Patent attributes
The present invention provides a search space configuration that is suitable for a communication system in which a plurality of fundamental frequency blocks are grouped together into a wide band. A base station apparatus (20) has a selection section (302) that selects a system band in fundamental frequency block units, a downlink control information generation section (306) that generates downlink control information for demodulating the data channels that are sent separately in the selected fundamental frequency blocks, and arranges, in the downlink control channel of a specific fundamental frequency block among a plurality of fundamental frequency blocks, a search space in which downlink control information for the plurality of fundamental frequency blocks is contained, and a transmission section (203) that transmits the downlink control channel in which the search space with the downlink control information is arranged.