KR20160014515A - Method and terminal for direct communication between terminals - Google Patents

Abstract

A method for performing device-to-device (D2D) communications by a first terminal comprises the followings steps: setting a value of a first field, which indicates continuous transmission of scheduling assignment (SA) information as a first value when transmitting SA information not only from a first SA resource pool for SA but also a second SA resource pool after the first SA resource pool; and transmitting the SA information including the first field by using the first SA resource included in the first SA resource pool.

Description

METHOD AND TERMINAL FOR DIRECT COMMUNICATION BETWEEN TERMINALS [0002]

The present invention relates to a direct communication method between terminals and a terminal supporting the same.

In D2D (Device to Device) communication, which is a direct communication between terminals, a terminal can directly communicate with other terminals via a network (e.g., a base station).

On the other hand, in order to control (mitigate) resource collision, congestion, etc. in the D2D communication environment, a method of allocating or selecting resources for D2D communication is being studied.

A problem to be solved by the present invention is to provide a resource allocation method capable of mitigating resource conflicts.

Another object of the present invention is to provide a method by which a terminal can randomly select transmission resources based on a sensing. In particular, a problem to be solved by the present invention is to provide a control required for a terminal to randomly select a transmission resource on a sensing basis.

In addition, a problem to be solved by the present invention is to provide a method of supporting scheduling in the form of Semi-Persistent Scheduling (SPS).

It is another object of the present invention to provide a method by which a transmitting terminal can know continuous transmission of SA information even if it does not decode Scheduling Assignment (SA) information.

In addition, a problem to be solved by the present invention is to provide a method for preventing continuous collision of SA information or D2D data.

According to the embodiment of the present invention, there is provided a D2D (Device to Device) communication method in which a first terminal directly communicates with another terminal without passing through a network. In the D2D communication method, when SA information is to be transmitted not only in a first SA resource pool for scheduling assignment (SA) but also in a second SA resource pool after the first SA resource pool, Setting a value of a first field indicating a continuous transmission of the SA information to a first value; And transmitting the SA information including the first field using a first SA resource included in the first SA resource pool.

A first resource area for D2D communication can be divided into the first SA resource pool and a first D2D data resource pool for D2D data transmission.

The second resource area after the first resource area may be divided into the second SA resource pool and a second D2D data resource pool after the first D2D data resource pool.

The D2D communication method may further include transmitting the SA information using a second SA resource located at the same position as the first SA resource among a plurality of SA resources included in the second SA resource pool .

The D2D communication method may further include setting a value of the first field to a second value different from the first value when the SA information is to be transmitted in the first SA resource pool have.

The D2D communication method may further include transmitting first D2D data using a first D2D data resource among a plurality of D2D data resources included in the first D2D data resource pool.

Wherein the SA information transmitted using the first SA resource comprises information of the first D2D data resource; Modulation scheme information of the first D2D data; Coding method information of the first D2D data; And an identifier associated with the terminal to receive the first D2D data.

The number of bits of the first field may be one.

Wherein the step of transmitting the SA information using the first SA resource comprises the step of transmitting M information of the first SA resource of N (where N is a natural number of 2 or more) M is a natural number equal to or less than N) monitoring whether SA information of another terminal is transmitted in the first SA resource; And repeatedly transmitting the SA information of the first terminal using the N first SA resources when the SA information of the other terminal is not transmitted in the Mth first SA resource.

The D2D communication method may further include: a first D2D data resource of M (where M is a natural number equal to or less than N) first D2D data among N first data D2D data resources (N is a natural number of 2 or more) included in the first D2D data resource pool Monitoring whether D2D data of another terminal is transmitted from the resource; And repeatedly transmitting D2D data of the first terminal using the N first D2D data resources when D2D data of the other terminal is not transmitted in the Mth first D2D data resource .

According to another embodiment of the present invention, there is provided a D2D (Device to Device) communication method in which a first terminal directly communicates with another terminal without passing through a network. The D2D communication method includes: monitoring first SA information transmitted through a first SA resource pool for scheduling assignment (SA); When the value of the first field included in the first SA information is the first value, it is determined that the first SA resource among the plurality of SA resources included in the second SA resource pool after the first SA resource pool is reserved ; And selecting at least one second SA resource from the plurality of SA resources excluding the first SA resource included in the second SA resource pool.

