CN108632980B

CN108632980B - Synchronization method and terminal

Info

Publication number: CN108632980B
Application number: CN201710178820.3A
Authority: CN
Inventors: 赵锐; 赵丽; 房家奕
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2017-03-23
Filing date: 2017-03-23
Publication date: 2019-12-20
Anticipated expiration: 2037-03-23
Also published as: WO2018171523A1; CN108632980A

Abstract

The invention provides a synchronization method and a terminal, which solve the problem that the synchronization grade of the terminal cannot be accurately distinguished according to the existing synchronization grade information. The method of the invention comprises the following steps: acquiring synchronization level indication information of each synchronization source according to synchronization signals and synchronization channels sent by a plurality of synchronization sources, wherein the synchronization level indication information comprises an identification set to which a synchronization identification of the synchronization source belongs, a position of a resource occupied by the synchronization signal and a coverage identification carried by the synchronization channel; determining a synchronization level corresponding to each synchronization source synchronization level indication information according to a corresponding relation table of preset synchronization level indication information and the synchronization levels, wherein an identification set in the corresponding relation table is obtained according to a first sub-identification set, a second sub-identification set and a third sub-identification set, and the synchronization level indication information corresponding to different synchronization levels in the corresponding relation table is different; and according to the determined synchronization level, selecting a target synchronization source from the multiple synchronization sources, and synchronizing according to the selected target synchronization source.

Description

Synchronization method and terminal

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a synchronization method and a terminal.

Background

In the synchronization technique of Rel-14V2X (Vehicle to X), when the system configures or pre-configures three synchronization resources (e.g., R1, R2 and R3, wherein R3 is fixed as the synchronization resource of the UE out-of-coverage directly synchronized with GNSS), the priority of the terminal synchronization source is distinguished by the location of the occupied resource, the Synchronization Source ID (SSID), and the coverage in _ coverage identification indicated in the BCH in the synchronization channel PSBCH.

When the eNB has the highest priority, the definition of the synchronization level is shown in table 1, and it can be seen from table 1 that when the eNB has the highest priority, P5 and P6 cannot be distinguished by the synchronization resource, SSID, and PSBCH.

TABLE 1

When the GNSS (Global Navigation Satellite System) is highest priority, it is considered that the base station eNB notifies the eNB of the time difference between the timing and the GNSS, and the definition of the synchronization level is shown in table 2, and it can be seen from table 2 that when the GNSS is highest priority, P3 and P4 cannot be distinguished by the synchronization resource, SSID, and PSBCH.

TABLE 2

Therefore, it can be seen that, in the prior art, a method for determining the synchronization priority of the terminal through the resource location occupied by the synchronization signal, the SSID, and the PSBCH has a problem that the synchronization priority of the synchronization source cannot be determined accurately.

Disclosure of Invention

The invention aims to provide a synchronization method and a terminal, which are used for solving the problem that the synchronization priority of a synchronization source cannot be accurately determined through a resource position, an SSID (service set identifier) and a PSBCH (packet switched channel) occupied by a synchronization signal in the prior art.

In order to achieve the above object, the present invention provides a synchronization method applied to a terminal, including:

acquiring synchronization level indication information of each synchronization source according to synchronization signals and synchronization channels respectively sent by a plurality of synchronization sources, wherein the synchronization level indication information comprises an identification set to which a synchronization identification of the synchronization source belongs, a position of a resource occupied by the synchronization signal and a coverage identification carried by the synchronization channel, and a first sub-identification set which is positioned in a coverage range of a base station and corresponds to the synchronization source synchronized with the base station, a second sub-identification set which is positioned in the coverage range of the base station and directly corresponds to the synchronization source synchronized with the GNSS, and a third sub-identification set which is positioned outside the coverage range of the base station and directly corresponds to the synchronization source synchronized with the GNSS are three sets which are different from each other;

determining a synchronization level corresponding to each synchronization source synchronization level indication information according to a corresponding relation table of preset synchronization level indication information and the synchronization levels, wherein an identifier set in the corresponding relation table is obtained according to the first sub identifier set, the second sub identifier set and the third sub identifier set, and synchronization level indication information corresponding to different synchronization levels in the corresponding relation table is different;

and selecting a target synchronization source from the multiple synchronization sources according to the determined synchronization level, and synchronizing according to the selected target synchronization source.

The step of selecting a target synchronization source from a plurality of synchronization sources according to the determined synchronization level comprises the following steps:

if the same synchronization grade exists in the multiple determined synchronization grades, selecting a target synchronization source from the multiple synchronization sources for synchronization according to the signal receiving intensity of the synchronization source and the determined synchronization grade;

and if the same synchronization grade does not exist in the plurality of determined synchronization grades, selecting the synchronization source with the highest synchronization grade as a target synchronization source according to the determined synchronization grade and synchronizing.

The step of synchronizing according to the selected target synchronization source comprises the following steps:

if the target synchronization source is a synchronization source which is within the coverage range of a base station and is directly synchronized with the base station or a synchronization source which is within the coverage range of the base station and is directly synchronized with a GNSS, taking the synchronization identifier of the target synchronization source as the synchronization identifier of a terminal, and setting the coverage identifier of the synchronization channel of the terminal as a second identifier different from the first synchronization identifier of the target synchronization source;

if the target synchronization source is a synchronization source which is out of the coverage range of the base station and is directly synchronous with the GNSS, taking the synchronization identifier of the target synchronization source as the synchronization identifier of the terminal, and setting the coverage identifier of the synchronization channel of the terminal as a second identifier;

if the target synchronization source is a synchronization source which is within the coverage range of the base station and is indirectly synchronized with the base station, or a synchronization source which is within the coverage range of the base station and is indirectly synchronized with the GNSS, or a synchronization source which is outside the coverage range of the base station and is directly synchronized with the GNSS, the synchronization identifier of the terminal is obtained according to the sum of the synchronization identifier of the target synchronization source and a preset threshold, and the coverage identifier of the synchronization channel of the terminal is set as a second identifier.

