Patent ID: 8660070

Claim:
A base station for a mobile communication system employing orthogonal frequency division multiplexing (OFDM) for downlink and using subframes each including multiple OFDM symbols, the base station comprising: a mapping unit configured to map a control channel to a predetermined number of OFDM symbols from a beginning of each subframe and to map a data channel to OFDM symbols that follow the OFDM symbols to which the control channel is mapped; and a transmitting unit configured to transmit the control channel and the data channel mapped by the mapping unit, wherein multiple control resource blocks are multiplexed in the control channel mapped by the mapping unit and each of the control resource blocks is mapped to every one of the OFDM symbols to which the control channel is mapped; and a fixed transmission format is used for transmission of the control channel to some user devices in a cell and various transmission formats are used for transmission of the control channel to other user devices in the cell.