CN110324889B

CN110324889B - Clock synchronization method, communication device and communication equipment

Info

Publication number: CN110324889B
Application number: CN201810276004.0A
Authority: CN
Inventors: 杨坤; 高峰; 于光炜; 张言飞; 汲桐
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-03-30
Filing date: 2018-03-30
Publication date: 2021-02-09
Anticipated expiration: 2038-03-30
Also published as: CN110324889A

Abstract

The embodiment of the application provides a clock synchronization method, a communication device and communication equipment, wherein the method comprises the following steps: the terminal equipment receives first time information from the network equipment; receiving a downlink signal from the network device; sending an uplink signal to the network device; receiving second time information from the network equipment, wherein the second time information is used for determining the receiving time of the network equipment for receiving the uplink signal; determining the sending time of the downlink signal according to the reference time point and the time sequence relation between the uplink signal and the downlink signal; and determining the clock deviation of the terminal equipment according to the transmitting time and the receiving time of the downlink signal and the transmitting time and the receiving time of the uplink signal. The sending time of the synchronous message is calculated by the terminal equipment, and the network equipment does not need to send the following message to the terminal equipment to carry the sending time of the synchronous message, so that time-frequency resources in a wireless network are saved, and the complexity of the network equipment for scheduling the time-frequency resources is reduced.

Description

Clock synchronization method, communication device and communication equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a clock synchronization method, a communication apparatus, and a communication device.

Background

In a wireless network, different terminal devices need to have the same time system, i.e., the terminal devices need to keep clocks synchronized.

In the prior art, one way to implement the terminal device to maintain clock synchronization is as follows: the network equipment sends a downlink signal to the terminal equipment, the network equipment records a first moment when the network equipment sends the downlink signal, and the terminal equipment records a second moment when the network equipment receives the downlink signal; the terminal equipment sends an uplink signal to the network equipment, the terminal equipment records the third moment when the terminal equipment sends the uplink signal, and the network equipment records the fourth moment when the network equipment receives the uplink signal; and the terminal equipment calculates the clock deviation of the local clock according to the first time, the second time, the third time and the fourth time, and corrects the local clock according to the clock deviation.

Since the terminal device needs to know the first time and the fourth time before calculating the clock offset according to the first time, the second time, the third time and the fourth time, the network device needs to send the time information corresponding to the first time to the terminal device after sending the downlink signal, and the network device needs to send the time information corresponding to the fourth time to the terminal device after receiving the uplink signal. When the network device corresponds to multiple terminal devices, the network device needs to send a downlink signal to each network device, and after sending the downlink signal, time information corresponding to the first time is sent to each network device, so that the network device needs to configure a large number of time-frequency resources, which causes high time-frequency resource overhead in a wireless network, and increases complexity of the network device in scheduling the time-frequency resources.

Disclosure of Invention

The application provides a clock synchronization method, a communication device and communication equipment, which are used for saving time-frequency resources in a wireless network and reducing the complexity of time-frequency resource scheduling of the network equipment.

In a first aspect, the present application provides a clock synchronization method, including: the terminal equipment receives first time information from the network equipment, wherein the first time information is used for indicating time information of a reference time point; the terminal equipment receives downlink signals such as synchronous messages from the network equipment and records the receiving time of the synchronous messages; the terminal equipment sends an uplink signal such as a delay request message to the network equipment and records the sending time of the delay request message; optionally, the downlink signal and the uplink signal have no fixed sequence; after the network equipment receives the delay request message, the terminal equipment receives second time information from the network equipment, and the terminal equipment can determine the receiving time of the network equipment for receiving the delay request message according to the second time information; the terminal device further calculates the sending time of the synchronous message sent by the network device according to the reference time point, the time sequence relation of the synchronous message and the delay request message; and calculating the local clock deviation of the terminal equipment according to the sending time and the receiving time of the synchronous message and the sending time and the receiving time of the delay request message. According to the scheme provided by the embodiment, after the network equipment sends the downlink signal such as the synchronization message to the terminal equipment, the network equipment does not need to send the follow-up message to the terminal equipment, that is, the network equipment does not need to send the follow-up message to the terminal equipment to carry the sending time of the synchronization message, the time required by a single clock synchronization process is shortened, and the terminal equipment can determine the sending time of the synchronization message according to the time sequence relation between the uplink signal such as the synchronization message and the downlink signal such as the delay request message and the reference time point received by the terminal equipment from the network equipment. When the network device corresponds to a plurality of terminal devices, the network device does not need to send a following message to each terminal device after sending a synchronization message to each terminal device, so that the network device does not need to configure time-frequency resources for each following message, thereby saving the time-frequency resources in a wireless network and reducing the complexity of the network device for scheduling the time-frequency resources.

In one possible design, the timing relationship between the upstream signal and the downstream signal includes: the offset of the downlink signal relative to a reference time point, and the offset of the uplink signal relative to the reference time point.

In one possible design, the determining, by the terminal device, the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal includes:

and the terminal equipment determines the sending time of the downlink signal according to the reference time point and the offset of the downlink signal relative to the reference time point.

In one possible design, the offset of the downlink signal from the reference time point includes:

a radio frame offset of a radio frame boundary corresponding to the downlink signal relative to the reference time; or

A subframe offset of a subframe boundary corresponding to the downlink signal relative to the reference time point; or

And the time slot boundary corresponding to the downlink signal is relative to the time slot offset of the reference time point.

In one possible design, the second time information includes a reception time at which the network device receives the uplink signal.

In one possible design, the second time information includes a time difference between a starting time when the network device starts receiving the uplink signal and a receiving time when the network device receives the uplink signal;

the method further comprises the following steps:

and the terminal equipment determines the receiving time when the network equipment receives the uplink signal according to the reference time point, the offset of the uplink signal relative to the reference time point and the time difference.

In one possible design, the offset of the uplink signal from the reference time point includes:

a radio frame offset of a radio frame boundary corresponding to the uplink signal relative to the reference time point; or

A subframe offset of a subframe boundary corresponding to the uplink signal relative to the reference time point; or

And the time slot boundary corresponding to the uplink signal is relative to the time slot offset of the reference time point.

In one possible design, the timing relationship between the upstream signal and the downstream signal includes: a transmission period of the uplink signal and the downlink signal, an offset of the uplink signal relative to the downlink signal, and a starting position of the uplink signal or the downlink signal relative to the reference time point.

the terminal equipment determines the sending time of the downlink signal according to the reference time point, the initial position of the downlink signal relative to the reference time point and the sending period of the downlink signal; or

And the terminal equipment determines the sending time of the downlink signal according to the reference time point, the initial position of the uplink signal relative to the reference time point, the sending period of the uplink signal and the offset of the uplink signal relative to the downlink signal.

In one possible design, before the terminal device receives the downlink signal from the network device, the method further includes:

and the terminal equipment receives configuration information from the network equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal.

In one possible design, the configuration information further includes: a transmission period of the first time information.

In one possible design, the configuration information further includes: and the time information of the corresponding reference time point in the current sending period of the first time information.

In a second aspect, the present application provides a clock synchronization method, including:

the method comprises the steps that network equipment sends first time information to terminal equipment, wherein the first time information is used for indicating time information of a reference time point;

the network equipment sends a downlink signal to the terminal equipment;

the network equipment receives an uplink signal from the terminal equipment;

and the network equipment sends second time information to the terminal equipment, wherein the second time information is used for determining the receiving time of the network equipment for receiving the uplink signal.

In one possible design, after the network device sends the first time information to the terminal device, the method further includes:

and the network equipment sends configuration information to the terminal equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal.

In one possible design, the second time information includes a reception time at which the network device receives the uplink signal; or

The second time information includes a time difference between a start time when the network device starts receiving the uplink signal and a receiving time when the network device receives the uplink signal.

In a third aspect, the present application provides a clock synchronization method, including:

the network equipment sends a downlink signal to the terminal equipment;

the network equipment receives an uplink signal from the terminal equipment;

the network equipment receives time information from the terminal equipment, wherein the time information comprises the receiving time of the downlink signal or the sending time of the uplink signal;

the network equipment determines the incidence relation between the receiving time of the downlink signal and the sending time of the uplink signal according to the time sequence relation between the uplink signal and the downlink signal and the sending advance time of the terminal equipment;

the network equipment determines the clock deviation of the terminal equipment according to the incidence relation between the receiving time of the downlink signal and the sending time of the uplink signal, the receiving time of the downlink signal or the sending time of the uplink signal, the sending time of the downlink signal and the receiving time of the uplink signal;

and the network equipment sends the clock deviation of the terminal equipment to the terminal equipment.

In one possible design, the timing relationship between the upstream signal and the downstream signal includes: and the wireless frame number, the subframe number or the time slot number corresponding to the time domain resource of the uplink signal, and the wireless frame number, the subframe number or the time slot number corresponding to the time domain resource of the downlink signal.

In one possible design, the timing relationship between the upstream signal and the downstream signal includes: the sending period of the uplink signal and the downlink signal, the offset of the uplink signal relative to the downlink signal, and the initial position of the uplink signal or the downlink signal.

In a possible design, before the network device sends the downlink signal to the terminal device, the method further includes:

In a fourth aspect, the present application provides a clock synchronization method, including:

the terminal equipment receives a downlink signal from the network equipment;

the terminal equipment sends an uplink signal to the network equipment;

the terminal equipment sends time information to the network equipment, wherein the time information comprises the receiving time of the downlink signal or the sending time of the uplink signal;

the terminal device receives the clock offset of the terminal device from the network device.

and the terminal equipment receives configuration information from network equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal.

In a fifth aspect, the present application provides a communication device, comprising:

a receiving module, configured to receive first time information from a network device, where the first time information is used to indicate time information of a reference time point; receiving a downlink signal from the network device;

a sending module, configured to send an uplink signal to the network device;

the receiving module is further configured to receive second time information from the network device, where the second time information is used to determine a receiving time at which the network device receives the uplink signal;

the determining module is used for determining the sending time of the downlink signal according to the reference time point and the time sequence relation between the uplink signal and the downlink signal; and determining the clock deviation of the communication device according to the sending time of the downlink signal, the receiving time of the downlink signal, the sending time of the uplink signal and the receiving time of the uplink signal.

In a possible design, when the determining module determines the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, the determining module is specifically configured to:

and determining the sending time of the downlink signal according to the reference time point and the offset of the downlink signal relative to the reference time point.

the determination module is further to: and determining the receiving time when the network equipment receives the uplink signal according to the reference time point, the offset of the uplink signal relative to the reference time point and the time difference.

determining the sending time of the downlink signal according to the reference time point, the initial position of the downlink signal relative to the reference time point and the sending period of the downlink signal; or

And determining the sending time of the downlink signal according to the reference time point, the initial position of the uplink signal relative to the reference time point, the sending period of the uplink signal and the offset of the uplink signal relative to the downlink signal.

In one possible design, the receiving module is further configured to: receiving configuration information from the network device, the configuration information including a timing relationship of the uplink signal and the downlink signal.

In a sixth aspect, the present application provides a communication apparatus comprising:

the terminal equipment comprises a sending module, a receiving module and a processing module, wherein the sending module is used for sending first time information to the terminal equipment, and the first time information is used for indicating time information of a reference time point; sending a downlink signal to the terminal equipment;

a receiving module, configured to receive an uplink signal from the terminal device;

the sending module is further configured to: and sending second time information to the terminal equipment, wherein the second time information is used for determining the receiving time of the communication device for receiving the uplink signal.

In one possible design, the sending module is further configured to:

and sending configuration information to the terminal equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal.

In a seventh aspect, the present application provides a communications apparatus, comprising:

the sending module is used for sending downlink signals to the terminal equipment;

a receiving module, configured to receive an uplink signal from the terminal device; receiving time information from the terminal equipment, wherein the time information comprises the receiving time of the downlink signal or the sending time of the uplink signal;

a determining module, configured to determine, according to a time sequence relationship between the uplink signal and the downlink signal and a sending advance time of the terminal device, an association relationship between a receiving time of the downlink signal and a sending time of the uplink signal; determining the clock deviation of the terminal equipment according to the incidence relation between the receiving time of the downlink signal and the transmitting time of the uplink signal, the receiving time of the downlink signal or the transmitting time of the uplink signal, the transmitting time of the downlink signal and the receiving time of the uplink signal;

the sending module is further configured to: and sending the clock deviation of the terminal equipment to the terminal equipment.