The location of the first SA resource in the second SA resource pool may be the same as the location of the third SA resource in the first SA resource pool.

The third SA resource may be a SA resource to which the first SA information is transmitted among a plurality of SA resources included in the first SA resource pool.

The D2D communication method may further include transmitting the second SA information using the at least one second SA resource.

The selecting of the at least one second SA resource may include selecting at least one second SA resource among the plurality of SA resources excluding the first SA resource among the plurality of SA resources included in the second SA resource pool, And a step of selecting the step.

The first SA information may be plural.

According to another embodiment of the present invention, there is provided a D2D (Device to Device) communication method in which a first terminal directly communicates with another terminal without passing through a network. The D2D communication method includes: determining whether a first transmission probability value for only the first terminal is set; And using the first transmission probability value and the first transmission probability value among the second transmission probability values for the first cell to which the first terminal belongs, when the first transmission probability value is set, To the mobile station.

The first information may be one of SA information for Scheduling Assignment (SA) and D2D data.

The first transmission probability value may be greater than the second transmission probability value.

The transmitting of the first information using the first transmission probability value may include selecting a first SA resource from among a plurality of SA resources included in the SA resource pool for the SA when the first information is the SA information ; And determining, based on the first transmission probability value, whether to transmit the SA information using the first SA resource.

The D2D communication method may further include transmitting the first information using the second transmission probability value when the first transmission probability value is not set.

The second transmission probability value may be commonly applied to all terminals existing in the first cell.

The first transmission probability value may be set by the base station of the first cell.

According to the embodiment of the present invention, in the D2D communication, the UE randomly selects a specific transmission resource from a designated resource pool and can transmit information using the selected transmission resource.

Also, according to the embodiment of the present invention, the terminal can randomly select a transmission resource based on a sensing. As a result, the collision between transmission resources can be further mitigated as compared with a case where the UE randomly selects a transmission resource without sensing.

Also, according to an embodiment of the present invention, the transmitting terminal can randomly select transmission resources based on sensing.

Further, according to the embodiment of the present invention, resources can be continuously occupied.

Also, according to the embodiment of the present invention, SPS type scheduling suitable for PTT (Push to Talk), still picture, and dynamic picture or moving picture service can be supported.

Also, according to the embodiment of the present invention, even if the receiving terminal does not decode the SA information, continuous transmission of the SA information can be known.

Further, according to the embodiment of the present invention, continuous collision of SA information or D2D data can be prevented.

1 is a diagram showing an example of SA information and Medium Access Control (MAC) PDU (Protocol Data Unit) transmission.
2 is a diagram showing an example of retransmission of SA information.
3 is a diagram illustrating a method by which a transmitting terminal displays continuous transmission of SA information according to an embodiment of the present invention.
4 is a diagram illustrating a method by which a receiving terminal can recognize continuous transmission of SA information without decoding SA information according to an embodiment of the present invention.
5 is a diagram illustrating a method by which a receiving terminal can recognize continuous transmission of SA information without decoding SA information according to another embodiment of the present invention.
6 is a diagram illustrating a configuration of a terminal according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, a terminal is referred to as a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), a high reliability mobile station ), A subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE) MS, AMS, HR-MS, SS, PSS, AT, UE, and the like.

In addition, the base station (BS) includes an advanced base station (ABS), a high reliability base station (HR-BS), a node B, an evolved node B an eNodeB, an access point (AP), a radio access station (RAS), a base transceiver station (BTS), a mobile multihop relay (MMR) a BS, an ABS, a HR-BS, a Node B, an eNodeB, a BS, a BS, a BS, a relay station (RS), a high reliability relay station (HR- AP, RAS, BTS, MMR-BS, RS, HR-RS, macro base station, small base station, and the like.

1 is a diagram illustrating an example of Scheduling Assignment (SA) information and Medium Access Control (MAC) PDU (Protocol Data Unit) transmission.

The D2D communication process includes an SA process and a D2D data transmission process.

The D2D resource area DR, which is a time-frequency resource area allocated for D2D communication, is divided into two resource areas, i.e., an SA resource pool SARP and a D2D data resource pool DRP, as illustrated in FIG. Respectively.

