Method and apparatus for allocating resources for D2D communication

1. A method for allocating resources for a device-to-device (D2D) communication at a device, the method comprising:

receiving, from a base station (BS), resource allocation information comprising information about a first resource and first power control information for the D2D communication, the first resource for the D2D communication being a part of a cellular communication resource;

measuring a channel quality of a downlink signal received from the BS;

if the measured channel quality is smaller than a predetermined threshold, conducting the D2D communication using the resource allocation information;

if the measured channel quality is larger than the predetermined threshold, transmitting, to the BS, a resource request for the D2D communication;

receiving, from the BS, a response in response to the resource request; and

transmitting data for the D2D communication using a second resource and second power control information indicated by the response.

2. The method of claim 1 , further comprising:

decreasing, if the measured channel quality is larger than the predetermined threshold, a transmission power of the device by a predetermined level obtained from the first power control information; and

conducting, if the decreased transmission power is equal or higher than a transmission power threshold, the D2D communication using the resource allocation information.

3. The method of claim 1 , wherein the second resource is a dedicated resource allocated for the D2D communication of the device among the first resource.

4. The method of claim 1 , wherein the response is broadcasted.

5. The method of claim 1 , wherein the first power control information includes at least one of a transmission power threshold and a plurality of power ranges determined based on a distance between the BS and the device.

6. The method of claim 1 , further comprising:

if a transmission power of the device is included in a minimum power range obtained from the first power control information, transmitting, to the BS, the resource request for the D2D communication.

7. The method of claim 1 , wherein if a transmission power of the device is included in a minimum power range obtained from the first power control information, the D2D communication is stopped.

8. A method for allocating resources for a device-to-device (D2D) communication to a device at a base station (BS), the method comprising:

broadcasting resource allocation information comprising information about a first resource and first power control information for the D2D communication the first resource for the D2D communication being part of a cellular communication resource;

receiving, from the device, a resource request;

when the resource request is received from the device, recognizing a channel quality of a downlink signal measured by the device is larger than a predetermined threshold; and

transmitting, to the device, a response comprising a second resource and second power control information, wherein the second resource is a dedicated resource allocated for the D2D communication of the device.

9. The method of claim 8 , wherein the response is broadcasted.

10. The method of claim 8 ,

wherein the first power control information includes at least one of a transmission power threshold and a plurality of power ranges determined based on a distance between the BS and the device.

11. The method of claim 8 , wherein if a transmission power of the device is included in a minimum power range obtained from the first power control information, the resource request for the D2D communication is received from the device or the D2D communication is stopped.

12. A device configured to conduct a device-to-device (D2D) communication, the device comprising:

a transceiver configured to receive, from a base station (BS), resource allocation information comprising information about a first resource and first power control information for the D2D communication, the first resource being a part of a cellular communication resource; and

a controller configured to:

measure a channel quality of a downlink signal received from the BS,

if the measured channel quality is smaller than a predetermined threshold, control the transceiver to conduct the D2D communication using the resource allocation information, and

if the measured channel quality is larger than the predetermined threshold, control the transceiver to:

transmit, to the BS, a resource request for the D2D communication,

receive, from the BS, a response in response to the resource request, and

transmit data for the D2D communication using a second resource and second power control information indicated by the response.

13. The device of claim 12 , wherein if the measured channel quality is larger than the threshold, the controller decreases a transmission power of the device by a predetermined level obtained from the first power control information, and

if the decreased transmission power is equal or higher than a transmission power threshold, the controller controls the transceiver to conduct the D2D communication using the resource allocation information.

14. The device of claim 12 , wherein the second resource is a dedicated resource allocated for the D2D communication of the device among the first resource.

15. The device of claim 12 , wherein the response is broadcasted.

16. The device of claim 12 , wherein the first power control information includes at least one of a transmission power threshold and a plurality of power ranges determined based on a distance between the BS and the device.

17. The device of claim 12 , wherein if a transmission power of the device is included in a minimum power range obtained from the first power control information, the controller configured to control the transceiver to transmit, to the BS, the resource request for the D2D communication.

18. The device of claim 12 , wherein if a transmission power of the device is included in a minimum power range obtained from the first power control information, the D2D communication is stopped.

19. A base station (BS) for allocating resources for a device-to-device (D2D) communication to a device, the BS comprising:

a transceiver configured to broadcast resource allocation information comprising information about a first resource and first power control information for the D2D communication, the first resource for the D2D communication being a part of a cellular communication resource, and receive, from the device, a resource request; and

a controller configured to, when the resource request is received from the device, recognize a channel quality of a downlink signal measured by the device is larger than a predetermined threshold, and control the transceiver to transmit, to the device, a response comprising a second resource and second power control information in response to the resource request, wherein the second resource is a dedicated resource allocated for the D2D communication of the device.

20. The BS of claim 19 , wherein the response is broadcasted.

21. The BS of claim 19 , wherein the first power control information includes at least one of a transmission power threshold and a plurality of power ranges determined based on a distance between the BS and the device.

22. The BS of claim 19 , wherein if a transmission power of the device is included in a minimum power range obtained from the first power control information, the resource request for the D2D communication is received from the device or the D2D communication is stopped.