Method and device for configuring central subcarrier

1. A method for configuring a central subcarrier, comprising:

mapping, by a base station, a first downlink control channel onto a part (f 1 ) of a downlink bandwidth (fW) of a cell, and configuring a first virtual central subcarrier in f 1 ; and

mapping, by the base station, a downlink data channel onto fW of the cell, and configuring, by the base station, a central subcarrier on fW, wherein

f 1 is different from a bandwidth f 2 mapped to a second downlink control channel of the cell or a neighboring cell, an overlap between f 1 and f 2 is at least one subcarrier, or at least one idle subcarrier exists between f 1 and f 2 , or at least one non-idle subcarrier and at least one idle subcarrier exist between f 1 and f 2 ; and

the first virtual central subcarrier is located on a grid position of a central frequency, a distance between the first virtual central subcarrier and a second virtual central subcarrier configured in f 2 is an integer multiple of a frequency domain width of the subcarrier, and borders of physical resource blocks (PRBs) are aligned between the cell and the neighboring cell.

2. The method according to claim 1 , wherein:

the first virtual central subcarrier is located on a grid position of a central frequency, and the distance between the first virtual central subcarrier and the second virtual central subcarrier configured in f 2 is an integer multiple of the frequency domain width of the subcarrier, which comprises:

the second virtual central subcarrier is located on the grid position of the central frequency, the distance between the first virtual central subcarrier and the second virtual central subcarrier is an integer multiple of a grid frequency domain width of the central frequency, and the distance between the first virtual central subcarrier and the second virtual central subcarrier is an integer multiple of the frequency domain width of the subcarrier.

3. The method according to claim 1 , wherein:

in the case of multi-carrier transmission, the bandwidth f 2 mapped to the second downlink control channel comprises the bandwidth f 2 of the second downlink control channel mapped to the cell; and

in the case of orthogonal transmission of the downlink control channel, the bandwidth f 2 mapped to the second downlink control channel comprises the bandwidth f 2 of the second downlink control channel mapped to the neighboring cell.

4. The method according to claim 1 , wherein the configuring, by the base station, the central subcarrier on fW comprises at least one of the following steps:

configuring, by the base station, the central subcarrier on an overlapping subcarrier between f 1 and f 2 , and configuring, by the base station, the central subcarrier on an idle subcarrier between f 1 and f 2 .

5. The method according to claim 4 , further comprising:

sending, by the base station, downlink control channel signals and/or downlink reference signals on subcarriers other than the overlapping subcarrier between f 1 and f 2 .

6. The method according to claim 5 , wherein the sending, by the base station, the downlink control channel signals and/or downlink reference signals on the subcarriers other than the overlapping subcarrier between f 1 and f 2 comprises:

sending, by the base station, signals of PCFICH, and/or PHICH, and/or CRS, and/or CSI-RS on the subcarriers other than the overlapping subcarrier between f 1 and f 2 .

7. The method according to claim 4 , wherein

physical resource blocks (PRBs) adjacent to the overlapping subcarrier between f 1 and f 2 comprise subcarriers other than the overlapping subcarrier between f 1 and f 2 .

8. The method according to claim 1 , further comprising:

when a coverage scope of the cell is less than a first threshold, increasing by the base station, bandwidth occupied in fW and decreasing, by the base station, protection bandwidth occupied in fW.

9. The method according to claim 1 , further comprising:

setting, by the base station, an idle subcarrier or a non-idle subcarrier on the second virtual central subcarrier of the cell, wherein the idle subcarrier or non-idle subcarrier belongs to a neighboring PRB.

10. A device for configuring a central subcarrier, comprising:

a first mapping and configuring unit, configured to: map a first downlink control channel onto a part (f 1 ) of a downlink bandwidth (fW) of a cell, and configure a first virtual central subcarrier in f 1 , wherein f 1 is different from a bandwidth (f 2 ) mapped to a second downlink control channel, an overlap between f 1 and f 2 is at least one subcarrier, or at least one idle subcarrier exists between f 1 and f 2 , or at least one non-idle subcarrier and at least one idle subcarrier exist between f 1 and f 2 ; the first virtual central subcarrier is located on a grid position of a central frequency, a distance between the first virtual central subcarrier and a second virtual central subcarrier configured in f 2 is an integer multiple of a frequency domain width of the subcarrier, and physical resource blocks (PRBs) are aligned between the cell and a neighboring cell; and

a second mapping and configuring unit, configured to map a downlink data channel onto fW of the cell, and configure a central subcarrier on fW.

11. The device according to claim 10 , wherein:

the first virtual central subcarrier is located on a grid position of a central frequency, and the distance between the first virtual central subcarrier and the second virtual central subcarrier configured in f 2 is an integer multiple of the frequency domain width of the subcarrier, which comprises:

the second virtual central subcarrier is located on the grid position of the central frequency, the distance between the first virtual central subcarrier and the second virtual central subcarrier is an integer multiple of a grid frequency domain width of the central frequency, and the distance between the first virtual central subcarrier and the second virtual central subcarrier is an integer multiple of the frequency domain width of the subcarrier.

12. The device according to claim 10 , wherein:

in the case of multi-carrier transmission, the bandwidth f 2 mapped to the second downlink control channel comprises the bandwidth f 2 of the second downlink control channel mapped to the cell; and

in the case of orthogonal transmission of the downlink control channel, the bandwidth f 2 mapped to the second downlink control channel comprises the bandwidth f 2 of the second downlink control channel mapped to the neighboring cell.

13. The device according to claim 10 , wherein the second mapping and configuring unit is specifically configured to:

map a downlink data channel onto fW of the cell;

configure at least one of the central subcarrier on an overlapping subcarrier between f 1 and f 2 and a central subcarrier on the idle subcarrier between f 1 and f 2 .

14. The device according to claim 13 , further comprising:

a sending unit, configured to send downlink control channel signals and/or downlink reference signals on subcarriers other than the overlapping subcarrier between f 1 and f 2 .

15. The device according to claim 14 , wherein the sending unit is specifically configured to:

send signals of PCFICH, and/or PHICH, and/or CRS, and/or CSI-RS on subcarriers other than the overlapping subcarrier between f 1 and f 2 .

16. The device according to claim 13 , wherein physical resource blocks (PRBs) adjacent to the overlapping subcarrier between f 1 and f 2 comprise subcarriers other than the overlapping subcarrier between f 1 and f 2 .

17. The device according to claim 10 , further comprising:

a bandwidth adjusting unit, configured to: increase the bandwidth occupied in fW and decrease the protection bandwidth occupied in fW when a coverage scope of the cell is less than a first threshold.

18. The device according to claim 10 , further comprising:

a configuring unit, configured to set an idle subcarrier or a non-idle subcarrier on the second virtual central subcarrier of the cell, wherein the idle subcarrier or non-idle subcarrier belongs to a neighboring PRB.