USER TERMINAL, RADIO BASE STATION AND RADIO COMMUNICATION METHOD
The present invention is designed to suitably realize UCI (Uplink Control Information) transmission at a desired timing in a carrier where LBT (Listen Before Talk) is configured. A user terminal, according to one embodiment of the present invention, has a transmission section that transmits signals in carriers where listening is performed before uplink transmission, a receiving section that receives PUCCH cell configuration information as to whether or not at least one of the carriers is a cell where a PUCCH (Physical Uplink Control Channel) is transmitted, and a control section that controls the transmission of uplink control information (UCI) in the carriers based on the PUCCH cell configuration information.
1 . A user terminal comprising:
a transmission section that transmits signals in carriers where listening is performed before uplink transmission;
a receiving section that receives PUCCH cell configuration information as to whether or not at least one of the carriers is a cell where a PUCCH (Physical Uplink Control Channel (PUCCH) is transmitted; and
a control section that controls transmission of uplink control information (UCI) in the carriers based on the PUCCH cell configuration information.
2 . The user terminal according to claim 1 , wherein:
the transmission section transmits terminal capability information as to whether or not PUCCH formats 4 and/or 5 are supported in at least one of the carriers; and
the terminal capability information is used to control whether or not at least one of the carriers is the cell where the PUCCH is transmitted.
3 . The user terminal according to claim 1 , wherein
the receiving section receives information as to whether or not simultaneous transmission of the PUCCH and a Physical Uplink Shared Channel (PUSCH) is possible, and
the control section, when determining that at least one of the carriers is the cell where the PUCCH is transmitted, controls the transmission of the UCI in the carriers based on the information as to whether or not the simultaneous transmission is possible.
4 . The user terminal according to claim 3 , wherein
the control section controls the UCI to be retained for a predetermined period, and the transmission section simultaneously transmits a plurality of UCIs pertaining to the carriers and retained, in at least one of the carriers.
5 . The user terminal according to claim 1 , wherein
the receiving section receives information about UCI transmission modes for specifying whether UCI of each carrier is transmitted in a carrier where listening is not carried out before uplink transmission, or in a carrier where listening is performed before uplink transmission, and
the control section, when determining that none of the carriers is the cell where the PUCCH is transmitted, controls the transmission of UCI in the carriers based on the information about UCI transmission modes.
6 . The user terminal according to claim 5 , wherein
the control section exerts control so that the UCI is retained for a first retention period before downlink control information for transmitting the UCI in the Physical Uplink Shared Channel (PUSCH) is received, and retained for a second retention period after the downlink control information is received, and
the transmission section simultaneously transmits a plurality of UCIs pertaining to the carriers and retained, in at least one of the carriers, in the PUSCH.
7 . (canceled)
8 . A radio communication method comprising the steps of:
transmitting signals in carriers where listening is performed before uplink transmission;
receiving PUCCH cell configuration information as to whether or not at least one of the carriers is a cell where a Physical Uplink Control Channel (PUCCH) is transmitted; and
controlling transmission of uplink control information (UCI) in the carriers based on the PUCCH cell configuration information.
9 . A user terminal comprising:
a receiving section that receives downlink signals;
a transmission section that transmits retransmission control information in response to the downlink signals in carries where listening is performed before transmission; and
a control section that determines a codebook size to use to transmit the retransmission control information based on a retention period for the retransmission control information.