Wherein, if the GNSS is the highest priority;

the step of determining the synchronization level corresponding to each synchronization source synchronization level indication information according to the corresponding relation table of the preset synchronization level indication information and the synchronization level comprises:

if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, and the position of the resource occupied by the synchronization signal is a first position or a third position, determining that the synchronization level of the synchronization source is a first level, where the first preset identifier set is a set corresponding to the synchronization identifier of the synchronization source of which the synchronization hop count of a base station or a GNSS is less than or equal to two hops, and the first preset identifier set includes the first sub-identifier set, the second sub-identifier set, and the third sub-identifier set;

if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a second level;

if the identifier set to which the synchronization identifier of the synchronization source belongs is a second preset identifier set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a third level, wherein the second preset identifier set is a set corresponding to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station or the GNSS is more than two hops, and the second preset identifier set is obtained by adding a preset threshold value to the value in the first preset identifier set;

wherein the priorities of the first level, the second level and the third level are sequentially reduced.

Wherein, if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, and the position of the resource occupied by the synchronization signal is a first position or a third position, the step of determining that the synchronization level of the synchronization source is a first level includes:

if the identification set of the synchronization source belongs to a first sub-identification set, the position of the resource occupied by the synchronization signal is a first position, and the coverage identification is a first identification, determining that the synchronization level of the synchronization source is a first level; or

If the identification set of the synchronization source belongs to the second sub-identification set, the position of the resource occupied by the synchronization signal is the first position, and the coverage identification is the first identification, determining that the synchronization level of the synchronization source is the first level; or

And if the identification set of the synchronous source belongs to a third sub-identification set, the position of the resource occupied by the synchronous signal is a third position, and the coverage identification is the first identification or the second identification, determining that the synchronization grade of the synchronous source is the first grade.

Wherein, if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, the step of determining that the synchronization level of the synchronization source is a second level includes:

if the identification set of the synchronization source belongs to the first sub-identification set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a second level; or

If the identification set of the synchronization source belongs to a second sub-identification set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a second level; or

And if the identification set of the synchronous source belongs to a third sub-identification set, the position of the resource occupied by the synchronous signal is a second position, and the coverage identification is a second identification, determining that the synchronization grade of the synchronous source is a second grade.

Wherein, if the identifier set to which the synchronization identifier of the synchronization source belongs is a second preset identifier set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage identifier is a second identifier, the step of determining that the synchronization level of the synchronization source is a third level includes:

if the identification set of the synchronization source belongs to a fourth sub-identification set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a third level, wherein the fourth sub-identification set is a set which is in the coverage area of the base station and corresponds to the synchronization identification of the synchronization source of which the synchronization hop count of the base station is more than two hops or a set corresponding to the synchronization identification of an independent synchronization source, and the fourth sub-identification set is obtained by adding a preset threshold value to the value in the first sub-identification set; or

If the identification set of the synchronization source belongs to a fifth sub-identification set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a third level, wherein the fifth sub-identification set is a set which is in the coverage area of the base station and corresponds to the synchronization identification of the synchronization source of which the synchronization hop count of the GNSS is more than two hops, and the fifth sub-identification set is obtained by adding a preset threshold value to the value in the second sub-identification set; or

If the identification set of the synchronous source belongs to a sixth sub-identification set, the position of the resource occupied by the synchronous signal is the first position or the second position, and the coverage identification is the second identification, the synchronous grade of the synchronous source is determined to be the third grade, the sixth sub-identification set is a set which is out of the coverage range of the base station and corresponds to the synchronous identification of the synchronous source with the GNSS synchronization hop count being greater than two hops, and the sixth sub-identification set is obtained by adding a preset threshold value to the value in the third sub-identification set.

Wherein, if the base station has the highest priority;

if the identifier set to which the synchronization identifier of the synchronization source belongs is a first sub-identifier set, the position of the resource occupied by the synchronization signal is a first position, and the coverage identifier is a first identifier, determining that the synchronization level of the synchronization source is a first level;

if the identifier set to which the synchronization identifier of the synchronization source belongs is a first sub-identifier set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a second level;

if the identifier set to which the synchronization identifier of the synchronization source belongs is a third sub-identifier set, the position of the resource occupied by the synchronization signal is a third position, and the coverage identifier is the first identifier or the second identifier, determining that the synchronization level of the synchronization source is a third level;

if the identifier set to which the synchronization identifier of the synchronization source belongs is a third sub-identifier set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a fourth level;

if the identifier set to which the synchronization identifier of the synchronization source belongs is the fourth sub-identifier set or the sixth sub-identifier set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage mark is a second mark, determining that the synchronization level of the synchronization source is a fifth level, the fourth sub-identifier set is a set which is within the coverage of the base station and corresponds to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station is more than two hops or a set corresponding to the synchronization identifier of an independent synchronization source, the sixth sub-identification set is a set which is out of the coverage area of the base station and corresponds to the synchronization identification of the synchronization source of which the number of the synchronization hops of the GNSS is more than two hops, and the fourth sub-identification set is obtained by adding a preset threshold value to the values in the first sub-identification set, the sixth sub-identifier set is obtained by adding a preset threshold to the value in the third sub-identifier set;

and the priorities of the first level, the second level, the third level, the fourth level and the fifth level are sequentially reduced.

In order to achieve the above object, an embodiment of the present invention further provides a terminal, including:

an obtaining module, configured to obtain synchronization level indication information of each synchronization source according to a synchronization signal and a synchronization channel respectively sent by multiple synchronization sources, where the synchronization level indication information includes an identifier set to which a synchronization identifier of the synchronization source belongs, a location of a resource occupied by the synchronization signal, and a coverage identifier carried by the synchronization channel, and a first sub-identifier set corresponding to a synchronization source that is within a coverage of a base station and is synchronized with the base station, a second sub-identifier set corresponding to a synchronization source that is within the coverage of the base station and is directly synchronized with a GNSS, and a third sub-identifier set corresponding to a synchronization source that is outside the coverage of the base station and is directly synchronized with the GNSS are three sets different from each other;

a determining module, configured to determine, according to a correspondence table between preset synchronization level indication information and synchronization levels, a synchronization level corresponding to each synchronization source synchronization level indication information, where an identifier set in the correspondence table is obtained according to the first sub-identifier set, the second sub-identifier set, and the third sub-identifier set, and synchronization level indication information corresponding to different synchronization levels in the correspondence table is different;

and the synchronization module is used for selecting a target synchronization source from the multiple synchronization sources according to the determined synchronization level and synchronizing according to the selected target synchronization source.

Wherein the synchronization module comprises:

the first determining submodule is used for selecting a target synchronization source from a plurality of synchronization sources to synchronize according to the signal receiving intensity of the synchronization source and the determined synchronization level if the same synchronization level exists in the plurality of determined synchronization levels;

and the second determining submodule is used for selecting the synchronization source with the highest synchronization level as the target synchronization source and synchronizing according to the determined synchronization level if the same synchronization level does not exist in the plurality of determined synchronization levels.