The SA Resource Pool (SARP) contains a plurality of SA resources that are time-frequency resources. Each of the SA resources may have the same size. One SA resource may include a plurality of REs (Resource Elements).

The UE randomly selects at least one of a plurality of SA resources and transmits SA information (or SA packet) using the selected SA resource. For example, when a terminal selects an SA resource (SARB1a) among a plurality of SA resources, it can transmit SA information (e.g., control information) through a SA resource (SARB1a) using a predefined modulation and coding scheme .

Specifically, when the terminal desires to transmit D2D data, control information included in the SA information can be transmitted using the SA resource (SARB1a). The control information of the SA information may include location information of a D2D data resource used by the terminal itself to transmit D2D data among a plurality of D2D data resources included in the D2D data resource pool (DRP). Here, one D2D data resource may include a plurality of REs. In addition, the control information of the SA information may include transmission / reception parameters (e.g., a modulation method of D2D data, a coding method of D2D data, etc.) necessary for another terminal to receive D2D data transmitted by the terminal itself. In addition, the control information of the SA information may include a terminal identifier (ID). The terminal ID included in the control information of the SA information may be an ID associated with the terminal to receive the D2D data. The ID associated with the receiving terminal may be a broadcast ID for broadcasting, a group ID for groupcasting to a D2D communication group to which the receiving terminal belongs, or a group ID for unicasting a receiving terminal. It can be a unicast ID.

Meanwhile, the UE can schedule transmission of a plurality of MAC PDUs through one SA information transmission. In addition, the UE may retransmit each MAC PDU multiple times in order to improve reception performance and improve link budget. In FIG. 1, for convenience of explanation, the UE transmits X (e.g., 4) MAC PDUs (MPDU1 to MPDU4) through one SA information transmission, and each MAC PDU (MPDU1 to MPDU4) 4, for example). 1, a terminal uses one SA resource (SARB1a) of a plurality of SA resources included in an SA resource pool (SARP) to determine location information of a D2D data resource to which each MAC PDU (MPDU1 to MPDU4) And transmits the SA information. Then, the UE retransmits the MAC PDU (MPDU1) four times using the four D2D data resources (DRB1a to DRB1d) among the plurality of D2D data resources included in the D2D data resource pool (DRP) DRB2a to DRB2d, and retransmits the MAC PDU (MPDU2) four times. Then, the MS retransmits the MAC PDU (MPDU3) four times using another four D2D data resources (DRB3a to DRB3d) and uses the other four D2D data resources (DRB4a to DRB4d) to transmit the MAC PDU Retransmit four times.

2 is a diagram showing an example of retransmission of SA information.

Like the D2D data retransmission illustrated in FIG. 1, the SA information can also be retransmitted. In FIG. 2, for convenience of explanation, the case where the terminal retransmits the SA information four times is illustrated. 2, the UE can retransmit SA information (e.g., the same SA information) four times using four SA resources (SARB1a to SARB1d) among a plurality of SA resources included in the SA resource pool (SARP) have.

On the other hand, the terminals always monitor the SA resource pool (SARP) and decode the transmitted SA resources (SA information). The receiving terminal decodes the SA resource (SA information) and confirms the terminal ID. When the terminal ID included in the SA information is related to the receiving terminal itself, the receiving terminal transmits the D2D data resource to be decoded by the receiving terminal itself among a plurality of D2D data resources included in the D2D data resource pool DR to the SA information The location information of the included D2D data resource is used. The receiving terminal decodes the D2D data transmitted through the determined D2D data resource using transmission / reception parameters (e.g., modulation scheme, coding scheme, etc.) included in the SA information. Meanwhile, this method basically corresponds to a dynamic scheduling method which does not require sensing.

A method of supporting UEs to randomly select transmission resources based on sensing and a method of supporting SPS (Semi-Persistent Scheduling) type scheduling will be described with reference to FIG.