In one possible design, the sending module is further configured to:

In an eighth aspect, the present application provides a communication apparatus, comprising:

a receiving module, configured to receive a downlink signal from a network device;

a sending module, configured to send an uplink signal to the network device; sending time information to the network equipment, wherein the time information comprises the receiving time of the downlink signal or the sending time of the uplink signal;

the receiving module is further configured to: receiving a clock offset of the communication device from the network equipment.

In one possible design, the receiving module is further configured to:

receiving configuration information from a network device, the configuration information including a timing relationship of the uplink signal and the downlink signal.

In a ninth aspect, the present application provides a communication device comprising:

an interface and a processor, the interface and the processor coupled;

the processor is configured to perform the clock synchronization method according to the first aspect and the fourth aspect.

In a possible design, the communication device in the ninth aspect may be a terminal device, or may be a chip; the interface can be integrated with the processor on the same chip or can be respectively arranged on different chips.

In a tenth aspect, the present application provides a communication device comprising:

an interface and a processor, the interface and the processor coupled;

the processor is configured to perform the clock synchronization method according to the second and third aspects.

In a possible design, the communication device in the tenth aspect may be a network device or a chip; the interface can be integrated with the processor on the same chip or can be respectively arranged on different chips.

In an eleventh aspect, the present application provides a computer readable storage medium having stored therein a computer program which, when run on a computer, causes the computer to perform the method according to the first and fourth aspects.

In a twelfth aspect, the present application provides a computer readable storage medium having stored therein a computer program which, when run on a computer, causes the computer to perform the method according to the second and third aspects.

In a thirteenth aspect, the present application provides a computer program for performing the method of the first and fourth aspects when the computer program is executed by a computer.

In a possible design, the program in the thirteenth aspect may be stored in whole or in part on a storage medium packaged with the processor, or in part or in whole on a memory not packaged with the processor.

In a fourteenth aspect, the present application provides a computer program for performing the method of the second and third aspects when the computer program is executed by a computer.

In a possible design, the program in the fourteenth aspect may be stored in whole or in part on a storage medium packaged with the processor, or in part or in whole on a memory not packaged with the processor.

In a fifteenth aspect, the present application provides a communication device comprising:

a memory and a processor, the memory and the processor coupled;

the processor is configured to perform the method according to the first and fourth aspects.

In a possible design, the communication device in the fifteenth aspect may be a terminal device or a chip; the memory may be integrated on the same chip as the processor or may be separately provided on different chips.

In a sixteenth aspect, the present application provides a communication device comprising:

a memory and a processor, the memory and the processor coupled;

the processor is configured to perform the method according to the second and third aspects.

In a possible design, the communication device in the sixteenth aspect may be a network device or a chip; the memory may be integrated on the same chip as the processor or may be separately provided on different chips.

In a seventeenth aspect, the present application provides a processor, comprising:

at least one circuit configured to receive first time information from a network device, the first time information indicating time information of a reference time point;

at least one circuit configured to receive a downlink signal from the network device;

at least one circuit configured to transmit an upstream signal to the network device;

at least one circuit configured to receive second time information from the network device, where the second time information is used to determine a receiving time at which the network device receives the uplink signal;

at least one circuit, configured to determine a sending time of the downlink signal according to the reference time point and a time sequence relationship between the uplink signal and the downlink signal;

and the at least one circuit is used for determining the clock deviation of the terminal equipment according to the sending time of the downlink signal, the receiving time of the downlink signal, the sending time of the uplink signal and the receiving time of the uplink signal.

In one possible design, the processor in the seventeenth aspect may be a chip.

In an eighteenth aspect, the present application provides a processor comprising:

at least one circuit configured to send first time information to a terminal device, where the first time information is used to indicate time information of a reference time point;

at least one circuit for transmitting a downlink signal to the terminal device;

at least one circuit configured to receive an uplink signal from the terminal device;

at least one circuit, configured to send second time information to the terminal device, where the second time information is used to determine a receiving time at which the network device receives the uplink signal.

In one possible design, the processor in the eighteenth aspect may be a chip.

In a nineteenth aspect, the present application provides a processor comprising:

at least one circuit for transmitting a downlink signal to a terminal device;

at least one circuit configured to receive time information from the terminal device, where the time information includes a reception time of the downlink signal or a transmission time of the uplink signal;

at least one circuit, configured to determine, according to a timing relationship between the uplink signal and the downlink signal and a transmission advance time of the terminal device, an association relationship between a reception time of the downlink signal and a transmission time of the uplink signal;

at least one circuit, configured to determine a clock skew of the terminal device according to an association relationship between a reception time of the downlink signal and a transmission time of the uplink signal, the reception time of the downlink signal or the transmission time of the uplink signal, the transmission time of the downlink signal, and the reception time of the uplink signal;

at least one circuit for transmitting a clock offset of the terminal device to the terminal device.

In one possible design, the processor in the nineteenth aspect may be a chip.

In a twentieth aspect, the present application provides a processor comprising:

at least one circuit configured to receive a downlink signal from a network device;

at least one circuit, configured to send time information to the network device, where the time information includes a receiving time of the downlink signal or a sending time of the uplink signal;

at least one circuit for receiving a clock offset for the terminal device from the network device.

In one possible design, the processor in the twentieth aspect may be a chip.

Therefore, in each aspect, after the network device sends the downlink signal, such as the synchronization message, to the terminal device, the network device does not need to send the follow-up message to the terminal device, that is, the network device does not need to send the follow-up message to the terminal device to carry the sending time of the synchronization message, so that the time required by a single clock synchronization process is shortened, and the terminal device can determine the sending time of the synchronization message according to the time sequence relationship between the uplink signal, such as the synchronization message, and the downlink signal, such as the delay request message, and the reference time point received by the terminal device from the network device. When the network device corresponds to a plurality of terminal devices, the network device does not need to send a following message to each terminal device after sending a synchronization message to each terminal device, so that the network device does not need to configure time-frequency resources for each following message, thereby saving the time-frequency resources in a wireless network and reducing the complexity of the network device for scheduling the time-frequency resources.

Drawings

Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application;

fig. 2 is a signaling diagram of a clock synchronization method provided in the present application;

FIG. 3 is a signaling diagram of another clock synchronization method provided herein;

fig. 4 is a schematic structural diagram of a radio frame provided in the present application;

fig. 5 is a schematic structural diagram of another radio frame provided in the present application;

fig. 6 is a schematic structural diagram of another radio frame provided in the present application;

fig. 7 is a signaling diagram of still another clock synchronization method provided in the present application;

FIG. 8 is a signaling diagram of yet another clock synchronization method provided herein;

FIG. 9 is a signaling diagram of yet another clock synchronization method provided herein;

FIG. 10 is a signaling diagram of yet another clock synchronization method provided herein;

FIG. 11 is a signaling diagram of another clock synchronization method provided herein;

fig. 12 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 15 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of a terminal device according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a network device according to an embodiment of the present application;

fig. 18 is a schematic structural diagram of another network device according to an embodiment of the present application.

Detailed Description

The terminology used in the description of the embodiments section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

The embodiment of the application can be applied to various types of communication systems. Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application. The communication system shown in fig. 1 mainly includes a network device 11 and a terminal device 12.

Wherein, 1) the network device 11 may be a network side device, for example, an access point AP of Wireless Fidelity (WIFI), a base station of next generation communication, such as a gNB or a small station of 5G, a micro station, a TRP, or a relay station, an access point, a vehicle-mounted device, a wearable device, and the like. In this embodiment, the base stations in the communication systems of different communication systems are different. For the sake of distinction, a base station of the 4G communication system is referred to as an LTE eNB, a base station of the 5G communication system is referred to as an NR gNB, and a base station supporting both the 4G communication system and the 5G communication system is referred to as an LTE eNB, and these names are for convenience of distinction only and are not intended to be limiting.

2) The terminal device 12, also referred to as a User Equipment (UE), is a device that provides voice and/or data connectivity to a User, such as a handheld device with wireless connection capability, a vehicle-mounted device, and so on. Common terminal devices include, for example: the mobile phone includes a mobile phone, a tablet computer, a notebook computer, a palm computer, a Mobile Internet Device (MID), and a wearable device such as a smart watch, a smart bracelet, a pedometer, and the like.

3) "plurality" means two or more, and other terms are analogous. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

It should be noted that the number and the type of the terminal devices 12 included in the communication system shown in fig. 1 are only one distance, and the embodiment of the present application is not limited thereto. For example, more terminal devices 12 communicating with the network device 11 may be included, and are not depicted in the figures one by one for simplicity of description. Furthermore, in the communication system shown in fig. 1, although the network device 11 and the terminal device 12 are shown, the communication system may not be limited to include the network device 11 and the terminal device 12, and may also include a core network device or a device for carrying a virtualized network function, which is obvious to those skilled in the art and is not described herein in detail.

The embodiments of the present application may be applied to a wireless cellular communication network system, which may be understood as a wireless communication system based on a cellular network architecture. For example, a Global System for Mobile communications (GSM) System, a Wideband Code Division Multiple Access (WCDMA) System, a Long Term Evolution (LTE), a 5G New air interface (NR) communication System, and the like. In addition, the embodiment of the application can also be applied to other systems which may appear in the future, such as wifi networks of the next generation, 5G car networking and the like.

In general, a terminal device needs to keep synchronization with absolute Time, such as Coordinated Universal Time (UTC), Global Navigation Satellite System (GNSS), and the like. For example, terminal devices in a factory need to achieve time synchronization according to the same time reference system to cooperatively perform tasks such as processing, measurement, and the like.

In a wireless network, different terminal devices also need to have the same time system, and perform clock synchronization according to the same time reference system. At present, one method for implementing clock synchronization is a process shown in fig. 2, where the process involves communication between a network device and a terminal device, and optionally, in a Wireless-Fidelity (WIFI) network, the network device may specifically be an Access Point (AP). In a mobile data network, the network device may specifically be a base station. In addition, the network device corresponds to a Master Clock node (Master Clock), and the terminal device corresponds to a Slave Clock node (Slave Clock). The master clock node may be provided with an external clock module such as an atomic clock, a Global Positioning System (GPS), or the like, or the master clock node may be calibrated with an external clock to acquire absolute time with high accuracy. And the slave clock node calculates the clock deviation of the local clock of the slave clock node relative to the master clock node in the communication process with the master clock node, and corrects the local clock of the slave clock node according to the clock deviation so as to keep the local clock of the slave clock node and the clock of the master clock node synchronous. In the following, a clock synchronization method shown in fig. 2 is described in detail by taking a base station as a master clock node and a terminal device as a slave clock node as an example, and the method specifically includes the following steps:

step S21, the master clock node sends a notification message to the slave clock node.

Specifically, the master clock node may be an optimal clock source selected from the network, and after the master clock node is selected, the master clock node may send a notification message to the slave clock node to notify the slave clock node that the slave clock node is the master clock node.

Step S22, the master clock node sends a synchronization Message (Sync Message) to the slave clock node, and the master clock node records the sending time t1 of the master clock node for sending the synchronization Message according to the master clock; when the slave clock node receives the synchronization message, the reception time t2 of the synchronization message is recorded according to the slave clock.

Step S23, the master clock node sends a Follow-up Message (Follow _ up Message) to the slave clock node, where the Follow-up Message carries time stamp information t1, that is, the sending time of the synchronization Message.

Step S24, the slave clock node sends a Delay request Message (Delay _ Req Message) to the master clock node, and the slave clock node records the sending time t3 of the Delay request Message according to the slave clock; when the master clock node receives the delay request message, it records the receiving time t4 of the delay request message according to the master clock.

