CN110461036B - A method and terminal for transmitting and receiving synchronization signals - Google Patents

Abstract

A method and a terminal for transmitting and receiving synchronous signals. The transmitting method comprises the following steps: the first terminal determines downlink timing; and the first terminal transmits a synchronous signal according to the determined downlink timing. By adopting the technical scheme of the method and the terminal for transmitting and receiving the synchronous signals, the transmitting terminal for user direct-connection communication uniformly adopts the downlink timing transmission synchronous signals, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronous signals, and the user direct-connection communication information sent by the transmitting terminal can be correctly received.

Description

A method and terminal for transmitting and receiving synchronization signals

technical field

The present invention relates to the field of communication technology, in particular to a method and terminal for transmitting and receiving synchronization signals.

Background technique

In the traditional long-term evolution (full name: Long Term Evolution, referred to as: LTE) communication technology, the interaction of signaling and data between user terminals or user equipment (full name: User Equipment, referred to as: UE) needs to go through their own Evolved base station (full name: evolved Node B, abbreviated: eNB or base station).

User direct communication (device to device, full name: Device to Device, abbreviation: D2D) as a direct communication technology, the data interaction between terminals does not need to be forwarded by the base station, and can be directly interacted between UEs or in Interact directly with the assistance of the network.

However, since the transmitting terminals of the user direct communication may transmit synchronization signals at different timings, the receiving terminals cannot accurately obtain the timing through the synchronization signals, which affects normal communication.

Contents of the invention

Embodiments of the present invention provide a method and a terminal for transmitting and receiving a synchronization signal, so that a receiving terminal of a user direct communication can accurately obtain timing through the synchronization signal.

In a first aspect, an embodiment of the present invention provides a method for transmitting a synchronization signal, the method including:

The first terminal within the coverage of the network determines downlink timing;

The first terminal transmits a synchronization signal according to the determined downlink timing.

In a first possible implementation manner, the method further includes:

The first terminal receives system configuration information, where the system configuration information includes resource information of the synchronization signal configured by the system and an indication of sending the synchronization signal.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner, when the system configuration information includes an indication to send a synchronization signal, the first terminal transmits according to the determined downlink timing Synchronization signals include:

The first terminal transmits the synchronization signal on the resource of the synchronization signal configured by the system according to the determined downlink timing.

With reference to the first aspect or the first possible implementation of the first aspect or the second possible implementation of the first aspect, in a third possible implementation, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

In a second aspect, an embodiment of the present invention provides a method for receiving a synchronization signal, the method including:

receiving the synchronization signal by the second terminal;

The second terminal determines the downlink timing of the transmitting terminal according to the received synchronization signal.

In a first possible implementation manner, the receiving the synchronization signal by the second terminal includes:

When the second terminal is within the coverage of the network, receiving the synchronization signal from a neighboring cell and/or the synchronization signal transmitted from a terminal outside the coverage of the network; or

When the second terminal is outside the network coverage, receiving the synchronization signal transmitted from the terminal within the network coverage and/or the synchronization signal transmitted from the terminal outside the network coverage.

With reference to the first possible implementation of the second aspect, in a second possible implementation, when the second terminal is within network coverage, receiving the synchronization signal of a neighboring cell includes:

When the second terminal is within the coverage of the network, the synchronization signal is received according to the cell identity or the physical synchronization source identity of the neighboring cell.

With reference to the second aspect or the first possible implementation of the second aspect or the second possible implementation of the second aspect, in a third possible implementation, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

In a third aspect, an embodiment of the present invention provides a terminal, including:

a determining unit, configured to determine downlink timing when the terminal is within the coverage of the network;

A transmitting unit, configured to transmit a synchronization signal according to the determined downlink timing.

In a first possible implementation manner, the terminal further includes:

The receiving unit is configured to receive system configuration information, wherein the system configuration information includes resource information of the synchronization signal configured by the system and an indication of sending the synchronization signal.

With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner, the transmitting unit is specifically configured to: when the system configuration information includes an indication to send a synchronization signal, according to the determined In downlink timing, the synchronization signal is transmitted on the resource of the synchronization signal configured by the system.

With reference to the third aspect or the first possible implementation of the third aspect or the second possible implementation of the third aspect, in the third possible implementation, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

In a fourth aspect, an embodiment of the present invention provides a terminal, including:

a receiving unit, configured to receive a synchronization signal;

A determining unit, configured to determine the downlink timing of the transmitting terminal according to the received synchronization signal.

In a first possible implementation manner, the receiving unit is specifically configured to:

When the terminal is within the coverage of the network, receiving the synchronization signal from a neighboring cell and/or the synchronization signal transmitted from a terminal outside the coverage of the network; or

When the terminal is outside the network coverage, receiving the synchronization signal transmitted from the terminal within the network coverage and/or the synchronization signal transmitted from the terminal outside the network coverage.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the receiving unit is specifically configured to:

When the second terminal is within the coverage of the network, the synchronization signal is received according to the cell identity or the physical synchronization source identity of the neighboring cell.

With reference to the fourth aspect or the first possible implementation manner of the fourth aspect or the second possible implementation manner of the fourth aspect, in a third possible implementation manner, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

In a fifth aspect, a terminal is provided, including: a processor and a transmitter;

The processor is configured to determine downlink timing when the terminal is within the coverage of the network;

The transmitter is used for transmitting a synchronization signal according to the determined downlink timing.

In a first possible implementation manner, the terminal further includes a receiver;

The receiver is configured to receive system configuration information, wherein the system configuration information includes resource information of the synchronization signal configured by the system and an indication of sending the synchronization signal.

With reference to the first possible implementation manner of the fifth aspect, in a second possible implementation manner, the transmitter is specifically configured to: when the system configuration information includes an indication to send a synchronization signal, according to the determined downlink Timing, transmitting the synchronization signal on the resource of the synchronization signal configured by the system.

With reference to the fifth aspect or the first possible implementation manner of the fifth aspect or the second possible implementation manner of the fifth aspect, in a third possible implementation manner, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

In a sixth aspect, a terminal is provided, including: a receiver and a processor;

The receiver is used to receive a synchronization signal;

The processor is configured to determine the downlink timing of the transmitting terminal according to the received synchronization signal.

In a first possible implementation manner, the receiver is specifically used for:

When the second terminal is within the coverage of the network, receiving the synchronization signal from a neighboring cell and/or the synchronization signal transmitted from a terminal outside the coverage of the network; or

When the second terminal is outside the network coverage, receiving the synchronization signal transmitted from the terminal within the network coverage and/or the synchronization signal transmitted from the terminal outside the network coverage.

With reference to the first possible implementation manner of the sixth aspect, in a second possible implementation manner, the receiver performs the receiving the synchronization of a neighboring cell when the second terminal is within network coverage. Signaling steps, including:

When the second terminal is within the coverage of the network, the synchronization signal is received according to the cell identity or the physical synchronization source identity of the adjacent cell.

With reference to the sixth aspect or the first possible implementation manner of the sixth aspect or the second possible implementation manner of the sixth aspect, in a third possible implementation manner, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

The embodiment of the present invention provides a method and terminal for transmitting and receiving synchronization signals. The transmitting terminal of the user direct communication uniformly adopts downlink timing to transmit the synchronization signal, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal. , so as to correctly receive the user direct communication information sent by the transmitting terminal.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is a schematic structural diagram of network communication provided by the prior art of the present invention;

FIG. 2 is a flowchart of a method for transmitting a synchronization signal provided by an embodiment of the present invention;

FIG. 3 is a flowchart of a method for receiving a synchronization signal provided by an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a terminal provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another terminal provided by an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another terminal provided by an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of another terminal provided by an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

LTE-D2D is the latest LTE-based terminal direct connection communication technology defined by the Third Generation Partnership Project (full name: 3rd Generation partnership project, referred to as 3GPP). LTE-D2D communication technology is an application of adding D2D to the existing LTE system. , that is, user direct communication and LTE communication will coexist. As shown in Figure 1, terminal 1 can transmit user direct communication data to terminal 2 and terminal 3 for user direct communication, and terminal 1 can also communicate with the base station. Among them, the process of terminal 1 transmitting communication data and base station receiving communication data is called uplink communication; the process of base station transmitting communication data and terminal 1 receiving communication data is called downlink communication; The communication between the terminal and the terminal is the user direct connection communication.

There are three working scenarios for user direct communication, namely network coverage, no network coverage and partial network coverage. In the scenario, the terminals participating in the direct user communication are all outside the coverage of the network; in the partial network coverage scenario, some terminals participating in the direct user communication are within the coverage of the network, and the other part of the terminals are within the coverage of the network outside.

