KR101413843B1 - Method for allocating Resource in D2D and Base Station for the Method - Google Patents

Abstract

A D2D resource allocation method and base station therefor are disclosed. The method includes: (a) receiving, from terminals located in a cell, whether a corresponding terminal is located at a boundary with another cell and neighboring cell information adjacent to the terminal; A step (b) of receiving resource information allocated to terminals located at the border of each peripheral cell from neighboring cells; And allocating D2D resources to terminals located in a cell using resource information allocated to terminals located in a border area of the neighboring cell. According to the disclosed method, there is an advantage that interference caused by the D2D terminal can be efficiently removed in a network supporting the D2D scheme

Description

[0001] D2D RESOURCE ALLOCATION METHOD AND BASE STATION [0002]

Embodiments of the present invention relate to D2D communication, and more particularly, to a base station to which a resource allocation method for interference cancellation occurring in a D2D terminal in D2D communication and a base station to which the method is applied.

D2D communication is a short-distance communication method that enables direct communication between terminals without passing through a base station (e-NodeB) when the terminals are located at a close distance from each other. The D2D communication can achieve a higher data rate than the conventional communication method, It is possible to increase the number of terminals that can use the same resource at the same time, thereby increasing the efficiency of resource utilization.

In a network supporting D2D communication, a terminal that communicates via a base station in a conventional cellular system coexists with a terminal that performs direct communication by the D2D method.

A terminal communicating by a cellular method should be allocated a dedicated resource to avoid interference. However, the D2D terminal can transmit data by sharing resources being used by other cellular terminals, and through this frequency reuse, Can be maximized. A prior art related to D2D communication is disclosed in Korean Patent Laid-Open No. 10-2009-5676.

However, when the D2D scheme is used, a UE using the D2D scheme may interfere with a UE existing in another cell if the UE is located at a cell boundary. In particular, when a UE existing in another cell uses a D2D scheme, Interference is inevitably further intensified.

The present invention proposes a resource allocation method and base station for efficiently eliminating interference caused by a D2D terminal in a network supporting the D2D scheme.

According to another aspect of the present invention, there is provided a mobile communication system including: a location information receiver for receiving, from terminals located in a cell, whether a corresponding terminal is located at a boundary with another cell and neighboring cell information adjacent to the terminal; A resource allocation information receiver for receiving resource information allocated to terminals located at a border of neighboring cells from neighboring cells; And a resource allocation unit allocating D2D resources to terminals located in a cell using resource information allocated to terminals located in a border area of the neighboring cell.

The UEs judge whether they are located at the boundary with other cells by using the synchronization signal from the base station of the cell to which they belong and the synchronization signal from the neighboring cell base station.

When the D2D terminal to which resources are to be allocated is located in a border area of the cell, the resource allocator allocates resources by avoiding the resources allocated to the terminals located at the border of the neighboring cell.

The resources allocated to the terminals located in the border area of the cell are fixedly maintained for a predetermined time.

The resource allocation unit provides resource information allocated to a D2D terminal located in the border area to a base station of a neighboring cell.

According to another aspect of the present invention, there is provided a method comprising: (a) receiving, from terminals located in a cell, whether a corresponding terminal is located at a boundary with another cell and neighboring cell information adjacent to the terminal; A step (b) of receiving resource information allocated to terminals located at the border of each peripheral cell from neighboring cells; And allocating D2D resources to terminals located within a cell using resource information allocated to terminals located in a border area of the neighboring cell, in a D2D communication, do.

According to the present invention, it is possible to efficiently remove interference caused by the D2D terminal in a network supporting the D2D scheme.

