A base station is disclosed including a processor that maps one or more control channel elements (CCEs) in a downlink control channel to one or more resource units that are obtained by an interleaver for interleaving indexes of a plurality of resource units in a control resource set, and a transmitter transmits the downlink control channel. Each of the one or more resource units are being defined as a plurality of resource element groups (REGs). A transmitter transmits the downlink control channel. In other aspects, a terminal and a radio communication method are disclosed.