User terminal, radio base station and radio communication method

A radio base station that communicates with a user terminal that can use a plurality of cells that include cells that use Time Division Duplex (TDD), the radio base station comprising:

• a transmitter that transmits downlink control information comprising:
• first information that indicates a total number of cells to be subjected to DL transmission scheduling in one or more predetermined subframes, and
• second information that indicates a cumulative number of the cells;
• and
• a receiver that receives delivery acknowledgement signals (HARQ-ACKs) transmitted from the user terminal based on the first information and the second information,
• wherein the first information is configured on a per subframe basis, and
• wherein a value of the first information is the same in each of the one or more predetermined subframes.

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

• transmitting delivery acknowledgement signals (HARQ-ACKs) in response to downlink (DL) signals transmitted from a plurality of cells, wherein the plurality of cells include cells that use Time Division Duplex (TDD);
• receiving downlink control information comprising:
• first information that indicates a total number of cells to be subjected to DL transmission scheduling in one or more predetermined subframes, and
• second information that indicates a cumulative number of the cells;
• and
• performing control to transmit the HARQ-ACKs in predetermined uplink (UL) subframes based on the first information and the second information,
• wherein a value of the first information is the same in each of the one or more predetermined subframes, and
• wherein the first information is updated on a per subframe basis.