A base station supporting uplink multiple input multiple output, UL MIMO, the base station comprising: a transceiver; and a controller configured to: transmit downlink control information, DCI, including uplink grant information on a physical downlink control channel, PDCCH; receive, via the transceiver, a physical uplink shared channel, PUSCH based on two transport blocks, TBs, in a first subframe, such transport blocks respectively corresponding to two codewords with indexes q=0 and q=1; transmit, via the transceiver, a hybrid automatic repeat request, HARQ, indicator for the PUSCH on a physical HARQ indicator channel, PHICH, and not transmit DCI on the PDCCH, in a second subframe; and in case that one of the two TBs is negatively acknowledged, receive, via the transceiver, retransmission of a negatively acknowledged TB by using a precoding matrix indicated by a precoding index 0 among a plurality of precoding matrices included in a codebook and a number of transmission layers equal to a number of layers corresponding to the negatively acknowledged TB, wherein an uplink reference signal, RS, is calculated based on a cyclic shift, an orthogonal cover code, OCC, and the number of layers corresponding to the negatively acknowledged TB, and wherein a scrambling sequence for retransmission of the negatively acknowledged TB is generated based on codeword with index q being 0. a transceiver; and a controller configured to: transmit downlink control information, DCI, including uplink grant information on a physical downlink control channel, PDCCH; receive, via the transceiver, a physical uplink shared channel, PUSCH based on two transport blocks, TBs, in a first subframe, such transport blocks respectively corresponding to two codewords with indexes q=0 and q=1; transmit, via the transceiver, a hybrid automatic repeat request, HARQ, indicator for the PUSCH on a physical HARQ indicator channel, PHICH, and not transmit DCI on the PDCCH, in a second subframe; and in case that one of the two TBs is negatively acknowledged, receive, via the transceiver, retransmission of a negatively acknowledged TB by using a precoding matrix indicated by a precoding index 0 among a plurality of precoding matrices included in a codebook and a number of transmission layers equal to a number of layers corresponding to the negatively acknowledged TB, wherein an uplink reference signal, RS, is calculated based on a cyclic shift, an orthogonal cover code, OCC, and the number of layers corresponding to the negatively acknowledged TB, and wherein a scrambling sequence for retransmission of the negatively acknowledged TB is generated based on codeword with index q being 0. transmit downlink control information, DCI, including uplink grant information on a physical downlink control channel, PDCCH; receive, via the transceiver, a physical uplink shared channel, PUSCH based on two transport blocks, TBs, in a first subframe, such transport blocks respectively corresponding to two codewords with indexes q=0 and q=1; transmit, via the transceiver, a hybrid automatic repeat request, HARQ, indicator for the PUSCH on a physical HARQ indicator channel, PHICH, and not transmit DCI on the PDCCH, in a second subframe; and in case that one of the two TBs is negatively acknowledged, receive, via the transceiver, retransmission of a negatively acknowledged TB by using a precoding matrix indicated by a precoding index 0 among a plurality of precoding matrices included in a codebook and a number of transmission layers equal to a number of layers corresponding to the negatively acknowledged TB, wherein an uplink reference signal, RS, is calculated based on a cyclic shift, an orthogonal cover code, OCC, and the number of layers corresponding to the negatively acknowledged TB, and wherein a scrambling sequence for retransmission of the negatively acknowledged TB is generated based on codeword with index q being 0. <EOS>