the second time 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 a signal according to the position coordinates of the compensation reference point.

[0154] Specifically, the terminal calculates the round-trip time delay between the compensation reference point and the second network device according to the position coordinates of the compensation reference point, and then obtains the second time delay compensation value; and then determines the TA used for sending a signal according to the round-trip time delay of the service link and the second time delay compensation value. For example, referring to Figure 6 , the position coordinates of the compensation reference point are located on the service link, the round-trip time delay B between the compensation reference point and the second network device represents the time delay compensation value made by the second network device for a signal sent by the terminal, and then the TA used for sending a signal by the terminal can be equal to the round-trip time delay of the service link minus the second time delay compensation value, i.e. A-B.

[0155] Similar to the above transparent mode, in the regeneration mode, the terminal can be a terminal with positioning function or a terminal without positioning function, which is not limited by the present application. For the terminal with positioning function, such terminal can calculate the distance between itself and the second network device based on the positioning function, and then calculate the round-trip time delay between itself and the second network device, and take it as the round-trip time delay of the service link. For the terminal without positioning function, the second network device can issue a second parameter, wherein the second parameter is the common round-trip time delay of the service link of the second network device coverage beam or cell, or the second parameter is used to determine the common round-trip time delay of the service link of the second network device coverage beam or cell. Such terminal can take the common round-trip time delay of the service link as the round-trip time delay of the service link between itself and the second network device. The specific implementation of the second parameter can refer to the specific implementation of the second parameter in the above transparent mode, which will not be described here.

[0156] Similarly, in the regeneration mode, the second network device can also send third indication information to the terminal, 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 position coordinates of the service link reference point.

[0157] Similarly, in the regeneration mode, the second network device can also send third indication information to the terminal, 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 position coordinates of the service link reference point.

[0158] In an alternative implementation, the second network device can directly send the second delay compensation value to the terminal, so that the terminal directly calculates the TA used for sending signals 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, it takes into account the case that the network side has made a part of delay compensation on the signal sent by the terminal, so the terminal can calculate a more accurate TA, thereby improving the ISI problem.

[0160] In the embodiments of the present application, the terminal can not distinguish between the regeneration mode and the transparent mode, or in other words, the terminal regards the first network device and the second network device as a whole (network side). After the terminal receives the parameters (such as the position coordinates of the compensation reference point, the difference value, 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 signals based on the received parameters, that is, Figure 5 and Figure 2 The two schemes shown in FIGS. 10 and 11 can be combined into one scheme.

[0161] For example, referring to Figure 7 Another method for determining TA provided by the embodiments of the present application can be applied to the communication system shown in FIG. 12. Figure 1

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

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

[0164] S702, the terminal determines the TA used by the sending 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 taken positive or negative according to the second indication information, and then the sum or difference of the round trip time delay of the service link is calculated to determine the TA used by the sending signal; if the third parameter is a second time delay compensation value, the second time delay compensation value is taken positive or negative according to the second indication information, and then the sum or difference of the round trip time delay of the service link is calculated to determine the TA used by the sending signal; if the third parameter is a position coordinate of the compensation reference point, the difference value or the second time delay compensation value is determined according to the position coordinate of the compensation reference point, and then the difference value or the second time delay compensation value is taken positive or negative according to the second indication information, and finally the sum or difference of the round trip time delay of the service link is calculated to determine the TA used by the sending signal.

[0166] It should be understood that the above Figure 2 or Figure 5 Various possible implementations in the method embodiments shown can be referred to in the method embodiments. For example, for a terminal without positioning function, the position coordinate of the service link reference point can also be received from the network side, and then the round trip time delay between the service link reference point and the second network device, i.e., the common round trip time delay of the service link, is determined according to the position coordinate of the service link reference point and the position coordinate of the second network device. Such a terminal can take the common round trip time delay of the service link as the round trip time delay of the service link between itself and the second network device. For a terminal with positioning function, the distance between itself and the second network device can be calculated based on the positioning function, and then the round trip time delay between itself and the second network device is calculated and taken as the round trip time delay of the service link. For specific methods, refer to the relevant parts described above, which will not be described here.

[0167] In the embodiments of the present application, the terminal does not need to distinguish (or need not know) whether the second network device is in transparent mode or regeneration mode, and the terminal can also calculate an accurate TA, i.e., the terminal receives the parameters and directly calculates the TA used by the sending signal according to the parameters, which reduces the difficulty of implementation on the terminal side.

[0168] The scheme of broadcasting a common timing advance value in the prior art is generally used in a satellite communication system. For an ATG communication system, since the coverage range of an ATG network device (generally at a height of 6-12 km and a diameter of about 100-300 km) is large, the round-trip delay of terminals and the ATG network device at different positions in the coverage range of the ATG network device is large, and therefore the scheme of broadcasting a common timing advance value is not applicable to the ATG communication.

[0169] Therefore, the embodiments of the present application further provide a method for determining a TA, to enable a terminal in an ATG network to determine a TA used for sending a signal.

[0170] The scheme can be applied to an ATG communication system. For example, Figure 8 A network architecture diagram of an ATG communication system to which the embodiments of the present application are applicable. The ATG communication system includes an air-to-ground ATG network device and a terminal, where the ATG network device includes a ground base station, and the terminal includes a high-altitude mobile terminal, such as a high-altitude aircraft. Referring to Figure 9 The method includes the following steps.

[0171] S901, the ATG network device determines a position coordinate of an ATG reference point.

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

[0173] S902, the ATG network device sends the position coordinate of the ATG reference point to the terminal.

[0174] The specific implementation of the ATG network device issuing the position coordinate of the ATG reference point can refer to the specific implementation of the first network device or the second network device issuing the position coordinate of the compensation reference point or the service link reference point, which is not described herein again.

[0175] S903, the terminal determines a TA used for sending a signal to the ATG network device according to the position coordinate of the ATG reference point.

[0176] Specifically, the terminal calculates a round-trip delay between the ATG reference point and itself according to the position coordinate of the ATG reference point and the position coordinate of the terminal, and determines the round-trip delay as the TA used for sending a signal to the ATG network device, or adds an offset to the round-trip delay to obtain the TA used for sending a signal to the ATG network device.

[0177] In the above scheme, the ATG network device sends the position coordinates of the ATG reference point to the terminal, so that the terminal can calculate the TA used for sending signals according to the position coordinates of the ATG reference point; and since the ATG network device tells the terminal the position coordinates of the ATG reference point instead of its own position coordinates, the position privacy of the ATG network device can be protected, and the security of the 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.

[0179] Referring to Figure 10 An NTN network architecture diagram applicable to the embodiments of the present application is shown, which includes devices in the satellite communication system (such as satellites, gateway stations, terminals, etc.) and devices in the ATG communication system (such as base stations, terminals, etc.).

[0180] Referring to Figure 11 Another method for determining TA provided by the embodiments of the present application can be applied to Figure 10 the communication system shown.

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

[0182] The network side can 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 can 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, used for such terminals 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 at a certain point within the coverage of a beam / cell, can be selected at a certain point on the horizontal plane or at a fixed height above the horizontal plane, and can be determined according to the network deployment requirements.

[0184] Compensation reference point: 1) when the compensation reference point is on the feeder link, the round-trip delay between the gateway and the compensation reference point is the time delay compensation value made by the network side to the uplink signal (i.e., the first time delay compensation value in the foregoing); 2) when the compensation reference point is on the service link, for the transparent mode, the round-trip delay between the gateway-satellite-compensation reference point is the time delay compensation value made by the network side to the uplink signal (i.e., the first time delay compensation value in the foregoing); for the regenerative mode, the round-trip delay between the satellite-compensation reference point is the time delay compensation value made by the network side to the uplink signal (i.e., the second time delay compensation value in the foregoing). The compensation reference point can be selected on the service link or the feeder link, and can be determined according to the time delay compensation value made by the network side to the signal sent by the terminal.

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

[0186] S1102, the terminal determines the TA used by the terminal according to the at least one parameter.

[0187] In a possible implementation, the terminal (for example, an aircraft or a ground mobile terminal) can perform the following calculation according to the received reference point coordinates:

[0188] 1) calculating the round-trip delay value (or the timing advance adjustment value) of the service link according to the satellite position (obtained from the ephemeris or satellite coordinates) and the service link reference point: A, A is a positive number. In the following description, A can be referred to as the common timing advance value of the service link for ease of description.

[0189] 2) calculating 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 on the feeder link, B is a positive value; if the compensation reference point is on the service link, B is a negative value; the positive or negative value of B can be indicated to the UE through the second indication information described above.

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

[0191] In the following description, B can be referred to as the common compensation timing advance value for ease of description.

[0192] 3) calculating the round-trip delay value between the terminal and the ATG reference point according to the terminal position and the ATG reference point: C, C is a positive number.

[0193] In another possible implementation, the network side can also directly send A, B or C, i.e., at least one of the parameters can include A, B or C. For example, the network side issues B without issuing the compensation reference point coordinate.

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

[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 the 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 the TA according to A and B, such as: TA = A + B.

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

[0199] The terminal can calculate the TA according to C, such as: TA = C.

[0200] In the following, several specific embodiments are used to introduce the specific implementation of the method in detail. Figure 11

[0201] Embodiment 1

[0202] The base station can send the reference point coordinate to the terminal in a broadcast, multicast or unicast manner. Referring to Figure 12 , a possible reference point coordinate signaling diagram provided for the embodiments of the present application.

[0203] The reference point coordinate can be in the same coordinate system as the satellite or a relative coordinate, for example, the service link reference point coordinate and the compensation reference point coordinate can be coordinates relative to the coordinate position of the satellite, i.e., taking the satellite as the coordinate origin.

[0204] The compensation reference point coordinate parameter can carry a positive-negative indication bit to indicate whether the positive value or the negative value is used when calculating the round-trip time delay between the second network device and the compensation reference point. For example, the positive-negative indication bit 0 represents a negative value and 1 represents a positive value. If the compensation reference point coordinate and the satellite coordinate calculate the round-trip time delay as x seconds, and the positive-negative indication bit is 0, then B = -x in the scheme.

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

[0206] ​1) ATG reference point coordinates can be set to zero, or ATG reference point coordinates are not sent.

[0207] 2) Compensation reference point coordinates can be sent or set to zero according to whether the network side compensates for the signals sent by the terminal. For example, if the network side does not compensate for the time delay of the signals sent by the terminal, compensation reference point coordinates can not be sent, or compensation reference point coordinates are set to zero.

[0208] 3) Compensation reference point coordinates can be sent or set to zero according to whether the satellite communication is a transparent mode or a regenerative mode. For example, when the satellite is in a transparent mode, even if the network side does not compensate for the time delay of the signals sent by the terminal, compensation reference point coordinates need to be sent 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 coordinates of the gateway station, and the terminal can calculate the round-trip delay value of the feeder link according to the compensation reference point coordinates and the satellite coordinates, and the round-trip delay value of the service link to obtain the complete communication link round-trip delay, which is used as the timing advance adjustment value of the terminal sending signals. When the satellite works in a regenerative mode, if the network side does not compensate for the time delay of the signals sent by the terminal, compensation reference point coordinates can not 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 can be set to zero, or the service link reference point coordinates and the compensation reference point coordinates are not sent.

[0211] 2) If the network side compensates for the time delay of the signals sent by the terminal in the ATG communication scenario, compensation reference point needs to be sent to inform the terminal of the time delay compensation value of the signals 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 the satellite communication scenario and the ATG communication scenario exist at the same time, the network side and the terminal can simultaneously perform the operations of the network side and the terminal in the above-mentioned ATG communication scenario and ATG communication scenario. The specific implementation method can be referred to the above-mentioned satellite communication scenario and ATG communication scenario, which will not be described here.