Step S25, the master clock node sends a Delay Response Message (Delay _ Response Message) to the slave clock node, where the Delay Response Message carries time stamp information t4, that is, the time of receiving the Delay request Message.

Step S26, the slave clock node calculates a clock offset and corrects the timing of the local clock.

Specifically, the slave clock node calculates the clock skew of the local clock of the slave clock node with respect to the master clock node, which is denoted as Offset, according to the transmission time t1 of the synchronization message, the reception time t2 of the synchronization message, the transmission time t3 of the delay request message, and the reception time t4 of the delay request message, and the relationship among Offset, t1, t2, t3, and t4 can be expressed by the following formula (1):

in addition, the slave clock node may also calculate a Delay of transmission of the signal from the master clock node to the slave clock node through t1, t2, t3 and t4, and the calculation formula of the Delay is expressed as the following formula (2):

after the clock deviation is calculated by the slave clock node, the timing of the local clock of the slave clock node is further corrected according to the clock deviation so as to keep the local clock of the slave clock node and the clock of the master clock node in high-precision synchronization, and therefore the local clock of the slave clock node and the absolute time are kept in high-precision synchronization.

As shown in fig. 2, steps S22 to S26 may be written as a clock synchronization procedure, in which the base station needs to send the timestamp information to the terminal device twice, once is the timestamp information t1 carried in the follow message, and the other time is the timestamp information t4 carried in the delay request message. The base station needs to send a following message after sending the synchronization message, and if the base station corresponds to multiple terminal devices, the base station needs to send the following message to each terminal device after sending the synchronization message to each terminal device, so the base station needs to configure time-frequency resources for sending the synchronization message and the following message and schedule the time-frequency resources. In order to solve the problem, embodiments of the present application provide a clock synchronization method, and the clock synchronization method is described in detail below with reference to the embodiments.

Fig. 3 is a signaling diagram of a clock synchronization method provided in the present application. In this embodiment, the network device may be a base station, and in the 4G communication system, the base station is an eNB; in the 5G communication system, the base station is a gNB, and the base station described in this embodiment is not limited to the eNB and the gNB. In addition, the network device may also be an access point AP in a WIFI network. The network device is provided with an external clock module, can acquire accurate absolute time and can provide absolute time information for the terminal device in the coverage area of the network device, and the network device can send configuration information and data information for the terminal device. The terminal device may specifically be a UE, and the terminal device has a clock module, can be accessed into a coverage area of the network device, and can also receive configuration information and data information sent by the network device, report data to the network device, and correct timing of a local clock according to clock deviation. The present embodiment is schematically illustrated by taking as an example a communication process between a base station and a terminal device, where the base station corresponds to a master clock node and the terminal device corresponds to a slave clock node. As shown in fig. 3, the clock synchronization method according to this embodiment includes the following steps:

step S31, the base station sends first time information to the terminal device, the first time information being used for indicating time information of the reference time point.

Specifically, the base station records a timestamp, for example, t0, t0 may be the current time recorded by the clock of the base station, or may be the historical time recorded by the clock of the base station, and the base station uses t0 as the reference time point. As shown in fig. 3, the base station determines time t0 and transmits first time information indicating time information of a reference time point t0 to the terminal device at a time after time t 0.

In this embodiment, the base station may send the first time information to the terminal device aperiodically or periodically.

If the bs sends the first time information to the ue aperiodically, a reference time point corresponding to the first time information, for example, t0, may correspond to a starting boundary of a certain radio frame.

If the bs periodically sends the first time information to the ue, for example, the bs sends the first time information to the ue in a period T0, the reference time point sent by the bs in each period corresponds to the starting boundary of a radio frame, and one way of representing the reference time point sent by the bs in each period is: the reference time point corresponds to the starting boundary of the radio frame with frame number SFN, and SFN mod 16 is 0. Taking the time length of the radio frame as 10ms as an example, T0 is 160ms, and the base station sends the first time information once every 160ms, i.e. the base station sends a reference time point every 160 ms. As shown in fig. 4, when the base station transmits the reference time point to the terminal device in a period T0, optionally, the reference time point transmitted by the base station to the terminal device in a certain period is T0, and T0 corresponds to a starting boundary of a radio frame with a frame number SFN of 16; the reference time point transmitted by the base station in the next period is T0+ T0, and T0+ T0 corresponds to the starting boundary of the radio frame with the frame number SFN equal to 32; the reference time point sent by the base station in the next cycle is T0+2 × T0, and T0+2 × T0 corresponds to the starting boundary of the radio frame with the frame number SFN of 48; and so on.

Optionally, the base station may send the reference time point to the terminal device through a system message or a system signaling. The System message may be one or a combination of several of a Master Information Block (MIB) message, a Remaining Minimum System Information (RMSI) message, and a System Information Block (SIB) message. The system signaling may be one or a combination of several of Radio Resource Control (RRC) signaling, Downlink Control Information (DCI) signaling, or Media Access Control (MAC) Control Element (CE) signaling.

Before the reference time point is sent, the base station may send configuration information of the reference time point to the terminal device through a system message or a system signaling. The configuration information comprises a reference time point sending period, and a wireless frame number, a subframe number and a time slot number corresponding to the initial reference time point. The System message may be one or a combination of several of a Master Information Block (MIB) message, a Remaining Minimum System Information (RMSI) message, and a System Information Block (SIB) message. The system signaling may be one or a combination of several of Radio Resource Control (RRC) signaling, Downlink Control Information (DCI) signaling, or Media Access Control (MAC) Control Element (CE) signaling.

Specifically, the base station may transmit the reference time point to the terminal device in a broadcast, multicast or unicast manner, for example, the base station may broadcast the reference time point to the terminal device according to the period T0, or the base station may broadcast, multicast or unicast the reference time point to the terminal device aperiodically.

Step S32, the base station sends a synchronization message to the terminal device.

In this embodiment, the synchronization message sent by the base station to the terminal device is a downlink signal. When the terminal device receives the synchronization message, the terminal device records the reception time t2 of the synchronization message according to the local clock of the terminal device. Since the wireless signal is delayed during transmission, the transmission time t1 at which the base station transmits the synchronization message and the reception time t2 at which the terminal device receives the synchronization message may be different.

Optionally, the Synchronization message sent by the base station to the terminal device may multiplex one or a combination of several signals existing in a New Radio (NR) system or Long Term Evolution (LTE), for example, a time-frequency tracking Reference Signal (TRS/CSI-RS for time and frequency tracking), a Phase Tracking Reference Signal (PTRS), a DeModulation Reference Signal (DMRS), a Primary Synchronization Signal (Primary Synchronization Signal, PSS), a Secondary Synchronization Signal (Secondary Synchronization Signal, SSS), a Sounding Reference Signal (SRS), and a Random Access Channel (RACH).

Step S33, the terminal device sends a delay request message to the base station.

In this embodiment, the delay request message sent by the terminal device to the base station is an uplink signal. When the terminal device transmits the delay request message, the transmission time t3 of the delay request message is recorded according to the local clock of the terminal device. When the base station receives the delay request message, the receiving time t4 of the delay request message is recorded according to the local clock of the base station. Since the wireless signal is delayed during transmission, the transmission time t3 at which the terminal device transmits the delay request message and the reception time t4 at which the base station receives the delay request message may be different.

Optionally, the sending time t3 of the delay request message and the receiving time t4 of the delay request message correspond to the same characteristic position of the timeslot, subframe, or radio frame where the delay request message is located, for example, both the sending time t3 of the delay request message and the receiving time t4 of the delay request message correspond to the starting boundary of the timeslot, subframe, or radio frame where the delay request message is located; alternatively, the transmission time t3 of the delay request message and the reception time t4 of the delay request message both correspond to the ending boundary of the slot, subframe, or radio frame in which the delay request message is located.

Optionally, the delay request message sent by the terminal device to the base station may multiplex signals existing in the NR or LTE system, for example, one or a combination of PTRS, DMRS, PSS, SSS, SRS, and RACH.

In this embodiment, the sequence of step S32 and step S33 is not limited, and the base station may send the synchronization message to the terminal device first, and the terminal device sends the delay request message to the base station, or the terminal device sends the delay request message to the base station first, and the base station sends the synchronization message to the terminal device.

In addition, the synchronization message and the delay request message may be periodic signals or non-periodic signals, that is, the base station may periodically send the synchronization message to the terminal device, and the terminal device periodically sends the delay request message to the base station; the base station may also transmit the synchronization message aperiodically to the terminal device, and the terminal device may transmit the delay request message aperiodically to the base station.

When the synchronization message and the delay request message are periodic signals, one timing relationship of the synchronization message and the delay request message is: the synchronization message is sent in a time slot 0 of a radio frame with the frame number of SFN and the SFN mod 8 ═ 0, and the delay request message is sent in a time slot 0 of a radio frame with the frame number of SFN and the SFN mod 8 ═ 1; taking the time length of a radio frame as an example of 10ms, the sending period of the synchronization message and the delay request message is 80ms, and the interval between adjacent synchronization messages and delay request messages is 10 ms.

When the synchronization message and the delay request message are non-periodic signals, one timing relationship between the synchronization message and the delay request message may be that, as shown in fig. 5, the base station transmits the synchronization message in slot 0 of the radio frame with frame number SFN-16, and the terminal device transmits the delay request message in slot 0 of the radio frame with frame number SFN-17.

Step S34, the base station sends second time information to the terminal device, the second time information including t4 or Δ t.

The base station transmits the second time information to the terminal device, and the second time information may include a reception time t4 of the delay request message, or the second time information may include a time difference Δ t between a start time when the base station starts receiving the delay request message and a reception time when the base station actually receives the delay request message. As shown in fig. 6, the base station transmits the synchronization message in slot 0 of the radio frame with frame number SFN ═ 16, and accordingly, the terminal device receives the synchronization message in slot 0 of the radio frame with frame number SFN ═ 16; the terminal equipment sends the delay request message in the time slot 0 of the radio frame with the frame number SFN being 17, and correspondingly, the base station receives the delay request message in the time slot 0 of the radio frame with the frame number SFN being 17. Specifically, the bs starts receiving the delay request message from the start boundary S1 of the radio frame with the frame number SFN of 17, but the time when the bs actually receives the delay request message is the time t4, and the time difference between S1 and t4 is Δ t.

As shown in fig. 6, the reference time point t0 sent by the base station to the terminal device corresponds to the starting boundary of the radio frame with frame number SFN equal to 16. The reception time t4 of the delay request message corresponds to time slot 0 of the radio frame with frame number SFN ═ 17. There are several possible implementations for the base station to calculate Δ t as follows:

one possible implementation is: and the base station omits the offsets of the time slot granularity, the subframe granularity and the radio frame granularity in the offset of t4 relative to t0 according to the offset of the time slot boundary corresponding to t4 relative to a reference time point t0, and obtains time data delta t smaller than the time slot length. For example, as shown in fig. 6, the slot boundary corresponding to t4 is the start boundary S1 of slot 0 of the radio frame with frame number SFN ═ 17, and the time difference between S1 and t4 is Δ t.

Another possible implementation is: and the base station omits the offsets of the subframe granularity and the radio frame granularity in the offset of t4 relative to t0 according to the offset of the subframe boundary corresponding to t4 relative to the reference time point t0, and obtains time data delta t smaller than the subframe length.

Yet another possible implementation is: and the base station omits the offset of the radio frame granularity in the offset of t4 relative to t0 according to the offset of the radio frame boundary corresponding to t4 relative to the reference time point t0, and obtains time data delta t smaller than the length of the radio frame.

Optionally, after successfully receiving the delay request message sent by the terminal device, the base station may send the timestamp corresponding to t4 completely to the terminal device, or send Δ t calculated by any one of the above feasible implementation manners to the terminal device. One possible implementation way for the base station to send t4 or Δ t to the terminal device is: the base station transmits t4 or Δ t to the terminal device through a system signaling after successfully receiving a plurality of Radio frames, a plurality of subframes, or a plurality of timeslots after the delay request message is successfully received, where the system signaling may specifically be one or a combination of several of Radio Resource Control (RRC) signaling, Downlink Control Information (DCI) signaling, or Media Access Control (MAC) Control Element (CE) signaling. In addition, t4 or Δ t sent by the base station to the terminal device may include the following possible expressions:

one possible way of representation is: t4 or Δ t is directly expressed by the precision of nanosecond ns.

