A method for indicating a De Modulation Reference Signal, DMRS, applying to a Base Station, BS, , the method comprising: allocating DMRS configuration parameters comprising a designated DMRS port, a number of layers, and a length of Orthogonal Cover Codes, OCC, to User Equipment, UE, , according to a table of DMRS configuration parameters, wherein the table of DMRS configuration parameters comprises entries indicating DMRS configuration parameters of combinations of at least two lengths of OCCs; and sending a DMRS indication, wherein the DMRS indication is generated corresponding to information on the DMRS configuration parameters allocated to the UE , wherein the information on the DMRS configuration parameters comprises the length of the OCCs, wherein the table of DMRS configuration parameters comprises entries indicating DMRS configuration parameters for one-codeword transmission and entries indicating DMRS configuration parameters for two-codeword transmission, wherein the entries indicating DMRS configuration parameters for one-codeword transmission comprise four entries indicating DMRS configuration parameters for one-layer transmission with a length of the OCCs of 2, eight entries indicating DMRS configuration parameters for one-layer transmission with a length of the OCCs of 4, three entries indicating DMRS configuration parameters for two-layer to four-layer retransmission with the length of the OCCs of 4, and a reserved entry, wherein the entries indicating DMRS configuration parameters for two-codeword transmission comprise two entries indicating DMRS configuration parameters for two-layer transmission with the length of the OCCs of 2, four entries indicating DMRS configuration parameters for two-layer transmission with the length of the OCCs of 4, six entries indicating DMRS configuration parameters for Single-User, SU, three-layer to eight-layer transmission with the length of the OCCs of 4, and a reserved entry. allocating DMRS configuration parameters comprising a designated DMRS port, a number of layers, and a length of Orthogonal Cover Codes, OCC, to User Equipment, UE, , according to a table of DMRS configuration parameters, wherein the table of DMRS configuration parameters comprises entries indicating DMRS configuration parameters of combinations of at least two lengths of OCCs; and sending a DMRS indication, wherein the DMRS indication is generated corresponding to information on the DMRS configuration parameters allocated to the UE , wherein the information on the DMRS configuration parameters comprises the length of the OCCs, wherein the table of DMRS configuration parameters comprises entries indicating DMRS configuration parameters for one-codeword transmission and entries indicating DMRS configuration parameters for two-codeword transmission, wherein the entries indicating DMRS configuration parameters for one-codeword transmission comprise four entries indicating DMRS configuration parameters for one-layer transmission with a length of the OCCs of 2, eight entries indicating DMRS configuration parameters for one-layer transmission with a length of the OCCs of 4, three entries indicating DMRS configuration parameters for two-layer to four-layer retransmission with the length of the OCCs of 4, and a reserved entry, wherein the entries indicating DMRS configuration parameters for two-codeword transmission comprise two entries indicating DMRS configuration parameters for two-layer transmission with the length of the OCCs of 2, four entries indicating DMRS configuration parameters for two-layer transmission with the length of the OCCs of 4, six entries indicating DMRS configuration parameters for Single-User, SU, three-layer to eight-layer transmission with the length of the OCCs of 4, and a reserved entry. <EOS>