[0213] In one possible design, the smallest coordinate granularity or unit for the serving link reference point coordinates, compensation reference point coordinates, and ATG reference point coordinates is based on meters (m). In another possible design, combinations of several length units can be used, such as a combination of km and m, to save signaling overhead. If a single length unit is used to represent the three-dimensional coordinates of the serving link reference point as (10300m, 9600m, 10070m), then representing the three numbers 10030, 9600, and 10070 requires 42 bits. Using a combination of km and m, it can be represented as (10km+300m, 9km+600m, 10km+70m), requiring the transmission of the numbers 10, 300, 9, 600, 10, and 70, occupying 39 bits. Using combinations of multiple length units can save signaling overhead.

[0214] To further reduce signaling overhead, one possible design is to transmit reference point coordinates using the satellite orbital altitude H as the reference length. For example, if the network sends reference point coordinates (a, b, c) to the terminal, the terminal can calculate the reference point coordinates to be used based on (a+H, b+H, c+H). Alternatively, the satellite coordinates can be used as the reference point for transmission. For example, if the satellite coordinates are (x, y, z), and the network sends reference point coordinates (a, b, c) to the terminal, 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 both satellite communication and ATG communication scenarios, and supports both terminals with and without positioning functions in determining the reference point coordinate (TA), thus saving signaling bits.

[0216] Example 2

[0217] See Figure 13 This is a schematic diagram of another possible reference point coordinate signaling provided in an embodiment of this application. It differs from Embodiment 1 in that: Figure 13 The signaling shown includes an added satellite communication / ATG communication scenario indication bit, used to indicate which scenario the reference point coordinates sent by the network side are applicable to. For example, it indicates to the terminal that the transmitted signaling is serving link reference point coordinates, compensation reference point coordinates, ATG reference point coordinates, or other combinations.

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

[0219] Example 3

[0220] Unlike Embodiment 1 or Embodiment 2 above, this embodiment replaces one or more reference point coordinates with a common timing advance value, that is, it uses both the common timing advance and the reference point coordinates. (For ease of description, the service link common timing advance value, the common compensation timing advance value, and the ATG common timing advance value can be collectively referred to as the common timing advance value, and the service link reference point, compensation reference point coordinates, and coordinate ATG reference point coordinates can be referred to as the reference point coordinates.)

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

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

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

[0224] The relationship between the common compensation timing advance and the compensation reference point can be: the common compensation timing advance is equal to the round-trip time 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 is used with a positive value, corresponding to... Figure 14D The positive and negative indicator bits are positive. 2) When the compensation reference point is on the service link, the common compensation timing advance value is negativeed before use, corresponding to... Figure 14D The positive / negative indicator bit is negative.

[0225] It should be noted that if the compensation reference point is always on the power supply link or the compensation for the signal delay sent by the terminal from the network side is no greater than the round-trip delay of the power supply link, then the round-trip delay or common compensation timing advance value calculated using the compensation reference point will always be a positive value. Therefore, the positive / negative indicator bit of the compensation reference point or common compensation timing advance value can be omitted, i.e., it defaults to a positive value. Alternatively, if the compensation reference point is always on the service link or the compensation for the signal delay sent by the terminal from the network side is no less than the round-trip delay of the power supply link, then the network side and the terminal agree that the round-trip delay or common compensation timing advance value calculated using the compensation reference point used by the terminal will always be a negative value. Therefore, the positive / negative indicator bit of the compensation reference point or common compensation timing advance value can also be omitted, i.e., it defaults to a negative value. The method of this embodiment applies to all embodiments herein.

[0226] In an optional embodiment, the service link common timing advance value / service link reference point coordinates and the common compensation timing advance value / compensation reference point coordinates can be used in combination for scenarios where the ATG reference point is not required to be transmitted.

[0227] Referring to Figure 14E In non-gazing communication, the service link common timing advance value and the common compensation timing advance value / compensation reference point coordinates are used in combination to reduce the complexity of system transmission signaling. In gazing mode, the service link reference point coordinates and the common compensation timing advance value / compensation reference point coordinates are used in combination to reduce the complexity of system transmission signaling. This is because in gazing mode, the service link reference point is constant during the period of time when the beam / cell continuously covers a certain area, and the service link reference point coordinates transmitted by the network side to the terminal do not need to be changed. The selection 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 transmitted by the terminal and whether the compensation value is fixed, which will not be described here.

[0228] In summary, the reasonable use 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 system transmission signaling.

[0229] In an optional embodiment, if it is a satellite communication scenario, the ATG reference point coordinates / ATG common timing advance value can be set to zero or not transmitted. 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 can be set to zero or not transmitted.

[0230] In an optional embodiment, 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, to fall back to the default coordinates of the satellite, i.e., the common compensation timing advance value is 0.

[0231] In an optional embodiment, 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 20.77 ms, when only the ms unit dimension is used, 12 bits are required to represent it. If the frame length (10 milliseconds) and the subframe length (1 millisecond) dimensions are used to jointly represent it: frame length + 0.77 subframe length. The network side only needs 9 bits 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: Ts + b Ts 10^3, only a and b need to be sent to the terminal.

[0232] In this embodiment, the terminal replaces the transmission of the reference point coordinates with the common timing advance value. For some scenarios, using the common timing advance value to replace the reference point coordinates can reduce the complexity of signaling and updating. For example, in the non-staring mode of satellite communication, the coverage area of the beam / cell moves with 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 is constant, and the round-trip delay is constant. In this case, the terminal is sent the service link common timing advance value instead of the service link reference point coordinates, which can avoid frequent changes in the transmitted service link reference point coordinates and reduce system complexity.

[0233] Embodiment 4

[0234] This embodiment is based on embodiment 3, and adds a satellite communication / ATG communication scenario indication bit to indicate the scenario to which the reference point coordinates transmitted by the network side apply.

[0235] For example, referring to Figure 15A 、 Figure 15B The communication scenario indication 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 multiplex the same signaling bit, which can reduce the signaling overhead of the entire NTN system.

[0237] Embodiment 5

[0238] Referring to Figure 15C , this embodiment can be based on embodiment 3, and a indication bit is 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 to inform the terminal in the form of a common timing advance value or in the form of a reference point coordinate according to whether the satellite is in a staring mode and whether the network side compensates for the time delay of the signal transmitted by the terminal, which can improve the flexibility of the system.

[0239] Similarly, an indication bit can also 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. This provides flexibility for the network side to configure signaling.

[0240] Referring to Figure 15DFor the scenario that the ATG reference point does not need to be transmitted, the combination of the serving link common timing advance value / serving link reference point coordinate and the common compensation timing advance value / compensation reference point coordinate can be separately transmitted.

[0241] Embodiment 6

[0242] This embodiment is based on Embodiment 5, and adds a satellite communication / ATG communication scenario indication bit to indicate that the reference point coordinate transmitted by the network side is applicable to a scenario.

[0243] For example, referring to Figure 16 The communication scenario indication bit indicates to the terminal that the transmitted signaling can be the serving link common timing advance value / serving link reference point coordinate, the common compensation timing advance value / compensation reference point coordinate, or the ATG reference point coordinate, or other combinations.

[0244] Through this embodiment, the satellite communication and ATG communication scenarios can multiplex the same signaling bit, and the signaling overhead can be reduced.

[0245] Embodiment 7

[0246] This embodiment provides that the network side indicates to the terminal the positive and negative of the common compensation timing advance value / compensation reference point coordinate by implicit indication (i.e., to indicate whether the value is positive or negative when using this part of the value).

[0247] In an optional implementation, the compensation reference point coordinate is represented in relative coordinates. For example, the compensation reference point coordinate is represented in coordinates relative to the satellite position, i.e., with the satellite as the coordinate system origin. If the compensation reference point coordinate is above the satellite, it represents a positive value, and if it is below the satellite, it represents a negative value.

[0248] In another optional implementation, the positive and negative of a certain dimension of the three-dimensional coordinates of the compensation reference point is used to represent whether the round-trip delay calculated using the compensation reference point is positive or negative. For example, the network side transmits to the terminal the coordinates of the compensation reference point as (-501km, 580km, 520km), and the network side and the terminal agree that the positive and negative of the first dimension value of the coordinate point represents whether the calculated round-trip delay is positive or negative, and then the terminal calculates the round-trip delay as a negative value according to the reference point coordinate (-501km, 580km, 520km).

[0249] Through this embodiment, the network side can not need to additionally indicate the positive and negative of the common compensation timing advance value / compensation reference point coordinate by signaling, and the signaling overhead can be saved.

[0250] Embodiment 8

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

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

[0253] Because the terminal with positioning function can calculate the round-trip delay of the service link according to its own position and the position of the satellite (the terminal can obtain the position of the satellite from ephemeris information), the common round-trip delay value of the service link indicated by the service link common timing advance value / service link reference point coordinates is not needed. The terminal with positioning function or the satellite cannot obtain the round-trip delay of the feeder link according to ephemeris information. If the network side compensates for the propagation delay of the signal sent to the terminal, the terminal cannot obtain the network side delay compensation value. 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 position information of the satellite.

[0254] For example, the signaling sent by the network side to the terminal only needs to have a common compensation timing advance value / compensation reference point coordinate parameter (including positive and negative indication bits). Alternatively, the signaling sent by the network side to the terminal only needs to have a common compensation timing advance value / compensation reference point coordinate parameter (including positive and negative indication bits), and ATG reference point coordinates. Figure 17If the compensation value of the propagation delay compensation made by the network side to the signal transmitted by the terminal is less than the round-trip delay of the feeder link or the compensation reference point is on the feeder link, the remaining propagation delay value after the delay compensated by the network side is subtracted in the feeder link can be represented by using the common compensation timing advance value. For example, if the propagation round-trip delay of the feeder link is a (i.e. the signal propagation round-trip delay between the satellite and the gateway station is a), the propagation delay compensation value of the network side to the feeder link is b (i.e. the round-trip delay between the gateway station and the compensation reference point is b), the common compensation timing advance value sent by the network side to the terminal is equal to a-b (i.e. the round-trip delay between the satellite and the compensation reference point is a-b). Alternatively, the network side can send the terminal the common compensation timing advance value of (a-b) / 2 (signaling overhead can be saved), i.e. the remaining propagation delay value after the one-way propagation delay of the feeder link is subtracted by the one-way delay compensated by the network side. When the terminal receives the common compensation timing advance value of (a-b) / 2, it is multiplied by 2 and then used. At this time, the positive and negative indication bit of the common compensation timing advance value indicates the positive sign, i.e. indicates that the subsequent operation is an addition operation. Then, the terminal adds the common compensation timing advance value (i.e. the value equal to a-b) to the service link round-trip delay value calculated by the terminal to obtain the TA for timing advance adjustment of the signal transmitted by the terminal. Similarly, the network side can send the compensation reference point coordinates, and the positive and negative indication bit indicates the positive sign. The terminal calculates the round-trip delay between 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 indication bit to obtain the TA that can be used by the terminal.

