Patent ID: 9584203
Date: 2017-02-28
CPC Classifications: H04B,H04L

Claim:
1. A method for transmitting channel status information, CSI, for a downlink transmission through uplink, the method comprising: determining whether to drop a first CSI for a first downlink carrier or a second CSI for a second downlink carrier based on priorities of the first downlink carrier and the second downlink carrier when the transmission time of the first CSI and the second CSI collide with each other; transmitting the first CSI and dropping the second CSI when the first downlink carrier has a higher priority than the second downlink carrier; when the dropped second CSI includes a first type precoding matrix indicator (PMI), generating a first rank indicator (RI), a second type precoding matrix indicator (PMI), and first channel quality indicator (CQI) as a third CSI following a last-transmitted CSI for the second downlink carrier, wherein the second type PMI and the first CQI are generated based on a last-transmitted first type PMI for the second downlink carrier and a rank applied to the last-transmitted first type PMI for the second downlink carrier; and transmitting at least one of the generated first RI, the generated second type PMI and the generated first CQI according to a predetermined order, wherein a precoding matrix used for the second downlink carrier is determined based on a combination of the last-transmitted first type PMI and the transmitted second type PMI.