| 摘要 |
PROBLEM TO BE SOLVED: To enable a user device to correctly identify a precoding vector used in downlink data transmission and make downlink signaling be efficient, in a mobile communication system using a MIMO method of a precoding type.SOLUTION: A user device comprises: means for receiving a downlink control signal including allocation information on radio resources from a base station device; means for determining a precoding matrix indicator (PMI) showing a precoding matrix applied to a plurality of antennas of the base station device, according to a channel state; and means for transmitting an uplink signal including the PMI to the base station device. When a radio resource is allocated to an uplink physical common channel of the user device, the PMI is transmitted using part of the radio resource. When a radio resource is not allocated to the uplink physical common channel of the user device, the PMI is transmitted using an uplink physical control channel fixedly allocated to the user device. |
