A terminal is disclosed including a receiver that receives a downlink control information; and a processor that determines a first parameter based on a control channel element (CCE) index and a field value in the downlink control information; determines, based on the CCE index, whether a second parameter is the first parameter or a sum of the first parameter and an offset; and determines an initial cyclic shift index for a physical uplink control channel (PUCCH) transmission based on the second parameter. In other aspects, a communication method for a terminal and a base station are disclosed.