Usually the two parties in communication need to establish synchronization first, and adjust the frequency and timing of the two devices to the same frequency and time. Synchronization requires specifying a common synchronization reference between two communicating terminals, and a synchronization source refers to a device that provides a synchronization reference. In the working scenario of network coverage, in the prior art, the base station in the network is used as a synchronization source, and the terminals synchronized to the base station form a group. In a working scenario without network coverage, one terminal or all terminals among multiple terminals without network coverage in the prior art are used as a synchronization source, and other terminals synchronized to a certain synchronization source form a group. In a working scenario with partial network coverage, some terminals are within the network coverage and the other part of the terminals are outside the network coverage. The terminals within the network coverage transmit synchronization signals as a synchronization reference for terminals outside the network coverage.

User direct communication is divided into two main application modes/types: D2D discovery (discovery) and D2D communication (communication).

D2D discovery means that a terminal sends a discovery message (discovery message), and other terminals obtain the information of the transmitting terminal by reading the discovery message, for example, including the identity information (identity) of the terminal.

D2D communication means that the terminal sends Scheduling Assignment (SA) information and data, and other terminals obtain the subsequent data transmission format and other information by reading the SA information, so as to correctly receive the subsequent data information. SA information and its scheduled data transmission format and resources can be scheduled by the base station together (that is, D2D communication mode 1, mode1), or the transmitting terminal can select resources by itself in the resource pool configured by the base station (that is, D2D communication mode 2, mode2 ). The resource pool is a communication term, that is, a group of communication resources is a set composed of multiple communication resources.

At present, D2D communication can be used in the above three scenarios, while D2D discovery only involves the working scenario of network coverage. However, this solution does not limit the D2D type and its corresponding working scenarios.

Terminals within network coverage transmit synchronization signals, such as D2DSS (Device to Device Synchronization Signal, user direct communication synchronization signal) and/or PD2DSCH (Physical Device to Device Synchronization Channel, physical user direct communication synchronization channel), so that part of the network coverage In the working scene, the terminals outside the network coverage can capture the synchronization signal, and then establish synchronization with the terminals within the network coverage and perform direct user communication (D2D discovery and/or D2D communication); In the case of a covered working scenario and when the cells are asynchronous, terminals in different cells (inter-cell) can detect and receive synchronization signals, and then can correctly receive user direct communication information (D2D discovery messages and/or D2D communication information).

The technical solutions provided by the embodiments of the present invention can be applied to the above-mentioned working scenario of partial network coverage and the situation of cross-cell D2D communication or D2D discovery in the network coverage scenario, such as the situation where cells are asynchronous.

Terminals located within the network coverage transmit synchronization signals, and terminals that need to obtain synchronization acquire synchronization signals through searching, such as terminals in asynchronous neighboring cells, or terminals outside network coverage in partial network coverage scenarios.

In the scenario of partial network coverage, some of the terminals performing direct user communication (D2D communication and/or D2D discovery) are within the coverage of the network, while the other part of terminals are outside the coverage of the network. The D2D in direct user communication communication as an example. The first D2D communication terminal located within the network coverage area transmits the synchronization signal corresponding to the D2D communication, and its synchronization reference comes from its serving cell. The second terminal of the D2D communication outside the network coverage area detects and receives the synchronization signal corresponding to the D2D communication, indirectly Synchronize to the network, and then obtain the system configuration information of the network for D2D communication, D2D frame number (D2D frame number) and other information according to PD2DSCH, and then the second terminal outside the network coverage is based on the configuration of the network for D2D communication and the network coverage. The terminal communicates; similarly, the first terminal located within the network coverage transmits a synchronization signal, and the second terminal located in an asynchronous neighboring cell within the network coverage detects and receives the synchronization signal, and indirectly synchronizes to the first terminal that transmits the captured synchronization signal. The cell where a terminal is located, and then search for D2D discovery messages based on the D2D discovery configuration information of the cell where the first terminal is located (delivered by the cell where the second terminal is located and/or obtained by PD2DSCH), D2D frame number (D2D frame number) and other information .

D2D communication and D2D discovery may be independent of each other and are not premised on each other. For example, only terminals performing D2D discovery or terminals performing D2D communication may exist in a cell.

