Method and apparatus for feeding back channel state information, user pairing method and apparatus, data transmitting method and apparatus and system

A user pairing apparatus in multi-user superposition transmission (MUST), applicable to an eNB, the apparatus comprising:

• a receiving unit configured to receive channel state information fed back by each UE;
• wherein, the channel state information fed back by each UE comprises:
• a precoding matrix index (PMI), a first channel quality indicator (CQI1) corresponding to the PMI, and azimuth angle reference information, or comprises:
• a precoding matrix index (PMI), a first channel quality indicator (CQI1) corresponding to the PMI, indication information of a second channel quality indicator (CQI2) corresponding to a channel direction indicator (CDI), and azimuth angle reference information;
• a grouping unit configured to group all UEs according to the precoding matrix indices (PMIs) in the channel state information fed back by the UEs, placing UEs with identical PMIs into the same group;
• and
• an evaluating unit configured to, according to a predefined evaluation condition, evaluate whether any two of UEs in the same group can be paired to perform MUST transmission, so as to determine a UE pair capable of being paired to perform MUST transmission.

A data transmitting apparatus, applicable to an eNB, the apparatus comprising:

• a pairing unit configured to pair all UEs according to channel state information fed back by the UEs, so as to determine a UE pair capable of performing MUST transmission and UE(s) incapable of performing MUST transmission;
• a first scheduling unit configured to, for the UE pair capable of performing MUST transmission, schedule two UEs constituting the UE pair to perform MUST transmission according to the channel state information fed back by the two UEs;
• and
• a second scheduling unit configured to, for the UE(s) incapable of performing MUST transmission, schedule the UE(s) to perform transmission according to the channel state information fed back by the UE(s);
• wherein, the channel state information fed back by each UE comprises:
• a precoding matrix index (PMI), a first channel quality indicator (CQI1) corresponding to the PMI, and azimuth angle reference information, or comprises:
• a precoding matrix index (PMI), a first channel quality indicator (CQI1) corresponding to the PMI, indication information of a second channel quality indicator (CQI2) corresponding to a channel direction indicator (CDI), and azimuth angle reference information.