Wherein the synchronization module comprises:

the first synchronization submodule is used for taking the synchronization identifier of the target synchronization source as the synchronization identifier of the terminal and setting the coverage identifier of the synchronization channel of the terminal as a second identifier different from the first synchronization identifier of the target synchronization source if the target synchronization source is a synchronization source which is within the coverage range of the base station and is directly synchronized with the base station or a synchronization source which is within the coverage range of the base station and is directly synchronized with the GNSS;

the second synchronization submodule is used for taking the synchronization identifier of the target synchronization source as the synchronization identifier of the terminal and setting the coverage identifier of the synchronization channel of the terminal as a second identifier if the target synchronization source is a synchronization source which is out of the coverage range of the base station and is directly synchronized with the GNSS;

and the third synchronization submodule is used for obtaining a synchronization identifier of the terminal according to the sum of the synchronization identifier of the target synchronization source and a preset threshold value and setting the coverage identifier of the synchronization channel of the terminal as a second identifier if the target synchronization source is a synchronization source which is within the coverage area of the base station and is indirectly synchronized with the base station, or a synchronization source which is within the coverage area of the base station and is indirectly synchronized with the GNSS, or a synchronization source which is outside the coverage area of the base station and is directly synchronized with the GNSS.

Wherein, if the GNSS is the highest priority;

the determining module comprises:

a third determining sub-module, configured to determine that the synchronization level of the synchronization source is the first level if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, and the position of the resource occupied by the synchronization signal is the first position or the third position, where the first preset identifier set is a set corresponding to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station or the GNSS is less than or equal to two hops, and the first preset identifier set includes the first sub-identifier set, the second sub-identifier set, and the third sub-identifier set;

a fourth determining submodule, configured to determine that the synchronization level of the synchronization source is the second level if the identifier set to which the synchronization identifier of the synchronization source belongs is the first preset identifier set, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier;

a fifth determining submodule, configured to determine that the synchronization level of the synchronization source is a third level if the identifier set to which the synchronization identifier of the synchronization source belongs is a second preset identifier set, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the second preset identifier set is a set corresponding to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station or the GNSS is greater than two hops, and the second preset identifier set is obtained by adding a preset threshold to a value in the first preset identifier set;

Wherein the third determination submodule includes:

a first determining unit, configured to determine that the synchronization level of the synchronization source is a first level if the identifier set of the synchronization source belongs to a first sub-identifier set, the location of the resource occupied by the synchronization signal is a first location, and the coverage identifier is a first identifier;

a second determining unit, configured to determine that the synchronization level of the synchronization source is the first level if the identifier set of the synchronization source belongs to the second sub-identifier set, the location of the resource occupied by the synchronization signal is the first location, and the coverage identifier is the first identifier;

and the third determining unit is used for determining that the synchronization level of the synchronization source is the first level if the identification set of the synchronization source belongs to the third sub-identification set, the position of the resource occupied by the synchronization signal is the third position, and the coverage identification is the first identification or the second identification.

Wherein the fourth determination submodule includes:

a fourth determining unit, configured to determine that the synchronization level of the synchronization source is the second level if the identifier set of the synchronization source belongs to the first sub-identifier set, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier;

a fifth determining unit, configured to determine that the synchronization level of the synchronization source is the second level if the identifier set of the synchronization source belongs to the second sub-identifier set, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier; or

A sixth determining unit, configured to determine that the synchronization level of the synchronization source is the second level if the identifier set of the synchronization source belongs to the third sub-identifier set, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier.

Wherein the fifth determination submodule includes:

a seventh determining unit, configured to determine that the synchronization level of the synchronization source is a third level if the identifier set of the synchronization source belongs to a fourth sub-identifier set, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the fourth sub-identifier set is a set that is within the coverage of the base station and corresponds to the synchronization identifier of the synchronization source with the number of synchronization hops of the base station being greater than two hops or a set that corresponds to the synchronization identifier of an independent synchronization source, and the fourth sub-identifier set is obtained by adding a preset threshold to the value in the first sub-identifier set; or

An eighth determining unit, configured to determine that the synchronization level of the synchronization source is a third level if the identifier set of the synchronization source belongs to a fifth sub-identifier set, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the fifth sub-identifier set is a set that is within a coverage area of the base station and corresponds to a synchronization identifier of the synchronization source of which the synchronization hop count of the GNSS is greater than two hops, and the fifth sub-identifier set is obtained by adding a preset threshold to a value in the second sub-identifier set; or

A ninth determining unit, configured to determine that the synchronization level of the synchronization source is the third level if the identifier set of the synchronization source belongs to the sixth sub-identifier set, where the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, the sixth sub-identifier set is a set that is outside the coverage of the base station and corresponds to the synchronization identifier of the synchronization source with which the synchronization hop count of the GNSS is greater than two hops, and the sixth sub-identifier set is obtained by adding a preset threshold to the value in the third sub-identifier set.

Wherein, if the base station has the highest priority;

the determining module comprises:

a sixth determining submodule, configured to determine that the synchronization level of the synchronization source is the first level if the identifier set to which the synchronization identifier of the synchronization source belongs is the first sub-identifier set, the position of the resource occupied by the synchronization signal is the first position, and the coverage identifier is the first identifier;

a seventh determining sub-module, configured to determine that the synchronization level of the synchronization source is the second level if the identifier set to which the synchronization identifier of the synchronization source belongs is the first sub-identifier set, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier;

an eighth determining submodule, configured to determine that the synchronization level of the synchronization source is the third level if the identifier set to which the synchronization identifier of the synchronization source belongs is the third sub-identifier set, the position of the resource occupied by the synchronization signal is the third position, and the coverage identifier is the first identifier or the second identifier;

a ninth determining sub-module, configured to determine that the synchronization level of the synchronization source is a fourth level if the identifier set to which the synchronization identifier of the synchronization source belongs is a third sub-identifier set, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier;

a tenth determining submodule, configured to, if the identifier set to which the synchronization identifier of the synchronization source belongs is the fourth sub-identifier set or the sixth sub-identifier set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage mark is a second mark, determining that the synchronization level of the synchronization source is a fifth level, the fourth sub-identifier set is a set which is within the coverage of the base station and corresponds to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station is more than two hops or a set corresponding to the synchronization identifier of an independent synchronization source, the sixth sub-identification set is a set which is out of the coverage area of the base station and corresponds to the synchronization identification of the synchronization source of which the number of the synchronization hops of the GNSS is more than two hops, and the fourth sub-identification set is obtained by adding a preset threshold value to the values in the first sub-identification set, the sixth sub-identifier set is obtained by adding a preset threshold to the value in the third sub-identifier set;