[0255] As Figure 18As shown, when the compensation value of the propagation delay compensation made by the network side to 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, i.e. the network side compensates the propagation round trip delay of the feeder link and the partial propagation round trip delay of the service link (the round trip delay of the gateway station-satellite-compensation reference point), then the common compensation timing advance value can be used to represent the compensation of the partial propagation round trip delay of the service link by the network side (i.e. 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, i.e. the common compensation timing advance value is d. Alternatively, in order to save signaling overhead, the common compensation timing advance value is d / 2, and the terminal receives d / 2 and then multiplies it by 2 for subsequent operations. At this time, the positive and negative indication bits of the common compensation timing advance value indicate the negative sign, i.e. the subsequent operation is a subtraction operation. Then, the terminal subtracts the common compensation timing advance value (i.e. the value equal to d) from 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 compensation reference point coordinates, and the positive and negative indication bits indicate the negative sign. The terminal calculates the round trip delay between the satellite position and the reference point position, and then subtracts the common compensation timing advance value from the calculated service link round trip delay value according to the negative sign indicated by the positive and negative indication bits to obtain the TA that can be used by the terminal.

[0256] Embodiment 9

[0257] As described in embodiments 2, 4, 6, when the network side indicates by the indication bits 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 inform the terminal of the reference point coordinates and the composition of the timing advance signaling in the form of a lookup table.

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

[0259] Table 1 Reference point coordinate and timing advance signaling composition table

[0260]

[0261] As an example, referring to Table 2, for the case that the terminal does not need the ATG reference point coordinates, the table can be further reduced to save the signaling overhead of the index number. For example, when the terminal receives the index number 3, it indicates 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 and timing advance signaling composition Table 2

[0263]

[0264] It should be noted that if the compensation reference point is always on the feeder link or the compensation of the signal delay sent by the network side to the terminal is not greater than the round-trip delay of the feeder link, the round-trip delay calculated using the compensation reference point or the common compensation timing advance value will always be positive, and therefore the positive and negative indication bit of the compensation reference point or the common compensation timing advance value can be omitted, i.e., the default is positive. Alternatively, if the compensation reference point is always on the service link or the compensation of the signal delay sent by the network side to the terminal is not less than the round-trip delay of the feeder link, the network side and the terminal agree that the round-trip delay calculated using the compensation reference point or the common compensation timing advance value by the terminal will always be negative. Therefore, the positive and negative indication bit of the compensation reference point or the common compensation timing advance value can be omitted, i.e., the default is negative.

[0265] As described in Embodiment 8, for the terminal with positioning function, only the common compensation timing advance value or the compensation reference point coordinate parameter needs to be sent to it. Correspondingly, referring to Table 3, if the terminal receives the index number 1, it indicates that the signaling received by the terminal is the compensation reference point coordinates.

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

[0267]

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

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

[0270] Embodiment 10

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

[0272] Manner 1: The network device can carry the serving link common timing advance value of the target cell / beam, the serving link reference point coordinates, the common compensation timing advance value / compensation reference point coordinates, the ATG reference point coordinates, and other parameters in the broadcast information of SIB1, OSI, MIB, etc. The network device sends the parameters to the terminal by unicast, broadcast or groupcast.

[0273] Manner 2: If sent in the RRC connection stage, the network device can carry these parameters in at least one of the RRC information, RRCReconfiguration message, DCI, group DCI, MAC element, TAC, or send the parameters to the terminal with data transmission or in a separately allocated PDSCH carrying.

[0274] Manner 2: When the terminal occurs cell / beam / BWP switching, the network device can send these parameters to the terminal in the RRC Reconfiguration message, BWP related signaling.

[0275] For example, when beam or BWP inter-switching occurs:

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

[0277] BWP ::= SEQUENCE {

[0278] locationAndBandwidth INTEGER (0..37949),

[0279] subcarrierSpacing SubcarrierSpacing,

[0280] cyclicPrefix ENUMERATED { extended} OPTIONAL

[0281] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList

[0282] }

[0283] Among them, the “ ReferencePointCoordinateGroup ” field can be used for the parameters involved in embodiments 1-9, including reference point coordinates, common timing advance value, etc. ReferencePointCoordinateGroupList The “ ” field represents the specific value of the reference point coordinates, common timing advance value, etc.

[0284] If in other non-initial BWP stage, the parameters are issued in BWP-DownlinkCommon signaling or BWP-UplinkCommon signaling, and the signaling format in non-initial BWP stage can be as follows:

[0285] BWP-DownlinkCommon ::= SEQUENCE {

[0286] genericParameters BWP,

[0287] pdcch-ConfigCommon SetupRelease { PDCCH-ConfigCommon}

[0288] pdsch-ConfigCommon SetupRelease { PDSCH-ConfigCommon}

[0289] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList

[0290] ...}

[0291] BWP-UplinkCommon ::= SEQUENCE {

[0292] genericParameters BWP,

[0293] rach-ConfigCommon SetupRelease { RACH-ConfigCommon}

[0294] pusch-ConfigCommon SetupRelease { PUSCH-ConfigCommon}

[0295] pucch-ConfigCommon SetupRelease { PUCCH-ConfigCommon}

[0296] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList

[0297] …

[0298] }

[0299] Among them, the “ ReferencePointCoordinateGroup ” field can be used for the parameters involved in embodiments 1-9, including reference point coordinates, common timing advance values, etc. The “ ReferencePointCoordinateGroupList ” field represents the specific values of the reference point coordinates, common timing advance values, etc.

[0300] The specific format of the “ ReferencePointCoordinateGroupList ” field is as follows (it should be understood that the following is only an example and is not limiting, and other different field formats can also appear according to different signaling combinations listed in the embodiments of the present application):

[0301] ReferencePointCoordinateGroupList ::= SEQUENCE {

[0302] ServiceLinkReferencePoint BIT STRING (SIZE (n)),

[0303] CompensatedReferencePoint BIT STRING (SIZE (n)),

[0304] }

[0305] Among them, the “ServiceLinkReferencePoint” field represents the service link reference point coordinate value, and the “CompensatedReferencePoint” field represents the compensated reference point coordinate value.

[0306] Or,

[0307] ReferencePointCoordinateGroupList ::= SEQUENCE {

[0308] ServiceLinkReferencePoint BIT STRING (SIZE (n)),

[0309] CompensatedReferencePoint BIT STRING (SIZE (n)) OPTIONAL,

[0310] ATGReferencePoint BIT STRING (SIZE (n)) OPTIONAL,

[0311] }

[0312] Among them, the “ATGReferencePoint” field represents the coordinate value of the ATG reference point.

[0313] Or,

[0314] ReferencePointCoordinateGroupList ::= SEQUENCE {

[0315] ServiceLinkCommonTimingAdvance BIT STRING (SIZE (n)),

[0316] CompensatedReferencePoint BIT STRING (SIZE (n)),

[0317] }

[0318] wherein, the field of “ServiceLinkCommonTimingAdvance” represents the value of service link common timing advance.

[0319] or,

[0320] ReferencePointCoordinateGroupList ::= SEQUENCE {

[0321] ServiceLinkTimingValue BIT STRING (SIZE (n)),

[0322] CompensatedTimingValue BIT STRING (SIZE (n)),}

[0323] wherein, the field of “ServiceLinkTimingValue” represents the value of timing advance or reference point coordinate, and there is 1-bit indication bit in “ServiceLinkTimingValue” indicating whether the parameter is the value of service link common timing advance or service link reference point coordinate, and meanwhile carrying the corresponding value of service link common timing advance / service link reference point coordinate. Similarly, the field of “CompensatedTimingValue” represents the value of common compensated timing advance or compensated reference point coordinate, and there is 1-bit indication bit in “CompensatedTimingValue” indicating whether the parameter is the value of common compensated timing advance or compensated reference point coordinate, and meanwhile carrying the corresponding value of common compensated timing advance / compensated reference point coordinate.

[0324] 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, beams or cells can be indicated according to BWP, TCI or SSB. For example, the switching of beams or cells between the terminal and the network device can be indicated by the switching of BWP, TCI or SSB, so that the terminal and / or network device actually perform the switching of BWP, TCI or SSB. In addition, the beams or cells described in this application can also be replaced by BWP, TCI or SSB.

[0325] Embodiment 11

[0326] This embodiment introduces the transmission of the service link common timing advance value / service link reference point coordinate value, the common compensation timing advance value / compensation reference point coordinate value and the ATG reference point coordinate value of the target cell / beam to the terminal through BWP-DownlinkDedicated signaling and BWP-UplinkDedicated signaling in the switching scenario between different beams or BWPs.

[0327] The format of the signaling issued can be as follows:

[0328] BWP-DownlinkDedicated::= SEQUENCE {

[0329] pdcch-Config SetupRelease { PDCCH-Config}

[0330] pdsch-Config SetupRelease { PDSCH-Config}

[0331] sps-Config SetupRelease { SPS-Config}

[0332] radioLinkMonitoringConfig SetupRelease { RadioLinkMonitoringConfig}

[0333] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList ...

[0335] }

[0336] BWP-UplinkDedicated ::= SEQUENCE {

[0337] pucch-Config SetupRelease { PUCCH-Config}

[0338] pusch-Config SetupRelease { PUSCH-Config}

[0339] configuredGrantConfig SetupRelease { ConfiguredGrantConfig}

[0340] srs-Config SetupRelease { SRS-Config}

[0341] beamFailureRecoveryConfig SetupRelease { BeamFailureRecoveryConfig}

[0342] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList

[0343] …

[0344] }

[0345] Wherein, the field “ ReferencePointCoordinateGroup ” can be used for the parameters involved in embodiments 1-9, including reference point coordinates, common timing advance values, etc. The field “ ReferencePointCoordinateGroupList ” represents the specific values of the reference point coordinates, common timing advance values, etc.

[0346] Embodiment 12

[0347] When initiating BWP or beam or cell switching, the measurement process can be triggered. Therefore, this embodiment will downlink the network side delay compensation value of the target BWP or beam or cell through the corresponding RRC signaling in the neighbor measurement configuration and switching.

[0348] For example, the network side downlinks the network side delay compensation value of the target BWP or beam or cell through the measurement signaling “MeasConfig” in RRC, and the downlink signaling format can be as follows:

[0349] MeasObjectNR ::= SEQUENCE {

[0350] carrierFreq ARFCN-ValueNR,

[0351] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList

[0352] …

[0353] }

[0354] wherein, the “ ReferencePointCoordinateGroup ” field can be used for the parameters involved in embodiments 1-9, including reference point coordinates, common timing advance values, etc. The “ ReferencePointCoordinateGroupList ” field represents the specific values of the reference point coordinates, common timing advance values, etc.

[0355] According to the handover signaling flow, the service link common timing advance value / service link reference point coordinate value, the common compensation timing advance value / compensation reference point coordinate value, and the ATG reference point coordinate value of the target BWP or beam or cell are issued within the service BWP or beam or cell through the RRC registration message (RRCReconfiguration), and specific signaling formats are as follows:

[0356] RRCReconfiguration ::= SEQUENCE {

[0357] rrc-TransactionIdentifier RRC-TransactionIdentifier,

[0358] criticalExtensions CHOICE {

[0359] rrcReconfiguration RRCReconfiguration-IEs,

[0360] criticalExtensionsFuture SEQUENCE {}

[0361] }

[0362] }

[0363] wherein, the “ rrcReconfiguration ” field represents the RRC registration signaling. The specific format of the “ RRCReconfiguration-IEs ” field can be as follows:

[0364] RRCReconfiguration-IEs : := SEQUENCE {

[0365] radioBearerConfig RadioBearerConfig OPTIONAL, -- Need M

[0366] ReferencePointCoordinateGroup ReferencePointCoordinateGroupList

[0367] secondaryCellGroup OCTET STRING (CONTAINING CellGroupConfig) OPTIONAL, -- Need M

[0368] measConfig MeasConfig OPTIONAL, -- Need M

[0369] lateNonCriticalExtension OCTET STRING OPTIONAL,

[0370] nonCriticalExtension SEQUENCE {} OPTIONAL

[0371] }

[0372] Embodiment 13

[0373] This embodiment describes that when ATG reference point coordinates need to be sent, the ATG reference point coordinates can be sent to the terminal instead of satellite position coordinates (or part of ephemeris information), so as to save signaling overhead.

