Base station and method

• US 8,345,706 B2
• Filed: 06/19/2007
• Issued: 01/01/2013
• Est. Priority Date: 06/19/2006
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Harada, Atsushi, Ishii, Minami, Abeta, Sadayuki
• Primary Examiner(s): Thier, Michael
• Assistant Examiner(s): Alia, Curtis A
• Application Number:
  US12/305,921
• Publication Number:
  US 20100232303A1
• Time in Patent Office: 2,023 Days
• Field of Search: 370/310, 370/329, 370/348, 370/431, 370/437, 370441-443, 370/464, 455/73, 455/561, 455/13.4, 455/522, 455/127.1
• US Class Current: 370/464
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0033 arrangements specific to the transmitter
• CPC Class Codes: H04L 1/1664 the supervisory signal being transmitted together with payload signals; piggybacking
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A base station (eNodeB) performing a radio communication with a user equipment (UE) includes: a transmission format determining unit (16) configured to determine a transmission format of a downlink data channel not to be associated by a control channel, based on a downlink reception signal quality measured by the user equipment; a notification unit (18) configured to notify, to the user equipment, the transmission format determined by the transmission format determining unit; a transmission power controlling unit (19) configured to control a transmission power of the downlink data channel; and a transmitting unit (18) configured to transmit downlink data to the user equipment via the downlink data channel, by using the transmission format determined by the transmission format determining unit.

Claims

1. A base station performing a radio communication with a user equipment and being included in a mobile communication system transmitting downlink data to be transmitted periodically in accordance with a persistent scheduling via a downlink data channel not associated by a control channel notifying a modulation method and a channel coding ratio applied to the user equipment, by using a transmission format including the modulation method and the channel coding ratio known to the user equipment, the base station comprising:

a processor executing instructions that cause the base station to;

determine the transmission format including the modulation method and the channel coding ratio known to the user equipment, based on a downlink reception signal quality measured by the user equipment;

change the transmission format of the downlink data channel, based on the downlink reception signal quality multiplexed on a response signal for the downlink data channel, the response signal being transmitted from the user equipment;

notify, to the user equipment, the determined transmission format;

control a transmission power of the downlink data channel;

transmitter configured to transmit the downlink data to the user equipment via the downlink data channel, by using the determined transmission format and

wherein the notifying further comprises transmitting the downlink data via the downlink data channel in a first cyclic period, so as to notify, to the user equipment, the changed transmission format by using the control channel in a second cyclic period longer than the first cyclic period.

2. The base station according to claim 1, wherein the processor is further configured to notify, to the user equipment, the determined transmission format by using an RRC (radio resource control) signaling message.

3. The base station according to claim 1, wherein the processor is further configured to notify, to the user equipment, the determined transmission format by using an MAC (media access control) control protocol data unit.

4. The base station according to claim 1, wherein the processor is further configured to control the transmission power of the control channel.

5. The base station according to claim 1, wherein the processor is further configured to determine the transmission format of the downlink data channel, based on the downlink reception signal quality multiplexed on an uplink data channel transmitted at a fixed timing in an uplink.

6. A method used in a base station performing a radio communication with a user equipment being included in a mobile communication system transmitting downlink data to be transmitted periodically in accordance with a persistent scheduling via a downlink data channel not associated by a control channel notifying a modulation method and a channel coding ratio applied to the user equipment, by using a transmission format including the modulation method and the channel coding ratio known to the user equipment, the method comprising:

determining the transmission format including the modulation method and the channel coding ratio known to the user equipment, based on a downlink reception signal quality measured by the user equipment;

changing the transmission format of the downlink data channel, based on the downlink reception signal quality multiplexed on a response signal for the downlink data channel, the response signal being transmitted from the user equipment;

notifying, to the user equipment, the determined transmission format;

controlling a transmission power of the downlink data channel; and

transmitting downlink data to the user equipment via the downlink data channel, by using the determined transmission format, wherein the downlink data is transmitted via the downlink data channel in a first cyclic period and notifying, to the user equipment, the changed transmission format by using the control channel in a second cyclic period longer than the first cyclic period.