Another possible representation is: t4 or Δ t is represented by a sampling period. The length of the sampling period may be different for different communication systems, for example, in LTE systems the sampling period Ts ═ 1 ÷ 30.82us ≈ 32 ns. In the NR system, the sampling period Tc ≈ 1 ÷ 30.82 ÷ 64us ≈ 0.5 ns. Actual sampling periods of different system bandwidths and frequency points in the NR may be different, and time granularity represented in different situations may be different.

Step S35, the terminal device determines the transmission time of the synchronization message.

Specifically, the terminal device determines the sending time of the synchronization message according to the reference time point, the timing relationship between the synchronization message and the delay request message. The timing relationship between the synchronization message and the delay request message may specifically refer to an offset of the synchronization message and the delay request message with respect to a reference time point, or may refer to a time interval between the synchronization message and the delay request message, that is, an offset of the synchronization message with respect to the delay request message. The terminal device may store the timing relationship between the synchronization message and the delay request message in advance, or may obtain the timing relationship between the synchronization message and the delay request message from the network side, for example, from the base station. The following feasible implementation manners are included in the following steps that the terminal device obtains the timing relationship between the synchronization message and the delay request message from the base station:

one possible implementation is: as shown in fig. 3, when the base station sends the first time information to the terminal device, the base station simultaneously sends the timing relationship between the synchronization message and the delay request message to the terminal device.

Another possible implementation is: as shown in fig. 3, when the base station sends the synchronization message to the terminal device, the base station simultaneously sends the timing relationship between the synchronization message and the delay request message to the terminal device.

Yet another possible implementation is: as shown in fig. 7, fig. 7 is different from fig. 3 in that: before the base station sends the synchronization message to the terminal equipment, the base station sends configuration information to the terminal equipment, wherein the configuration information comprises the time sequence relation between the synchronization message and the delay request message. In addition, the configuration information may further include time-frequency resources of a synchronization message and a delay request message. Optionally, the base station may send the configuration Information to the terminal device through one or more combinations of New Radio, NR (New Radio, NR) system signaling or Long Term Evolution (LTE) system signaling, for example, Downlink Control Information (DCI) signaling, Media Access Control (MAC) Control Element (CE) signaling, and Radio Resource Control (RRC) signaling. In addition, the configuration information may further include a time-frequency resource corresponding to a reference time point, for example, T0, a transmission period T0 of the reference time point, and a meaning of the reference time point.

Specifically, when the synchronization message and the delay request message are non-periodic signals, the timing relationship of the synchronization message and the delay request message may include an offset of the synchronization message with respect to the reference time point and an offset of the delay request message with respect to the reference time point. In this case, one way that the terminal device determines the sending time of the synchronization message according to the reference time point, the timing relationship between the synchronization message and the delay request message is to: and the terminal equipment determines the sending time of the synchronous message according to the reference time point and the offset of the synchronous message relative to the reference time point.

In this embodiment, the offset of the synchronization message with respect to the reference time point may specifically be: the subframe offset of the subframe boundary corresponding to the synchronization message with respect to the reference time point may also be a slot offset of the slot boundary corresponding to the synchronization message with respect to the reference time point, or may also be a radio frame offset of the frame boundary of the radio frame corresponding to the synchronization message with respect to the reference time point. The offset of the delayed request message with respect to the reference time point may specifically be: the subframe offset of the subframe boundary corresponding to the delay request message with respect to the reference time point may be a slot offset of the slot boundary corresponding to the delay request message with respect to the reference time point, or a radio frame offset of the frame boundary of the radio frame corresponding to the delay request message with respect to the reference time point.

For time-frequency resource structure Numerology of different NR or LTE systems, the slot lengths of the systems may not be equal, and therefore, the terminal device needs to calculate t1 according to the characteristics of the time-frequency resource structure of the NR or LTE system, and the calculation method of t1 is as shown in the following formula (3):

t1＝t0+α₁·T_subframe+β₁·T_short+γ₁·T_long (3)

wherein, T_subframeDenotes the time length of the subframe, T_longIndicates the time length, T, of the slot in which an extended Cyclic Prefix (CP) symbol is located_shortIndicating the time length, alpha, of the slot not including the extended CP symbol₁、β₁、γ₁Representing a known natural number, the terminal device can derive α from the configuration information sent by the base station₁、β₁、γ₁。

Optionally, the sending time t1 of the synchronization message calculated by the terminal device and the receiving time t2 of the synchronization message recorded by the terminal device correspond to the same characteristic position of the time slot, the subframe, or the radio frame where the synchronization message is located, for example, both the sending time t1 of the synchronization message calculated by the terminal device and the receiving time t2 of the synchronization message correspond to the starting boundary of the time slot, the subframe, or the radio frame where the synchronization message is located; alternatively, the sending time t1 of the synchronization message and the receiving time t2 of the synchronization message calculated by the terminal device both correspond to the ending boundary of the slot, subframe or radio frame where the synchronization message is located.

In other embodiments, when the synchronization message and the delay request message are non-periodic signals, the timing relationship of the synchronization message and the delay request message may include: an offset of the synchronization message with respect to the reference time point and an offset of the synchronization message with respect to the delayed request message; alternatively, the timing relationship between the synchronization message and the delay request message may include: the terminal device may determine the offset of the synchronization message with respect to the reference time point according to the offset of the delay request message with respect to the reference time point and the offset of the synchronization message with respect to the delay request message. Further, the terminal device determines the transmission timing of the synchronization message according to the reference time point and the offset of the synchronization message with respect to the reference time point, as shown in the above formula (3).

In addition, when the synchronization message and the delay request message are periodic signals, the timing relationship between the synchronization message and the delay request message may include: a transmission period of the synchronization message and the delay request message, an offset of the synchronization message with respect to the delay request message, a start position of the synchronization message or the delay request message with respect to a reference time point. Alternatively, in some embodiments, when the synchronization message and the delay request message are periodic signals, the timing relationship of the synchronization message and the delay request message may include: the transmission period of the synchronization message and the delay request message, the offset of the synchronization message relative to the delay request message, the radio frame number, the subframe number and the slot number of the start position of the synchronization message or the delay request message. In addition, the offset of the synchronization message relative to the delay request message may specifically refer to a slot offset, a subframe offset, or a radio frame offset of the synchronization message relative to the delay request message.

As shown in fig. 3, steps S32-S36 are described as a clock synchronization flow, and if the synchronization message and the delay request message are non-periodic signals, the clock synchronization flow occurs non-periodically. If the synchronization message and the delay request message are periodic signals, the clock synchronization process occurs periodically, as shown in fig. 8, the period of the reference time point T0 transmitted by the base station is T0, and the clock synchronization process occurs twice from the time T0 to the time (T0+ T0), which is only an exemplary illustration and is not limited to the occurrence period of the clock synchronization process. As shown in fig. 8, if the transmission cycle of the synchronization message and the delay request message is T1, in two adjacent clock synchronization flows, an interval T1 is between the transmission time of the synchronization message in the previous clock synchronization flow and the transmission time of the synchronization message in the next clock synchronization flow, and an interval T1 is between the transmission time of the delay request message in the previous clock synchronization flow and the transmission time of the delay request message in the next clock synchronization flow. For example, the interval between the transmission time T1 of the synchronization message in step S83 and the transmission time T5 of the synchronization message in step S88 is T1, and the interval between the transmission time T3 of the delay request message in step S84 and the transmission time T7 of the delay request message in step S89 is T1. The offset of the synchronization message with respect to the delay request message may specifically refer to an offset of the transmission time of the synchronization message with respect to the transmission time of the delay request message in the same clock synchronization flow, and for example, the offset may be a time difference between the transmission time t1 of the synchronization message in step S83 and the transmission time t3 of the delay request message in step S84, or a time difference between the transmission time t5 of the synchronization message in step S88 and the transmission time t7 of the delay request message in step S89. The start position of the synchronization message with respect to the reference time point specifically refers to the transmission time t1 of the synchronization message in step S83, and the start position of the delayed request message with respect to the reference time point specifically refers to the transmission time t3 of the delayed request message in step S84.

As shown in fig. 8, the timing relationship between the synchronization message and the delay request message may include: a transmission period of the synchronization message and the delay request message, for example, T1, an offset of the synchronization message with respect to the delay request message, for example, a time difference between T1 and T3, a start position of the synchronization message or the delay request message with respect to a reference time point, for example, T1 or T3. The terminal device determines the sending time of the synchronization message according to the reference time point, the timing relationship between the synchronization message and the delay request message, and includes the following feasible implementation manners:

one possible implementation is: and the terminal equipment determines the sending time of the synchronous message according to the reference time point, the initial position of the synchronous message relative to the reference time point and the sending period of the synchronous message.

For example, the terminal device determines the transmission timings T1 and T5 of the synchronization message according to the reference time point T0, the start position T1 of the synchronization message with respect to the reference time point T0, and the transmission cycle T1 of the synchronization message.

Another possible implementation is: the terminal equipment determines the sending time of the synchronous message according to the reference time point, the initial position of the delay request message relative to the reference time point, the sending period of the delay request message and the offset of the synchronous message relative to the delay request message.

For example, the terminal device determines the transmission timings T3 and T7 of the delay request message according to the reference time point T0, the start position T3 of the delay request message with respect to the reference time point, and the transmission cycle T1 of the delay request message; further, the terminal device determines the sending time t1 and t5 of the synchronization message according to the sending time t3 and t7 of the delay request message and the offset of the synchronization message relative to the delay request message. As shown in fig. 8, this embodiment takes one sending period T0 of the reference time point as an example for schematic description, and describes a method for the terminal device to calculate the sending time of the synchronization message in the clock synchronization process that occurs periodically in one sending period T0 of the reference time point, and in other sending periods of the reference time point, the method for the terminal device to calculate the sending time of the synchronization message is similar to this, which is not repeated here.

Step S36, the terminal device determines a local clock offset.

If the clock synchronization process such as step S32-step S36 occurs non-periodically and the second time information transmitted from the base station to the terminal device in step S34 includes the reception time t4 of the delay request message, the terminal device calculates the same in step S32After the transmission time t1 of the message is stepped, the deviation Offset of the local clock of the terminal device from the clock of the base station, that is, the clock deviation Offset of the slave clock node from the master clock node can be calculated by the above formula (1) based on the transmission time t1 of the synchronization message, the reception time t2 of the synchronization message, the transmission time t3 of the delay request message, and the reception time t4 of the delay request message, and the terminal device corrects the timing of the local clock based on the clock deviation to keep the local clock of the terminal device synchronized with the clock of the base station, thereby keeping the local clock of the terminal device synchronized with the absolute time with high accuracy. In other embodiments, the terminal device may also correct the timing of the local clock in such a way that, specifically, the terminal device calculates the Delay of transmission of the wireless signal from the base station to the terminal device according to the above formula (2). Since the terminal device can calculate the sending time t1 of the synchronization message according to the above formula (3), further, the terminal device can calculate the time information t2 of the local clock of the base station when the synchronization message reaches the terminal device according to the sending time t1 of the synchronization message and the transmission Delay of the wireless signal from the base station to the terminal device_gNB，t2_gNBT1+ Delay. The terminal device may compare the reception times t2 and t2 of the synchronization message_gNBClock correction is performed, specifically, the terminal device is according to t2 and t2_gNBThe difference between them is corrected for the clock.