[0374] In satellite communication of NTN, the network side sends satellite position coordinates or ephemeris information to the terminal, so when the terminal switches to the ATG communication scenario, the ATG reference point coordinates can replace the satellite position coordinates or ephemeris information.

[0375] As shown in FIG. 19 , the ATG reference point coordinates / satellite position coordinates occupy the same or part of the same signaling bits, and can be sent together 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. or sent separately.

[0376] 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.

[0377] Further, 1 bit can be used to indicate the terminal whether the network side sends the ATG reference point coordinate information or the satellite position coordinate / ephemeris information to the terminal, as shown in FIG. 20 .

[0378] Embodiment 14

[0379] This embodiment describes the calculation method of TA.

[0380] In the prior art, the timing advance used by the terminal is . Among them, N TAis a TA adjustment value obtained by the terminal according to the parameter indicated by the network side, for example, a TA adjustment value obtained by the terminal according to the common TA value sent by the network side and / or the reference point coordinates and / or the location information of the terminal in the patent of the present application. TAoffset represents a timing interval from uplink to downlink transmission, which is sent to the terminal through SIB information. For FDD mode, N Aoffset = 0; for TDD mode, N TAoffset = 624. This time interval can allow 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 kHz.

[0381] The TA adjustment value obtained by the terminal according to the common TA value sent by the network side and / or the reference point coordinates and / or the location information of the terminal in the embodiment of the present application can be added with a fixed value (for example, N TAoffset ) to obtain the TA that can be used by the terminal.

[0382] In the embodiments of the present application, the fixed value includes but is not limited to the following three implementation manners:

[0383] Manner one, the fixed value is an offset.

[0384] The offset can be related to one or more of the following factors:

[0385] 1) duplex mode, including time division duplex (TDD) mode and frequency division duplex (FDD) mode;

[0386] 2) position error or positioning error of the second network device (such as satellite, etc.);

[0387] It should be understood that the positioning error and the position error only represent different expressions, and have the same meaning.

[0388] 3) position error or positioning error of the terminal.

[0389] Of course, the above three factors are only examples and are not limited to, and in actual application, it can also be related to other factors.

[0390] In a possible design, the network side can send an offset (such as 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, that is, the quotient of the positioning error and the speed of light, or the quotient of 2 times the position error or positioning error of the second network device and the speed of light, that is, 2

[0391] It should be understood that the speed of light refers to the propagation speed of light waves in air or outer space, for example, the speed of light is often used = 3 10 8 .

[0392] Optionally, the offset can be a positive value, a negative value or 0, i.e. the offset sent by the network side to the terminal can be: + (positioning error / light speed), or - (positioning error / light speed), or + (2 (positioning error / light speed), or - (2 (positioning error / light speed).

[0393] When it is needed to avoid the TA value obtained by the terminal being too large to cause ISI, the offset can use a negative value; when it is needed to avoid the TA value being too small to cause 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 the terminal uses the offset after taking a negative value of the offset after receiving the offset.

[0394] The unit of the offset can be nanosecond (ns), microsecond (us), millisecond (ms), 16 Ts / 2 μ and the like, which are not limited by the embodiments of the present application.

[0395] Understandably, the position error or positioning error of the second network device can be understood as the deviation distance between the position coordinate of the second network device (the position coordinate can be represented by ephemeris information or three-dimensional coordinate) affected by the perturbation and the actual position of the second network device. The position error or positioning error can be the maximum possible deviation distance between the position coordinate 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.

[0396] Understandably, the position error or positioning error of the terminal represents the position deviation of the terminal using the positioning system or the positioning method to position its own position, i.e. the deviation distance or the maximum possible deviation distance between the position coordinate obtained by positioning and the actual position coordinate.

[0397] Understandably, the network side and the terminal can agree that the network side sends a positive offset to the terminal, and the terminal subtracts the offset from the TA adjustment value obtained by calculation to obtain the timing advance that can be used by the terminal; which is equivalent to the network side sending a negative offset to the terminal, and the terminal adds the offset to the TA adjustment value obtained by calculation to obtain the timing advance that can be used by the terminal.

[0398] In summary, the fixed value can be an offset, and the network side can send / configure the offset to the terminal, and the terminal adds or subtracts the offset from the TA adjustment value obtained by calculation to obtain the timing advance that can be used by the terminal. The TA adjustment value obtained by the terminal can be the sum of the round-trip delay of the service link and the common compensation timing advance value (or difference value).

[0399] In another possible design, the network side can send to the UE a value of a position error or a positioning error that can be used to determine the offset.

[0400] The position error or the positioning error value here can be a position error or a value of a second network device (e.g., a satellite, etc.) and / or a position error of the terminal. The position error or the positioning error value is denoted as position_err, which can be in meters, and is used to indicate a possible position error of the second network device.

[0401] After the terminal receives the position_err, the terminal calculates the offset according to the position_err.

[0402] For example, the terminal device can use any of the following ways to calculate the value of the offset to be used by the terminal:

[0403] 1) -2 position_err / light speed, i.e., -2 position_err / light speed;

[0404] 2) +2 position_err / light speed, +2 position_err / light speed;

[0405] 3) position_err / light speed, i.e., position_err / light speed;

[0406] 4) -position_err / light speed, i.e., -position_err / light speed.

[0407] Similarly, a negative value can be used to avoid ISI, and a positive value can be used to avoid too small TA value. Finally, the terminal can add or subtract the calculated TA adjustment value to or from the offset (e.g., -2 position_err / light speed) to obtain the timing advance that can be used by the terminal. The TA adjustment value calculated by the terminal can be the sum of the round-trip delay of the serving link and the common compensation timing advance value (or the difference value).

[0408] It should be noted that the offset may include one or more of the following: a TDD or FDD mode related portion, a location error portion of the second network device, and a location error portion of the terminal. If the offset includes both the TDD or FDD mode related portion and the location error portion of the second network device and / or the terminal's location error portion, the network side can either combine (e.g., add / subtract) these portions before sending them to the terminal or send these portions separately to the terminal. Accordingly, the terminal can directly use the combined offset; or, after receiving the above portions, the terminal can combine (add / subtract) them to use as the final offset. The value of this offset can be agreed upon through a protocol or sent / configured to the terminal by the network side.

[0409] Method 2: The fixed value is a numerical offset.

[0410] As described above (e.g., Example 3), the common compensation timing advance value (i.e., the round-trip time delay between the satellite and the compensation reference point) sent by the network side to the terminal replaces the location coordinates of the compensation reference point. When the compensation reference point is on the power supply link, the common compensation timing advance value needs to be taken as positive; when the compensation reference point is on the service link, the common compensation timing advance value needs to be taken as negative.

[0411] To improve the flexibility of the solution, in this embodiment, the terminal may not know whether the compensation reference point is on the feeder link or the service link. Instead, 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 to the numerical offset to obtain the common compensation timing advance value used by the terminal, i.e.:

[0412] Common compensation timing advance value = common timing parameter + numerical offset; or,

[0413] Common compensation timing advance value = Common timing parameter - Numerical offset.

[0414] The common compensation timing advance value calculated from the common timing parameter + / - numerical offset may be positive or negative.

[0415] Accordingly, the terminal can sum the round-trip time of the service link, the common timing parameter, and the ± numerical offset in the NTN to obtain the TA to be used. Here, ± represents + or -. That is:

[0416] TA = Round-trip time of the service link (or the timing advance adjustment value of the service link).

[0417] +Public compensation time advance value

[0418] = Round-trip delay of service link + common timing parameter ± numerical offset.

[0419] For example, when the numerical offset is a positive value, a common compensation timing advance value used by the terminal can be calculated as common timing parameter - numerical offset. The numerical value of the numerical offset can be agreed by protocol or sent / configured by the network side to the terminal. For example, the common timing parameter sent by the sending end ranges from 0 to 10, and the receiving end subtracts a numerical offset (assuming 5) from the received common timing parameter to obtain a common compensation timing advance value ranging from -5 to 5. This method is equivalent to shifting the common timing parameter sent by the sending end by a numerical offset length at the receiving end, thereby obtaining the representation range of the common compensation timing advance value to be used.

[0420] It can be understood that this method can also be used in the sending of other numerical parameters to achieve the sending of positive or negative values by the sending end, and the numerical range can be shifted at the receiving end to achieve the effect of representing the positive / negative value range. This can improve the flexibility of the scheme and simplify the complexity of the sending end.

[0421] Method three, the fixed value includes two parts of the offset and the numerical offset.

[0422] The network side sends the offset to the terminal and agrees on the numerical offset value (or the network side sends the numerical offset value to the terminal) with the terminal, and the terminal side can add the round-trip delay of the service link in the NTN, the common timing parameter, ± numerical offset, ± offset, and obtain the TA to be used, that is:

[0423] TA = Round-trip delay of service link + common compensation timing advance value ± offset

[0424] = Round-trip delay of service link + common timing parameter ± numerical offset ± offset.

[0425] It should be understood that the above three methods are only examples of fixed values and not limitations, and in actual applications, there is a possibility of other implementation methods.

[0426] Further, the fixed value such as offset, common timing parameter or numerical offset, etc. can be carried in at least one of the broadcast information in system information block (SIB) 1, other system information (OSI), master information block (MIB), etc., and broadcasted or groupcasted by the network device to the terminal. In addition, if the offset, common timing parameter, numerical offset, etc. are sent in the radio resource control (RRC) connection stage, the network side can carry these information in at least one of the RRC information, RRCReconfiguration message, downlink control information (DCI), group DCI, media access control (MAC) control element (CE), timing advance command (TAC), or send to the UE with data transmission or in a separately allocated PDSCH bearer.

[0427] The signaling design of offset, common timing parameter, numerical offset, etc. is specifically illustrated below.

[0428] Example 1, the network side can add a new variable domain such as T-offset representing offset in the random access generic configuration (RACH-ConfigGeneric) parameter, wherein the RACH-ConfigGeneric parameter is usually sent to the UE in the broadcast message or RRC message to provide the UE with the general parameters used in the random access process. For example:

[0429] RACH-ConfigGeneric ::= SEQUENCE {

[0430] prach-ConfigurationIndex INTEGER (0..255),

[0431] T-offset INTEGER (0.. 511),

[0432] …

[0433] }

[0434] Optionally, the network side can determine the representation range of T-offset according to the possible maximum distance value of ephemeris error or satellite position error or satellite positioning error. For example, taking the maximum value of ephemeris error or satellite position error as 10km, T-offset is represented as 16 Ts / 2 μ The dimension unit is T-offset, and the representation range is 0~511, which requires 9-bit signaling to represent.

[0435] 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 the TA adjustment value obtained by the terminal is subtracted from the T-offset value and the timing interval N TAoffset , to finally obtain the timing advance TA value used by the terminal, that is, or TA = (N TA +N TAoffset -T-offset) 16 Ts / 2 μ . Wherein, N TA 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 at least one of the common timing advance value, the common compensation timing advance value, the reference point coordinates, and the location information of the terminal sent by the network side.

