Cross carrier scheduling method and apparatus

1. A cross carrier scheduling method performed by a terminal, the method comprising:

receiving a control element from a base station, the control element comprising cross carrier scheduling configuration information;

setting a scheduling cell of a secondary cell, in accordance with the cross carrier scheduling configuration information; and

monitoring scheduling information of the secondary cell at the scheduling cell, starting from a point in time at which a predetermined amount of time has elapsed from a transmission time of the control element,

wherein the predetermined amount of time is predefined as a same value for the base station and the termininal, and

wherein the cross carrier scheduling configuration information comprises a CIF-presence (carrier indicator field presence) in a case that the secondary cell is equal to the scheduling cell and a pdsch-start (physical downlink shared channel start) in a case that the secondary cell is different from the scheduling cell.

2. The method of claim 1 , wherein the transmission time of the control element is included in a subframe of the frame in which the control element is transmitted.

3. The method of claim 1 , wherein the predefined point in time comprises a point in time after a hybrid automatic retransmit request (HARQ) timing sent to the control element.

4. The method of claim 1 , wherein the cross carrier scheduling configuration information further comprises:

an index of the secondary cell, and

an identifier of the scheduling cell.

5. The method of claim 4 , wherein in response to the index indicating that the secondary cell is set to correspond to the terminal, setting the scheduling cell comprises:

setting the scheduling cell of the secondary cell to correspond to a scheduling cell indicated by the identifier.

6. The method of claim 1 , wherein monitoring the scheduling information comprises:

monitoring the scheduling information of the secondary cell at the scheduling cell, in response to the secondary cell being in an activation state.

7. The method of claim 1 , wherein the CIF-presence indicates that a CIF exists in a physical downlink control channel (PDCCH) of the secondary cell, and

wherein the pdsch-start indicates a position of a symbol on which the a physical downlink shared channel (PDSCH) of the secondary cell starts.

8. A cross carrier scheduling method performed by a base station, the method comprising:

transmitting a control element to a terminal, the control element comprising cross carrier scheduling configuration information;

receiving an acknowledgement (ACK) sent from the terminal in response to the terminal receiving the control element;

setting a scheduling cell of a secondary cell, in accordance with the cross carrier scheduling configuration information; and

indicating to transmit scheduling information of the secondary cell at the scheduling cell, from a point in time at which a predetermined amount of time has elapsed from a transmission time of the control element to which the ACK is received,

wherein the predetermined amount of time is predefined as a same value for the base station and the terminal, and

wherein the cross carrier scheduling configuration information comprises a CIF-presence (carrier indicator field presence) in a case that the secondary cell is equal to the scheduling cell and a pdsch-start (physical downlink shared channel start) in a case that the secondary cell is different from the scheduling cell.

9. The method of claim 8 , wherein the transmission time of the control element is included in a subframe of the frame in which the control element is transmitted.

10. The method of claim 8 , wherein the predefined point in time comprises a point in time after a timing of receiving the ACK.

11. The method of claim 8 , wherein the cross carrier scheduling configuration information further comprises:

an index of the secondary cell, and

an identifier of the scheduling cell.

12. The method of claim 11 , wherein in response to the index indicating that the secondary cell is set to correspond to the terminal, setting the scheduling cell comprises:

setting the scheduling cell of the secondary cell to correspond to a scheduling cell indicated by the identifier.

13. The method of claim 8 , wherein indicating to transmit the scheduling information comprises:

indicating to transmit the scheduling information of the secondary cell at the scheduling cell in response to the secondary cell being in an activation state.

14. The method of claim 8 , wherein the CIF-presence indicates that a CIF exists in a physical downlink control channel (PDCCH) of the secondary cell, and

wherein the pdsch-start indicates a position of a symbol on which the a PDSCH of the secondary cell starts.

15. A cross carrier scheduling apparatus, the apparatus comprising:

a transceiver configured to receive a control element from a base station, the control element comprising cross carrier scheduling configuration information; and

a processor configured to set a scheduling cell of a secondary cell in accordance with the cross carrier scheduling configuration information, and to monitor scheduling information of the secondary cell at the scheduling cell, starting from a point in time at which a predetermined amount of time has elapsed from a transmission time of the control element,

wherein the predetermined amount of time is predefined as a same value for the base station and the terminal, and

wherein the cross carrier scheduling configuration information comprises a CIF-presence (carrier indicator field presence) in a case that the secondary cell is equal to the scheduling cell and a pdsch-start (physical downlink shared channel start) in a case that the secondary cell is different from the scheduling cell.

16. The apparatus of claim 15 , wherein the predefined point in time comprises a point in time after a hybrid automatic retransmit request (HARQ) timing sent to the control element.

17. The apparatus of claim 15 , wherein the CIF-presence indicates that a CIF exists in a physical downlink control channel (PDCCH) of the secondary cell, and

wherein the pdsch-start indicates a position of a symbol on which the a PDSCH of the secondary cell starts.

18. A cross carrier scheduling apparatus, the apparatus comprising:

a transceiver configured to transmit a control element to a terminal, the control element comprising cross carrier scheduling configuration information, and to receive an acknowledgement (ACK) sent from the terminal in response to the terminal receiving the control element; and

a processor configured to set a scheduling cell of a secondary cell in accordance with the cross carrier scheduling configuration information, and to indicate to transmit scheduling information of the secondary cell at the scheduling cell, from a point in time at which a predetermined amount of time has elapsed from a transmission time of the control element to which the ACK is received,

wherein the predetermined amount of time is predefined as a same value for the base station and the terminal, and

wherein the cross carrier scheduling configuration information comprises a CIF-presence (carrier indicator field presence) in a case that the secondary cell is equal to the scheduling cell and a pdsch-start (physical downlink shared channel start) in a case that the secondary cell is different from the scheduling cell.

19. The apparatus of claim 18 , wherein the predefined point in time comprises a point in time after a timing of receiving the ACK.

20. The apparatus of claim 18 , wherein the CIF-presence indicates that a CIF exists in a physical downlink control channel (PDCCH) of the secondary cell, and

wherein the pdsch-start indicates a position of a symbol on which the a PDSCH of the secondary cell starts.