If the clock synchronization process, for example, the step S32-the step S36, occurs non-periodically and the second time information sent by the base station to the terminal device in the step S34 includes a time difference Δ t between the starting time when the base station starts receiving the delay request message and the receiving time when the base station actually receives the delay request message, the terminal device further needs to calculate the receiving time t4 of the delay request message according to the Δ t. In the NR system, there are different time-frequency resource structures Numerology in the radio frame, and the time lengths corresponding to different timeslots may be different. If Δ t is the offset of the base station with respect to the reference time point t0 according to the time slot boundary corresponding to t4, and omits the offset of the time slot granularity, the subframe granularity, and the radio frame granularity in the offset of t4 with respect to t0, the terminal device may calculate t4 according to the characteristics of the time-frequency resource structure of the NR or LTE system, and the calculation method of t4 is as shown in the following formula (4):

t4＝t0+α₄·T_subframe+β₄·T_short+γ₄·T_long+Δt (4)

wherein, T_subframeDenotes the time length of the subframe, T_longIndicates the time length, T, of the slot in which an extended Cyclic Prefix (CP) symbol is located_shortIndicating the time length, alpha, of the slot not including the extended CP symbol₄、β₄、γ₄Representing a known natural number, the terminal device can derive α from the configuration information sent by the base station₄、β₄、γ₄. Further, the terminal device calculates the Offset of the local clock of the terminal device with respect to the clock of the base station by the above equation (1) based on the transmission time t1 of the synchronization message, the reception time t2 of the synchronization message, the transmission time t3 of the delay request message, and the reception time t4 of the delay request message, and further, the terminal device corrects the timing of the local clock based on the clock Offset so that the local clock of the terminal device and the clock of the base station are kept in synchronization, thereby keeping the local clock of the terminal device and the absolute time in synchronization with each other at high accuracy. In other embodiments, the terminal device may also correct the timing of the local clock in such a way that, specifically, the terminal device calculates the Delay of transmission of the wireless signal from the base station to the terminal device according to the above formula (2). Since the terminal device can calculate the sending time t1 of the synchronization message according to the above formula (3), further, the terminal device can calculate the time information t2 of the local clock of the base station when the synchronization message reaches the terminal device according to the sending time t1 of the synchronization message and the transmission Delay of the wireless signal from the base station to the terminal device_gNB，t2_gNBT1+ Delay. The terminal device may compare the reception times t2 and t2 of the synchronization message_gNBClock correction is performed, specifically, the terminal device is according to t2 and t2_gNBThe difference between them is corrected for the clock.

If the clock synchronization process occurs periodically, the terminal device may periodically calculate a local clock offset,as shown in fig. 8, the period T0 includes two clock synchronization flows, and in each clock synchronization flow, the terminal device can calculate a local clock skew once, for example, in the clock synchronization flow corresponding to step S83-step S87, the terminal device can calculate a local clock skew once, corresponding to step S87; in the clock synchronization flow corresponding to step S88-step S812, the terminal device may calculate the local clock skew again, corresponding to step S812. For the clock synchronization procedure corresponding to steps S83-S87, if the second time information sent by the base station to the terminal device at step S85 includes the reception time t4 of the delay request message, then at step S87, the terminal device can calculate the Offset1 of the local clock of the terminal device relative to the clock of the base station according to the above formula (1),

the terminal device corrects the timing of the local clock once based on the clock Offset 1. For the clock synchronization flow corresponding to steps S88-S812, if the second time information transmitted from the base station to the terminal device includes the reception time t8 of the delay request message in step S810, the terminal device can calculate the Offset2 of the local clock of the terminal device from the clock of the base station according to the same principle as the above formula (1) based on the transmission time t5 of the synchronization message, the reception time t6 of the synchronization message, the transmission time t7 of the delay request message, and the reception time t8 of the delay request message in step S812,

the terminal device corrects the timing of the local clock again based on the clock Offset 2. Alternatively, Offset1 and Offset2 may be the same or different. In other embodiments, the terminal device may further correct the timing of the local clock by calculating a Delay1 of the wireless signal from the base station to the terminal device according to the above formula (2) and further calculating a Delay1 of the wireless signal from the base station to the terminal device according to the sending time t1 of the synchronization message and the clock synchronization procedure corresponding to the step S83 to the step S87Time information t2 of the local clock of the base station when the synchronization message arrives at the terminal device_gNB，t2_gNBT1+ Delay1, terminal device according to t2 and t2_gNBThe difference between them corrects the primary clock. In the clock synchronization process corresponding to step S88-step S812, the terminal device may calculate the transmission Delay2 of the wireless signal from the base station to the terminal device according to the above formula (2), and further calculate the time information t6 of the local clock of the base station when the synchronization message reaches the terminal device according to the transmission time t5 of the synchronization message and the transmission Delay2 of the wireless signal from the base station to the terminal device_gNB，t6_gNBT5+ Delay2, terminal device according to t6 and t6_gNBThe difference between them corrects the clock again. Alternatively, Delay1 and Delay2 may be the same or different.

If the clock synchronization process occurs periodically and the second time information sent by the base station to the terminal device in each clock synchronization process includes a time difference between a starting time when the base station starts to receive the delay request message and a receiving time when the base station actually receives the delay request message, the terminal device may calculate the receiving time of the delay request message in each clock synchronization process according to the time difference received by the terminal device from the base station in each clock synchronization process. As shown in fig. 8, in the clock synchronization process corresponding to steps S83-S87, if the second time information sent by the base station to the terminal device in step S85 includes a time difference Δ t1 between the starting time when the base station starts receiving the delay request message and the receiving time when the base station actually receives the delay request message, in step S87, the terminal device needs to calculate the receiving time t4 of the delay request message according to Δ t1, and the calculation method of t4 is similar to formula (4); further, the terminal device calculates Offset1 of the local clock of the terminal device with respect to the clock of the base station from the transmission time t1 of the synchronization message, the reception time t2 of the synchronization message, the transmission time t3 of the delay request message, and the reception time t4 of the delay request message, and corrects the timing of the local clock once based on the clock Offset 1. In the clock synchronization process corresponding to steps S88-S812, if the second time information sent by the base station to the terminal device in step S810 includes thatIf the time difference Δ t2 between the starting time when the base station starts receiving the delay request message and the receiving time when the base station actually receives the delay request message is obtained, in step S812, the terminal device needs to calculate the receiving time t8 of the delay request message according to Δ t2, and the calculation method of t8 is similar to formula (4); further, the terminal device calculates Offset2 of the local clock of the terminal device with respect to the clock of the base station from the transmission time t5 of the synchronization message, the reception time t6 of the synchronization message, the transmission time t7 of the delay request message, and the reception time t8 of the delay request message, and the terminal device corrects the timing of the local clock again from the clock Offset 2. Alternatively, Offset1 and Offset2 may be the same or different; Δ t1 and Δ t2 may or may not be the same. In other embodiments, the terminal device may further correct the timing of the local clock by calculating the receiving time t4 of the Delay request message according to Δ t1, then calculating the transmission Delay1 of the wireless signal from the base station to the terminal device according to the above formula (2), and further calculating the time information t2 of the local clock of the base station when the synchronization message reaches the terminal device according to the transmitting time t1 of the synchronization message and the transmission Delay1 of the wireless signal from the base station to the terminal device in the clock synchronization process corresponding to steps S83-S87_gNB，t2_gNBT1+ Delay1, terminal device according to t2 and t2_gNBThe difference between them corrects the primary clock. In the clock synchronization process corresponding to step S88-step S812, after the terminal device calculates the receiving time t8 of the Delay request message according to Δ t2, the transmission Delay2 of the wireless signal from the base station to the terminal device is calculated according to the above formula (2), and further, the time information t6 of the local clock of the base station when the synchronization message reaches the terminal device is calculated according to the transmitting time t5 of the synchronization message and the transmission Delay2 of the wireless signal from the base station to the terminal device_gNB，t6_gNBT5+ Delay2, terminal device according to t6 and t6_gNBThe difference between them corrects the clock again. Alternatively, Delay1 and Delay2 may be the same or different.

Therefore, if the clock synchronization process cycle occurs, in each clock synchronization process, the terminal device can correct the timing of a local clock and perform high-precision synchronization with the absolute time.

In this embodiment, after the network device sends the downlink signal, for example, the synchronization message, to the terminal device, the network device does not need to send the follow-up message to the terminal device, that is, the network device does not need to send the follow-up message to the terminal device to carry the sending time of the synchronization message, so that the time required by a single clock synchronization process is shortened, and the terminal device can determine the sending time of the synchronization message according to the time sequence relationship between the uplink signal, for example, the synchronization message, and the downlink signal, for example, the delay request message, and the reference time point received by the terminal device from the network device. When the network device corresponds to a plurality of terminal devices, the network device does not need to send a following message to each terminal device after sending a synchronization message to each terminal device, so that the network device does not need to configure time-frequency resources for each following message, thereby saving the time-frequency resources in a wireless network and reducing the complexity of the network device for scheduling the time-frequency resources.

On the basis of the above embodiments, the terminal device may be mobile, and then the terminal device may move out of the cell corresponding to the base station or move into the cell corresponding to the base station. If the base station sends the reference time point t0 in a broadcast or multicast manner, and the terminal device does not access the cell corresponding to the base station, the terminal device will not receive the reference time point t0 broadcasted or multicasted by the base station, and subsequently, when the terminal device accesses the cell corresponding to the base station, the terminal device will not perform clock synchronization because the reference time point sent by the base station is not received. In order to solve the problem, the present embodiment provides another clock synchronization method, specifically as shown in fig. 9, the clock synchronization method includes the following steps:

step S91, the base station broadcasts or multicasts the reference time point t 0.

In this embodiment, the base station periodically transmits the reference time point in a broadcast or multicast manner, for example, the transmission period of the reference time point is T0. If the terminal device does not access the cell corresponding to the base station when the base station broadcasts or multicasts the reference time point, the terminal device cannot receive the reference time point.

And step S92, the terminal equipment accesses the cell.

In T0 time after the reference time point T0, broadcast or multicast by the base station, the terminal device accesses the cell corresponding to the base station, for example, the terminal device has performed cell handover, i.e. moved from other cells to the cell corresponding to the base station.

Step S93, the base station sends the configuration information to the terminal device.

The base station sends configuration information to the terminal equipment of the newly accessed cell, wherein the configuration information comprises: a transmission period T0 of a reference time point, a start position of an uplink signal or a downlink signal with respect to the reference time point, a transmission period T1 of the uplink signal and the downlink signal, an offset of the uplink signal with respect to the downlink signal, time-frequency resources of the uplink signal and the downlink signal, and a reference time point, for example, T0, transmitted within the transmission period T0 of the current reference time point.

Optionally, the downlink signal may specifically be a synchronization message, and the uplink signal may specifically be a delay request message. The base station may send the configuration information to the terminal device through a system signaling, where the system signaling may specifically be one or a combination of RRC signaling, MAC CE signaling, and DCI signaling.

Step S94, the base station sends a synchronization message to the terminal device.

The base station sends a synchronization message to the terminal device, and when the terminal device receives the synchronization message, the terminal device records the receiving time t2 of the synchronization message.

Step S95, the terminal device sends a delay request message to the base station.

When the terminal device sends the delay request message to the base station, the sending time t3 of the delay request message is recorded. When the base station receives the delay request message, the receiving time t4 of the delay request message is recorded.

Step S96, the base station sends second time information to the terminal device, the second time information including t4 or Δ t.

The base station transmits the second time information to the terminal device, and the second time information may include a reception time t4 of the delay request message, or the second time information may include a time difference Δ t between a start time when the base station starts receiving the delay request message and a reception time when the base station actually receives the delay request message. The method of calculating Δ t by the base station is the same as described in the above embodiments.

Step S97, the terminal device determines the transmission time of the synchronization message.

Specifically, the terminal device may determine the transmission time of the downlink signal, i.e., the synchronization message, according to the reference time point, e.g., t0, in the configuration information sent by the base station in step S93 and the starting position of the downlink signal relative to the reference time point.

Step S98, the terminal device determines a local clock offset.

The method for determining the local clock offset by the terminal device is consistent with the above embodiments, and is not described herein again.

In this embodiment, a base station sends configuration information to a terminal device of a new access cell, where the configuration information includes: the method comprises the steps of referencing a transmission period T0 of a time point, a starting position of an uplink signal or a downlink signal relative to the reference time point, a transmission period T1 of the uplink signal and the downlink signal, an offset of the uplink signal relative to the downlink signal, time-frequency resources of the uplink signal and the downlink signal, and a reference time point such as T0 transmitted in a transmission period T0 of the current reference time point, and ensuring that terminal equipment of a newly accessed cell can perform clock synchronization according to configuration information.