[0436] Optionally, the RACH-ConfigGeneric parameter can be transmitted in SIB1, RRC setup signaling (RRCSetup), RRC reconfiguration signaling (RRCReconfiguration), RRC resume signaling (RRCResume), etc. The offset, common timing parameter, and numerical offset can be ensured to be received by the terminal in the initial access stage and the connected state switching, and accurate uplink time synchronization is established.

[0437] Example 2, the network side can send the distance value of ephemeris error or position error or positioning error that can determine the offset to the terminal through the random access general configuration (RACH-ConfigGeneric) parameter, which is represented as D-offset.

[0438] RACH-ConfigGeneric ::= SEQUENCE {

[0439] prach-ConfigurationIndex INTEGER (0..255),

[0440] D-offset INTEGER (0.. 1000),

[0441] …

[0442] }

[0443] This example adds a new variable field D-offset in the RACH-ConfigGeneric parameter to represent the distance value of ephemeris error or position error or positioning error that determines the offset.

[0444] In this example, the network side can determine the representation range of D-offset according to the possible maximum distance value of ephemeris error or satellite position error or satellite positioning error. For example, taking the maximum value of ephemeris error or satellite position error as 10 km, D-offset is in the unit of meter, and the representation range of D-offset is 0~1000, which needs 10 bits of signaling to represent. 10 bits can represent the range of 0~1023, among which 1001~1023 are reserved, which can also be left for other indication purposes.

[0445] It can be understood that if different maximum satellite positioning error ranges and distance dimension units are assumed, D-offset can have different representation ranges.

[0446] For example, after the terminal receives D-offset, it can use the TA adjustment value obtained by the terminal to subtract D-offset / light speed, or use the TA adjustment value to subtract D-offset / light speed / (16·64·T c / 2 u ) , and then obtain the timing advance TA value used by the terminal. " indicates rounding up. That is:

[0447] TA = N TA 16 Ts / 2 μ -D-offset / light speed; or,

[0448] TA = (N TA - D-offset / light speed / (16·64·Tc / 2 u ) +N TAoffset ) 16 Ts / 2 μ 。

[0449] wherein Tc represents a time unit , Hz, . From the definition of Ts, it can be known that i.e. , , .

[0450] Example 3, in order for the terminal to obtain more accurate TA value to apply for access to the communication system, the network side can send a common compensation timing advance value to the terminal through the random access general configuration (RACH-ConfigGeneric) parameter, here use TA-common to represent the common compensation timing advance value:

[0451] RACH-ConfigGeneric ::= SEQUENCE {

[0452] prach-ConfigurationIndex INTEGER (0..255),

[0453] TA-common INTEGER (-4155513.. 4155513),

[0454] …

[0455] }

[0456] The network side of this example adds a new variable domain such as TA-common in the RACH-ConfigGeneric parameter to represent the parameter value used to determine the common compensation timing advance value or the common timing advance value.

[0457] Optionally, the network side can determine the representation range of TA-common according to the maximum possible orbit height of the satellite and the possible minimum communication elevation angle.

[0458] For example, assuming that the orbit height is GEO orbit and the minimum communication elevation angle is 10 degrees, the maximum possible orbit height is 42160 km, and the minimum communication elevation angle is 10 degrees, so the maximum possible distance between the satellite and the terminal is 16·64·T c / 2 uFor dimensional unit, the range of TA-common is -4155513 ~ +4155513, which needs 23 bits signaling to express. The range that 23 bits can express is: - 4194303 ~ + 4194303. Among them, - 4194303 ~ -4155513 and 4194303 ~ 4155513 range are reserved, which can also be left for other indication purposes. It can be understood that if different satellite orbital height, minimum elevation angle and time dimensional unit are assumed, the indication range of TA-common can be different.

[0459] After the terminal receives TA-common, it can calculate the round-trip delay of the service link according to the terminal position and the satellite position, add it to the time length represented by TA-common to obtain the TA adjustment value.

[0460] It should be understood that TA-common can represent both a common compensation timing advance value and a common propagation delay that the terminal needs to compensate.

[0461] It should be understood that TA-common can represent positive, negative and zero, and the positive value represents sending the uplink signal in advance, and the negative value represents sending the uplink signal in delay.

[0462] Example 4, in order to save signaling bits, the network side can combine the common compensation timing advance signaling according to the orbital height range. For example:

[0463] RACH-ConfigGeneric ::= SEQUENCE {

[0464] prach-ConfigurationIndex INTEGER (0..255),

[0465] TA-common-LEO BIT STRING (SIZE(20)),

[0466] TA-common-complement BIT STRING (SIZE(3)) OPTIONAL,

[0467] …

[0468] }

[0469] The network side of the present example adds two new variable fields, i.e., low-orbit common timing advance TA-common-LEO and common timing advance supplement TA-common-complement, in the RACH-ConfigGeneric parameter, to represent the common compensation timing advance value or the common propagation delay that needs to be compensated by the terminal. Among them, TA-common-complement is optional, i.e., the network side can choose to send or not send the TA-common-complement parameter. The network side can determine whether to send the TA-common-complement parameter according to the orbit height of the second network device, and specific reference can be made to the following examples.

[0470] Optionally, the network side can determine the representation range and bit number of TA-common-LEO and TA-common-complement according to the orbit height range and the possible minimum communication elevation angle of the satellite.

[0471] For example, for a scenario with an orbit height not higher than 1200 km, the network side can only send TA-common-LEO signaling (20 bits), i.e., without sending TA-common-complement. At this time, only 20-bit signaling needs to be sent to represent the common compensation timing advance value, and the range represented is -320609~+320609. 20 bits can indicate the range of - 524287 ~+524287, wherein the ranges of - 524287~-320609 and 320609~524287 are reserved (reserved) and can also be left for other indication purposes.

[0472] For example, for a scenario with an orbit height greater than 1200 km, the network side can send TA-common-LEO and TA-common-complement signaling (3 bits) to the UE, where TA-common-LEO represents high bits and TA-common-complement represents low bits. TA-common-LEO and TA-common-complement together constitute 23-bit signaling, representing the range of -4155513~ 4155513. 23 bits can represent the range of - 4194303 ~ + 4194303. Among them, the ranges of - 4194303~-4155513 and 4194303~4155513 are reserved (reserved) and can also be left for other indication purposes.

[0473] After the terminal receives the common compensation timing advance value represented by TA-common-LEO and TA-common-complement, it can calculate the round-trip time delay of the service link according to the terminal position and satellite position, add it to the time length represented by the common compensation timing advance value, and obtain the TA adjustment value. Such signaling transmission method not only provides flexibility, but also saves a part of signaling bits in the scenario of low orbit height.

[0474] 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:

[0475] RACH-ConfigGeneric := SEQUENCE {

[0476] prach-ConfigurationIndex INTEGER (0..255),

[0477] TA-common-LEO-600 INTEGER (-197800.. 197800) OPTIONAL,

[0478] TA-common-LEO-1200 INTEGER (-320609.. 320609) OPTIONAL,

[0479] TA-common-GEO INTEGER (-4155513.. 4155513) OPTIONAL,

[0480] …

[0481] }

[0482] This example adds three new variable domains, i.e. low orbit 600 common timing advance TA-common-LEO-600, low orbit 1200 common timing advance TA-common-LEO-1200 and synchronous orbit common timing advance TA-common-GEO, to the RACH-ConfigGeneric parameter, representing the parameter value used to determine the common compensation timing advance value or the common propagation delay that the terminal needs to compensate. Among them, TA-common-LEO-600, TA-common-LEO-1200 and TA-common-GEO are optional, i.e. the network side can choose to send only one or only two of the three parameters or send all of them.

[0483] Optionally, the network side can determine the representation range and bit number of TA-common-LEO-600, TA-common-LEO-1200 and TA-common-GEO according to the orbit height range and the possible minimum communication elevation angle of the satellite. Wherein, TA-common-LEO-600 represents the common compensation timing advance value related parameter of the orbit height not greater than 600km, TA-common-LEO-1200 represents the common compensation timing advance value related parameter of the orbit height not greater than 1200km, and TA-common-GEO represents the common compensation timing advance value related parameter of the orbit height not greater than 36000km.

[0484] For example, for the scenario of the orbit height not higher than 600km, the network side can send TA-common-LEO-600 signaling (19 bits), i.e. not send TA-common-LEO-1200 and TA-common-GEO. At this time, only 19 bits of signaling need to be sent for the terminal to determine the common compensation timing advance value, and the range represented is -197800…+197800. The range indicated by 19 bits is: -262143~+262143, wherein the -262143~-197800 and 197800~262143 ranges are reserved, which can also be left for other indication purposes.

[0485] For example, for the scenario of the orbit height greater than 600km and not greater than 1200km, the network side can send TA-common-LEO-1200 signaling (20 bits) to the UE, i.e. not send TA-common-LEO-600 and TA-common-GEO. 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 represented is -320609…320609. The range indicated by 20 bits is: -524287~+524287, wherein the -524287~-320609 and 320609~524287 ranges are reserved, which can also be left for other indication purposes.

[0486] For example, for the scenario of orbit height higher than 1200km, the network side needs to send TA-common-GEO signaling (23 bits), i.e. not to send TA-common-LEO-600 and TA-common-LEO-1200. At this time, 23 bits of signaling need to be sent for the terminal to determine the common compensation timing advance value, which represents the range of -4155513 ~ +4155513. 23 bits can represent the range of -4194303 ~ +4194303. Among them, - 4194303 ~ -4155513 and 4194303 ~ 4155513 ranges are reserved (reserved), which can also be left for other indication purposes.

[0487] 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, the terminal can calculate the round-trip time of the service link according to the terminal position and satellite position, and add it to the time length represented by the common compensation timing advance value to obtain the TA adjustment value.

[0488] Example 6, the network side can send the parameter value (i.e. common timing parameter, here represented by TA-common-timing) used to determine the common compensation timing advance value or common timing advance value to the terminal through the random access general configuration (RACH-ConfigGeneric) parameter:

[0489] RACH-ConfigGeneric ::= SEQUENCE {

[0490] prach-ConfigurationIndex INTEGER (0..255),

[0491] TA-common-timing INTEGER (0... 8311026),

[0492] …

[0493] }

[0494] In this example, the network side adds a new variable domain common timing parameter, i.e. TA-common-timing, in the RACH-ConfigGeneric parameter to represent the parameter value used to determine the common compensation timing advance value or common timing advance value.

[0495] Optionally, the network side can determine the representation range of TA-common-timing according to the maximum possible orbit height of the satellite and the possible minimum communication elevation angle.

[0496] For example, assuming the orbit height is GEO orbit and the minimum communication elevation angle is 10 degrees, the time dimension unit is 16 · 64 · T c / 2 u TA-common-timing is expressed in the range of 0 ~ 8311026, 23 bits of signaling are needed to express it. The range that 23 bits can express is: 0 ~ 8388607, and the range of 8311027 ~ 8388607 is reserved, which can also be used for other purposes.

[0497] It can be understood that if different satellite orbit heights, minimum elevation angles and time dimension units are assumed, the indication range of TA-common-timing can be different.

[0498] After the terminal receives the common timing parameter TA-common-timing, it subtracts the numerical offset to obtain the common compensation timing advance value or the common timing advance value.

