User terminal
A user terminal according to the present invention includes: a receiving section that receives a plurality of pieces of downlink control information (DCI) each of which includes a certain field value indicating a same slot for an uplink control channel used for transmission of transmission confirmation information to a plurality of downlink shared channels; and a control section that controls derivation of an index of a control channel element (CCE) used for determination of a resource for the uplink control channel. With this, it is possible to appropriately determine a resource for the uplink control channel.
1. A terminal comprising:
a receiver that receives, in a first symbol, first downlink control information (DCI) scheduling a first physical downlink shared channel (PDSCH) and receives, in a second symbol later than the first symbol, second DCI scheduling a second PDSCH;
a processor that, in response to the first DCI indicating a slot for a transmission of first hybrid automatic repeat request acknowledgement (HARQ-ACK) information corresponding to the first PDSCH and the second DCI indicating the slot for a transmission of second HARQ-ACK information corresponding to the second PDSCH, determines, based on a timing when the second DCI is received, a control channel element (CCE) index, and determines, based on the second symbol of the second DCI and the CCE index, a resource for the transmission of the second HARQ-ACK information,
wherein the processor determines, based on the first symbol and the second symbol, whether the resource is used for the transmission of the first HARQ-ACK information, and
wherein the processor determines, when the resource is used for the transmission of the first HARQ-ACK information, a HARQ-ACK codebook based on a counter downlink assignment index (DAI) counting the first DCI and the second DCI, and a total DAI; and
a transmitter that transmits the first HARQ-ACK information and the second HARQ-ACK information using the determined resource.
2. A radio communication method for a terminal, the method comprising:
receiving, in a first symbol, first downlink control information (DCI) scheduling a first physical downlink shared channel (PDSCH) and receiving, in a second symbol later than the first symbol, second DCI scheduling a second PDSCH;
in response to the first DCI indicating a slot for a transmission of first hybrid automatic repeat request acknowledgement (HARQ-ACK) information corresponding to the first PDSCH and the second DCI indicating the slot for a transmission of second HARQ-ACK information corresponding to the second PDSCH, determining a control channel element (CCE) index based on a timing when the second DCI is received, and determining a resource for the transmission of the second HARQ-ACK information based on the second symbol of the second DCI and the CCE index,
wherein a determination whether the resource is used for the transmission of the first HARQ-ACK information is based on the first symbol and the second symbol, and
wherein the terminal further determines, when the resource is used for the transmission of the first HARQ-ACK information, a HARQ-ACK codebook based on a counter downlink assignment index (DAI) counting the first DCI and the second DCI, and a total DAI; and
transmitting the first HARQ-ACK information and the second HARQ-ACK information using the determined resource.
3. A system comprising a terminal and a base station, wherein the terminal comprises:
a receiver that receives, in a first symbol, first downlink control information (DCI) scheduling a first physical downlink shared channel (PDSCH) and receives, in a second symbol later than the first symbol, second DCI scheduling a second PDSCH;
a processor that, in response to the first DCI indicating a slot for a transmission of first hybrid automatic repeat request acknowledgement (HARQ-ACK) information corresponding to the first PDSCH and the second DCI indicating the slot for a transmission of second HARQ-ACK information corresponding to the second PDSCH, determines, based on a timing when the second DCI is received, a control channel element (CCE) index, and determines, based on the second symbol of the second DCI and the CCE index, a resource for the transmission of the second HARQ-ACK information,
wherein the processor determines, based on the first symbol and the second symbol, whether the resource is used for the transmission of the first HARQ-ACK information, and
wherein the processor determines, when the resource is used for the transmission of the first HARQ-ACK information, a HARQ-ACK codebook based on a counter downlink assignment index (DAI) counting the first DCI and the second DCI, and a total DAI; and
a transmitter that transmits the first HARQ-ACK information and the second HARQ-ACK information using the determined resource, and
the base station comprises:
a transmitter that transmits the first DCI and the second DCI; and
a receiver that receives the first HARQ-ACK information and the second HARQ-ACK information.