3 is a diagram illustrating a method by which a transmitting terminal displays continuous transmission of SA information according to an embodiment of the present invention. In FIG. 3, three D2D resource regions DR _n to DR _{n +2} among a plurality of D2D resource regions are illustrated. The n-th D2D resource region DR _n is divided into an n-th SA resource pool SARP _n and an n-th D2D data resource pool DRP _n . The (n + 1) th D2D resource area DR _{n +1} is divided into an ( _{n + 1} ) th SA resource pool (SARP _{n +1} ) and an ( _{n + 1} ) th D2D data resource pool DRP _{n + 1} . n + 2 beonjjae D2D resource region (DR _{n +2)} is divided into n + 2 beonjjae SA resource pool (SARP _{n +2)} and n + 2 beonjjae D2D data resource pool (DRP _{n + 2).}

The nth SA resource pool (SARP _n ) and the (n + 1) th SA resource pool (SARP _{n +1} ) must be related in order for the UE to use sensing-based random resource selection.

First, a procedure for selecting a sensing based random resource will be described.

The SA information may include a L (linkage) - field. Here, the number of bits of the L-field may be one and may indicate continuous transmission of the SA information. That is, the L-field may indicate the association between two consecutive SA information transmissions. Specifically, when the transmitting terminal wishes to continuously transmit SA information, the transmitting terminal transmits SA (SA ( _n )) using the first SA resource among the plurality of SA resources included in the current SA resource pool transmitting information, and then SA resource pool (that is, n + 1 beonjjae SA resource pool (SARP _{n +1))} using the SA resource 2 in the same position and the SA 1 resources from among a plurality of resources contained in the SA SA Information can be transmitted. Here, the first SA resource and the second SA resource may be one or more. More specifically, when the transmitting terminal desires to transmit SA information not only in the nth SA resource pool (SARP _n ) but also in the n + 1th SA resource pool (SARP _{n +1} ), the nth SA resource pool (SARP _n The L-field of the SA information to be transmitted can be set to 1. The transmitting terminal to a first transmission by using the SA resource, n + 1-th SA resource pool (SARP _{n +1)} of the SA information including an L- field having a value of 1 n th SA resource pool (SARP _n) And may reserve a second SA resource in the same location as the first SA resource among a plurality of included SA resources. Then, the transmitting terminal can transmit the SA information using the reserved second SA resource of the (n + 1) th SA resource pool (SARP _{n +1} ).

On the other hand, when the transmitting terminal is scheduled to continuously transmit SA information (e.g., SA information is transmitted in the _nth SA resource pool (SARP _n ) and SA information is transmitted in the n + 1th SA resource pool (SARP _{n +1} ) Field is to be transmitted), the L-field of the SA information to be transmitted in the _nth SA resource pool (SARP _n ) may be set to zero. The transmitting terminal of the first transmission by using the SA resource, n + 1-th SA resource pool (SARP _{n + 1)} the n-th SA resource pool (SARP _n) to SA information including an L- field having a value of 0 Releases the second SA resource and does not transmit SA information using the second SA resource of the ( _{n + 1} ) th SA resource pool (SARP _{n + 1} ).

On the other hand, when another UE desires to transmit SA information in the (n + 1) th SA resource pool (SARP _{n +1} ), the SA resource in the non-busy state (or idle state) (Monitors) the SA information in the _nth SA resource pool (SARP _n ). The received SA information may be one or more. Upon receiving the SA information in the _nth SA resource pool (SARP _n ), the UE confirms the L-field value of the received SA information and transmits the SA information to a plurality of SAs included in the n + 1th SA resource pool (SARP _{n +1} ) The SA resource to be released or the non-busy SA resource is determined. Specifically, the n-th terminal SA resource pool of non SA of resources (SARP _n) - the busy state of the resource SA (SA resources that are not currently in use) are the (n + 1) th SA resource pool (SARP _{n +1)} in the non-busy State. ≪ / RTI > When the UE receives the SA information including the L-field having a value of 1 in the n-th SA resource pool (SARP _n ), the terminal selects the SA resource among the plurality of SA resources of the ( _{n + 1} ) It is determined that the specific SA resource (SA resource in the same position as the SA resource to which the corresponding SA information is transmitted) is reserved. And the terminal randomly selects at least one of the SA resources that are determined to be non-busy or released. That is, the UE can randomly select at least one of the plurality of SA resources included in the (n + 1) th SA resource pool (SARP _{n +1} ) from among the remaining SA resources excluding the reserved SA resources. Then, the UE transmits the SA information using the selected SA resource among the SA resources of the (n + 1) th SA resource pool (SARP _{n +1} ).

