RADIO BASE STATION AND MOBILE COMMUNICATION METHOD

• US 20120087324A1
• Filed: 05/18/2010
• Published: 04/12/2012
• Est. Priority Date: 05/18/2009
• Status: Abandoned Application

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Kiyoshima, Kohei, Ishii, Hiroyuki, Okubo, Naoto
• Application Number:
  US13/320,836
• Publication Number:
  US 20120087324A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/58 Format of the TPC bits

Abstract

A radio base station according to the present invention comprising: a radio base station configured to transmit a transmission power control command for a mobile station for controlling transmission power of an uplink data signal of the mobile station via a downlink control channel for a transmission power control command mapped to a specific subframe in a downlink channel, the radio base station including a resource assignment unit configured to decide the specific subframe and a transmission unit configured to transmit the transmission power control command for the mobile station via the downlink control channel for the transmission power control command mapped to the specific subframe decided by the resource assignment unit, in which the resource assignment unit is configured to decide the specific subframe according to a number of transmission power control commands transmitted in each subframe.

Claims

1. A radio base station configured to transmit a transmission power control command for a mobile station for controlling transmission power of an uplink data signal of the mobile station via a downlink control channel for a transmission power control command mapped to a specific subframe in a downlink channel, the radio base station comprising:

a resource assignment unit configured to decide the specific subframe; and

a transmission unit configured to transmit the transmission power control command for the mobile station via the downlink control channel for the transmission power control command mapped to the specific subframe decided by the resource assignment unit, wherein

the resource assignment unit is configured to decide the specific subframe according to a number of transmission power control commands transmitted in each subframe.

2. The radio base station according to claim 1, wherein the resource assignment unit is configured to decide a subframe, in which a largest number of transmission power control commands are transmitted among the subframes, as the specific subframe.

3. The radio base station according to claim 1, wherein

the resource assignment unit is configured to assign temporal identification information and the index indicating a multiplexing position of the transmission power control command for the mobile station in the downlink control channel for the transmission power control command mapped to the specific subframe to the mobile station, and

the transmission unit is configured to multiplex the transmission power control command for the mobile station to the multiplexing position indicated by the index in the downlink control channel for the transmission power control command mapped to the specific subframe, and add an error detecting code, for which a scrambling process has been performed using the temporal identification information, to the multiplexing position.

4. The radio base station according to claim 1, wherein when the mobile station is in a discontinuous reception state, the resource assignment unit is configured to decide any one of a predetermined number of subframes corresponding to a first half of a reception interval of the mobile station as the specific subframe.

5. The radio base station according to claim 1, wherein the resource assignment unit is configured to allow a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

6. The radio base station according to claim 1, wherein

the resource assignment unit is configured to decide the specific subframe among subframes in which transmission power control commands have been already transmitted, and

when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the resource assignment unit is configured to decide the specific subframe in subframes in which transmission power control commands have not been transmitted.

13. The radio base station according to claim 2, wherein

the resource assignment unit is configured to assign temporal identification information and the index indicating a multiplexing position of the transmission power control command for the mobile station in the downlink control channel for the transmission power control command mapped to the specific subframe to the mobile station, and

the transmission unit is configured to multiplex the transmission power control command for the mobile station to the multiplexing position indicated by the index in the downlink control channel for the transmission power control command mapped to the specific subframe, and add an error detecting code, for which a scrambling process has been performed using the temporal identification information, to the multiplexing position.

14. The radio base station according to claim 2, wherein when the mobile station is in a discontinuous reception state, the resource assignment unit is configured to decide any one of a predetermined number of subframes corresponding to a first half of a reception interval of the mobile station as the specific subframe.

15. The radio base station according to claim 3, wherein when the mobile station is in a discontinuous reception state, the resource assignment unit is configured to decide any one of a predetermined number of subframes corresponding to a first half of a reception interval of the mobile station as the specific subframe.

16. The radio base station according to claim 2, wherein the resource assignment unit is configured to allow a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

17. The radio base station according to claim 3, wherein the resource assignment unit is configured to allow a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

18. The radio base station according to claim 4, wherein the resource assignment unit is configured to allow a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

19. The radio base station according to claim 2, wherein

the resource assignment unit is configured to decide the specific subframe among subframes in which transmission power control commands have been already transmitted, and

when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the resource assignment unit is configured to decide the specific subframe in subframes in which transmission power control commands have not been transmitted.

20. The radio base station according to claim 3, wherein

the resource assignment unit is configured to decide the specific subframe among subframes in which transmission power control commands have been already transmitted, and

when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the resource assignment unit is configured to decide the specific subframe in subframes in which transmission power control commands have not been transmitted.

21. The radio base station according to claim 4, wherein

the resource assignment unit is configured to decide the specific subframe among subframes in which transmission power control commands have been already transmitted, and

when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the resource assignment unit is configured to decide the specific subframe in subframes in which transmission power control commands have not been transmitted.