[0499] For example, assuming the numerical offset is 4155513 (the numerical value of the numerical offset can be agreed by the protocol or configured by the network side to the UE), after the terminal receives TA-common-timing, the common compensation timing advance value is obtained by TA-common-timing - 4155513, and the representation range of the common compensation timing advance value is -4155513 ~ +4155513. This method is equivalent to performing an offset operation on the received TA-common-timing value, that is, TA-common-timing - numerical offset, and in this example, the numerical offset is equal to 4155513, but in actual use, it is not limited to this value. For another example, after the terminal receives TA-common-timing, the common compensation timing advance value can be calculated, and then the round-trip time of the service link is calculated according to the terminal position and the satellite position, which is added to the time length represented by the common compensation timing advance value to obtain the TA adjustment value.

[0500] Further, the transmission signaling methods of the above several examples can also be combined for use.

[0501] For example, the network side can add three new variable domains of low orbit 600 common timing parameter TA-common-timing-LEO-600, low orbit 1200 common timing parameter TA-common-timing-LEO-1200 and synchronous orbit common timing parameter TA-common-timing-GEO in the RACH-ConfigGeneric parameter to represent 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:

[0502] RACH-ConfigGeneric ::= SEQUENCE {

[0503] prach-ConfigurationIndex INTEGER (0..255),

[0504] TA-common-timing-LEO-600 INTEGER (0.. 395600) OPTIONAL,

[0505] TA-common-timing-LEO-1200 INTEGER (0.. 641218) OPTIONAL,

[0506] TA-common-timing-GEO INTEGER (0.. 8311026) OPTIONAL,

[0507] ...

[0508] }

[0509] Optionally, the representation range and number of bits for TA-common-timing-LEO-600, TA-common-timing-LEO-1200, and TA-common-timing-GEO can be determined based on the satellite's orbital altitude range and the possible minimum communication angle. Specifically, TA-common-timing-LEO-600 represents common timing parameters related to common compensated timing advance values ​​at orbital altitudes not exceeding 600 km; TA-common-timing-LEO-1200 represents common timing parameters related to common compensated timing advance values ​​at orbital altitudes not exceeding 1200 km; and TA-common-timing-GEO represents common timing parameters related to common compensated timing advance values ​​at orbital altitudes not exceeding 36000 km. All three parameters (TA-common-timing-LEO-600, TA-common-timing-LEO-1200, and TA-common-timing-GEO) are optional; the network can choose not to transmit any of these three parameters and instead transmit only one of them.

[0510] For example, in scenarios where the orbital altitude is no higher than 600km, the minimum beacon angle is 10 degrees, with 16.64T. c / 2 uFor the dimension unit, the network side can send TA-common-timing-LEO-600 signaling (19 bits), i.e. not send TA-common-timing-LEO-1200 and TA-common-timing-GEO. 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 ~ 395600. 19 bits can indicate the range of 0 ~ 524287, wherein the range of 395601 ~ 524287 is reserved (reserved) and can also be left for other indication purposes. Similarly, TA-common-timing-LEO-1200 and TA-common-timing-GEO signaling respectively use 20 bits and 23 bits of signaling to represent the range of 0 ~ 641218 and 0 ~ 8311026.

[0511] For example, assuming that the common timing parameters for different orbit parameter ranges have different numerical offset values, 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 the terminal receives TA-common-timing-LEO-600, the common compensation timing advance value is obtained by TA-common-timing-LEO-600 - 197800, and the representation range of the common compensation timing advance value is -197800 ~ 197800.

[0512] For example, for different satellite orbit altitudes, minimum elevation angles, and time dimension units, the indication range of TA-common-timing-LEO-600, TA-common-timing-LEO-1200, or TA-common-timing-GEO can be different. After the terminal receives the common timing parameter TA-common-timing-LEO-600, TA-common-timing-LEO-1200, or TA-common-timing-GEO, the common compensation timing advance value or the common timing advance value is obtained by subtracting the corresponding numerical offset. The terminal can calculate the round-trip delay of the service link according to the terminal position and the satellite position, add it to the time length represented by the common compensation timing advance value, and obtain the TA adjustment value.

[0513] The following further illustrates several detailed examples to introduce how the terminal calculates the used TA value according to the terminal position, satellite position, common compensation timing advance value, etc.

[0514] Assuming 16 · 64 · T c / 2 u , the quantized value of the round-trip delay of the serving link is:

[0515] NT service = RTD service / (16 · 64 · T c / 2 u ) = (2 distance service / velocity) / (16 · 64 · T c / 2 u ) ; (1)

[0516] where RTD service denotes the round-trip delay between the terminal and the satellite, which is equal to twice the quotient of the distance between the terminal and the satellite and the speed of light. ” denotes the floor function.

[0517] The common compensation timing advance value obtained by the terminal is NT common , then the TA value used by the terminal for sending the random access preamble or uplink data is:

[0518] (2)

[0519] If the offset T-offset, the common timing parameter and the numerical offset are considered, the TA value used by the terminal is:

[0520] (3)

[0521] If the position error D-offset, the common timing parameter and the numerical offset are considered, the TA value used by the terminal is:

[0522] TA= (NT service + NT common - (2 D-offset / velocity) / (16 · 64 · T c / 2 u ) ) 16 64 T c / 2 u (4)

[0523] It can be seen that formula (4) is based on (2 D-offset / speed of light) / (16.64T) c / 2 u ) The T-offset in formula (3) is partially replaced, representing the time uncertainty caused by satellite positioning error subtracted 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 rounded up for quantization.

[0524] The TA quantity used by the terminal can also be:

[0525] TA = (NT) service + TA-common-timing (numerical offset) 16 64 T c / 2 u (5)

[0526] Among them, the common-common-timing numerical offset is replaced by the NT value for common-common-timing advance. common .

[0527] The TA quantity used by the terminal can also be:

[0528] TA = (NT) service + TA-common-timing (numerical offset - T-offset) 16 64 T c / 2 u (6)

[0529] The TA quantity used by the terminal can also be:

[0530] TA = (NT) service + TA-common-timing - Numerical Offset -

[0531] (2 D-offset / speed of light) / (16.64T) c / 2 u ) ) 16 64 T c / 2 u (7)

[0532] It should be understood that if the TA quantity is obtained by calculation using other time units, then it is only necessary to replace (16·64·T) in the above formulas (1)~(7) with the new time unit. c / 2 u Any time unit is acceptable. For example, use 64·T. c / 2 u If the unit is dimensional, then in the above formulas (1) to (7), (16·64·T) c / 2 u The time unit has been replaced with 64·T c / 2 u Any time unit will suffice.

[0533] If NT is calculated service At 64 T c / 2 u The public compensation timing advance value NT is obtained in units of time. common Common timing parameters and numerical offsets are based on 16.64T. c / 2 u It is a unit of time. Therefore, NT... service = RTD service / (64·T c / 2 u ) = (2 distance service / speed of light) / ( 64·T c / 2 u ) Therefore, the TA quantity used by the terminal is:

[0534] TA = (NT) service / 16+ NT common ) 16 64 T c / 2 u (8)

[0535] If we consider the offset T-offset or position error D-offset, the common timing parameters, and the numerical offset, then the TA quantity used by the terminal is:

[0536] TA = (NT) service / 16+ NT common -T-offset) 16 64 T c / 2 u (9)

[0537] or,

[0538] TA = (NT) service / 16+ NT common -

[0539] (2 D-offset / speed of light) / (16.64T) c / 2 u ) ) 16 64 T c / 2 u (10)

[0540] Similarly, formula (10) is based on (2 D-offset / speed of light) / (16.64T) c / 2 u ) In the partial substitution formula (9), T-offset represents the timing uncertainty caused by satellite positioning error subtracted 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 rounded up for quantization.

[0541] The TA quantity used by the terminal can also be:

[0542] TA = (NT) service / 16+ TA-common-timing (numerical offset) 16 64 T c / 2 u (11)

[0543] In this context, the common-common-timing value is replaced by (TA-common-timing - numerical offset) instead of NT. common .

[0544] The TA quantity used by the terminal can also be:

[0545] TA = (NT) service / 16+ TA-common-timing-

[0546] Numerical offset (T-offset) 16 64 T c / 2 u (12)

[0547] The TA quantity used by the terminal can also be:

[0548] TA = (NT) service / 16+ TA-common-timing - Numerical Offset -

[0549] (2 D-offset / speed of light) / (16.64T) c / 2 u ) ) 16 64 T c / 2 u (13)

[0550] The following section describes the impact of cell handover, beam switch, gateway switch, and satellite switch on advance public compensation timing or advance public timing.

[0551] 1. Cell handover:

[0552] 1) During the Cell handover procedure, the UE performs measurements and reports the neighboring cell channel quality according to the network side's instructions. Then, the gNB where the source cell is located (hereinafter referred to as the source gNB, which may be 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 common compensation timing advance or common timing advance signaling exists in RRCReconfiguration. Therefore, the common compensation timing advance or common timing advance of the target cell can be carried in RRCReconfiguration. For non-random access handover (RACHless handover), the source gNB also sends RRCReconfiguration signaling to the UE, and can also send the common compensation timing advance value or common timing advance value of the target gNB to the UE.

[0553] 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.

[0554] 2. Satellite switch: You can refer to the process of cell handover, which will not be repeated here.

[0555] 3、Beam switch: When source beam and target beam belong to the same cell. Common compensation timing advance or common timing advance is broadcasted in SIB1, which is cell level signaling. Therefore, when beam switch happens, two beams use the same common compensation timing advance or common timing advance, and there is no timing jump situation. (If common compensation timing advance or common timing advance is beam level, there may be different timing compensation values for different beams on the network side, and then timing jump may occur. Therefore, common compensation timing advance value or common timing advance value needs to be carried in BWP switching signaling, for example, in BWP-UplinkDedicated signaling.)

[0556] 4、Gateway switch:

[0557] When gateway soft switch happens, i.e. UE can establish connection with two gateways at the same time and can receive messages from two gateways, the gateway switch scenario can be equivalent to cell handover process, i.e. common compensation timing advance value or common timing advance value of target gateway can be sent to UE in RRCReconfiguration signaling.

[0558] When gateway hard switch happens, i.e. UE can only establish connection with one gateway at the same time. When UE disconnects with one gateway and establishes connection with another gateway at the same time, i.e. hard switch happens, feeder link part delay will change. gNB can send common compensation timing advance value or common timing advance value used in target gateway to UE before gateway switch or difference value with currently used common compensation timing advance value or common timing advance value. For example, UE in whole beam or cell needs to update common compensation timing advance value or common timing advance value, so RRCReconfiguration signaling can be used to carry the above parameters to update them.

[0559] Further, when gateway soft switch or gateway hard switch happens, gNB sends common compensation timing advance value or common timing advance value of target gateway to UE using MAC CE signaling or difference value with currently used common compensation timing advance value or common timing advance value.

[0560] In some special scenarios, the same number of bits is needed to send the common compensation TA difference value or the common TA difference value as to send the complete common compensation TA value or the complete common TA value. For example, when the network side compensates the uplink timing before handover, but does not compensate the uplink timing after handover, the complete feeder link round trip time needs to be indicated, and the number of bits needed for the common compensation TA difference value is the same as that for the complete common compensation TA value. If the protocol does not support these special scenarios, the signaling overhead can be saved by sending the common compensation TA difference value instead of the complete common compensation TA value.

[0561] The validity of the common compensation TA value or the common TA value is described below.

[0562] If the common compensation TA value or the common TA value is carried by SIB1, the SIB1 update period determines the maximum error of the common compensation TA value or the common TA value. The error is caused by the relative motion between the satellite and the gateway.

[0563] The system message (including SIB1) is updated only at the start frame of the modification period, and the start frame of the modification period satisfies:

[0564] SFN mod m = 0;

[0565] wherein m represents the number of system frames included in the modification period length, SFN represents the system frame number, and mod represents the remainder.

[0566] m = modificationPeriodCoeff defaultPagingCycle, unit: frame;

[0567] modificationPeriodCoeff = 2 / 4 / 8 / 16;

[0568] defaultPagingCycle = 32 / 64 / 128 / 256.

[0569] Wherein the modificationPeriodCoeff and the defaultPagingCycle can be configured by SIB1.

[0570] It can be seen that the minimum modification period is 64 frames = 640 ms.

[0571] The common compensation timing advance value indicates the difference between feeder link round trip delay and network side uplink data timing compensation value. If the satellite is closer and closer to the gateway, the value of the common compensation timing advance indication is likely to be larger, and the preamble or uplink data will arrive early, resulting in inter-symbol interference ISI.

[0572] To avoid ISI, the common compensation timing advance value or common timing advance value corresponding to the next update period start time can be sent at the start time of the update period. The common compensation timing advance value or common timing advance value sent in this way is smaller, and the UE sending preamble or uplink data will arrive later at the network side, thereby avoiding ISI. For example, if the update period is 640 ms, the late arrival time is not more than 33.28us.

[0573] Embodiment 15

[0574] The concept of the technical solution of the present application can also be applied to the transmission of timing advance rate (TA rate) reference points, Doppler pre-compensation reference points / Doppler post-compensation reference points.

[0575] 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 hereinafter refers to the common TA rate of the service link.

[0576] The service link timing advance rate (TA rate) reference point: the terminal can calculate the common timing advance rate of the service link of the beam or cell according to the relative motion speed or distance change rate between the satellite (the terminal can obtain the position and speed information of the satellite through ephemeris information) and the service link TA rate reference point. For example, according to the motion direction of the satellite, the position of the satellite 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 away from each other, 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 according to TA rate as △T 2 V / c. The corrected TA is TA_original+△T 2 V / c, TA_original is the TA used before. Thus, the terminal can use the common timing advance rate to correct the timing advance of the signal sent by the terminal (if there is a feeder link common timing advance rate, the service link common timing advance rate and the feeder link common timing advance rate can be used jointly, i.e., the sum of the two, to calculate the final TA rate, to correct the uplink timing advance adjustment value).

[0577] Feeder link timing advance rate (TA rate) reference point: the terminal can calculate the feeder link common timing advance rate of the beam or cell according to the relative motion speed or distance rate between the satellite (the terminal can obtain the position and speed information of the satellite through ephemeris information) and the feeder link TA rate reference point (the same as the description above). The terminal uses the common timing advance rate to correct the timing advance adjustment value of the signal sent by the terminal (if there is a service link common timing advance rate, the service link common timing advance rate and the feeder link common timing advance rate can be used jointly, i.e., the sum of the two, to calculate the final TA rate, to correct the uplink timing advance adjustment value). The feeder link timing advance rate reference point can be the position coordinates of the gateway.

[0578] Doppler pre / post compensation reference point: the terminal can calculate the Doppler pre / post compensation value of the beam or cell according to the relative motion speed between the satellite (the terminal can obtain the position and speed information of the satellite through 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 to the signal sent by the terminal received in the corresponding beam / cell, and the Doppler pre compensation value made by the satellite to the downlink signal sent in the corresponding beam / cell. Alternatively, the Doppler pre / post compensation value can represent the Doppler pre compensation value needed by the terminal to the signal sent by the terminal when sending the signal, and the Doppler post compensation value made by the terminal to 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 the needs of the system, for example, the center point of the beam / cell.

[0579] If the Doppler value calculated according to the Doppler pre / post compensation reference point and the satellite position, motion direction represents the Doppler pre-compensation value made by the network side to the downlink signal, the terminal with global navigation satellite system (GNSS) function can calculate the frequency offset of the crystal oscillator according to the Doppler pre-compensation value and the frequency offset value of the downlink signal. At the same time, the terminal with GNSS function can calculate the Doppler frequency offset value caused by the uplink channel according to its own position, the position of the satellite and the motion direction of the satellite. The pre-compensation value made by the terminal with GNSS function to the signal sent by the terminal can be obtained by using the uplink channel Doppler frequency offset value minus the Doppler post-compensation value made by the satellite side to the signal sent by the terminal.

[0580] In a possible design, referring to FIG. 21A , a reference point group can be defined, including the serving link reference point coordinate, the compensation reference point coordinate, the ATG reference point coordinate, the serving link TA rate reference point coordinate, the feeder link TA rate reference point coordinate, and the Doppler pre / post compensation reference point coordinate. In another possible design, referring to FIG. 21B , the network side can separately send the serving link TA rate reference point coordinate, the feeder link TA rate reference point coordinate, and the Doppler pre / post compensation reference point coordinate.

[0581] It should be understood that the multiple reference points mentioned above (such as the serving link TA rate reference point, the feeder link TA rate reference point coordinate, and the Doppler pre / post compensation reference point) can be the same reference point, or the multiple reference points are located at the same position. For example, two or three of the serving link reference point coordinate, the serving link TA rate reference point coordinate, and the Doppler pre / post compensation reference point coordinate are the same reference coordinate, so the system only needs to transmit one reference coordinate, and the use mode of the reference point is agreed with the terminal in advance. For example, if the serving link TA rate reference point coordinate and the serving link reference point coordinate are the same reference point, the system and the terminal agree that, when the terminal receives the reference point, the terminal can calculate the common timing advance change rate of the beam or the cell according to the relative motion speed or the distance change rate between the satellite (the terminal can obtain the position and speed information of the satellite through ephemeris information) and the reference point, and the terminal obtains the common timing advance adjustment value of the serving link according to the round-trip delay between the position of the satellite and the reference point.

[0582] The reference point group can use the signaling to transmit the position as used in the foregoing embodiments.

[0583] In one possible implementation, 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 can be replaced by service link TA rate values ​​(with positive / negative indications), feeder link TA rate values ​​(with positive / negative indications), and Doppler pre / post-compensation values ​​(with positive / negative indications), respectively. Similar to Embodiment 3, the reference point coordinates and TA rate values, and Doppler pre / post-compensation values ​​can be used in combination. For example... FIG. 22 As shown, the service link TA rate reference point coordinates can be used in combination with the feeder link TA rate value and the Doppler pre / post compensation value.

[0584] Another possible implementation, such as FIG. 23 As shown, each signaling instruction can be supplemented with an indicator bit to indicate whether the transmitted signaling is the coordinates of the serving link TA rate reference point or the serving link TA rate value (with a positive or negative sign), the coordinates of the feeder link TA rate reference point or the feeder link TA rate value (with a positive or negative sign), or the coordinates of the Doppler pre / post-compensation reference point or the Doppler pre / post-compensation value. For non-staring mode, the common TA rate of the serving link for a certain beam / cell does not change. Therefore, sending signaling to the terminal using the serving link TA rate value (with a positive or negative sign) 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 the system sending signaling.

[0585] When the network side does not send TA rate reference point coordinates or Doppler compensation reference point coordinates to the terminal, or sends invalid coordinate points (such as coordinate values ​​of all zeros), the terminal can use the default reference point coordinate values, such as the coordinate values ​​of the gateway station. That is, when the network side does not send TA rate reference point coordinates or Doppler compensation reference point coordinates to the terminal, or sends invalid coordinate points (such as coordinate values ​​of all zeros), the TA rate reference point coordinates or Doppler compensation reference points revert to the default reference points.

[0586] Example 16

[0587] This embodiment is based on embodiment 14, but replaces the service link / feeder link TA rate reference point coordinates and / or service link / feeder link TA rate values ​​with the service link / feeder link TA rate angles.

[0588] See FIG. 24 Assuming the network side will consider the TA rate of the service link from the perspective of... and / or the TA rate angle of the feeder link is sent to the terminal, and the velocity of the satellite along the moving direction is A. After the terminal receives the TA rate angle, the corresponding TA rate value of the feeder link can be calculated according to the formula [-2 cos( ) A / c] and the corresponding TA rate value of the service link can be calculated according to the formula [-2 cos( ) A / c]. Then, the change value of the TA after a period of time AT can be calculated according to the TA rate as [-2 cos( ) A / c] + [-2 cos( ) A / c]. The corrected TA is TA_original + [-2 cos( ) A / c] + [-2 cos( ) A / c], where TA_original is the TA used before. If the network side only sends the terminal the TA rate angle of the service link or the TA rate angle of the feeder link , the terminal only needs to calculate the updated TA according to TA_original + [-2 cos( ) A / c] or TA_original + [-2 cos( ) A / c].

[0589] Embodiment 17

[0590] In this embodiment, the parameters sent to the terminal, such as the link reference point coordinates, the compensation reference point coordinates, the TA rate reference point coordinates, etc., can be sent to the terminal with the corresponding valid period of the parameters at the same time. This is because the LEO satellite moves at a time, and the position relationship between the terminal and the satellite changes all the time. The public timing advance value or the reference point coordinates sent by the network to the terminal have a valid period of use, and are no longer applicable after the valid period.

[0591] For example, when the network side sends the terminal the compensation reference point coordinates, the valid period of the reference point coordinates is AT at the same time. Wherein, AT can be a value in time slots or a value in Ts. If in time slots, the terminal receives the reference point coordinates after AT / 2μ The compensation reference point is no longer applicable after ms. If in Ts units, then the terminal receives the reference point coordinates after △T The compensation reference point is no longer applicable after Ts seconds.

[0592] If the network side sends the link reference point coordinates, the compensation reference point coordinates, the TA rate reference point coordinates, etc. to the terminal in a periodic broadcast manner, when the parameters expire, the terminal can obtain the new parameter values by re-receiving the parameters, decoding manner. If the network side sends the link reference point coordinates, the compensation reference point coordinates, the TA rate reference point coordinates, etc. to the terminal in a non-periodic broadcast manner, when the parameters expire, the terminal can obtain the new parameter values by re-applying the parameters to the network side.

[0593] In the embodiment, the network side sends the terminal the parameters configured with the corresponding validity period, which can further improve the reliability of communication.

[0594] It should be noted that in the embodiments 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 of the network side and the terminal in the above ATG communication scenario and ATG communication scenario. The specific implementation method in this case can be referred to the satellite communication scenario and the ATG communication scenario respectively, which will not be described here.

[0595] The above embodiments can be combined with each other to achieve different technical effects.

[0596] The above embodiments provided by the present application are introduced from the perspective of interaction between the network device (such as satellite, gateway station, ATG network device, etc.) and the terminal. In order to realize the functions in the above embodiments provided by the present application, the terminal and the network device can include hardware structures and / or software modules, and the above functions can be realized in the form of hardware structures, software modules, or hardware structures and software modules. Whether a certain function in the above functions is executed in the form of hardware structure, software module, or hardware structure and software module depends on the specific application of the technical solution and the design constraint conditions. The communication device of the embodiments of the present application is introduced as follows.

[0597] The embodiment of the present application further provides a communication device 2500, which can be the first network device in the method embodiment, or a device (for example, a chip, or a chip system, or a circuit) in the first network device, or a device capable of being used in matching with the first network device. The device 2500 can include a module corresponding to the method / operation / step / action performed by the first network device in the method embodiment, which can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0598] For example, referring to FIG. 25 , the device 2500 includes:

[0599] The processing unit 2501 is configured to determine a first parameter according to a first time delay compensation value, wherein the first time delay compensation value is a time delay compensation made by the first network device for a signal sent by a terminal, and the first parameter is used to indicate a difference between a round trip time delay of a feeder link in a non-terrestrial network (NTN) and the first time delay compensation value, and the difference is used to determine a TA used by the terminal for sending a signal.