There are two types of timing in D2D communication, that is, downlink timing and uplink timing can be used. The downlink timing is the timing when the terminal receives the downlink signal of the serving base station (for example, the primary synchronization signal Primary Synchroniazation Signal, the secondary synchronization signal Secondary Synchronization Signal, the cell-specific reference signal) and captures the timing; the uplink timing is the timing sent by the terminal according to the serving base station The timing after the timing adjustment (Timing Advance) information is adjusted. The last time symbol (Single carrier frequency division multiple access symbol SC-FDMA, Single carrier frequency division multiplex access) of the D2D subframe (subframe) transmitted at the downlink timing is stopped as the gap (gap), while the D2D subframe transmitted at the uplink timing is used Frames have no gaps. If some terminals use uplink timing to send synchronization signals, and some terminals use downlink timing to send synchronization signals, terminals using these two types of timing respectively cannot send synchronization signals in the same subframe, wasting system resources; similarly, receiving terminals cannot pass D2DSS To know whether it is uplink timing or downlink timing, there are two possibilities for receiving and demodulating the last symbol. Blind detection is required to obtain information about which timing is used for transmission. However, if the D2D subframe only includes D2DSS signals, a total of 4 time symbols, and the remaining time symbols do not transmit signals, the terminal cannot know at what timing the D2DSS is transmitted, and the timing information is the subsequent SA and data or D2D The necessary information for the correct reception and demodulation of the message is found, and the lack of this information causes the subsequent D2D signal to be incorrectly received and demodulated.

Embodiments of the present invention provide a method and terminal for transmitting and receiving synchronization signals. The transmission terminals of the user direct communication uniformly use downlink timing to transmit synchronization signals, so that the receiving terminal can accurately determine the timing information of the transmission terminal according to the received synchronization signal. Therefore, the user direct communication information sent by the transmitting terminal is correctly received.

Describe in detail below by specific embodiment:

Figure 2 is a method for transmitting a synchronization signal provided by an embodiment of the present invention, as shown in Figure 2, the method includes:

S101. A first terminal within a network coverage determines downlink timing.

The transmitting terminals that perform user direct communication uniformly adopt downlink timing, that is, uniformly determine that the last symbol of the transmitted D2D subframe is stopped as an interval, and the receiving terminal does not need to receive and demodulate the last symbol.

S102. The first terminal transmits a synchronization signal according to the determined downlink timing.

All transmitting terminals transmit synchronization signals according to the downlink timing, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive the user direct communication information sent by the transmitting terminal.

Further, the method further includes: the first terminal receiving system configuration information, wherein the system configuration information includes resource information of the synchronization signal configured by the system and an indication of sending the synchronization signal.

Specifically, the system uses signaling to configure the first terminal to transmit a synchronization signal; where the signaling notification can be a high-layer (for example: Radio Resource Control radio resource control layer, RRC for short) and/or physical layer broadcast signaling; The notification may also be higher layer and/or physical layer dedicated signaling.

Wherein, when the system configuration information includes an instruction to send a synchronization signal, the first terminal transmits a synchronization signal according to the determined downlink timing, including:

The first terminal transmits the synchronization signal on the resource of the synchronization signal configured by the system according to the determined downlink timing.

Wherein, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

It can be seen that, according to a method for transmitting a synchronization signal provided by an embodiment of the present invention, the transmitting terminal of the user direct communication uniformly adopts downlink timing to transmit the synchronization signal, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, Therefore, the user direct communication information sent by the transmitting terminal is correctly received.

FIG. 3 is a method for receiving a synchronization signal provided by an embodiment of the present invention. As shown in FIG. 3, the method includes:

S201. The second terminal receives a synchronization signal.

The second terminal searches and detects surrounding synchronization signals, detects and receives the synchronization signals. For example, when the second terminal is within the coverage of the network, it detects and receives a synchronization signal from a neighboring cell and/or a synchronization signal transmitted from a terminal outside the coverage of the network, specifically, according to the cell identity of the neighboring cell or the physical synchronization source Identification (PSSIDP Physical Synchronization Source Identity) detects and receives a synchronization signal; or when the second terminal is outside the network coverage, detects and receives a synchronization signal transmitted from a terminal within the network coverage and/or a signal from outside the network coverage The synchronization signal transmitted by the terminal.

Wherein, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

S202. The second terminal determines the downlink timing of the transmitting terminal according to the received synchronization signal.