The embodiment of the invention has the following beneficial effects:

according to the technical scheme of the embodiment of the invention, the synchronization grade indication information of each synchronization source is obtained according to the synchronization signals and the synchronization channels respectively sent by a plurality of synchronization sources; according to a corresponding relation table of preset synchronization grade indication information and synchronization grades, determining a synchronization grade corresponding to each synchronization source synchronization grade indication information, selecting a target synchronization source from a plurality of synchronization sources according to the determined synchronization grade, and synchronizing according to the selected target synchronization source SSID, and PSBCH, cannot accurately determine the synchronization priority of the synchronization source.

Drawings

FIG. 1 is a flowchart illustrating a synchronization method according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating synchronization hops in a synchronization method according to an embodiment of the present invention;

fig. 3 is a first block diagram of a terminal according to an embodiment of the present invention;

fig. 4 is a second structural block diagram of the terminal according to the embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings.

The embodiment of the invention provides a synchronization method and a terminal, and solves the problem that the synchronization priority of a synchronization source cannot be accurately determined through a resource position, an SSID (service set identifier) and a PSBCH (packet switched channel) occupied by a synchronization signal in the prior art.

As shown in fig. 1, the synchronization method according to the embodiment of the present invention includes:

step 101: the method comprises the steps of obtaining synchronous grade indicating information of each synchronous source according to synchronous signals and synchronous channels respectively sent by a plurality of synchronous sources, wherein the synchronous grade indicating information comprises an identification set to which a synchronous identification of the synchronous source belongs, positions of resources occupied by the synchronous signals and coverage identifications born by the synchronous channels, and a first sub-identification set which is positioned in a coverage range of a base station and corresponds to the synchronous source synchronous with the base station, a second sub-identification set which is positioned in the coverage range of the base station and corresponds to the synchronous source synchronous with GNSS directly and a third sub-identification set which is positioned outside the coverage range of the base station and corresponds to the synchronous source synchronous with the GNSS directly are three sets which are different from each other.

In a specific embodiment of the present invention, a terminal directly synchronized with GNSS outside the coverage of the base station and a terminal directly synchronized with GNSS in the coverage have two different sets of synchronization source identifiers ID (a second sub-set of identifiers and a third sub-set of identifiers) when transmitting synchronization signals and synchronization channels, and both sets of identifiers ID are different from the first sub-set of identifiers of UEs synchronized with eNB in the coverage.

Step 102: and determining the synchronization level corresponding to each synchronization source synchronization level indication information according to a corresponding relation table of preset synchronization level indication information and the synchronization levels, wherein the identification set in the corresponding relation table is obtained according to the first sub-identification set, the second sub-identification set and the third sub-identification set, and the synchronization level indication information corresponding to different synchronization levels in the corresponding relation table is different.

In this embodiment of the present invention, the identifier sets in the correspondence table include the first sub identifier set, the second sub identifier set, the third sub identifier set, and a fourth sub identifier set, a fifth sub identifier set, and a sixth sub identifier set, which are obtained by adding a preset threshold to values in the first sub identifier set, the second sub identifier set, and the third sub identifier set, respectively.

When the correspondence table is established, the overlay identifier of the synchronization channel (PSBCH) of the first terminal directly synchronized with the GNSS outside the overlay may be specifically set as a first identifier, such as True, or may be set as a second identifier, such as False. And selecting the second terminal out of coverage which is directly synchronized with the GNSS as a third terminal of a synchronization source, wherein when the synchronization signal and the synchronization channel are transmitted, the synchronization source ID of the third terminal is the same as the synchronization source ID of the second terminal out of coverage which is directly synchronized with the GNSS, and the coverage identifier of the synchronization channel (PSBCH) of the third terminal is a second identifier, such as False.

And selecting a fourth terminal indirectly synchronized with the GNSS as a fifth terminal of a synchronization source, wherein the synchronization hop count of the fourth terminal and the GNSS is more than 2 hops, and the synchronization source ID of the fifth terminal is the sum of the synchronization source ID of the fourth terminal and a preset threshold (168) when the fifth terminal transmits a synchronization signal and a synchronization channel. In the embodiment of the present invention, the definition of the synchronization hop count is shown in fig. 2, where the synchronization hop count of the terminal a directly synchronized with the GNSS or the base station is 1 hop, the synchronization hop count of the terminal B using the terminal a as the synchronization source is 2 hops, and the synchronization hop count of the terminal C using the terminal B as the synchronization source is 3 hops.

Specifically, as shown in tables 3 and 4, table 3 shows the correspondence between the synchronization level indication information and the synchronization level when the GNSS has the highest priority, and table 4 shows the correspondence between the synchronization level indication information and the synchronization level when the base station has the highest priority.

TABLE 3

As can be seen from table 3, the P2 levels include UE1 directly synchronized with the base station in coverage, UE2 directly synchronized with the GNSS in coverage, and UE3 directly synchronized with the GNSS outside coverage, where the identity sets corresponding to the three types of synchronization information in the P2 level are different, the identity set corresponding to UE1 directly synchronized with the base station in coverage is [2,167], the identity set corresponding to UE2 directly synchronized with the GNSS in coverage is 1, and the identity set corresponding to UE3 directly synchronized with the GNSS outside coverage is 0.

The identification sets corresponding to the three synchronization information in the P3 level are obtained according to the identification sets corresponding to the three synchronization information in the P2 level, the identification set corresponding to the UE4 which is indirectly synchronized with the base station through the UE1 is [2,167], the identification set corresponding to the UE5 which is indirectly synchronized with the GNSS through the UE2 is 1, and the identification set corresponding to the UE6 which is indirectly synchronized with the GNSS through the UE3 is 0.

An identifier set corresponding to the UE7 in the P4 level is obtained by adding a preset threshold to the coverage identifier of the UE1, an identifier set corresponding to the UE8 is obtained by adding a preset threshold to the coverage identifier of the UE2, an identifier set corresponding to the UE9 is obtained by adding a preset threshold to the coverage identifier of the UE3, and an identifier set corresponding to the UE10 is obtained by adding a preset threshold to the coverage identifier of the UE 1.