1 illustrates an example of a communication system to which the D2D resource allocation method of the present invention is applied.
2 is a block diagram illustrating a module configuration of a base station according to an embodiment of the present invention;
3 is a diagram for explaining a method for determining whether a cell is a neighboring cell using a synchronization signal.
4 is a diagram for explaining a process of providing resource allocation information from a base station of each cell to an adjacent base station according to an embodiment of the present invention;
5 is a flowchart illustrating an operation of a base station for interference cancellation according to an embodiment of the present invention;
6 is a diagram illustrating an operation of a terminal for interference cancellation according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an example of a communication system to which the D2D resource allocation method of the present invention is applied.

Referring to FIG. 1, the present invention is applied to a cellular communication system in which a plurality of cells (cell1, cell2) are provided with respective base stations. The base station of each cell (cell1, cell2) performs resource allocation for D2D communication to a specific terminal existing in the cell area.

1, the D2D1 terminal and the D2D2 terminal of the cell 1 are terminals performing D2D communication and are provided with resource allocation information for the D2D from the base station of the cell 1. In the cell 2, the D2D3 terminal and the D2D4 terminal perform D2D communication, and the base station of the cell 2 receives the resource allocation information for the D2D.

When the terminals D2D1 and D2D2 performing D2D in cell 1 are adjacent to the boundary between cell 1 and cell 2, the D2D terminals D2D1 and D2D2 of the cell 1 are connected to the terminals D2D3 , D2D4, celluar1) may occur.

This interference occurs when the D2D terminal of the cell 1 is adjacent to the cell boundary and the D2D terminal or the cellular terminal using the same resource exists in the adjacent cell, and the D2D is mainly allowed to the terminals adjacent to the cell boundary This interference is expected to occur frequently.

In the present invention, a D2D resource allocation method for preventing such interference is proposed.

2 is a block diagram illustrating a module configuration of a base station according to an embodiment of the present invention.

2 is a block diagram illustrating a base station module configuration of a communication system according to an embodiment of the present invention.

2, a base station according to an embodiment of the present invention may include a resource allocation information receiver 200, a location information receiver 202, and a resource allocator 204.

The resource allocation information receiving unit 200 receives the resource information allocated from the base station of the adjacent cell to the terminals at the cell boundary of the adjacent cell. For example, when the cell 1 is adjacent to the cell 2 and the cell 2 is adjacent to the cell 1, the base station of the cell 1 receives the resource information allocated from the cell 2 to the terminals adjacent to the boundary of the cell 1.

At this time, the cell 2 may provide only the resource information allocated to the D2D terminals adjacent to the boundary of the cell 1, or may provide all of the resource information allocated to the D2D terminal and the cellular terminal.

The resource allocation information may be received by the base station through the base station of the neighboring cell or may be received from the base station of the neighboring cell at a predetermined time interval.

The resource allocation information of the received neighbor cell is stored in a separate database, and the database is updated each time the received information is changed.

The location information receiving unit 202 receives location information of the corresponding terminal and cell information adjacent to the terminal from the D2D terminal existing in the cell. Here, the location information indicates whether or not the corresponding terminal is adjacent to a boundary with another cell.

According to a preferred embodiment of the present invention, a terminal can provide position information using a synchronization signal.

3 is a diagram for explaining a method of determining whether a cell is a neighboring cell using a synchronization signal.

Referring to FIG. 3, the D2D terminal D2D1 of the cell 1 is adjacent to the boundary between the cell 1 and the cell 2. In this case, the D2D terminal D2D1 of the cell 1 is connected to the base station (e-NodeB1) And receives the synchronization signals SS1 and SS2 from the base station e-NodeB2.

The D2D terminal D2D1 uses the synchronization signal SS1 transmitted from the base station of the cell 1 and the synchronization signal SS2 transmitted from the base station of the cell 2 to determine whether the terminal itself is adjacent to the cell boundary.

)보다 작을 경우 단말은 셀 경계에 인접해 있다고 판단하며, 두 개의 동기 신호의 파워의 비가 미리 설정된 경계값(

)보다 클 경우 단말은 셀 경계에 인접해있지 않다고 판단한다. According to a preferred embodiment of the present invention, it is determined whether the terminal is a cell boundary by using the power ratio of the two synchronization signals SS1 and SS2. The ratio of the powers of the two synchronizing signals is set to a preset boundary value (< EMI ID = 1.0 >

), The UE determines that it is adjacent to the cell boundary, and if the power ratio of the two synchronization signals is less than a preset threshold value

), The UE determines that the UE is not adjacent to the cell boundary.