On the basis of the above embodiment, the base station may determine a period of calibration between the base station and an external clock, that is, a period of accurate absolute time acquired by the base station, according to the stability of the local clock module and a preset clock precision error range, where the period is denoted as T, and the period T is also an update period of the local clock of the base station. Optionally, the base station broadcasts or multicasts the reference time point after calibrating the local clock, so as to ensure the accuracy of the clock synchronization of the terminal device, and therefore, the transmission period T0 of the reference time point is less than or equal to the update period T of the local clock of the base station.

In addition, the base station may further determine the transmission period T1 of the uplink signal or the downlink signal according to the clock synchronization accuracy of the terminal device and the clock stability of the terminal device, and since there may be a certain difference between clocks of different terminal devices, the transmission period T1 of the uplink signal or the downlink signal corresponding to different terminal devices may be different, for example, as shown in fig. 8, the period of the reference time point T0 transmitted by the base station is T0, and a clock synchronization procedure occurs twice in a time from the time T0 to the time (T0+ T0), that is, the uplink signal or the downlink signal is periodically transmitted twice in one transmission period T0 of the reference time point. If different terminal devices correspond to different transmission periods T1 of uplink signals or downlink signals, the number of times of uplink signals periodically transmitted by different terminal devices may be different in one transmission period T0 of the reference time point, for example, terminal device a and terminal device B may periodically transmit an uplink signal twice and terminal device B may periodically transmit an uplink signal three times in one transmission period T0 of the reference time point within the coverage of the base station, terminal device a may perform clock synchronization twice and terminal device B may perform clock synchronization three times. Since terminal device B performs clock synchronization more times than terminal device a performs clock synchronization in one transmission period T0 at the reference time point, the clock accuracy of terminal device B is higher than that of terminal device a.

In this embodiment, the base station determines the sending periods of the uplink signal or the downlink signal corresponding to different terminal devices according to the clock synchronization precision of the terminal device and the clock stability of the terminal device, so that different terminal devices can correspond to clock synchronization processes of different periods, and different terminal devices do not need to perform clock synchronization simultaneously, thereby improving the flexibility of performing clock synchronization by different terminal devices.

Fig. 10 is a flowchart of another clock synchronization method according to an embodiment of the present application. As shown in fig. 10, the clock synchronization method according to this embodiment includes the following steps:

step S101, the base station sends a synchronization message to the terminal equipment.

In this embodiment, the synchronization message sent by the base station to the terminal device is a downlink signal. When the terminal device receives the synchronization message, the terminal device records the reception time t2 of the synchronization message. Since the wireless signal is delayed during transmission, the transmission time t1 at which the base station transmits the synchronization message and the reception time t2 at which the terminal device receives the synchronization message may be different.

Optionally, the sending time t1 of the synchronization message and the receiving time t2 of the synchronization message correspond to the same characteristic position of the timeslot, subframe, or radio frame where the synchronization message is located, for example, both the sending time t1 of the synchronization message and the receiving time t2 of the synchronization message correspond to the starting boundary of the timeslot, subframe, or radio frame where the synchronization message is located; alternatively, the transmission time t1 of the synchronization message and the reception time t2 of the synchronization message both correspond to the ending boundary of the slot, subframe, or radio frame in which the synchronization message is located.

Step S102, the terminal equipment sends a delay request message to the base station.

In this embodiment, the delay request message sent by the terminal device to the base station is an uplink signal. When the terminal device transmits the delay request message, the transmission time t3 of the delay request message is recorded. When the base station receives the delay request message, the receiving time t4 of the delay request message is recorded. Since the wireless signal is delayed during transmission, the transmission time t3 at which the terminal device transmits the delay request message and the reception time t4 at which the base station receives the delay request message may be different.

In this embodiment, the sequence of step S101 and step S102 is not limited, and the base station may send the synchronization message to the terminal device first, and the terminal device sends the delay request message to the base station, or the terminal device sends the delay request message to the base station first, and the base station sends the synchronization message to the terminal device, that is, the sequence of the synchronization message and the delay request message is not limited, and the sequence of the synchronization message and the delay request message may be different for different terminal devices.

Step S103, the terminal equipment transmits time information to the base station, wherein the time information comprises the receiving time t2 of the synchronous message or the transmitting time t3 of the delay request message.

Alternatively, if the time information sent by the terminal device to the base station includes the receiving time t2 of the synchronization message, step S103 may be after step S101, or after step S102, that is, the terminal device may send t2 to the base station after receiving the synchronization message and before sending the delay request message, or send t2 to the base station after sending the delay request message. If the time information transmitted by the terminal device to the base station includes the transmission time t3 of the delay request message, step S103 follows step S102, i.e., the terminal device transmits t3 to the base station after transmitting the delay request message.

Step S104, the base station determines the association relationship between the receiving time t2 of the synchronous message and the transmitting time t3 of the delay request message.

Specifically, the base station determines the association relationship between the receiving time t2 of the synchronization message and the sending time t3 of the delay request message according to the timing relationship between the synchronization message and the delay request message and the sending advance time of the terminal device. Specifically, the terminal device may store the timing relationship between the synchronization message and the delay request message in advance, or may obtain the timing relationship between the synchronization message and the delay request message from the network side, for example, from the base station. The following feasible implementation manners are included in the following steps that the terminal device obtains the timing relationship between the synchronization message and the delay request message from the base station:

one possible implementation is: as shown in fig. 10, when transmitting a synchronization message to a terminal device, a base station simultaneously transmits a timing relationship between the synchronization message and a delay request message to the terminal device.

Another possible implementation is: as shown in fig. 11, fig. 11 is different from fig. 10 in that: before the base station sends the synchronization message to the terminal device, the base station sends configuration information to the terminal device, as shown in step S100 in fig. 11, where the configuration information includes a timing relationship between the synchronization message and the delay request message. In addition, the configuration information may further include time-frequency resources of a synchronization message and a delay request message. Optionally, the base station may send the configuration Information to the terminal device through one or more combinations of New Radio, NR (New Radio, NR) system signaling or Long Term Evolution (LTE) system signaling, for example, Downlink Control Information (DCI) signaling, Media Access Control (MAC) Control Element (CE) signaling, and Radio Resource Control (RRC) signaling.

Specifically, when the synchronization message and the delay request message are non-periodic signals, the timing relationship between the synchronization message and the delay request message may include: the radio frame number, the subframe number or the time slot number corresponding to the time domain resource of the synchronization message, and the radio frame number, the subframe number or the time slot number corresponding to the time domain resource of the delay request message. In addition, the timing relationship between the synchronization message and the delay request message may further include: the offset of the synchronization message relative to the delayed request message. The offset of the synchronization message relative to the delay request message may be a slot offset, a subframe offset, or a radio frame offset of the synchronization message relative to the delay request message.

When the synchronization message and the delay request message are periodic signals, the timing relationship between the synchronization message and the delay request message may include: a transmission period of the synchronization message and the delayed request message, an offset of the synchronization message with respect to the delayed request message, a start position of the synchronization message or the delayed request message. The offset of the synchronization message relative to the delay request message may be a slot offset, a subframe offset, or a radio frame offset of the synchronization message relative to the delay request message.

Since there may be a time difference between the starting time when the base station starts to receive the uplink signal and the receiving time when the base station actually receives the uplink signal each time the terminal device sends the uplink signal to the base station, and the time difference is time-varying, optionally, the time difference is denoted as ta (t), for example, the base station may send the time difference ta (t) calculated at different times to the terminal device, and the terminal device may determine the advance amount of the terminal device for sending the uplink signal at the next time according to the time difference received at the current time and the time difference received at the historical time. In this embodiment, the base station may calculate the transmission advance time of the terminal device according to the time difference TA (t) that the base station transmits to the terminal device at different times, where the transmission advance time of the terminal device is denoted as TA_legacy，TA_legacyThe calculation method of (2) is shown in the following formula (5):

TA_legacy＝∑TA(t) (5)

optionally, TA_legacyMay be an accumulated value of ta (t) during a period from when the terminal device accesses the cell corresponding to the base station to when the base station receives the delay request message.

The base station sends a synchronization message and a delay request message according to the time sequence relation of the synchronization message and the delay request message and the sending advance time TA of the terminal equipment_legacyThe association relationship between the determined receiving time t2 of the synchronization message and the sending time t3 of the delay request message is specifically shown in the following formula (6):

t3＝t2+α₂·T_subframe+β₂·T_short+γ₂·T_long-TA_legacy (6)

wherein, T_subframeDenotes the time length of the subframe, T_longIndicates the time length, T, of the slot in which an extended Cyclic Prefix (CP) symbol is located_shortIndicating the time length, alpha, of the slot not including the extended CP symbol₂、β₂、γ₂Representing a known natural number, the terminal device can derive α from the configuration information sent by the base station₂、β₂、γ₂。

Step S105, the base station determines the clock deviation of the terminal equipment.

Specifically, the base station determines the clock skew of the terminal device according to the association relationship between the receiving time t2 of the synchronization message and the transmitting time t3 of the delay request message, the receiving time t2 of the synchronization message or the transmitting time t3 of the delay request message, the transmitting time t1 of the synchronization message, and the receiving time t4 of the delay request message.

If the time information transmitted by the terminal device to the base station includes the reception time t2 of the synchronization message in step S103, the base station may calculate the transmission time t3 of the delay request message according to the association relationship, for example, formula (6), of the reception time t2 of the synchronization message and the transmission time t3 of the delay request message. The base station further calculates the clock skew of the terminal device by the above equation (1) based on the transmission time t1 of the synchronization message, the reception time t2 of the synchronization message, the transmission time t3 of the delay request message, and the reception time t4 of the delay request message.

If the time information transmitted by the terminal device to the base station includes the transmission time t3 of the delay request message in step S103, the base station may calculate the reception time t2 of the synchronization message according to the association relationship, for example, formula (6), of the reception time t2 of the synchronization message and the transmission time t3 of the delay request message. The base station further calculates the clock skew of the terminal device by the above equation (1) based on the transmission time t1 of the synchronization message, the reception time t2 of the synchronization message, the transmission time t3 of the delay request message, and the reception time t4 of the delay request message.

And step S106, the base station sends the clock deviation to the terminal equipment.

The base station sends clock deviation to the terminal equipment, and after receiving the clock deviation, the terminal equipment can correct the timing of the local clock according to the clock deviation so as to keep the local clock of the terminal equipment and the clock of the base station synchronous, thereby keeping the local clock of the terminal equipment and the absolute time synchronous with high precision.

Taking fig. 10 as an example, steps S101 to S106 are described as a clock synchronization flow, and if the synchronization message and the delay request message are non-periodic signals, the clock synchronization flow occurs non-periodically. If the synchronization message and the delay request message are periodic signals, the clock synchronization process occurs periodically, in each clock synchronization process, the base station can calculate the clock offset of the terminal equipment once, and the terminal equipment can correct the timing of the local clock according to the clock offset. The clock skew of different terminal devices may be different, and the base station may further determine, according to the clock skew of each terminal device, an occurrence period of the clock synchronization flow corresponding to each terminal device, for example, for a terminal device with a large clock skew, the base station may decrease the occurrence period of the clock synchronization flow corresponding to the terminal device, for example, the base station may decrease the occurrence period of the clock synchronization flow corresponding to the terminal device by decreasing a period of sending a synchronization message to the terminal device, so that the occurrence frequency of the clock synchronization flow corresponding to the terminal device is increased, so that the terminal device corrects the timing of the local clock multiple times, and thus the local clock of the terminal device maintains high-accuracy synchronization with the absolute time.

