Base station, terminal, and communication method

1. A base station comprising:

a controller, which, in operation, in a case of communicating with a terminal using a time unit including a downlink time resource for a downlink control signal, a downlink time resource for downlink data assigned by the downlink control signal, and an uplink time resource for a response signal for the downlink data, sets an amount of the uplink time resource per the time unit to be used by the terminal to transmit the response signal, wherein the amount of the uplink time resource is expressed as a number of consecutive symbols, and sets a number of repetitions by which the transmission of the response signal is repeated over a plurality of the time units, wherein the number of consecutive symbols is a fixed value that remains the same value over the plurality of the time units either when the transmission of the response signal is repeated or not repeated over the plurality of the time units;

a transmitter, which, in operation, transmits time unit information including at least one of the amount of the uplink time resource per the time unit and the number of repetitions to be used by the terminal to transmit the response signal; and

a receiver, which, in operation, receives the response signal repeatedly transmitted from the terminal over the plurality of the time units.

2. The base station according to claim 1 , wherein the receiver, in operation, receives the response signal repeatedly transmitted from the terminal over the plurality of the time units at a constant time interval.

3. The base station according to claim 1 , wherein the transmitter, in operation, transmits the time unit information by a cell-specific notification.

4. The base station according to claim 1 , wherein the transmitter, in operation, transmits the time unit information by a radio access technology (RAT)-specific notification.

5. The base station according to claim 1 , wherein the transmitter, in operation, transmits the time unit information by a user equipment (UE)-specific notification.

6. The base station according to claim 1 , wherein the uplink time resource is a physical uplink control channel (PUCCH) resource.

7. A terminal comprising:

a receiver, which, in operation, in a case of communicating with a base station using a time unit including a downlink time resource for a downlink control signal, a downlink time resource for downlink data assigned by the downlink control signal, and an uplink time resource for a response signal for the downlink data, receives time unit information related to an amount of the uplink time resource per the time unit to be used by the terminal to transmit the response signal and a number of repetitions by which the transmission of the response signal is repeated over a plurality of the time units, wherein the amount of the uplink time resource is expressed as a fixed number of consecutive symbols that remains the same number over the plurality of the time units either when the transmission of the response signal is repeated or not repeated over the plurality of the time units; and

a transmitter, which, in operation, transmits the response signal repeatedly over the plurality of the time units.

8. A communication method implemented by a base station, the communication method comprising:

setting, when communicating with a terminal using a time unit including a downlink time resource for a downlink control signal, a downlink time resource for downlink data assigned by the downlink control signal, and an uplink time resource for a response signal for the downlink data, an amount of the uplink time resource per the time unit to be used by the terminal to transmit the response signal, wherein the amount of the uplink time resource is expressed as a number of consecutive symbols, and setting a number of repetitions by which the transmission of the response signal is repeated over a plurality of the time units, wherein the number of consecutive symbols is a fixed value that remains the same value over the plurality of the time units either when the transmission of the response signal is repeated or not repeated over the plurality of the time units;

transmitting time unit information including at least one of the amount of the uplink time resource per the time unit and the number of repetitions to be used by the terminal to transmit the response signal; and

receiving the response signal repeatedly transmitted from the terminal over the plurality of the time units.

9. The communication method according to claim 8 , comprising receiving the response signal repeatedly transmitted from the terminal over the plurality of the time units at a constant time interval.

10. The communication method according to claim 8 , wherein the time unit information is transmitted by a cell-specific notification.

11. The communication method according to claim 8 , wherein the time unit information is transmitted by a radio access technology (RAT)-specific notification.

12. The communication method according to claim 8 , wherein the time unit information is transmitted by a user equipment (UE)-specific notification.

13. A communication method implemented by a terminal, the communication method comprising:

receiving, when communicating with a base station using a time unit including a downlink time resource for a downlink control signal, a downlink time resource for downlink data assigned by the downlink control signal, and an uplink time resource for a response signal for the downlink data, time unit information related to an amount of the uplink time resource per the time unit to be used by the terminal to transmit the response signal and a number of repetitions by which the transmission of the response signal is repeated over the plurality of the time units, wherein the amount of the uplink time resource is expressed as a fixed number of consecutive symbols that remains the same number over the plurality of the time units either when the transmission of the response signal is repeated or not repeated over the plurality of the time units; and

transmitting the response signal repeatedly over the plurality of time units.