Next, a method of supporting SPS-like scheduling will be described.

As described in FIG. 1, in order to schedule transmission of one MAC PDU or transmission of a plurality of MAC PDUs (for example, scheduling for D2D data resources), it is necessary to transmit one SA information beforehand, . ≪ / RTI >

Meanwhile, transmission of PTT (Push To Talk), still picture and moving picture (dynamic picure or moving picture) is an important service of PS (Public Safety). In order to provide such a service, it is more effective to allocate resources using the SPS type scheduling method than the dynamic scheduling method.

When the SA information includes the L-field, the transmitting terminal can consecutively use (occupy) resources. Specifically, when the transmitting terminal needs to transmit continuous D2D data, it can set the L-field of the SA information to 1 until the D2D data successive transmission is completed. Through this, the transmitting terminal can consecutively use the specific SA resources of the SA resource pools (SARP _n to SARP _{n + m} ). For example, the transmitting terminal may transmit SA information including an L-field having a value of 1 by using the first SA resource of the n-th SA resource pool (SARP _n ) _{n + 1} ) second SA resources (which are in the same position as the first SA resources). Then, the transmitting terminal transmits the SA information including the L-field having the value of 1 to the second SA resource (located at the same position as the first SA resource) of the (n + 1) th SA resource pool (SARP _{n +1} ) (Located at the same position as the first SA resource) of the (n + 2) th SA resource pool (SARP _{n + 2} ). As a result, the terminal can obtain the advantages provided by the SPS.

On the other hand, when the transmitting terminal indicates the continuity (association) between the two SA information transmissions using the L-field included in the SA information, the receiving terminal must decode the transmitted SA information before the value of the L- . 4 and 5, a description will be given of a method in which the receiving terminal can recognize continuous transmission of SA information even when the receiving terminal does not decode the SA information (that is, a method of expressing continuous transmission of SA information using a physical signal).

4 is a diagram illustrating a method by which a receiving terminal can recognize continuous transmission of SA information without decoding SA information according to an embodiment of the present invention.

A sequence (L-sequence) indicating 1 or 0 is predefined. That is, an L-sequence may be used instead of the L-field.

The transmitting terminal transmits an L-sequence using a part (RL) of a plurality of REs included in the SA resource. That is, the transmitting terminal can display continuous transmission of the SA information using the L-sequence. Specifically, when the transmitting terminal desires to transmit SA information not only in the nth SA resource pool (SARP _n ) but also in the (n + 1) th SA resource pool (SARP _{n +1} ), the nth SA resource pool (SARP _n ) (RL) included in the SA resource (SARB2) among the plurality of SA resources of the mobile station (MN). Here, the L-resource (RL) may include a plurality of REs. Then, the transmitting terminal can transmit a sequence of Demodulation Reference Signal (DMRS) using a channel estimation resource (RCH) included in the SA resource (SARB2). Here, the channel estimation resource (RCH) may include a plurality of REs. The transmitting terminal can transmit control information (e.g., D2D data resource information, transmission / reception parameters, terminal ID, etc.) using a control information resource (RCI) included in the SA resource (SARB2). Here, the control information resource (RCI) may include a plurality of REs. On the other hand, when the transmitting terminal is scheduled to continuously transmit SA information (e.g., SA information is transmitted in the _nth SA resource pool (SARP _n ) and SA information is transmitted in the n + 1th SA resource pool (SARP _{n +1} ) (RL) included in the SA resource (SARB2) among the plurality of SA resources of the n-th SA resource pool (SARP _n ) can be used to transmit an L-sequence indicating 0 .

Even if the receiving terminal does not decode the SA information (before decoding the SA information), it can check whether or not the SA information is continuously transmitted through detection of the L-sequence for the SA information.

5 is a diagram illustrating a method by which a receiving terminal can recognize continuous transmission of SA information without decoding SA information according to another embodiment of the present invention. The method of FIG. 5 differs from the method of FIG. 4 in that a DMRS sequence is used instead of a separate L-sequence.