Judge to be at cell boundary

I do not think there is a cell boundary

Of course, it will be apparent to those skilled in the art that it is possible to determine whether or not the signal is located at the cell boundary using a signal other than the synchronization signal.

Also, the UE can confirm the base station information located in the vicinity of the UE through the synchronization signal, and can provide neighbor cell information using the information.

The resource allocation unit 204 allocates resources for the D2D to the D2D terminal using the resource allocation information of the neighboring cell received from the resource allocation information receiver 200 and the location information of the terminal received from the location information receiver 202 .

According to a preferred embodiment of the present invention, the resource allocator 204 can perform a normal D2D resource allocation when the D2D terminal to allocate resources is not adjacent to a boundary with another neighboring cell.

However, when the D2D terminal to which resources are to be allocated is adjacent to a boundary with another neighboring cell, resources allocated to the terminals of neighboring cells are allocated to avoid interference caused by the terminals of neighboring cells.

4 is a diagram for explaining a process of providing resource allocation information to a neighboring BS in a BS of each cell according to an embodiment of the present invention.

Referring to FIG. 4, three neighboring cells are shown, and each cell has a base station (e-NodeB1, e-NodeB2, e-NodeB3) and D2D terminals D2D1, D2D2 and D2D3.

Each of the base stations (e-NodeB1, e-NodeB2, and e-NodeB3) determines whether the terminal is located at a cell boundary or located adjacent to a cell through location information transmitted by the terminals D2D1, D2D2, You can check whether there is.

It can be seen that the cellular terminal 1 of the cell 1 is adjacent to the boundary of the cell 2 and the cell 3 through the location information and that the D2D terminal D2D1 of the cell 1 is adjacent to the boundary of the cell 3 through the location information Points can be confirmed.

It can be seen that the D2D terminal D2D2 of the cell 2 is adjacent to the boundary of the cell 1 and the cell 2 through the location information.

It can also be seen that the cellular terminal (celluar 2) of cell 3 is adjacent to the boundary of cell 1 and cell 2 and the D2D terminal D2D3 is adjacent to the boundary of cell 2.

Each of the base stations (e-NodeB1, e-NodeB2, and e-NodeB3) provides resource information allocated to the terminals located at the cell boundary to the neighbor base stations. For example, the base station (e-NodeB2) of the cell 2 transmits the resource information allocated to the terminal (for example, the D2D2 terminal) located at the cell boundary to the base station (e-NodeB1) (-NodeB3).

The resource allocation unit 204 of the base station of each cell allocates resources of the D2D terminal located at the cell boundary using the location information of the terminal and the resource allocation information transmitted to the neighboring base stations.

For example, the base station (e-NodeB3) of the cell 3 allocates resources to the D2D terminal D2D3 close to the cell 2 by avoiding resources allocated to the neighboring terminal D2D2 of the cell 2.

As another example, the base station of the cell 2 may allocate resources to the D2D terminal (D2D2) close to the cell 1 and the cell 3 by avoiding the resources allocated to the celluar 1 adjacent to the cell 1 and celluar2 and D2D3 adjacent to the cell 3 do.

If the cellular terminals are dynamically allocated resources, the resource allocation information of the cellular terminals may not be considered.

In order to allocate a resource according to the present invention, a fixed resource must be used for a certain period of time. Therefore, when resources are allocated to UEs located at cell boundaries, fixed resource allocation Method is used.

However, when the D2D terminal to which the resource is to be allocated is not located at the cell boundary, any of the dynamic resource allocation method and the fixed resource allocation method may be used.

