Mobile station, base station, uplink transmission method, and downlink transmission method

1. A mobile station, comprising:

a channel quality estimation unit configured to estimate downlink channel quality based on a signal from a base station and to output the estimated downlink channel quality as channel estimation information;

an acknowledgement information determining unit configured to determine whether a downlink data channel from the base station is correctly received and to output the determination result as acknowledgement information; and

an acknowledgement information prioritizing unit configured to cause the acknowledgement information to be preferentially transmitted to the base station if transmission timings of the channel estimation information and the acknowledgement information coincide, wherein

the acknowledgement information prioritizing unit is connected to the channel quality estimation unit and the acknowledgement information determining unit; and

when receiving the channel estimation information and the acknowledgement information in a same subframe, the acknowledgement information prioritizing unit is configured to discard the channel estimation information.

2. An uplink transmission method performed by a mobile station, the method comprising the steps of:

estimating downlink channel quality based on a signal from a base station and outputting the estimated downlink channel quality as channel estimation information;

determining whether a downlink data channel from the base station is correctly received and outputting the determination result as acknowledgement information; and

if transmission timings of the channel estimation information and the acknowledgement information coincide, preferentially transmitting the acknowledgement information to the base station, wherein

an acknowledgement information prioritizing unit is connected to a channel quality estimation unit and a acknowledgement information determining unit; and

when receiving the channel estimation information and the acknowledgement information in a same subframe, the acknowledgement information prioritizing unit discards the channel estimation information.

3. A communication system, comprising:

a base station; and

a mobile station communicating with the base station, wherein the mobile station includes:

a channel quality estimation unit configured to estimate downlink channel quality based on a signal from the base station and to output the estimated downlink channel quality as channel estimation information;

an acknowledgement information determining unit configured to determine whether a downlink data channel from the base station is correctly received and to output the determination result as acknowledgement information; and

an acknowledgement information prioritizing unit configured to cause the acknowledgement information to be preferentially transmitted to the base station if transmission timing of the channel estimation information and the acknowledgement information coincide, wherein

the acknowledgement information prioritizing unit is connected to the channel quality estimation unit and the acknowledgement information determining unit; and

when receiving the channel estimation information and the acknowledgement information in a same subframe, the acknowledgement information prioritizing unit is configured to discard the channel estimation information.

4. A mobile station, comprising:

a channel quality estimation unit configured to estimate downlink channel quality based on a signal from a base station and to output the estimated downlink channel quality as channel estimation information;

an acknowledgement information determining unit configured to determine whether a downlink data channel from the base station is correctly received and to output the determination result as acknowledgement information; and

a transmitting unit configured to transmit the channel estimation information output from the channel quality estimation unit and the acknowledgement information output from the acknowledgement information determining unit via one of a PUCCH and a PUSCH, wherein

when transmission timing of the channel estimation information and the acknowledgement information coincide in a same subframe and the PUCCH is used, the transmitting unit preferentially includes the acknowledgement information in the PUCCH; and

when transmission timings of the channel estimation information and the acknowledgement information coincide in the same subframe and the PUSCH is used, the transmitting unit includes the channel estimation information in the PUSCH.

5. The mobile station as claimed in claim 4 , wherein

the transmitting unit is connected to the channel quality estimation unit and the acknowledgement information determining unit; and

when the channel estimation information and the acknowledgement information are received in the same subframe, the transmitting unit discards the received channel estimation information.

6. The mobile station as claimed in claim 4 , wherein

the transmitting unit is connected to the channel quality estimation unit and the acknowledgement information determining unit; and

when the acknowledgement information and the channel estimation information are received in a same subframe, the transmitting unit sequentially outputs the acknowledgement information and the channel estimation information such that the channel estimation information is transmitted after a predetermined number of subframes from when the acknowledgement information is transmitted.

7. An uplink transmission method performed by a mobile station communicating with a base station, the method comprising the steps of:

estimating downlink channel quality based on a signal from the base station and outputting the estimated downlink channel quality as channel estimation information;

determining whether a downlink data channel from the base station is correctly received and outputting the determination result as acknowledgement information; and

transmitting the channel estimation information and the acknowledgement information via one of a PUCCH and a PUSCH, wherein

when transmission timing of the channel estimation information and the acknowledgement information coincide in a same subframe and the PUCCH is used, the acknowledgement information is preferentially included in the PUCCH in the transmitting step; and

when transmission timings of the channel estimation information and the acknowledgement information coincide in the same subframe and the PUSCH is used, the channel estimation information and the acknowledgement information are included in the PUSCH in the transmitting step.

8. A communication system, comprising:

a base station; and

a mobile station communicating with the base station, wherein the mobile station includes:

a channel quality estimation unit configured to estimate downlink channel quality based on a signal from the base station and to output the estimated downlink channel quality as channel estimation information;

an acknowledgement information determining unit configured to determine whether a downlink data channel from the base station is correctly received and to output the determination result as acknowledgement information; and

a transmitting unit configured to transmit the channel estimation information output from the channel quality estimation unit and the acknowledgement information output from the acknowledgement information determining unit via one of a PUCCH and a PUSCH, wherein

when transmission timing of the channel estimation information and the acknowledgement information coincide in a same subframe and the PUCCH is used, the transmitting unit preferentially includes the acknowledgement information in the PUCCH; and

when transmission timings of the channel estimation information and the acknowledgement information coincide in the same subframe and the PUSCH is used, the transmitting unit includes the channel estimation information in the PUSCH.