The transmitting terminal can display the continuous transmission of the SA information using the DMRS sequence for channel estimation. Here, the DMRS sequence may include an L-sequence. Specifically, when the transmitting terminal desires to transmit SA information not only in the nth SA resource pool (SARP _n ) but also in the (n + 1) th SA resource pool (SARP _{n +1} ), the nth SA resource pool (SARP _n ) Using a channel estimation resource (RCH) included in the SA resource (SARB3) among the plurality of SA resources of the base station (BS). Here, the channel estimation resource (RCH) may include a plurality of REs. Then, the transmitting terminal can transmit control information (e.g., D2D data resource information, transmission / reception parameters, terminal ID, etc.) using the control information resource (RCI) included in the SA resource (SARB3). Here, the control information resource (RCI) may include a plurality of REs. On the other hand, when the transmitting terminal is scheduled to continuously transmit SA information (e.g., SA information is transmitted in the _nth SA resource pool (SARP _n ) and SA information is transmitted in the n + 1th SA resource pool (SARP _{n +1} ) (I.e., when it is not to be transmitted), a DMRS sequence indicating 0 can be transmitted using a channel estimation resource (RCH) included in the SA resource (SARB3) among the plurality of SA resources of the _nth SA resource pool (SARPn).

Even if the receiving terminal does not decode the SA information (before decoding the SA information), the receiving terminal can check whether or not the SA information is continuously transmitted through detection of the DMRS sequence for the SA information.

Next, a method for preventing continuous resource conflicts will be described.

When terminals randomly select SA resources, terminals may select SA resources at different positions, but may select SA resources at the same position. A resource conflict occurs when a plurality of terminals select an SA resource of the same location. If a plurality of terminals continuously transmit SA information, a resource conflict may occur consecutively.

In order to prevent such a continuous resource collision, the transmitting terminal randomly selects one of k SA resources for retransmission when retransmitting SA information k times, as shown in FIG. 2, and transmits SA It is possible to stop retransmission of information and to monitor (monitor) whether another terminal transmits SA information at the location of the selected SA resource. For example, the transmitting terminal randomly selects one of four SA resources (SARB1a to SARB1d) for retransmission of SA information and monitors whether the SA information of another terminal is transmitted at the location of the selected SA resource (e.g., SARB1c) can do. If the transmitting terminal confirms that the SA information of another terminal is transmitted at the location of the selected SA resource (e.g., SARB1c), it recognizes that a resource conflict has occurred and transmits the SA information (or continuous transmission of the SA information) Stop and try scheduling again. If the transmitting terminal confirms that the SA information of another terminal is not transmitted at the location of the selected SA resource (e.g., SARB1c), it can continue to retransmit the SA information or continuously transmit the SA information.

On the other hand, the above-described method for preventing continuous resource conflict can be applied to the same or similar to the D2D data retransmission. For example, referring to FIG. 2, a transmitting terminal randomly selects one of four D2D data resources DRB1a to DRB1d for D2D data retransmission and transmits the selected D2D data resource (e.g., DRB1b) It is possible to monitor whether D2D data of another terminal is transmitted. If the transmitting terminal confirms that the D2D data of another terminal is transmitted at the location of the selected D2D data resource (e.g., DRB1b), it recognizes that a resource collision has occurred, stops the transmission of the D2D data, and retries the scheduling again .

Next, a method of supporting an emergency call (emergency transmission) or a priority call (priority transmission) will be described.

When the transmitting terminal wishes to transmit SA information, it can transmit SA information according to a cell-specific transmission probability p ₁ after selecting the SA resource in the SA resource pool (SARP). When a collision occurs due to an increase in the number of terminals and a performance degradation occurs in the terminal due to a collision, the terminal can use this method advantageously. Specifically, the cell's base station can adjust the value of the cell specific transmission probability (p ₁ ). For example, if the cell specific transmission probability (p ₁ ) = 1, the terminal selects the SA resource in the SA resource pool (SARP), and then immediately transmits the SA information. In another example, when the cell specific transmission probability (p ₁ ) = 0.5, the UE selects an SA resource in the SA resource pool (SARP), and then transmits SA information with a probability of 0.5. For example, the UE transmits the SA information when an even number is received and the SA information is not transmitted when an odd number is received. That is, when the cell specific transmission probability (p ₁ ) = 0.5, the probability that the UE transmits the SA information is 0.5. The cell specific transmission probability (p ₁ ) is commonly applied to all terminals within the sphere of influence of the corresponding cell.