TABLE 4

As can be seen from table 4, the identity set corresponding to the UE5 in the P6 level is obtained by adding a preset threshold to the coverage identity of the UE1, the identity set corresponding to the UE6 is obtained by adding a preset threshold to the coverage identity of the UE3, the identity set corresponding to the UE7 is obtained by adding a preset threshold to the coverage identity of the UE3, and the identity set corresponding to the UE10 is obtained by adding a preset threshold to the coverage identity of the UE 1.

In summary, in the embodiment of the present invention, the synchronization level indication information corresponding to different synchronization levels in the correspondence table obtained according to the first sub-identifier set, the second sub-identifier set, and the third sub-identifier set is different, and the terminal can determine a synchronization level corresponding to the synchronization level indication information of the synchronization source according to the correspondence, so as to solve the problem that the synchronization priority of the synchronization source cannot be accurately determined through the resource location, SSID, and PSBCH occupied by the synchronization signal in the prior art.

Step 103: and selecting a target synchronization source from the multiple synchronization sources according to the determined synchronization level, and synchronizing according to the selected target synchronization source.

if the same synchronization grade does not exist in the plurality of determined synchronization grades, selecting the synchronization source with the highest synchronization grade as a target synchronization source according to the determined synchronization grade and synchronizing; and if the same synchronization grade exists in the plurality of determined synchronization grades, selecting a target synchronization source from the plurality of synchronization sources for synchronization according to the signal receiving strength of the synchronization source and the determined synchronization grade.

And when the same synchronization grade exists in the plurality of determined synchronization grades, selecting the synchronization source with the strongest received signal from the synchronization sources corresponding to the same synchronization grade, and selecting the synchronization source with the highest synchronization grade as the target synchronization source according to the synchronization grade of the selected synchronization source and other synchronization grades except the same synchronization grade from the plurality of synchronization grades.

Further, in step 103, the step of performing synchronization according to the selected target synchronization source includes:

and if the target synchronization source is a synchronization source which is within the coverage range of the base station and is directly synchronized with the base station or a synchronization source which is within the coverage range of the base station and is directly synchronized with the GNSS, taking the synchronization identifier of the target synchronization source as the synchronization identifier of the terminal, and setting the coverage identifier of the synchronization channel of the terminal as a second identifier different from the first synchronization identifier of the target synchronization source. Such as UE4 with UE1 as the synchronization source and UE5 with UE2 as the synchronization source in table 3.

And if the target synchronization source is a synchronization source which is out of the coverage range of the base station and is directly synchronized with the GNSS, taking the synchronization identifier of the target synchronization source as the synchronization identifier of the terminal, and setting the coverage identifier of the synchronization channel of the terminal as a second identifier. Such as UE6 with UE3 as the synchronization source in table 3.

If the target synchronization source is a synchronization source which is within the coverage range of the base station and is indirectly synchronized with the base station, or a synchronization source which is within the coverage range of the base station and is indirectly synchronized with the GNSS, or a synchronization source which is outside the coverage range of the base station and is directly synchronized with the GNSS, the synchronization identifier of the terminal is obtained according to the sum of the synchronization identifier of the target synchronization source and a preset threshold, and the coverage identifier of the synchronization channel of the terminal is set as a second identifier. Such as UE7, UE8, UE9, and UE10 in table 3.

Further, when the GNSS has the highest priority, the step 102 specifically includes:

step 1021: if the identification set to which the synchronization identification of the synchronization source belongs is a first preset identification set, and the position of the resource occupied by the synchronization signal is a first position or a third position, determining that the synchronization level of the synchronization source is a first level, wherein the first preset identification set is a set corresponding to the synchronization identification of the synchronization source with the synchronization hop count of the base station or the GNSS being less than or equal to two hops, and the first preset identification set comprises the first sub-identification set, the second sub-identification set and the third sub-identification set. The first sub-id set may be specifically [2,167], the second sub-id set is specifically 1, and the third sub-id set is specifically 0.

Step 1022: and if the identification set to which the synchronous identification of the synchronous source belongs is a first preset identification set, the position of the resource occupied by the synchronous signal is a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronous source is a second level.

Step 1023: if the identification set to which the synchronous identification of the synchronous source belongs is a second preset identification set, the position of the resource occupied by the synchronous signal is a first position or a second position, and the coverage identification is a second identification, the synchronization grade of the synchronous source is determined to be a third grade, the second preset identification set is a set corresponding to the synchronous identification of the synchronous source of which the synchronous hop count of the base station or the GNSS is more than two hops, and the second preset identification set is obtained by adding a preset threshold value to the value in the first preset identification set.

Further, the step 1021 includes: if the identification set of the synchronization source belongs to a first sub-identification set, the position of the resource occupied by the synchronization signal is a first position, and the coverage identification is a first identification, determining that the synchronization level of the synchronization source is a first level; or

Further, the step 1022 includes: if the identification set of the synchronization source belongs to the first sub-identification set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a second level; or

Further, the step 1023 includes: if the identification set of the synchronization source belongs to a fourth sub-identification set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a third level, wherein the fourth sub-identification set is a set which is positioned in the coverage of the base station and corresponds to the synchronization identification of the synchronization source of which the synchronization hop count of the base station is more than two hops or a set corresponding to the synchronization identification of an independent synchronization source, and the fourth sub-identification set is obtained by adding a preset threshold value to the value in the first sub-identification set, and when the preset threshold value is 168, the fourth sub-identification set is a [170,335 ]; or

If the identifier set of the synchronization source belongs to a fifth sub-identifier set, the position of the resource occupied by the synchronization signal is the first position or the second position, and the coverage identifier is the second identifier, determining that the synchronization level of the synchronization source is the third level, where the fifth sub-identifier set is a set which is within the coverage of the base station and corresponds to the synchronization identifier of the synchronization source of which the synchronization hop count of the GNSS is greater than two hops, and the fifth sub-identifier set is obtained by adding a preset threshold to the value in the second sub-identifier set, and may be specifically 169 in table 3; or

If the identification set of the synchronization source belongs to a sixth sub-identification set, the position of the resource occupied by the synchronization signal is the first position or the second position, and the coverage identification is the second identification, the synchronization level of the synchronization source is determined to be the third level, the sixth sub-identification set is a set which is out of the coverage area of the base station and corresponds to the synchronization identification of the synchronization source of which the synchronization hop count of the GNSS is greater than two hops, and the sixth sub-identification set is obtained by adding a preset threshold value to the value in the third sub-identification set, and is specifically 168 in table 3.