In this embodiment, after the network device sends the downlink signal, for example, the synchronization message, to the terminal device, the network device does not need to send the follow-up message to the terminal device, that is, the network device does not need to send the follow-up message to the terminal device to carry the sending time of the synchronization message, so that the time required by a single clock synchronization process is shortened, and the terminal device can determine the sending time of the synchronization message according to the time sequence relationship between the uplink signal, for example, the synchronization message, and the downlink signal, for example, the delay request message, and the reference time point received by the terminal device from the network device. When the network device corresponds to a plurality of terminal devices, the network device does not need to send a following message to each terminal device after sending a synchronization message to each terminal device, so that the network device does not need to configure time-frequency resources for each following message, thereby saving the time-frequency resources in a wireless network and reducing the complexity of the network device for scheduling the time-frequency resources. In addition, the clock deviation of the terminal equipment is calculated through the network equipment, and the occurrence period of the clock synchronization process corresponding to each terminal equipment is determined according to the clock deviation of each terminal equipment, so that the flexibility of clock synchronization of different terminal equipment is improved.

Fig. 12 is a schematic structural diagram of a communication device according to an embodiment of the present application. As shown in fig. 12, the communication device 120 includes: a receiving module 121, a sending module 122, and a determining module 123. The receiving module 121 is configured to receive first time information from a network device, where the first time information is used to indicate time information of a reference time point; receiving a downlink signal from the network device; the sending module 122 is configured to send an uplink signal to the network device; the receiving module 121 is further configured to receive second time information from the network device, where the second time information is used to determine a receiving time at which the network device receives the uplink signal; the determining module 123 is configured to determine a sending time of the downlink signal according to the reference time point and a time sequence relationship between the uplink signal and the downlink signal; the clock skew of the communication device 120 is determined based on the transmission time of the downlink signal, the reception time of the downlink signal, the transmission time of the uplink signal, and the reception time of the uplink signal.

In fig. 12, further, the timing relationship between the uplink signal and the downlink signal includes: the offset of the downlink signal relative to a reference time point, and the offset of the uplink signal relative to the reference time point.

In the above embodiment, when the determining module 123 determines the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, it is specifically configured to: and determining the sending time of the downlink signal according to the reference time point and the offset of the downlink signal relative to the reference time point.

In the above embodiment, the offset of the uplink signal with respect to the reference time point includes: a radio frame offset of a radio frame boundary corresponding to the uplink signal relative to the reference time point; or the subframe offset of the subframe boundary corresponding to the uplink signal relative to the reference time point; or a slot offset of a slot boundary corresponding to the uplink signal with respect to the reference time point.

In the above embodiment, the offset of the downlink signal with respect to the reference time point includes: a radio frame offset of a radio frame boundary corresponding to the downlink signal relative to the reference time; or a subframe offset of a subframe boundary corresponding to the downlink signal relative to the reference time point; or a time slot offset of a time slot boundary corresponding to the downlink signal relative to the reference time point.

In the above embodiment, the second time information includes a receiving time when the network device receives the uplink signal.

In the above embodiment, the second time information includes a time difference between a starting time when the network device starts receiving the uplink signal and a receiving time when the network device receives the uplink signal; the determining module 123 is further configured to: and determining the receiving time when the network equipment receives the uplink signal according to the reference time point, the offset of the uplink signal relative to the reference time point and the time difference.

In the above embodiment, the timing relationship between the uplink signal and the downlink signal includes: a transmission period of the uplink signal and the downlink signal, an offset of the uplink signal relative to the downlink signal, and a starting position of the uplink signal or the downlink signal relative to the reference time point.

In the above embodiment, when the determining module 123 determines the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, it is specifically configured to: determining the sending time of the downlink signal according to the reference time point, the initial position of the downlink signal relative to the reference time point and the sending period of the downlink signal; or determining the sending time of the downlink signal according to the reference time point, the initial position of the uplink signal relative to the reference time point, the sending period of the uplink signal and the offset of the uplink signal relative to the downlink signal.

In the above embodiment, the receiving module 121 is further configured to: receiving configuration information from the network device, the configuration information including a timing relationship of the uplink signal and the downlink signal.

In the above embodiment, the configuration information further includes: a transmission period of the first time information.

In the above embodiment, the configuration information further includes: and the time information of the corresponding reference time point in the current sending period of the first time information.

The communication apparatus in the embodiment shown in fig. 12 can be used to implement the technical solution of the above method embodiment, and the implementation principle and technical effect are similar, which are not described herein again.

Fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 13, the communication device 130 includes: a sending module 131 and a receiving module 132. The sending module 131 is configured to send first time information to the terminal device, where the first time information is used to indicate time information of a reference time point; sending a downlink signal to the terminal equipment; the receiving module 132 is configured to receive an uplink signal from the terminal device; the sending module 131 is further configured to: and sending second time information to the terminal device, where the second time information is used to determine a receiving time at which the communication device 130 receives the uplink signal.

In fig. 13, further, the sending module 131 is further configured to: and sending configuration information to the terminal equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal.

In the above embodiment, the timing relationship between the uplink signal and the downlink signal includes: the offset of the downlink signal relative to a reference time point, and the offset of the uplink signal relative to the reference time point.

The communication apparatus in the embodiment shown in fig. 13 can be used to implement the technical solution of the above method embodiment, and the implementation principle and technical effect are similar, which are not described herein again.

Fig. 14 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 14, the communication device 140 includes: a sending module 141, a receiving module 142, and a determining module 143. The sending module 141 is configured to send a downlink signal to the terminal device; the receiving module 142 is configured to receive an uplink signal from the terminal device; receiving time information from the terminal equipment, wherein the time information comprises the receiving time of the downlink signal or the sending time of the uplink signal; the determining module 143 is configured to determine, according to the time sequence relationship between the uplink signal and the downlink signal and the sending advance time of the terminal device, an association relationship between the receiving time of the downlink signal and the sending time of the uplink signal; determining the clock deviation of the terminal equipment according to the incidence relation between the receiving time of the downlink signal and the transmitting time of the uplink signal, the receiving time of the downlink signal or the transmitting time of the uplink signal, the transmitting time of the downlink signal and the receiving time of the uplink signal; the sending module 141 is further configured to: and sending the clock deviation of the terminal equipment to the terminal equipment.

In fig. 14, further, the sending module 141 is further configured to: and sending configuration information to the terminal equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal.

In the above embodiment, the timing relationship between the uplink signal and the downlink signal includes: and the radio frame number, the subframe number or the time slot number corresponding to the time domain resource of the uplink signal, and the radio frame number, the subframe number or the time slot number corresponding to the time domain resource of the downlink signal.

In the above embodiment, the timing relationship between the uplink signal and the downlink signal includes: the sending period of the uplink signal and the downlink signal, the offset of the uplink signal relative to the downlink signal, and the initial position of the uplink signal or the downlink signal.

The communication apparatus in the embodiment shown in fig. 14 can be used to implement the technical solutions of the above method embodiments, and the implementation principles and technical effects are similar, and are not described herein again.

Fig. 15 is a schematic structural diagram of another communication device according to an embodiment of the present application. As shown in fig. 15, the communication device 150 includes: a receiving module 151 and a sending module 152. The receiving module 151 is configured to receive a downlink signal from a network device; the sending module 152 is configured to send an uplink signal to the network device; sending time information to the network equipment, wherein the time information comprises the receiving time of the downlink signal or the sending time of the uplink signal; the receiving module 151 is further configured to: the clock offset of the communication device 150 is received from the network equipment.

In fig. 15, further, the receiving module 151 is further configured to: receiving configuration information from a network device, the configuration information including a timing relationship of the uplink signal and the downlink signal.

The communication apparatus in the embodiment shown in fig. 15 can be used to implement the technical solutions of the above method embodiments, and the implementation principles and technical effects are similar, and are not described herein again.

It should be understood that the above division of the modules of the communication device is only a logical division, and the actual implementation may be wholly or partially integrated into one physical entity or may be physically separated. And these modules can be realized in the form of software called by processing element; or may be implemented entirely in hardware; and part of the modules can be realized in the form of calling by the processing element in software, and part of the modules can be realized in the form of hardware. For example, the determining module may be a processing element that is set up separately, or may be implemented by being integrated in a chip of a communication apparatus, such as a base station or a terminal device, or may be stored in a memory of the communication apparatus in the form of a program, and the processing element of the communication apparatus calls and executes the functions of the above modules. Other modules are implemented similarly. In addition, all or part of the modules can be integrated together or can be independently realized. The processing element described herein may be an integrated circuit having signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in the form of software.

For example, the above modules may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), among others. As another example, when one of the above modules is implemented in the form of a Processing element scheduler, the Processing element may be a general purpose processor, such as a Central Processing Unit (CPU) or other processor capable of invoking programs. As another example, these modules may be integrated together, implemented in the form of a system-on-a-chip (SOC).

Fig. 16 is a schematic structural diagram of a terminal device according to an embodiment of the present application. As shown in fig. 16, the terminal device 160 includes: a memory 161, a processor 162, and a transceiver 163, wherein the memory 161 is used for storing computer programs; the processor 162 invokes the computer program, which when executed, is operable to: receiving first time information from the network device through the transceiving means 163, the first time information indicating time information of a reference time point; receiving a downlink signal from the network device through the transceiving means 163; sending an uplink signal to the network device via the transceiver 163; receiving, by the transceiver 163, second time information from the network device, where the second time information is used to determine a receiving time when the network device receives the uplink signal; determining the sending time of the downlink signal according to the reference time point and the time sequence relation between the uplink signal and the downlink signal; and determining the clock deviation of the terminal equipment according to the sending time of the downlink signal, the receiving time of the downlink signal, the sending time of the uplink signal and the receiving time of the uplink signal.

In fig. 16, further, the timing relationship between the uplink signal and the downlink signal includes: the offset of the downlink signal relative to a reference time point, and the offset of the uplink signal relative to the reference time point.

In the above embodiment, when the processor 162 determines the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, the processor is specifically configured to: and determining the sending time of the downlink signal according to the reference time point and the offset of the downlink signal relative to the reference time point.

In the above embodiment, the second time information includes a time difference between a starting time when the network device starts receiving the uplink signal and a receiving time when the network device receives the uplink signal; the processor 162 is further configured to: and determining the receiving time when the network equipment receives the uplink signal according to the reference time point, the offset of the uplink signal relative to the reference time point and the time difference.

In the above embodiment, when the processor 162 determines the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, the processor is specifically configured to: determining the sending time of the downlink signal according to the reference time point, the initial position of the downlink signal relative to the reference time point and the sending period of the downlink signal; or determining the sending time of the downlink signal according to the reference time point, the initial position of the uplink signal relative to the reference time point, the sending period of the uplink signal and the offset of the uplink signal relative to the downlink signal.

In the above embodiment, the processor 162 is further configured to: configuration information is received from the network device by the transceiver 163, and the configuration information includes the timing relationship between the uplink signal and the downlink signal.

In other embodiments, the memory 161 is used to store computer programs; the processor 162 invokes the computer program, which when executed, is operable to: receiving a downlink signal from the network device through the transceiving means 163; sending an uplink signal to the network device via the transceiver 163; sending time information to the network device through the transceiver 163, where the time information includes a receiving time of the downlink signal or a sending time of the uplink signal; the clock offset of the terminal device is received from the network device via the transceiving means 163.

Further, the processor 162 is further configured to: configuration information is received from the network device via the transceiver 163, the configuration information including the timing relationship of the uplink signal and the downlink signal.

The terminal device in the embodiment shown in fig. 16 may be configured to execute the technical solution of the above method embodiment, and the implementation principle and the technical effect are similar, which are not described herein again.

In fig. 16, the transceiver 163 may be connected to an antenna. In the downlink direction, the transceiver 163 receives information transmitted by the base station via the antenna and sends the information to the processor 162 for processing. In the uplink direction, the processor 162 processes the data of the terminal device and transmits the data to the base station through the transceiver 163.

The memory 161 is used for storing a program for implementing the above method embodiment, or each module of the embodiment shown in fig. 12, and the processor 162 calls the program to execute the operation of the above method embodiment to implement each module shown in fig. 12.