22. The radio base station according to claim 5, wherein

the resource assignment unit is configured to decide the specific subframe among subframes in which transmission power control commands have been already transmitted, and

when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the resource assignment unit is configured to decide the specific subframe in subframes in which transmission power control commands have not been transmitted.

7. A mobile communication method, by which a radio base station transmits a transmission power control command for a mobile station for controlling transmission power of an uplink data signal of the mobile station via a downlink control channel for a transmission power control command mapped to a specific subframe in a downlink channel, the mobile communication method comprising:

a step A of deciding the specific subframe;

a step B of transmitting the transmission power control command for the mobile station via the downlink control channel for the transmission power control command mapped to the specific subframe decided in step A; and

a step C in which the mobile station acquires the transmission power control command for the mobile station via the downlink control channel for the transmission power control command, and controls the transmission power of the uplink data signal based on the transmission power control command for the mobile station, wherein,

in the step A, the specific subframe is configured to be decided according to a number of transmission power control commands transmitted in each subframe.

8. The mobile communication method according to claim 7, wherein, in the step A, a subframe, in which a largest number of transmission power control commands are transmitted among the subframes, is decided as the specific subframe.

9. The mobile communication method according to claim 7, wherein,

in the step A, temporal identification information and an index are assigned to the mobile station, the index indicating a multiplexing position of the transmission power control command for the mobile station in the downlink control channel for the transmission power control command mapped to the specific subframe,

in the step B, the transmission power control command for the mobile station is multiplexed to the multiplexing position indicated by the index in the downlink control channel for the transmission power control command mapped to the specific subframe, and an error detecting code, for which a scrambling process has been performed using the temporal identification information, is added to the multiplexing position, and

in the step C, the mobile station attempts to receive a signal on a downlink control channel for a transmission power control command for the mobile station by using the temporal identification information in each subframe.

10. The mobile communication method according to claim 7, wherein, when the mobile station is in a discontinuous reception state, in the step A, any one of a predetermined number of subframes corresponding to a first half of a reception interval of the mobile station is decided as the specific subframe.

11. The mobile communication method according to claim 7, wherein, in the step A, a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, is allowed to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

12. The mobile communication method according to claim 7, wherein, in the step A, the specific subframe is decided among subframes in which transmission power control commands have been already transmitted, and when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the specific subframe is decided in subframes in which transmission power control commands have not been transmitted.

23. The mobile communication method according to claim 8, wherein,

in the step A, temporal identification information and an index are assigned to the mobile station, the index indicating a multiplexing position of the transmission power control command for the mobile station in the downlink control channel for the transmission power control command mapped to the specific subframe,

in the step B, the transmission power control command for the mobile station is multiplexed to the multiplexing position indicated by the index in the downlink control channel for the transmission power control command mapped to the specific subframe, and an error detecting code, for which a scrambling process has been performed using the temporal identification information, is added to the multiplexing position, and

in the step C, the mobile station attempts to receive a signal on a downlink control channel for a transmission power control command for the mobile station by using the temporal identification information in each subframe.

24. The mobile communication method according to claim 8, wherein, when the mobile station is in a discontinuous reception state, in the step A, any one of a predetermined number of subframes corresponding to a first half of a reception interval of the mobile station is decided as the specific subframe.

25. The mobile communication method according to claim 9, wherein, when the mobile station is in a discontinuous reception state, in the step A, any one of a predetermined number of subframes corresponding to a first half of a reception interval of the mobile station is decided as the specific subframe.

26. The mobile communication method according to claim 8, wherein, in the step A, a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, is allowed to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

27. The mobile communication method according to claim 9, wherein, in the step A, a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, is allowed to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

28. The mobile communication method according to claim 10, wherein, in the step A, a subframe interval, in which the downlink control channel for the transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink data signal of each mobile station is mapped, is allowed to be different from a subframe interval in which a downlink control channel for a transmission power control command for transmitting a transmission power control command for controlling transmission power of an uplink control signal of each mobile station is mapped.

29. The mobile communication method according to claim 8, wherein, in the step A, the specific subframe is decided among subframes in which transmission power control commands have been already transmitted, and when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the specific subframe is decided in subframes in which transmission power control commands have not been transmitted.

30. The mobile communication method according to claim 9, wherein, in the step A, the specific subframe is decided among subframes in which transmission power control commands have been already transmitted, and when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the specific subframe is decided in subframes in which transmission power control commands have not been transmitted.

31. The mobile communication method according to claim 10, wherein, in the step A, the specific subframe is decided among subframes in which transmission power control commands have been already transmitted, and when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the specific subframe is decided in subframes in which transmission power control commands have not been transmitted.

32. The mobile communication method according to claim 11, wherein, in the step A, the specific subframe is decided among subframes in which transmission power control commands have been already transmitted, and when a subframe to be decided as the specific subframe does not exist in the subframes in which the transmission power control commands have been already transmitted, the specific subframe is decided in subframes in which transmission power control commands have not been transmitted.