Terminal, radio communication method, and base station

A terminal comprising:

• 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.

A communication method for a terminal comprising:

• receiving a downlink control information;
• determining a first parameter based on a control channel element (CCE) index and a field value in the downlink control information;
• determining, based on the CCE index, whether a second parameter is the first parameter or a sum of the first parameter and an offset;
• and
• determining an initial cyclic shift index for a physical uplink control channel (PUCCH) transmission based on the second parameter.

A base station comprising:

• a transmitter that transmits a downlink control information;
• and
• a processor that controls receiving of a physical uplink control channel (PUCCH),
• wherein a first parameter is determined based on a control channel element (CCE) index, and a field value in the downlink control information;
• whether a second parameter is the first parameter or is a sum of the first parameter and an offset is determined based on the CCE index;
• and an initial cyclic shift index for the PUCCH is determined based on the second parameter.