[0600] The sending unit 2502 is configured to send the first parameter.

[0601] The specific implementation of the operation performed by each unit above can refer to the specific implementation of the operation performed by the first network device in the method embodiment, which will not be described here.

[0602] The embodiment of the present application further provides a communication device 2600, which can be the second network device in the method embodiment, or a device (for example, a chip, or a chip system, or a circuit) in the second network device, or a device capable of being used in matching with the first network device. The device 2500 can include a module corresponding to the method / operation / step / action performed by the second network device in the method embodiment, which can be a hardware circuit, or software, or a combination of hardware circuit and software.

[0603] For example, referring to FIG. 26 , the device 2600 includes:

[0604] The processing unit 2601 is configured to determine a position coordinate of a compensation reference point according to a second time delay compensation value, wherein the second time delay compensation value is a time delay compensation value made by the second network device for a signal sent by a terminal, and the second time delay compensation value is used to determine a TA used by the terminal for sending a signal, and the TA is equal to a round trip time delay of a service link in an NTN minus the second time delay compensation value.

[0605] The sending unit 2602 is configured to send the position coordinates of the compensation reference point.

[0606] 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 method embodiments, which will not be described here.

[0607] Embodiments of the present application further provide a communication apparatus 2700. The apparatus 2700 can be the ATG network device in the above method embodiments, or a device (for example, a chip, or a chip system, or a circuit) in the ATG network device, or a device that can be used in matching with the ATG network device. The apparatus 2700 can include modules corresponding to the methods / operations / steps / actions performed by the ATG network device in the method embodiments. The modules can be hardware circuits, software, or a combination of hardware circuits and software.

[0608] For example, referring to FIG. 27 , the apparatus 2700 includes:

[0609] The processing unit 2701 is configured to determine the position coordinates of the ATG reference point, wherein the position coordinates of the ATG reference point are used to determine the TA used by a terminal to send a signal to the ATG network device.

[0610] The sending unit 2702 is configured to send the position coordinates of the ATG reference point.

[0611] 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 method embodiments, which will not be described here.

[0612] Embodiments of the present application further provide a communication apparatus 2800. The apparatus 280 can be the terminal in the above method embodiments, or a terminal (for example, a chip, or a chip system, or a circuit) in the ATG network device, or a device that can be used in matching with the terminal. The apparatus 2800 can include modules corresponding to the methods / operations / steps / actions performed by the terminal in the method embodiments. The modules can be hardware circuits, software, or a combination of hardware circuits and software.

[0613] For example, referring to FIG. 28 , the apparatus 2800 includes:

[0614] The 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 made by the first network device for a signal sent by a terminal, and the difference is used to determine a TA used by the terminal for sending a signal.

[0615] The processing unit 2802 is configured to determine a TA value used for sending a signal according to the first parameter.

[0616] Alternatively,

[0617] The receiving unit 2801 is configured to receive a position coordinate of a compensation reference point, wherein the second delay compensation value is a delay compensation made by the second network device for a signal sent by a terminal, the second delay compensation value is used to determine a TA used by the terminal for sending 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.

[0618] The processing unit 2802 is configured to determine a TA used for sending a signal according to the position coordinate of the compensation reference point.

[0619] Alternatively,

[0620] The receiving unit 2801 is configured to receive a position coordinate of an air-to-ground (ATG) reference point.

[0621] The processing unit 2802 is configured to determine a TA used for sending a signal according to the position coordinate of the ATG reference point.

[0622] 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 method embodiments described above, and will not be described here.

[0623] The communication device in the embodiments of the present application is introduced above, and possible product forms of the communication device are introduced below. It should be understood that any product form that has 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 introduction is only an example, and the product form of the communication device in the embodiments of the present application is not limited to this. FIGS. 25-28 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 introduction is only an example, and the product form of the communication device in the embodiments of the present application is not limited to this.

[0624] FIG. 29 The communication device 2900 provided in the embodiments of the present application can be used to execute the method performed by the first network device, the second network device, the ATG device or the terminal. The device 2900 can include a processor 2901 and a communication interface, the communication interface is configured to communicate with other communication devices; the processor 2901 is configured to run a set of programs to enable the device to implement the method steps in the method embodiments described above.

[0625] The processor 2901 can be a general 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 component, a discrete hardware component, and can implement or execute the methods, steps, and logical block diagrams disclosed in the embodiments of the present application. The general processor 2901 can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of the present application can be directly embodied as hardware processor execution or executed by a combination of hardware and software modules in the processor.

[0626] The communication interface 2902 can be a transceiver, a circuit, a bus, a module or other types of communication interfaces, used for communication with other devices through a transmission medium. When the device is a terminal, the other device can be a satellite, a gateway or an ATG network device. When the device is a satellite, a gateway or an ATG network device, the other device can be a terminal.

[0627] Optionally, the device 2900 can further include a memory 2903 for storing program instructions and / or data. The memory 2903 can be a non-volatile memory such as a hard disk drive (HDD) or a solid-state drive (SSD), and can also be a volatile memory such as a random-access memory 2903 (RAM). The memory can be any other medium capable of carrying or storing desired program codes in the form of instructions or data structures and capable of being accessed by a computer, but is not limited thereto. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, used for storing program instructions and / or data.

[0628] The memory 2903 can be coupled with the processor 2901. The coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, used for information interaction between devices, units or modules. The processor 2901 can operate in cooperation with the memory 2903. The processor 2901 can execute program instructions stored in the memory 2903. At least one of the at least one memory 2903 can be included in the processor 2901.

[0629] It should be understood that the specific connection medium between the communication interface 2902, the processor 2901 and the memory 2903 in the embodiments of the present application is not limited. In the embodiments of the present application, the memory 2903, the communication interface 2902 and the processor 2901 are connected through a bus, and the bus is connected through a bus in the embodiments of the present application. FIG. 29 FIG. 29 ​The connection between the other components is indicated by a thick line, which is only illustrative and not limited. The bus can be divided into an address bus, a data bus, a control bus, etc. For convenience, FIG. 29 The bus is indicated by a thick line, but it does not mean that there is only one bus or only one type of bus.

[0630] FIG. 30 An apparatus 3000 provided by the embodiment of the present application can be used to execute the method performed by the first network device, the second network device, the ATG device or the terminal, and the apparatus 3000 can be a communication device or a chip in the communication device. As shown in FIG. 30 The apparatus 3000 includes at least one input interface (Input(s)) 3001, a logic circuit 3002, and at least one output interface (Output(s)) 3003.

[0631] Optionally, the logic circuit 3002 can be a chip, an encoder, an encoding circuit or other integrated circuits that can implement the method of the present application.

[0632] Since the specific method and embodiment have been introduced in the foregoing, the functions of the input interface 3001, the logic circuit 3002 or the output interface 3003 can refer to the related part of the corresponding embodiment, which will not be described here.

[0633] The embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium stores computer readable instructions. When the computer readable instructions run on a communication device, the communication device executes the method performed by the first network device, the second network device, the ATG device or the terminal.

[0634] The embodiment of the present application provides a computer program product, which includes instructions. When the instructions run on a computer, the computer executes the method performed by the first network device, the second network device, the ATG device or the terminal.

[0635] The embodiment of the present application is described with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of the flows and / or blocks can be realized by computer program instructions. These computer program instructions can be provided to a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the computer or other programmable data processing device produce a device for implementing the functions specified in the flowchart and / or block diagram. FIG. 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks FIG. 1 one block or multiple blocks.

[0636] In the embodiments described above, all or some of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or some of the embodiments can be implemented in the form of a computer program product storing computer program instructions. The computer program instructions are executed in a computer to implement the procedures or functions according to the embodiments of the present application. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatuses. The computer program instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another. For example, the computer program instructions can be transmitted from a website, a computer, a server or a data center to another website, computer, server or data center through wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium or a set of medium that is accessible by a computer or a data storage device such as a server, data center, etc. that includes one or more of the available medium. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, digital versatile disc (DVD)), or a semiconductor medium (for example, solid state disk (SSD)), etc.

[0637] Obviously, persons of skill in the art can make various modifications and variations 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 belong to 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 characterized by comprising: include: Obtain common timing parameters, a first fixed value and a second fixed value, wherein the first fixed value is obtained based on at least one of a timing advance command (TAC) or a media access control element (MAC CE), and the second fixed value is obtained based on a radio resource control (RRC) message, or the second fixed value is a value agreed upon by the protocol. Based on the common timing parameters, the first fixed value, the second fixed value, and the round-trip delay of the service link, the timing advance TA is determined.

2. The method of claim 1, wherein, The timing advance is the round-trip delay of the service link, the common timing parameter, the first fixed value, and the second fixed value.

3. The method of claim 2, wherein, The round-trip delay of the service link, the common timing parameter, and the first fixed value and the second fixed value have the same time unit.

4. The method according to any one of claims 1-3, characterized in that, The common timing parameters are carried in the Radio Resource Control (RRC) message.

5. The method according to any one of claims 1 to 4, characterized in that, The common timing parameters are obtained from the system message SIB.

6. The method according to any one of claims 1 to 5, 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, characterized in that, The round-trip latency of the service link is determined based on the location of the terminal and the location of the satellite.

8. The method of claim 7, wherein, Also includes: The round-trip time of the service link is determined based on the location of the terminal and the location of the satellite.

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

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

11. The method according to claim 9 or 10, characterized in that, The TA rate is carried in the Radio Resource Control (RRC) message.

12. The method according to any one of claims 1-11, characterized in that, The validity period of the common timing parameters is received, and the common timing parameters are no longer applicable after the validity period.

13. A method of communication, comprising: include: Determine the common timing parameters, including the first fixed value and the second fixed value; Send the common timing parameters, the first fixed value and the second fixed value; The first fixed value is carried in at least one of the Timing Advance Command (TAC) or the Media Access Control (MAC) Control Element (CE), and the second fixed value is carried in the Radio Resource Control (RRC) message; the common timing parameters, the first fixed value, and the second fixed value are used to determine the Timing Advance (TA).

14. The method of claim 13, wherein, The timing advance is the round-trip delay of the service link, and the common timing parameter is the sum of the first fixed value and the second fixed value.

15. The method of claim 14, wherein, The round-trip delay of the service link, the common timing parameter, and the first fixed value and the second fixed value have the same time unit.

16. The method according to any one of claims 13-15, characterized in that, The common timing parameters are carried in the Radio Resource Control (RRC) message.

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

18. The method according to any one of claims 13-17, characterized by, Also includes: Send the timing advance change rate (TA rate), which is used to correct the TA.

19. The method of claim 18, wherein, The TA rate is carried in the Radio Resource Control (RRC) message.

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

21. A communications device, characterized by Includes units or modules for performing the method according to any one of claims 1-12.

22. A communication device, characterized in that, Includes units or modules for performing the method according to any one of claims 13-20.

23. A communication device, characterized in that, The device includes a processor coupled to a memory storing a computer program, the processor being configured to run the computer program such that the communication device performs the method according to any one of claims 1-12.

24. A communication device, characterized in that, The device includes a processor coupled to a memory storing a computer program, the processor being configured to run the computer program such that the communication device performs the method according to any one of claims 13-20.

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

26. A computer program product containing instructions, characterized in that, When it is run on a computer, it causes the method of any one of claims 1-12 to be performed; or causes the method of any one of claims 13-20 to be performed.

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