5 is a flowchart illustrating an operation of a base station for interference cancellation according to an embodiment of the present invention.

Referring to FIG. 5, location information and adjacent cell list information are received from terminals in the cell (step 500).

Each terminal provides the base station with neighbor cell list information and whether it is located at the cell boundary using the power ratio of the sync signal transmitted from the base station to which it belongs and the neighbor base station.

In addition, the base station requests resource allocation information of the terminals located at the boundary of the corresponding cell to the base station of the adjacent cell. For example, a base station requests resource information allocated to neighboring terminals by neighboring base stations.

The base station receives the requested resource allocation information (step 504). As described above, the resource allocation information of the neighbor base station may be periodically provided by a predetermined time interval instead of the request.

If the D2D terminal to which resources are to be allocated is located at the cell boundary, resources are fixedly allocated to the corresponding D2D terminal using the resource allocation information of adjacent cells (step 506). If the D2D terminal to which the resource is to be allocated is not located at the cell boundary, the resource can be dynamically allocated or fixedly allocated.

When the resource allocation is completed, the resource information allocated to the D2D terminal located at the cell boundary is provided to the neighbor base stations (step 506).

6 is a diagram illustrating an operation of a terminal for interference cancellation according to an embodiment of the present invention.

Referring to FIG. 6, a terminal receives a synchronization signal from a base station to which the terminal belongs and an adjacent base station (step 600). Using the received synchronization signal, the terminal determines whether it is located at the cell boundary.

In addition, the UE confirms neighboring cell information using the received synchronization signal (step 602).

If the neighboring cell information and the neighboring cell are confirmed, the terminal transmits the information to the base station (step 604).

After transmitting the above-described information, the terminal receives a resource for D2D communication from the base station (step 606).

The UE having allocated resources performs D2D communication using the corresponding resources, and the allocated resources are held fixed for a predetermined time (step 608).

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (10)

A location information receiving unit for receiving, from terminals located within a cell, whether the corresponding terminal is located at a boundary with another cell and neighboring cell information adjacent to the terminal;
A resource allocation information receiver for receiving resource information allocated to terminals located at a border of neighboring cells from neighboring cells; And
And a resource allocator allocating D2D resources to terminals located in a cell using resource information allocated to terminals located in a border area of the neighboring cell,
Wherein the resource allocation unit allocates resources by avoiding resources allocated to the terminals located at the boundary when the D2D terminal to which resources are to be allocated is located in a boundary region of the cell. The method according to claim 1,
Wherein the terminals determine whether they are located at a boundary with other cells by using a synchronization signal from a base station of a cell to which the base station belongs and a synchronization signal from a peripheral cell base station. delete The method according to claim 1,
Wherein resources allocated to terminals located in a boundary region of the cell are fixedly maintained for a predetermined period of time. The method according to claim 1,
Wherein the resource allocation unit provides resource information allocated to a D2D terminal located in the boundary region to a base station of a neighboring cell. (A) receiving, from terminals located in a cell, whether a corresponding terminal is located at a boundary with another cell and neighboring cell information adjacent to the terminal;
A step (b) of receiving resource information allocated to terminals located at the border of each peripheral cell from neighboring cells; And
(C) allocating D2D resources to terminals located in a cell using resource information allocated to terminals located in a border region of the neighboring cell,
Wherein the step (c) allocates resources by avoiding the resources allocated to the terminals located at the boundary when the D2D terminal to which resources are to be allocated is located in the boundary region of the cell, A method for allocating resources for. The method according to claim 6,
Wherein the UEs are located at a boundary with other cells using a synchronization signal from a base station of a cell to which the base station belongs and a synchronization signal from a neighboring cell base station. delete The method according to claim 6,
Wherein the resource allocated to a terminal located in a boundary region of the cell is fixedly maintained for a predetermined period of time. The method according to claim 6,
Wherein the step (c) provides resource information allocated to a D2D terminal located in the boundary region to a base station of a neighboring cell.

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