Since the synchronization signal sent by the first terminal is always sent at the downlink timing, the timing obtained by the second terminal according to the received synchronization signal is determined as the downlink timing of the transmitting terminal, that is, the last time symbol is not received.

Since all transmitting terminals transmit synchronization signals according to the downlink timing, the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive the user direct communication information sent by the transmitting terminal. In working scenarios with partial network coverage, it is possible to realize and enable more effective discovery and/or communication of terminals inside and outside the network coverage, and reduce the difficulty of contacting users inside and outside the network coverage; at the same time, it can realize and This enables more efficient inter-cell discovery and/or communication of terminals within network coverage.

It can be seen that, according to a method for receiving a synchronization signal provided by an embodiment of the present invention, the receiving terminal of the user direct communication adopts the synchronization signal transmitted at a downlink timing by receiving the transmitting terminal, so that the receiving terminal can accurately determine the transmission according to the received synchronization signal. The timing information of the terminal, so as to correctly receive the user direct communication information sent by the transmitting terminal.

FIG. 4 is a schematic structural diagram of a terminal provided by an embodiment of the present invention. As shown in FIG. 4, the terminal 1000 includes:

The determining unit 11 is configured to determine downlink timing when the terminal is within the coverage of the network.

The transmitting terminals performing user direct communication uniformly adopt downlink timing, that is, the determination unit 11 uniformly determines that the last symbol of the transmitted D2D subframe is stopped as an interval, and the receiving terminal does not need to receive and demodulate the last symbol.

The transmitting unit 12 is configured to transmit a synchronization signal according to the determined downlink timing.

All transmitting terminals transmit synchronization signals according to the downlink timing, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive the user direct communication information sent by the transmitting terminal.

Further, the terminal further includes: a receiving unit (not shown in the figure), configured to receive system configuration information, wherein the system configuration information includes resource information of the synchronization signal configured by the system and sending the synchronization signal signal indication.

Specifically, the system uses signaling to configure the first terminal to transmit a synchronization signal; where the signaling notification can be a high-layer (for example: Radio Resource Control radio resource control layer, RRC for short) and/or physical layer broadcast signaling; The notification may also be higher layer and/or physical layer dedicated signaling.

Wherein, when the system configuration information includes an indication to send a synchronization signal, the transmitting unit 12 is specifically configured to:

According to the determined downlink timing, transmit the synchronization signal on the resource of the synchronization signal configured by the system.

Wherein, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

It can be seen that according to a terminal provided by an embodiment of the present invention, the terminal uniformly uses downlink timing to transmit synchronization signals, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive the user information sent by the transmitting terminal. Direct communication information.

FIG. 5 is a schematic structural diagram of another terminal provided by an embodiment of the present invention. As shown in FIG. 5, the terminal 2000 includes:

The receiving unit 21 is configured to receive a synchronization signal.

The receiving unit 21 searches and detects surrounding synchronization signals, detects and receives the synchronization signals. For example, when the second terminal is within the coverage of the network, it detects and receives a synchronization signal from a neighboring cell and/or a synchronization signal transmitted from a terminal outside the coverage of the network, specifically, according to the cell identity of the neighboring cell or the physical synchronization source Identification (PSSIDP Physical Synchronization Source Identity) detects and receives a synchronization signal; or when the second terminal is outside the network coverage, detects and receives a synchronization signal transmitted from a terminal within the network coverage and/or a signal from outside the network coverage The synchronization signal transmitted by the terminal.

Wherein, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

The determining unit 22 is configured to determine the downlink timing of the transmitting terminal according to the received synchronization signal.

Since the synchronization signal sent by the first terminal is always sent at the downlink timing, the timing obtained by the second terminal according to the received synchronization signal is determined as the downlink timing of the transmitting terminal, that is, the last time symbol is not received.

Since all transmitting terminals transmit synchronization signals according to the downlink timing, the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive the user direct communication information sent by the transmitting terminal. In working scenarios with partial network coverage, it is possible to realize and enable more effective discovery and/or communication of terminals inside and outside the network coverage, and reduce the difficulty of contacting users inside and outside the network coverage; at the same time, it can realize and This enables more efficient inter-cell discovery and/or communication of terminals within network coverage.

It can be seen that, according to a terminal provided by an embodiment of the present invention, the terminal uniformly adopts the synchronization signal transmitted by downlink timing by receiving the transmitting terminal, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive Transmit user direct communication information sent by the terminal.

