User terminal, radio base station and radio communication method

A radio base station comprising:

• a transmission section that transmits a DL signal to a user terminal;
• and
• a receiving section that receives a delivery acknowledgement signal in response to the DL signal,
• wherein the transmission section transmits information on whether or not transmission of the delivery acknowledgement signal is possible in higher layer signaling and/or in downlink control information.

A radio communication method for a user terminal that communicates with a radio base station, the radio communication method comprising the steps of:

• a receiving section that receives a DL signal;
• and
• a control section that controls transmission of a delivery acknowledgement signal in response to the DL signal, wherein:
• the control section controls whether or not the delivery acknowledgement signal can be transmitted based on information on reported in higher layer signaling and/or in downlink control information.