Further, when the base station has the highest priority, the step 102 specifically includes:

According to the synchronization method provided by the embodiment of the invention, the synchronization grade indication information of each synchronization source is obtained according to the synchronization signals and the synchronization channels respectively sent by a plurality of synchronization sources; according to a corresponding relation table of preset synchronization grade indication information and synchronization grades, determining a synchronization grade corresponding to each synchronization source synchronization grade indication information, selecting a target synchronization source from a plurality of synchronization sources according to the determined synchronization grade, and synchronizing according to the selected target synchronization source SSID, and PSBCH, cannot accurately determine the synchronization priority of the synchronization source.

An embodiment of the present invention further provides a terminal, as shown in fig. 3, including:

an obtaining module 301, configured to obtain synchronization level indication information of each synchronization source according to a synchronization signal and a synchronization channel respectively sent by multiple synchronization sources, where the synchronization level indication information includes an identifier set to which a synchronization identifier of the synchronization source belongs, a location of a resource occupied by the synchronization signal, and a coverage identifier carried by the synchronization channel, and a first sub-identifier set corresponding to a synchronization source that is within a coverage area of a base station and is synchronized with the base station, a second sub-identifier set corresponding to a synchronization source that is within the coverage area of the base station and is directly synchronized with a GNSS, and a third sub-identifier set corresponding to a synchronization source that is outside the coverage area of the base station and is directly synchronized with the GNSS are three sets different from each other;

a determining module 302, configured to determine, according to a correspondence table between preset synchronization level indication information and synchronization levels, a synchronization level corresponding to each synchronization source synchronization level indication information, where an identifier set in the correspondence table is obtained according to the first sub-identifier set, the second sub-identifier set, and the third sub-identifier set, and synchronization level indication information corresponding to different synchronization levels in the correspondence table is different;

and the synchronization module 303 is configured to select a target synchronization source from the multiple synchronization sources according to the determined synchronization level, and perform synchronization according to the selected target synchronization source.

In the terminal of the embodiment of the present invention, the synchronization module includes:

In the terminal of the embodiment of the invention, if the GNSS is the highest priority;

the determining module comprises:

In the terminal of the embodiment of the present invention, the third determining sub-module includes:

In the terminal of the embodiment of the present invention, the fourth determining sub-module includes:

In the terminal of the embodiment of the present invention, the fifth determining sub-module includes:

In the terminal of the embodiment of the invention, if the base station has the highest priority;

the determining module comprises:

According to the terminal of the embodiment of the invention, the synchronization grade indication information of each synchronization source is obtained according to the synchronization signals and the synchronization channels respectively sent by a plurality of synchronization sources; according to a corresponding relation table of preset synchronization grade indication information and synchronization grades, determining a synchronization grade corresponding to each synchronization source synchronization grade indication information, selecting a target synchronization source from a plurality of synchronization sources according to the determined synchronization grade, and synchronizing according to the selected target synchronization source SSID, and PSBCH, cannot accurately determine the synchronization priority of the synchronization source.

As shown in fig. 4, an embodiment of the present invention further provides a terminal including: a memory 420, a processor 400 and a computer program stored on the memory 420 and executable on the processor 400, the processor 400 being configured to read the program in the memory 420 and execute the following processes:

A transceiver 410 for receiving and transmitting data under the control of the processor 400.

Where in fig. 4, the bus architecture may include any number of interconnected buses and bridges, with various circuits of one or more processors, represented by processor 400, and memory, represented by memory 420, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 410 may be a number of elements, including a transmitter and a transceiver, providing a means for communicating with various other apparatus over a transmission medium. For different user devices, the user interface 430 may also be an interface capable of interfacing with a desired device externally, including but not limited to a keypad, display, speaker, microphone, joystick, etc.

The processor 400 is responsible for managing the bus architecture and general processing, and the memory 420 may store data used by the processor 400 in performing operations.

The processor 400 is further configured to select a target synchronization source from the multiple synchronization sources for synchronization according to the signal receiving strength of the synchronization source and the determined synchronization level if the same synchronization level exists in the multiple determined synchronization levels; and if the same synchronization grade does not exist in the plurality of determined synchronization grades, selecting the synchronization source with the highest synchronization grade as a target synchronization source according to the determined synchronization grade and synchronizing.

The processor 400 is further configured to, if the target synchronization source is a synchronization source that is within a coverage area of a base station and is directly synchronized with the base station or a synchronization source that is within the coverage area of the base station and is directly synchronized with a GNSS, use a synchronization identifier of the target synchronization source as a synchronization identifier of a terminal, and set a coverage identifier of a synchronization channel of the terminal to a second identifier different from the first synchronization identifier of the target synchronization source; if the target synchronization source is a synchronization source which is out of the coverage range of the base station and is directly synchronous with the GNSS, taking the synchronization identifier of the target synchronization source as the synchronization identifier of the terminal, and setting the coverage identifier of the synchronization channel of the terminal as a second identifier; if the target synchronization source is a synchronization source which is within the coverage range of the base station and is indirectly synchronized with the base station, or a synchronization source which is within the coverage range of the base station and is indirectly synchronized with the GNSS, or a synchronization source which is outside the coverage range of the base station and is directly synchronized with the GNSS, the synchronization identifier of the terminal is obtained according to the sum of the synchronization identifier of the target synchronization source and a preset threshold, and the coverage identifier of the synchronization channel of the terminal is set as a second identifier.

The processor 400 is further configured to determine that the synchronization level of the synchronization source is a first level if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, and the position of the resource occupied by the synchronization signal is a first position or a third position, where the first preset identifier set is a set corresponding to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station or the GNSS is less than or equal to two hops, and the first preset identifier set includes the first sub-identifier set, the second sub-identifier set, and the third sub-identifier set; if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a second level; if the identifier set to which the synchronization identifier of the synchronization source belongs is a second preset identifier set, the position of the resource occupied by the synchronization signal is a first position or a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a third level, wherein the second preset identifier set is a set corresponding to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station or the GNSS is more than two hops, and the second preset identifier set is obtained by adding a preset threshold value to the value in the first preset identifier set; wherein the priorities of the first level, the second level and the third level are sequentially reduced.