FIG. 6 is a schematic structural diagram of another terminal provided by an embodiment of the present invention. As shown in FIG. 6, the terminal 3000 includes: a processor 31 and a transmitter 32;

The processor 31 is configured to determine downlink timing when the terminal is within the coverage of the network;

The transmitter 32 is used for transmitting a synchronization signal according to the determined downlink timing.

As an implementation manner, the terminal 3000 further includes a receiver (not shown in the figure);

The receiver is configured to receive system configuration information, wherein the system configuration information includes resource information of the synchronization signal configured by the system and an indication of sending the synchronization signal.

The transmitter 32 is specifically configured to transmit the synchronization signal on resources of the synchronization signal configured by the system according to the determined downlink timing when the system configuration information includes an instruction to send a synchronization signal.

Wherein, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

It can be seen that according to a terminal provided by an embodiment of the present invention, the terminal uniformly uses downlink timing to transmit synchronization signals, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive the user information sent by the transmitting terminal. Direct communication information.

FIG. 7 is a schematic structural diagram of another terminal provided by an embodiment of the present invention. As shown in FIG. 7 , the terminal 4000 includes: a receiver 41 and a processor 42;

The receiver 41 is used to receive a synchronization signal;

The processor 42 is configured to determine the downlink timing of the transmitting terminal according to the received synchronization signal.

As an implementation manner, the receiver 41 is specifically used for:

When the second terminal is within the coverage of the network, receiving the synchronization signal from a neighboring cell and/or the synchronization signal transmitted from a terminal outside the coverage of the network; or

When the second terminal is outside the network coverage, receiving the synchronization signal transmitted from the terminal within the network coverage and/or the synchronization signal transmitted from the terminal outside the network coverage.

Specifically, the receiver 41 performs the step of receiving the synchronization signal of a neighboring cell when the second terminal is within the coverage of the network, including:

When the second terminal is within the coverage of the network, the synchronization signal is received according to the cell identity or the physical synchronization source identity of the adjacent cell.

Wherein, the synchronization signal includes:

D2D synchronization signal; or

D2D synchronization signal and physical D2D synchronization channel;

Wherein, the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

It can be seen that, according to a terminal provided by an embodiment of the present invention, the terminal uniformly adopts the synchronization signal transmitted by downlink timing by receiving the transmitting terminal, so that the receiving terminal can accurately determine the timing information of the transmitting terminal according to the received synchronization signal, so as to correctly receive Transmit user direct communication information sent by the terminal.

It should be noted that for the foregoing method embodiments, for the sake of simple description, they are expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence. Because according to the present invention, certain steps may be performed in other order or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

The steps in the methods of the embodiments of the present invention can be adjusted, combined and deleted according to actual needs.

The units in the device of the embodiment of the present invention can be combined, divided and deleted according to actual needs. Those skilled in the art may combine or combine different embodiments and features of different embodiments described in this specification.

Through the above description of the implementation manners, those skilled in the art can clearly understand that the present invention can be implemented by hardware, firmware, or a combination thereof. When implemented in software, the functions described above may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. Take this as an example but not limited to: computer-readable media may include Random Access Memory (Random Access Memory, RAM), Read-Only Memory (Read-Only Memory, ROM), Electrically Erasable Programmable Read-Only Memory (Electrically Erasable Programmable Read-Only Memory) -Only Memory, EEPROM), CD-ROM (Compact Disc Read-Only Memory, CD-ROM) or other optical disk storage, magnetic disk storage medium or other magnetic storage devices, or can be used to carry or store information in the form of instructions or data structures desired program code and any other medium that can be accessed by a computer. also. Any connection can suitably be a computer-readable medium. For example, if the Software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, Coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, wireless and microwave are then included in the fixation of the associated medium. As used herein, disk and disc include compact disc (CD), laser disc, compact disc, digital versatile disc (DVD), floppy disc, and Blu-ray disc, where discs usually reproduce data magnetically, and discs Lasers are used to optically reproduce the data. Combinations of the above should also be included within the scope of computer-readable media.

