The present disclosure proposes a channel quality indicator (CQI) feedback method applicable to a user equipment (UE) using the same method. According to one of the exemplary embodiments, the channel quality indicator (CQI) feedback method would be applicable to a user equipment (UE) and would include steps of at least but not limited to receiving a N×L precoding matrix having N rows and L columns with each of the N rows corresponding to an antenna port and each of the L columns corresponding to a user, wherein N and L are both integers greater than one, performing a channel quality indicator (CQI) calculation for K of the L columns, where 0