Base station, communication terminal, transmission method, and reception method

A transmission method used by a base station employing a multicarrier scheme and designed to perform frequency scheduling, the method comprising the steps of:

• receiving channel condition information from communication terminals and generating scheduling information to allocate one or more of resource blocks each including one or more subcarriers to each of selected ones of the communication terminals having good channel conditions based on the channel condition information;
• encoding and modulating control channels including a general control channel to be decoded by the communication terminals and specific control channels to be decoded by the selected ones of the communication terminals that are allocated one or more of the resource blocks, wherein the general control channel is encoded separately for the respective communication terminals;
• time-division-multiplexing the general control channel and the specific control channels according to the scheduling information;
• and
• transmitting the time-division-multiplexed signal according to the multicarrier scheme.

A communication terminal used in a communication system where a multicarrier scheme is employed and frequency scheduling is performed, the communication terminal comprising:

• a receiving unit configured to receive control channels including a general control channel to be decoded by communication terminals and specific control channels to be decoded by selected ones of the communication terminals to each of which one or more resource blocks are allocated;
• a separating unit configured to separate the general control channel and the specific control channels that are time-division-multiplexed;
• a control channel decoding unit configured to decode the general control channel and to decode a corresponding one of the specific control channels that is mapped to the one or more of the resource blocks allocated to the own communication terminal based on resource block allocation information in the general control channel;
• and
• a data channel decoding unit configured to decode a data channel transmitted using the one or more of the resource blocks allocated to the own communication terminal.

A reception method used by a communication terminal in a communication system where a multicarrier scheme is employed and frequency scheduling is performed, the method comprising the steps of:

• receiving control channels including a general control channel to be decoded by communication terminals and specific control channels to be decoded by selected ones of the communication terminals to each of which one or more resource blocks are allocated;
• separating the general control channel and the specific control channels that are time-division-multiplexed;
• decoding the general control channel and decoding a corresponding one of the specific control channels that is mapped to the one or more of the resource blocks allocated to the own communication terminal based on resource block allocation information in the general control channel;
• and
• decoding a data channel transmitted using the one or more of the resource blocks allocated to the own communication terminal.