The UE-specific transmission probability p ₂ can be independently set to the individual UE together with the cell-specific transmission probability p ₁ . The UE-specific transmission probability p ₂ can be set only for a specific UE.

Specifically, the base station of the cell sets the value of the cell specific transmission probability (p ₁ ) according to the amount of traffic in the cell. For example, the cell's base station may set the value of the cell specific transmission probability (p ₁ ) for all terminals in the cell for collision mitigation.

The base station of the cell can set the value of the UE-specific transmission probability (p ₂ ) applied to the individual UE when necessary (for example, priority transmission, urgent transmission). Alternatively, the value of the UE-specific transmission probability may be preset in a specific UE at the time of implementation of the specific UE. The value of the UE-specific transmission probability (p ₂ ) may be greater than the value of the cell-specific transmission probability (p ₁ ).

A specific terminal determines whether two types of transmission probability (p ₁ , p ₂ ) values are set.

If a particular terminal has two different transmission probability (p _1, p ₂₎ in a cell with a particular transmission probability (p ₁₎ and the terminal UE-specific transmission probability (p ₂₎ of a particular transmission probability (p _2), SA information is transmitted. That is, the UE-specific transmission probability p ₂ takes precedence over the cell-specific transmission probability p ₁ . For example, when two types of transmission probability values (p ₁ = 0.5, p ₂ = 1) are set for a specific terminal having a high priority, a specific terminal preferentially transmits an SA resource to other terminals existing in the same cell And SA information can be transmitted. This is because other terminals having only the cell specific transmission probability p ₁ transmit the SA information with a probability of 0.5, but the value of the UE specific transmission probability p ₂ as well as the cell specific transmission probability p ₁ This is because the set specific terminal can transmit the SA information with a probability of 1. Through this, priority can be secured for emergency call support. Thus, the UE-specific transmission probability p ₂ may be useful for emergency call support.

On the other hand, a specific UE having two types of transmission probabilities (p ₁ , p ₂ ) may transmit not only SA information but also D ₂ D data according to the value of the UE-specific transmission probability p ₂ .

6 is a diagram showing a configuration of a terminal 100 according to an embodiment of the present invention.

The terminal 100 includes a processor 110, a memory 120, and a radio frequency (RF) converter 130.

The processor 110 may be configured to implement the procedures, functions, and methods associated with the terminal described above.

The memory 120 is coupled to the processor 110 and stores various information related to the operation of the processor 110. [

RF converter 130 is coupled to processor 110 and transmits or receives radio signals. The terminal 100 may have a single antenna or multiple antennas.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (20)

A D2D (Device to Device) communication method in which a first terminal directly communicates with another terminal without passing through a network,
When it is desired to transmit SA information not only in the first SA resource pool for scheduling assignment (SA: Scheduling Assignment) but also in the second SA resource pool after the first SA resource pool, setting a value of a first field indicating a continuous transmission to a first value; And
Transmitting the SA information including the first field using a first SA resource included in the first SA resource pool
≪ / RTI > The method according to claim 1,
A first resource area for D2D communication is divided into the first SA resource pool and a first D2D data resource pool for D2D data transmission,
Wherein the second resource area after the first resource area is divided into the second SA resource pool and a second D2D data resource pool after the first D2D data resource pool
D2D communication method. 3. The method of claim 2,
Transmitting the SA information using a second SA resource located at the same position as the first SA resource among a plurality of SA resources included in the second SA resource pool
Further comprising: 3. The method of claim 2,
Setting a value of the first field to a second value different from the first value when it is desired to complete transmission of the SA information in the first SA resource pool
Further comprising: 3. The method of claim 2,
Further comprising transmitting first D2D data using a first one of a plurality of D2D data resources included in the first D2D data resource pool,
Wherein the SA information transmitted using the first SA resource comprises:
Information of the first D2D data resource;
Modulation scheme information of the first D2D data;
Coding method information of the first D2D data; And
Further comprising an identifier associated with a terminal to receive the first D2D data
D2D communication method. 3. The method of claim 2,
The number of bits of the first field is one
D2D communication method. The method according to claim 1,
Wherein the step of transmitting the SA information using the first SA resource comprises:
(M is a natural number equal to or less than N) SA among the first SA resources of N (where N is a natural number equal to or greater than 2) for transmitting SA information of the first terminal, Monitoring whether information is transmitted; And
And repeatedly transmitting SA information of the first terminal using the N first SA resources when the SA information of the other terminal is not transmitted in the Mth first SA resource
D2D communication method. 3. The method of claim 2,
(N is a natural number equal to or greater than 2) among the first D2D data resources of the first D2D data resource included in the first D2D data resource pool, Monitoring whether data is being transmitted; And
And repeatedly transmitting D2D data of the first terminal using the N first D2D data resources when the D2D data of the other terminal is not transmitted in the Mth first D2D data resource
D2D communication method. A D2D (Device to Device) communication method in which a first terminal directly communicates with another terminal without passing through a network,
Monitoring first SA information transmitted through a first SA resource pool for Scheduling Assignment (SA);
When the value of the first field included in the first SA information is the first value, it is determined that the first SA resource among the plurality of SA resources included in the second SA resource pool after the first SA resource pool is reserved ; And
Selecting at least one second SA resource among the plurality of SA resources excluding the first SA resource among the plurality of SA resources included in the second SA resource pool
≪ / RTI > 10. The method of claim 9,
Wherein the location of the first SA resource in the second SA resource pool is the same as the location of the third SA resource in the first SA resource pool,
Wherein the third SA resource is a SA resource to which the first SA information is transmitted among a plurality of SA resources included in the first SA resource pool
D2D communication method. 10. The method of claim 9,
Further comprising transmitting second SA information using the at least one second SA resource,
Wherein selecting the at least one second SA resource comprises:
Randomly selecting the at least one second SA resource among the plurality of SA resources excluding the first SA resource among the plurality of SA resources included in the second SA resource pool
D2D communication method. 10. The method of claim 9,
A first resource area for D2D communication is divided into the first SA resource pool and a first D2D data resource pool for D2D data transmission,
Wherein the second resource area for D2D communication after the first resource area is divided into the second SA resource pool and a second D2D data resource pool after the first D2D data resource pool
D2D communication method. 13. The method of claim 12,
Wherein the first SA information comprises:
Information about a first D2D data resource used by a terminal that transmits the first SA information to transmit first D2D data among a plurality of D2D data resources included in the first D2D data resource pool;
Modulation scheme information of the first D2D data;
Coding method information of the first D2D data; And
Further comprising an identifier associated with a terminal to receive the first D2D data
D2D communication method. 10. The method of claim 9,
The first SA information includes a plurality of
D2D communication method. 10. The method of claim 9,
The number of bits of the first field is one
D2D communication method. A D2D (Device to Device) communication method in which a first terminal directly communicates with another terminal without passing through a network,
Determining whether a first transmission probability value for only the first terminal is set; And
Using the first transmission probability value and the first transmission probability value among the second transmission probability values for the first cell to which the first terminal belongs, and when the first transmission probability value is set, Steps to transfer
≪ / RTI > 17. The method of claim 16,
The first information is one of SA information and D2D data for Scheduling Assignment (SA)
Wherein the first transmission probability value is greater than the second transmission probability value
D2D communication method. 18. The method of claim 17,
Wherein the transmitting the first information using the first transmission probability value comprises:
Selecting a first SA resource among a plurality of SA resources included in an SA resource pool for an SA when the first information is the SA information; And
Determining whether to transmit the SA information using the first SA resource based on the first transmission probability value,
The resource area for D2D communication is divided into the SA resource pool and the D2D data resource pool for D2D data transmission
D2D communication method. 19. The method of claim 18,
And transmitting the first information using the second transmission probability value when the first transmission probability value is not set,
The second transmission probability value is commonly applied to all terminals existing in the first cell
D2D communication method. 17. The method of claim 16,
Wherein the first transmission probability value is set by the base station of the first cell
D2D communication method.

Images