A user equipment, UE, for channel state information, CSI, feedback in a wireless communication system, the UE comprising: a transceiver configured to receive, from a base station, BS, CSI feedback configuration information for a pre-coding matrix indicator, PMI, feedback associated with a linear combination, LC, pre-coding matrix that corresponds to a linear combination of a plurality of L beams and a plurality of coefficients, wherein: each of the plurality of coefficients comprises at least an amplitude coefficient and a phase coefficient, the PMI comprises a first PMI i 1 and a second PMI i 2 indicating wideband, WB, and subband, SB, components of the LC pre-coding matrix, respectively, the first PMI i 1 includes first and second sets of indicators indicating common WB components for all layers of at least one layer and independent WB components for each layer of the at least one layer, respectively, and the second PMI i 2 includes a set of indicators indicating independent SB components for each layer of the at least one layer, and the at least one layer is determined based on a value υ associated with a rank indicator, RI; and at least one processor configured to determine the first PMI i 1 and the second PMI i 2, wherein the transceiver is further configured to transmit, to the BS, the CSI feedback including the first PMI i 1 and the second PMI i 2 on an uplink channel, wherein the CSI feedback configuration information includes a number of antenna ports in a first direction, N 1, and a second direction, N 2, a number of beams L, a value of N PSK, configured as one of 4 or 8, for the phase coefficient, and information indicating whether a WB amplitude feedback or a WB and SB amplitude feedback is performed, wherein the L beams are identified by quantities q 1, q 2, n 1, n 2, indicated by the first PMI i 1 where i 1,2 = n 1 n 2 i 1,1 = q 1 q 2 n 1 = n 1 0,..., n 1 L − 1 q 1 ∈ 0,1,..., O 1 − 1 and n 2 = n 2 0,..., n 2 L − 1 q 2 ∈ 0,1,..., O 2 − 1 n 1 i ∈ 0,1,..., N 1 − 1 n 2 i ∈ 0,1,..., N 2 − 1, O 1 and O 2 are oversampling factors in the first and second direction, respectively, of a DFT codebook with O 1 N 1 x O 2 N 2 DFT beams, and in case that ( N 1, N 2) = (2,1), n 1 = [0,1] and n 2 = [0,0], n 1 and n 2 are not reported, in case that ( N 1, N 2) = (4,1) and L = 4, n 1 = [0,1,2,3] and n 2 = [0,0,0,0], n 1 and n 2 are not reported, and in case that ( N 1,N 2) = (2,2) and L = 4, n 1 = [0,0,1,1] and n 2 =[0,1,0,1], n 1 and n 2 are not reported. a transceiver configured to receive, from a base station, BS, CSI feedback configuration information for a pre-coding matrix indicator, PMI, feedback associated with a linear combination, LC, pre-coding matrix that corresponds to a linear combination of a plurality of L beams and a plurality of coefficients, wherein: each of the plurality of coefficients comprises at least an amplitude coefficient and a phase coefficient, the PMI comprises a first PMI i 1 and a second PMI i 2 indicating wideband, WB, and subband, SB, components of the LC pre-coding matrix, respectively, the first PMI i 1 includes first and second sets of indicators indicating common WB components for all layers of at least one layer and independent WB components for each layer of the at least one layer, respectively, and the second PMI i 2 includes a set of indicators indicating independent SB components for each layer of the at least one layer, and the at least one layer is determined based on a value υ associated with a rank indicator, RI; and each of the plurality of coefficients comprises at least an amplitude coefficient and a phase coefficient, the PMI comprises a first PMI i 1 and a second PMI i 2 indicating wideband, WB, and subband, SB, components of the LC pre-coding matrix, respectively, the first PMI i 1 includes first and second sets of indicators indicating common WB components for all layers of at least one layer and independent WB components for each layer of the at least one layer, respectively, and the second PMI i 2 includes a set of indicators indicating independent SB components for each layer of the at least one layer, and the at least one layer is determined based on a value υ associated with a rank indicator, RI; and at least one processor configured to determine the first PMI i 1 and the second PMI i 2, wherein the transceiver is further configured to transmit, to the BS, the CSI feedback including the first PMI i 1 and the second PMI i 2 on an uplink channel, wherein the CSI feedback configuration information includes a number of antenna ports in a first direction, N 1, and a second direction, N 2, a number of beams L, a value of N PSK, configured as one of 4 or 8, for the phase coefficient, and information indicating whether a WB amplitude feedback or a WB and SB amplitude feedback is performed, wherein the L beams are identified by quantities q 1, q 2, n 1, n 2, indicated by the first PMI i 1 where i 1,2 = n 1 n 2 i 1,1 = q 1 q 2 n 1 = n 1 0,..., n 1 L − 1 q 1 ∈ 0,1,..., O 1 − 1 and n 2 = n 2 0,..., n 2 L − 1 q 2 ∈ 0,1,..., O 2 − 1 n 1 i ∈ 0,1,..., N 1 − 1 n 2 i ∈ 0,1,..., N 2 − 1, O 1 and O 2 are oversampling factors in the first and second direction, respectively, of a DFT codebook with O 1 N 1 x O 2 N 2 DFT beams, and in case that ( N 1, N 2) = (2,1), n 1 = [0,1] and n 2 = [0,0], n 1 and n 2 are not reported, in case that ( N 1, N 2) = (4,1) and L = 4, n 1 = [0,1,2,3] and n 2 = [0,0,0,0], n 1 and n 2 are not reported, and in case that ( N 1,N 2) = (2,2) and L = 4, n 1 = [0,0,1,1] and n 2 =[0,1,0,1], n 1 and n 2 are not reported.