Alternatively, part or all of the above modules may be implemented by being embedded in a chip of the terminal device in the form of an integrated circuit. And they may be implemented separately or integrated together. That is, the above modules may be configured as one or more integrated circuits implementing the above methods, for example: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), among others.

Fig. 17 is a schematic structural diagram of a network device according to an embodiment of the present application. As shown in fig. 17, the network device 170 includes: a memory 171, a processor 172 and a transceiver 173, wherein the memory 171 is used for storing computer programs; the processor 172 invokes the computer program, which when executed, is operable to: transmitting first time information indicating time information of a reference time point to the terminal device through the transceiving means 173; sending a downlink signal to the terminal equipment; receiving an uplink signal from the terminal device via the transceiver 173; and sending second time information to the terminal device through the transceiver 173, where the second time information is used to determine a receiving time at which the network device receives the uplink signal.

In fig. 17, further, the processor 172 is further configured to: the configuration information is sent to the terminal device through the transceiver 173, and the configuration information includes the timing relationship between the uplink signal and the downlink signal.

In other embodiments, the memory 171 is used to store computer programs; the processor 172 invokes the computer program, which when executed, is operable to: transmitting a downlink signal to the terminal device via the transceiver 173; receiving an uplink signal from the terminal device via the transceiver 173; receiving time information from the terminal device by the transceiver 173, wherein the time information includes a receiving time of the downlink signal or a transmitting time of the uplink signal; determining an incidence relation between the receiving time of the downlink signal and the transmitting time of the uplink signal according to the time sequence relation between the uplink signal and the downlink signal and the transmitting advance time of the terminal equipment; determining the clock deviation of the terminal equipment according to the incidence relation between the receiving time of the downlink signal and the transmitting time of the uplink signal, the receiving time of the downlink signal or the transmitting time of the uplink signal, the transmitting time of the downlink signal and the receiving time of the uplink signal; the clock offset of the terminal device is transmitted to the terminal device via the transceiver 173.

Further, the processor 172 is further configured to: and sending configuration information to the terminal device through the transceiver 173, where the configuration information includes a timing relationship between the uplink signal and the downlink signal.

The network device in the embodiment shown in fig. 17 may be configured to execute the technical solution of the method embodiment, and the implementation principle and the technical effect are similar, which are not described herein again.

Fig. 18 is a schematic structural diagram of another network device according to an embodiment of the present application. The network device may specifically be a base station, as shown in fig. 18, where the base station includes: antenna 180, radio frequency device 190, baseband device 200. The antenna 180 is connected to a radio frequency device 190. In the uplink direction, the rf device 190 receives the information sent by the terminal device through the antenna 180, and sends the information sent by the terminal device to the baseband device 200 for processing. In the downlink direction, the baseband device 200 processes the information of the terminal device and sends the information to the rf device 190, and the rf device 190 processes the information of the terminal device and sends the processed information to the terminal device through the antenna 180.

The above communication device may be located in the baseband device 200, and in one implementation, the above modules are implemented in the form of a processing element scheduler, for example, the baseband device 200 includes a processing element 201 and a storage element 202, and the processing element 201 calls a program stored in the storage element 202 to execute the method in the above method embodiment. The baseband device 200 may further include an interface 203 for exchanging information with the rf device 190, such as a Common Public Radio Interface (CPRI).

In another implementation, the above modules may be one or more processing elements configured to implement the above method, the processing elements being disposed on the baseband apparatus 200, where the processing elements may be integrated circuits, such as: one or more ASICs, or one or more DSPs, or one or more FPGAs, etc. These integrated circuits may be integrated together to form a chip.

For example, the above modules may be integrated together and implemented in the form of a system-on-a-chip (SOC), for example, the baseband apparatus 200 includes an SOC chip for implementing the above method. The chip can integrate a processing element 201 and a storage element 202, and the processing element 201 calls the stored program of the storage element 202 to realize the functions of the above methods or the above modules; or, at least one integrated circuit may be integrated in the chip, so as to implement the functions of the above method or the above modules; or, the above implementation modes may be combined, the functions of some modules are implemented in the form of a processing element calling program, and the functions of some modules are implemented in the form of an integrated circuit.

In any case, the above communication device comprises at least one processing element, a storage element and a communication interface, wherein the at least one processing element is configured to perform the method provided by the above method embodiments. The processing element may: i.e. the way the program stored by the storage element is executed, performs part or all of the steps in the above method embodiments; it is also possible to: that is, some or all of the steps in the above method embodiments are performed by integrated logic circuits of hardware in the processing element in combination with instructions; of course, the method provided by the above method embodiment can also be executed in combination with the first manner and the second manner.

The Processing element may be a general-purpose processor, such as a Central Processing Unit (CPU), or one or more integrated circuits configured to implement the above methods, as described above, for example: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), among others. The storage element may be a memory or a combination of a plurality of storage elements.

In addition, an embodiment of the present application further provides a computer-readable storage medium, in which a computer program is stored, and when the computer program runs on a computer, the computer is caused to execute the clock synchronization method described in the foregoing embodiment.

In addition, the present application also provides a computer program product, which includes a computer program that, when running on a computer, causes the computer to execute the clock synchronization method described in the above embodiments.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedures or functions described in accordance with the present application are generated, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, fiber optic, digital subscriber line) or wirelessly (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk), among others.

Claims

1. A method of clock synchronization, comprising:

the terminal equipment receives first time information from the network equipment, wherein the first time information is used for indicating time information of a reference time point;

the terminal equipment receives a downlink signal from the network equipment;

the terminal equipment sends an uplink signal to the network equipment;

the terminal equipment receives second time information from the network equipment, wherein the second time information is used for determining the receiving time of the network equipment for receiving the uplink signal;

the terminal equipment determines the sending time of the downlink signal according to the reference time point and the time sequence relation between the uplink signal and the downlink signal;

the terminal equipment determines the clock deviation of the terminal equipment according to the sending time of the downlink signal, the receiving time of the downlink signal, the sending time of the uplink signal and the receiving time of the uplink signal;

wherein the content of the first and second substances,

the timing relationship between the uplink signal and the downlink signal comprises: the offset of the downlink signal relative to a reference time point and the offset of the uplink signal relative to the reference time point;

alternatively, the first and second electrodes may be,

the timing relationship between the uplink signal and the downlink signal comprises: a transmission period of the uplink signal and the downlink signal, an offset of the uplink signal relative to the downlink signal, and a starting position of the uplink signal or the downlink signal relative to the reference time point.

2. The method according to claim 1, wherein the determining, by the terminal device, the transmission time of the downlink signal according to the reference time point and the timing relationship between the uplink signal and the downlink signal comprises:

3. The method of claim 2, wherein the offset of the downlink signal relative to the reference time point comprises:

4. The method according to claim 2 or 3, wherein the second time information comprises a receiving time of the network device receiving the uplink signal.

5. The method according to claim 2 or 3, wherein the second time information comprises a time difference between a starting time when the network device starts receiving the uplink signal and a receiving time when the network device receives the uplink signal;

the method further comprises the following steps:

6. The method of claim 5, wherein the offset of the uplink signal relative to the reference time point comprises:

7. The method according to claim 1, wherein the determining, by the terminal device, the transmission time of the downlink signal according to the reference time point and the timing relationship between the uplink signal and the downlink signal comprises:

8. The method according to any one of claims 1-3, wherein before the terminal device receives the downlink signal from the network device, the method further comprises:

9. The method of claim 8, wherein the configuration information further comprises: a transmission period of the first time information.

10. The method of claim 9, wherein the configuration information further comprises: and the time information of the corresponding reference time point in the current sending period of the first time information.

11. A method of clock synchronization, comprising:

the network equipment sends a downlink signal to the terminal equipment;

the network equipment receives an uplink signal from the terminal equipment;

the network equipment sends second time information to the terminal equipment, wherein the second time information is used for determining the receiving time of the network equipment for receiving the uplink signal;

wherein the content of the first and second substances,

after the network device sends the first time information to the terminal device, the method further includes:

the network equipment sends configuration information to terminal equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal;

alternatively, the first and second electrodes may be,

12. The method of claim 11, wherein the second time information comprises a receiving time when the network device receives the uplink signal; or

13. A method of clock synchronization, comprising:

the network equipment sends a downlink signal to the terminal equipment;

the network equipment receives an uplink signal from the terminal equipment;

the network equipment sends the clock deviation of the terminal equipment to the terminal equipment;

wherein the content of the first and second substances,

the timing relationship between the uplink signal and the downlink signal comprises: the wireless frame number, the subframe number or the time slot number corresponding to the time domain resource of the uplink signal, and the wireless frame number, the subframe number or the time slot number corresponding to the time domain resource of the downlink signal;

alternatively, the first and second electrodes may be,

the timing relationship between the uplink signal and the downlink signal comprises: the sending period of the uplink signal and the downlink signal, the offset of the uplink signal relative to the downlink signal, and the initial position of the uplink signal or the downlink signal.

14. The method of claim 13, wherein before the network device sends the downlink signal to the terminal device, the method further comprises:

15. A method of clock synchronization, comprising:

the terminal equipment receives a downlink signal from the network equipment;

the terminal equipment sends an uplink signal to the network equipment;

the terminal equipment receives the clock deviation of the terminal equipment from the network equipment;

wherein the content of the first and second substances,

before the terminal device receives the downlink signal from the network device, the method further includes:

the terminal equipment receives configuration information from network equipment, wherein the configuration information comprises the time sequence relation of the uplink signal and the downlink signal;

alternatively, the first and second electrodes may be,

16. A communications apparatus, comprising:

a sending module, configured to send an uplink signal to the network device;

the determining module is used for determining the sending time of the downlink signal according to the reference time point and the time sequence relation between the uplink signal and the downlink signal; determining the clock deviation of the communication device according to the sending time of the downlink signal, the receiving time of the downlink signal, the sending time of the uplink signal and the receiving time of the uplink signal;

wherein the content of the first and second substances,

alternatively, the first and second electrodes may be,

17. The communications apparatus as claimed in claim 16, wherein the determining module determines the sending time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, and is specifically configured to:

18. The apparatus according to claim 16 or 17, wherein the second time information comprises a receiving time when the network device receives the uplink signal.

19. The apparatus according to claim 16 or 17, wherein the second time information comprises a time difference between a starting time when the network device starts receiving the uplink signal and a receiving time when the network device receives the uplink signal;

20. The communications apparatus as claimed in claim 16, wherein the determining module is configured to, when determining the transmission time of the downlink signal according to the reference time point and the time sequence relationship between the uplink signal and the downlink signal, specifically:

21. The communications apparatus according to claim 16 or 17, wherein the receiving module is further configured to: receiving configuration information from the network device, the configuration information including a timing relationship of the uplink signal and the downlink signal.

22. A communications apparatus, comprising:

the sending module is further configured to: sending second time information to the terminal equipment, wherein the second time information is used for determining the receiving time of the communication device for receiving the uplink signal;

wherein the content of the first and second substances,

the sending module is further configured to:

sending configuration information to a terminal device, wherein the configuration information comprises a time sequence relation between the uplink signal and the downlink signal;

alternatively, the first and second electrodes may be,

23. A communications apparatus, comprising:

the sending module is further configured to: sending the clock deviation of the terminal equipment to the terminal equipment;

wherein the content of the first and second substances,

alternatively, the first and second electrodes may be,

24. The communications apparatus of claim 23, wherein the means for transmitting is further configured to:

25. A communications apparatus, comprising:

the receiving module is further configured to: receiving a clock offset of the communication device from the network apparatus;

wherein the content of the first and second substances,

the receiving module is further configured to:

receiving configuration information from a network device, the configuration information including a timing relationship of the uplink signal and the downlink signal;

alternatively, the first and second electrodes may be,

26. A communication device, comprising:

an interface and a processor, the interface and the processor coupled;

the processor is configured to perform the method of any one of claims 1-10, 15.

27. A communication device, comprising:

an interface and a processor, the interface and the processor coupled;

the processor is configured to perform the method of any one of claims 11-14.

28. A computer-readable storage medium, in which a computer program is stored which, when run on a computer, causes the computer to carry out the method according to any one of claims 1 to 15.