The processor 400 is further configured to determine that the synchronization level of the synchronization source is a first level if the identifier set of the synchronization source belongs to a first sub-identifier set, the position of the resource occupied by the synchronization signal is a first position, and the coverage identifier is a first identifier; or if the identification set of the synchronization source belongs to a second sub-identification set, the position of the resource occupied by the synchronization signal is a first position, and the coverage identification is a first identification, determining that the synchronization level of the synchronization source is a first level; or if the identification set of the synchronization source belongs to a third sub-identification set, the position of the resource occupied by the synchronization signal is a third position, and the coverage identification is the first identification or the second identification, determining that the synchronization level of the synchronization source is the first level.

The processor 400 is further configured to determine that the synchronization level of the synchronization source is a second level if the identifier set of the synchronization source belongs to the first sub-identifier set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier; or if the identification set of the synchronization source belongs to a second sub-identification set, the position of the resource occupied by the synchronization signal is a second position, and the coverage identification is a second identification, determining that the synchronization level of the synchronization source is a second level; or if the identification set of the synchronization source belongs to the third sub-identification set, the position of the resource occupied by the synchronization signal is the second position, and the coverage identification is the second identification, determining that the synchronization level of the synchronization source is the second level.

The processor 400 is further configured to determine that the synchronization level of the synchronization source is a third level if the identifier set of the synchronization source belongs to a fourth sub-identifier set, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the fourth sub-identifier set is a set corresponding to the synchronization identifier of the synchronization source or a set corresponding to the synchronization identifier of the independent synchronization source, where the synchronization hop count of the base station is greater than two hops, and the fourth sub-identifier set is obtained by adding a preset threshold to the value in the first sub-identifier set; or if the identification set of the synchronization source belongs to a fifth sub-identification set, the position of the resource occupied by the synchronization signal is the first position or the second position, and the coverage identification is the second identification, determining that the synchronization level of the synchronization source is the third level, wherein the fifth sub-identification set is a set which is in the coverage area of the base station and corresponds to the synchronization identification of the synchronization source of which the synchronization hop count of the GNSS is more than two hops, and the fifth sub-identification set is obtained by adding a preset threshold value to the value in the second sub-identification set; or if the identification set of the synchronization source belongs to a sixth sub-identification set, the position of the resource occupied by the synchronization signal is the first position or the second position, and the coverage identification is the second identification, the synchronization grade of the synchronization source is determined to be the third grade, the sixth sub-identification set is a set which is out of the coverage range of the base station and corresponds to the synchronization identification of the synchronization source of which the number of synchronization hops is greater than two hops with the GNSS, and the sixth sub-identification set is obtained by adding a preset threshold value to the value in the third sub-identification set.

The processor 400 is further configured to determine that the synchronization level of the synchronization source is a first level if the identifier set to which the synchronization identifier of the synchronization source belongs is a first sub-identifier set, the position of the resource occupied by the synchronization signal is a first position, and the coverage identifier is a first identifier;

In some embodiments of the invention, there is also provided a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

the method comprises the steps of obtaining synchronous grade indicating information of each synchronous source according to synchronous signals and synchronous channels respectively sent by a plurality of synchronous sources, wherein the synchronous grade indicating information comprises an identification set to which a synchronous identification of the synchronous source belongs, positions of resources occupied by the synchronous signals and coverage identifications born by the synchronous channels, and a first sub-identification set which is positioned in a coverage range of a base station and corresponds to the synchronous source synchronous with the base station, a second sub-identification set which is positioned in the coverage range of the base station and corresponds to the synchronous source synchronous with GNSS directly and a third sub-identification set which is positioned outside the coverage range of the base station and corresponds to the synchronous source synchronous with the GNSS directly are three sets which are different from each other.

In the terminal of the embodiment of the present invention, the processor 400 is configured to obtain synchronization level indication information of each synchronization source according to a synchronization signal and a synchronization channel respectively sent by a plurality of synchronization sources; according to a corresponding relation table of preset synchronization grade indication information and synchronization grades, determining a synchronization grade corresponding to each synchronization source synchronization grade indication information, selecting a target synchronization source from a plurality of synchronization sources according to the determined synchronization grade, and synchronizing according to the selected target synchronization source SSID, and PSBCH, cannot accurately determine the synchronization priority of the synchronization source.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A synchronization method applied to a terminal is characterized by comprising the following steps:

selecting a target synchronization source from the multiple synchronization sources according to the determined synchronization level, and synchronizing according to the selected target synchronization source;

if the synchronization identifier of the target synchronization source belongs to the first sub-identifier set and the target synchronization source is a synchronization source indirectly synchronized with the base station, or the synchronization identifier of the target synchronization source belongs to the second sub-identifier set and the target synchronization source is a synchronization source indirectly synchronized with the GNSS, or the synchronization identifier of the target synchronization source belongs to the third sub-identifier set and the target synchronization source is a synchronization source indirectly synchronized with the GNSS, the synchronization identifier of the terminal is obtained according to the sum of the synchronization identifier of the target synchronization source and a preset threshold, and the coverage identifier of the synchronization channel of the terminal is set as the second identifier.

2. The synchronization method according to claim 1, wherein the step of selecting the target synchronization source among the plurality of synchronization sources according to the determined synchronization level comprises:

3. The synchronization method of claim 1, wherein if the GNSS is highest priority;

4. The synchronization method according to claim 3, wherein if the identifier set to which the synchronization identifier of the synchronization source belongs is a first preset identifier set, and the location of the resource occupied by the synchronization signal is a first location or a third location, the step of determining that the synchronization level of the synchronization source is a first level includes:

if the first sub-identifier set comprises the identifier set of the synchronization source, the position of the resource occupied by the synchronization signal is a first position, and the coverage identifier is a first identifier, determining that the synchronization level of the synchronization source is a first level; or

If the second sub-identifier set comprises the identifier set of the synchronization source, the position of the resource occupied by the synchronization signal is a first position, and the coverage identifier is a first identifier, determining that the synchronization level of the synchronization source is a first level; or

And if the third sub-identifier set comprises the identifier set of the synchronous source, the position of the resource occupied by the synchronous signal is a third position, and the coverage identifier is the first identifier or the second identifier, determining that the synchronization level of the synchronous source is the first level.

5. The synchronization method according to claim 3, wherein if the first preset identifier set includes an identifier set to which the synchronization identifier of the synchronization source belongs, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier, the step of determining that the synchronization level of the synchronization source is the second level includes:

if the first sub-identifier set comprises the identifier set of the synchronization source, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a second level; or

If the second sub-identifier set comprises the identifier set of the synchronization source, the position of the resource occupied by the synchronization signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronization source is a second level; or

And if the third sub-identifier set comprises the identifier set of the synchronous source, the position of the resource occupied by the synchronous signal is a second position, and the coverage identifier is a second identifier, determining that the synchronization level of the synchronous source is a second level.

6. The synchronization method according to claim 3, wherein if the identifier set to which the synchronization identifier of the synchronization source belongs is a second preset identifier set, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, the step of determining that the synchronization level of the synchronization source is the third level includes:

if the fourth sub-identifier set comprises the identifier set of the synchronization source, the position of the resource occupied by the synchronization signal is the first position or the second position, and the coverage identifier is the second identifier, determining that the synchronization level of the synchronization source is the third level, wherein the fourth sub-identifier set is a set which is positioned in the coverage area of the base station and corresponds to the synchronization identifier of the synchronization source of which the synchronization hop count of the base station is more than two hops or a set which corresponds to the synchronization identifier of an independent synchronization source, and the fourth sub-identifier set is obtained by adding a preset threshold value to the value in the first sub-identifier set; or

If the fifth sub-identifier set comprises the identifier set of the synchronization source, the position of the resource occupied by the synchronization signal is the first position or the second position, and the coverage identifier is the second identifier, determining that the synchronization level of the synchronization source is the third level, wherein the fifth sub-identifier set is a set which is positioned in the coverage area of the base station and corresponds to the synchronization identifier of the synchronization source of which the synchronization hop count of the GNSS is more than two hops, and the fifth sub-identifier set is obtained by adding a preset threshold value to the value in the second sub-identifier set; or

If the sixth sub-identification set comprises the identification set of the synchronous source, the position of the resource occupied by the synchronous signal is the first position or the second position, and the coverage identification is the second identification, the synchronous grade of the synchronous source is determined to be the third grade, the sixth sub-identification set is a set which is out of the coverage range of the base station and corresponds to the synchronous identification of the synchronous source with the GNSS synchronization hop count being greater than two hops, and the sixth sub-identification set is obtained by adding a preset threshold value to the value in the third sub-identification set.

7. The synchronization method of claim 1, wherein if the base station is the highest priority;

8. A terminal, comprising:

the synchronization module is used for selecting a target synchronization source from the multiple synchronization sources according to the determined synchronization level and synchronizing according to the selected target synchronization source;

the synchronization module includes:

and the third synchronization submodule is used for obtaining the synchronization identifier of the terminal according to the sum of the synchronization identifier of the target synchronization source and a preset threshold value and setting the coverage identifier of the synchronization channel of the terminal as the second identifier if the synchronization identifier of the target synchronization source belongs to the first sub-identifier set and the target synchronization source is a synchronization source indirectly synchronized with the base station, or the synchronization identifier of the target synchronization source belongs to the second sub-identifier set and the target synchronization source is a synchronization source indirectly synchronized with the GNSS, or the synchronization identifier of the target synchronization source belongs to the third sub-identifier set and the target synchronization source is a synchronization source indirectly synchronized with the GNSS.

9. The terminal of claim 8, wherein the synchronization module comprises:

10. The terminal of claim 8, wherein if the GNSS is the highest priority;

the determining module comprises:

11. The terminal of claim 10, wherein the third determining submodule comprises:

a first determining unit, configured to determine that the synchronization level of the synchronization source is a first level if the first sub-identifier set includes the identifier set of the synchronization source, the location of the resource occupied by the synchronization signal is a first location, and the coverage identifier is a first identifier;

a second determining unit, configured to determine that the synchronization level of the synchronization source is the first level if the second sub-identifier set includes the identifier set of the synchronization source, the location of the resource occupied by the synchronization signal is the first location, and the coverage identifier is the first identifier;

and the third determining unit is used for determining that the synchronization level of the synchronized source is the first level if the third sub-identifier set contains the identifier set of the synchronized source, the position of the resource occupied by the synchronization signal is the third position, and the coverage identifier is the first identifier or the second identifier.

12. The terminal of claim 10, wherein the fourth determination submodule comprises:

a fourth determining unit, configured to determine that the synchronization level of the synchronization source is the second level if the first sub-identifier set includes the identifier set of the synchronization source, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier;

a fifth determining unit, configured to determine that the synchronization level of the synchronization source is the second level if the second sub-identifier set includes the identifier set of the synchronization source, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier; or

A sixth determining unit, configured to determine that the synchronization level of the synchronized source is the second level if the third sub-identifier set includes the identifier set of the synchronized source, the location of the resource occupied by the synchronization signal is the second location, and the coverage identifier is the second identifier.

13. The terminal of claim 10, wherein the fifth determination submodule comprises:

a seventh determining unit, configured to determine that the synchronization level of the synchronization source is a third level if a fourth sub-identifier set includes the identifier set of the synchronization source, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the fourth sub-identifier set is a set that is within the coverage of the base station and corresponds to the synchronization identifier of the synchronization source whose number of synchronization hops is greater than two hops in the base station or a set that corresponds to the synchronization identifier of an independent synchronization source, and the fourth sub-identifier set is obtained by adding a preset threshold to the value in the first sub-identifier set; or

An eighth determining unit, configured to determine that the synchronization level of the synchronization source is a third level if a fifth sub-identifier set includes the identifier set of the synchronization source, the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the fifth sub-identifier set is a set that is within a coverage area of the base station and corresponds to a synchronization identifier of the synchronization source of which the synchronization hop count of the GNSS is greater than two hops, and the fifth sub-identifier set is obtained by adding a preset threshold to a value in the second sub-identifier set; or

A ninth determining unit, configured to determine that the synchronization level of the synchronization source is the third level if the sixth sub-identifier set includes the identifier set of the synchronization source, where the location of the resource occupied by the synchronization signal is the first location or the second location, and the coverage identifier is the second identifier, where the sixth sub-identifier set is a set that is outside the coverage of the base station and corresponds to the synchronization identifier of the synchronization source with which the number of synchronization hops of the GNSS is greater than two hops, and the sixth sub-identifier set is obtained by adding a preset threshold to the value in the third sub-identifier set.

14. The terminal of claim 8, wherein if the base station is of highest priority;

the determining module comprises: