Communications apparatus and communications system using multicarrier transmission mode

1. A communications system for exchange of information between a base station and a terminal by a multicarrier transmission mode using a plurality of frequency bands, the communication system comprising:

a transmission data generator configured to generate frequency band information indicating which frequency band is to be used for transmission of dedicated user data information between said base station and said terminal;

a transmitter configured to transmit the frequency band information by using a specific frequency band which is set from among a plurality of frequency band assigned to the communications system, and to transmit dedicated user data information by using at least one frequency band set from among said plurality of frequency bands and the specific frequency band at a time; and

a receiver configured to receive the frequency band information by using the specific frequency band, wherein

said specific frequency band also transmits dedicated user data information and said specific frequency band is made variable.

2. The communications system as set forth in claim 1 , wherein

said specific frequency band is selected among said plurality of frequency bands based on a channel quality.

3. The communications system as set forth in claim 1 , wherein

at the time of a new setting of said specific frequency band, a change of the frequency band thereof is notified to the receiver.

4. The communications system as set forth in claim 2 , wherein

said channel quality is measured and the measured channel quality is transmitted to the base station through a control channel of a specific frequency band.

5. The communications system as set forth in claim 2 , wherein

said specific frequency band is selected among said plurality of frequency bands based on a channel quality and individually carried out for each of said plurality of frequency bands.

6. The communications system as set forth in claim 1 , wherein

said specific frequency band is selected based on a channel quality obtained in response to a transmitted pilot channel or pilot signal between said communications apparatuses.

7. The communications system as set forth in claim 2 , wherein

the measurement of said channel quality is sequentially or simultaneously carried out for all of said plurality of frequency bands.

8. A base station for exchange of information with a terminal in a communications system, the base station comprising:

a transmission data generator configured to generate frequency band information indicating which frequency band is to be used for transmission of dedicated user data information between said base station and said terminal; and

a transmitter configured to transmit the frequency band information by using a specific frequency band which is set from among a plurality of frequency band assigned to the communications system, and to transmit dedicated user data information by using at least one frequency band set from among said plurality of frequency bands and the specific frequency band at a time.

9. A terminal for exchange of information with a base station in a communications system, the terminal comprising

a receiver configured to receive frequency band information indicating which frequency band is to be used for transmission of dedicated user data information between the terminal and said base station, wherein,

the frequency band information is generated and notified to the terminal by the base station.

10. A communications system for exchange of information between a base station and a terminal by a multicarrier transmission mode using a plurality of frequency bands, the communication system comprising:

a base station comprising

a transmission data generator configured to generate frequency band information indicating which frequency band is to be used for transmission of dedicated user data information between said base station and said terminal; and

a transmitter configured to transmit the frequency band information by using a specific frequency band which is set from among a plurality of frequency band assigned to the communications system, and to transmit dedicated user data information by using at least one frequency band set from among said plurality of frequency bands and the specific frequency band at a time; and

a terminal comprising a receiver configured to receive the frequency band information by using the specific band,

wherein, said specific frequency band also transmits individual user data information and said specific frequency band is made variable.