Patent ID: 9648598
Date: 2017-05-09
CPC Classifications: H04L,H04W

Claim:
1. A user terminal that communicates with a radio base station by means of time division duplexing, in a communication band that is broadbanded by carrier aggregation between a first cell and a second cell, the user terminal comprising: a receiving section that receives downlink control information for the first cell and downlink control information for the second cell, allocated to a downlink control channel of the first cell, by cross-carrier scheduling; a retransmission control determining section that determines retransmission control for downlink signals transmitted from each cell; a transmitting section that feeds back retransmission control signals to the radio base station using an uplink control channel of the first cell; and a resource selection section that selects resources for the uplink control channels to feed back the retransmission control signals, wherein, when a ratio of downlink subframes is higher in the second cell than in the first cell, the resource selection section determines the resources for the uplink control channel to allocate the retransmission control signals corresponding to the downlink signals of the first cell to, and the resources for the uplink control channel to allocate the retransmission control signals corresponding to the downlink signals of the second cell to, by different methods, so that these resources are distributed, when determining the resources for the unlink control channels to allocate the retransmission control signals to, using indices m of subframes to feed back the retransmission control signals, the resource selection section makes the indices m of subframes to transmit downlink signals in the first cell and in the second cell the same along a time axis direction, and makes the indices m of subframes to transmit downlink signals from the second cell alone be indices that do not overlap with the indices m assigned to the subframes of the first cell, and wherein the resource selection section selects the resources for the uplink control channel to allocate the retransmission control signals corresponding to the downlink signals of the second cell to, using following equation 2: where: