A base station able to maintain backward compatibility with an LTE mobile station while minimizing the amount of increase in uplink scheduling information reception and demodulation/decoding processing in independent uplink/downlink cell data transmission. A wireless communication system includes a cell #1, a cell #2, and an LTE-A mobile station, and supports independent uplink/downlink cell data transmission. The base station of the cell #2 arranges a PDCCH+, which includes uplink scheduling information from the LTE-A mobile station to the base station of the cell #2, in a downlink data region in the downlink connection of the base station of the cell #1.