Method and apparatus for transmitting channel state information in wireless communication system
摘要
說明書
As described above, CSI in the LTE system includes, but is not limited to, CQI, PMI, and RI. According to transmission mode of each UE, all or some of the CQI, PMI, and RI is transmitted. Periodic transmission of CSI is referred to as periodic reporting and transmission of CSI at the request of an eNB is referred to as aperiodic reporting. In aperiodic reporting, a request bit included in uplink scheduling information transmitted by the eNB is transmitted to the UE. Then, the UE transmits CSI considering transmission mode thereof to the eNB through an uplink data channel (PUSCH). In periodic reporting, a period of CSI and an offset at the period are signaled in the unit of subframes by a semi-static scheme through a higher-layer signal per UE. The UE transmits CSI considering transmission mode to the eNB through an uplink control channel (PUCCH). If there is uplink data in a subframe in which CSI is transmitted, the CSI is transmitted through an uplink data channel (PUSCH) together with the uplink data. The eNB transmits transmission timing information suitable for each UE to the UE in consideration of a channel state of each UE and a UE distributed situation in a cell. The transmission timing information includes a period and an offset necessary for transmitting CSI and may be transmitted to each UE through an RRC message.