In a word, the above descriptions are only preferred embodiments of the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (17)

1. A method of transmitting a synchronization signal, comprising:

a first terminal in a network coverage area determines downlink timing;

the first terminal receives system configuration information, wherein the system configuration information comprises information of resources of synchronous signals configured by a system;

and when the system configuration information comprises an indication for sending the synchronous signal, the first terminal transmits the synchronous signal on the resource of the synchronous signal configured by the system according to the determined downlink timing.

2. The method of claim 1, wherein the first terminal uses a last time symbol of the D2D subframe of the downlink timing transmission as an interval.

3. The method according to claim 1 or 2, wherein the synchronization signal comprises:

D2D synchronization signals; or alternatively

D2D synchronization signals and physical D2D synchronization channels;

wherein the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

4. A method of communication, comprising:

transmitting system configuration information to a first terminal in a network coverage range, wherein the system configuration information comprises information of resources of a synchronization signal configured by a system;

and transmitting a downlink signal to the first terminal, wherein the downlink signal is used for determining downlink timing by the first terminal, and when the system configuration information comprises an indication for transmitting a synchronization signal, the first terminal transmits the synchronization signal on a resource of the synchronization signal configured by the system according to the determined downlink timing.

5. The method of claim 4, wherein the synchronization signal comprises:

D2D synchronization signals; or alternatively

D2D synchronization signals and physical D2D synchronization channels;

wherein the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

6. An apparatus for transmitting a synchronization signal in a first terminal, comprising:

a determining unit, configured to determine downlink timing when the first terminal is within a network coverage area;

a receiving unit configured to receive system configuration information including information of resources of a synchronization signal configured by a system;

and the transmitting unit is used for transmitting the synchronous signal on the resources of the synchronous signal configured by the system according to the determined downlink timing when the system configuration information comprises the indication of transmitting the synchronous signal.

7. The apparatus of claim 6, wherein the means for determining is further configured to determine a last time symbol of the D2D subframe of the downlink timing transmission to be stalled as an interval.

8. The apparatus of claim 6 or 7, wherein the synchronization signal comprises:

D2D synchronization signals; or alternatively

D2D synchronization signals and physical D2D synchronization channels;

wherein the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

9. A communication device, comprising:

a transmitting unit, configured to transmit system configuration information to a first terminal device, where the system configuration information includes information of resources of a synchronization signal configured by a system;

the sending unit is further configured to send a downlink signal to the first terminal device, where the downlink signal is used for the first terminal to determine downlink timing, and when the system configuration information includes an indication of sending a synchronization signal, the first terminal sends the synchronization signal on a resource of the synchronization signal configured by the system according to the determined downlink timing.

10. The apparatus of claim 9, wherein the synchronization signal comprises:

D2D synchronization signals; or alternatively

D2D synchronization signals and physical D2D synchronization channels;

wherein the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

11. A first terminal, comprising: a processor, a receiver, and a transmitter;

the processor is used for determining downlink timing when the first terminal is in network coverage;

the receiver is used for receiving system configuration information, and the system configuration information comprises information of resources of synchronous signals configured by a system;

and when the system configuration information comprises an indication for sending the synchronous signal, the transmitter is used for transmitting the synchronous signal on the resource of the synchronous signal configured by the system according to the determined downlink timing.

12. The first terminal of claim 11, wherein the transmitter is further configured to stall a last time symbol of a D2D subframe transmitted by the first terminal with the downlink timing as an interval.

13. The first terminal according to claim 11 or 12, wherein the synchronization signal comprises:

D2D synchronization signals; or alternatively

D2D synchronization signals and physical D2D synchronization channels;

wherein the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

14. A base station comprising a transmitter:

the transmitter is used for transmitting system configuration information to the first terminal, wherein the system configuration information comprises information of resources of synchronous signals configured by a system;

the transmitter is further configured to send a downlink signal to the first terminal, where the downlink signal is used for the first terminal to determine downlink timing, and when the system configuration information includes an indication of sending a synchronization signal, the first terminal transmits the synchronization signal on a resource of the synchronization signal configured by the system according to the determined downlink timing.

15. The base station of claim 14, wherein the synchronization signal comprises:

D2D synchronization signals; or alternatively

D2D synchronization signals and physical D2D synchronization channels;

wherein the D2D synchronization signal includes: a primary D2D synchronization signal and a secondary D2D synchronization signal.

16. A computer readable storage medium for storing a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 1 to 3.

17. A computer readable storage medium for storing a computer program which, when run on a computer, causes the computer to perform the method of any one of claims 4 to 5.

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