A method for transmitting signals in a multi-antenna system, the method being performed by a user equipment, UE, the method comprising: generating a plurality of reference signal sequences to which a plurality of cyclic shift values is respectively applied; generating an orthogonal frequency division multiplexing, OFDM, symbol to which the plurality of reference signal sequences is mapped; and transmitting the OFDM symbol to a base station through a plurality of antennas, wherein the plurality of cyclic shift values is pre-defined based on a 3-bit cyclic shift field transmitted through a physical downlink control channel, PDCCH, wherein a first cyclic shift value and a second cyclic shift value among the plurality of cyclic shift values are separated by 6, wherein the first cyclic shift value is mapped to a layer of an index 1 among the plurality of transmission layers, and wherein the second cyclic shift value is mapped to a layer of an index 2 among the plurality of transmission layers, wherein, when the number of the plurality of transmission layers is 4: a third cyclic shift value and a fourth cyclic shift value among the plurality of cyclic shift values are separated by 6, the third cyclic shift value being mapped to a layer of an index 3 among the plurality of transmission layers, and the fourth cyclic shift value being mapped to a layer of an index 4 among the plurality of transmission layers, and the third cyclic shift value is separated from each of the first cyclic shift value and the second cyclic shift value by 3, and the first, second, third, fourth cyclic shift values are {0, 6, 3, 9}, {6, 0, 9, 3}, {3, 9, 6, 0}, {4, 10, 7, 1}, {2, 8, 5, 11}, {8, 2, 11, 5}, {10, 4, 1, 7} or {9, 3, 0, 6}, respectively, based on the 3-bit cyclic shift field transmitted through the PDCCH, wherein each of the plurality of reference signal sequences is mapped to a second slot of a subframe, wherein a first reference signal sequence, mapped to the layer of the index 1, among the plurality of reference signal sequences and a second reference signal, mapped to the layer of the index 2, among the plurality of reference signal sequences are multiplied by 1, and wherein a third reference signal sequence, mapped to the layer of the index 3, among the plurality of reference signal sequences and a fourth reference signal, mapped to the layer of the index 4, among the plurality of reference signal sequences are multiplied by -1. generating a plurality of reference signal sequences to which a plurality of cyclic shift values is respectively applied; generating an orthogonal frequency division multiplexing, OFDM, symbol to which the plurality of reference signal sequences is mapped; and transmitting the OFDM symbol to a base station through a plurality of antennas, wherein the plurality of cyclic shift values is pre-defined based on a 3-bit cyclic shift field transmitted through a physical downlink control channel, PDCCH, wherein a first cyclic shift value and a second cyclic shift value among the plurality of cyclic shift values are separated by 6, wherein the first cyclic shift value is mapped to a layer of an index 1 among the plurality of transmission layers, and wherein the second cyclic shift value is mapped to a layer of an index 2 among the plurality of transmission layers, wherein, when the number of the plurality of transmission layers is 4: a third cyclic shift value and a fourth cyclic shift value among the plurality of cyclic shift values are separated by 6, the third cyclic shift value being mapped to a layer of an index 3 among the plurality of transmission layers, and the fourth cyclic shift value being mapped to a layer of an index 4 among the plurality of transmission layers, and the third cyclic shift value is separated from each of the first cyclic shift value and the second cyclic shift value by 3, and the first, second, third, fourth cyclic shift values are {0, 6, 3, 9}, {6, 0, 9, 3}, {3, 9, 6, 0}, {4, 10, 7, 1}, {2, 8, 5, 11}, {8, 2, 11, 5}, {10, 4, 1, 7} or {9, 3, 0, 6}, respectively, based on the 3-bit cyclic shift field transmitted through the PDCCH, a third cyclic shift value and a fourth cyclic shift value among the plurality of cyclic shift values are separated by 6, the third cyclic shift value being mapped to a layer of an index 3 among the plurality of transmission layers, and the fourth cyclic shift value being mapped to a layer of an index 4 among the plurality of transmission layers, and the third cyclic shift value is separated from each of the first cyclic shift value and the second cyclic shift value by 3, and the first, second, third, fourth cyclic shift values are {0, 6, 3, 9}, {6, 0, 9, 3}, {3, 9, 6, 0}, {4, 10, 7, 1}, {2, 8, 5, 11}, {8, 2, 11, 5}, {10, 4, 1, 7} or {9, 3, 0, 6}, respectively, based on the 3-bit cyclic shift field transmitted through the PDCCH, wherein each of the plurality of reference signal sequences is mapped to a second slot of a subframe, wherein a first reference signal sequence, mapped to the layer of the index 1, among the plurality of reference signal sequences and a second reference signal, mapped to the layer of the index 2, among the plurality of reference signal sequences are multiplied by 1, and wherein a third reference signal sequence, mapped to the layer of the index 3, among the plurality of reference signal sequences and a fourth reference signal, mapped to the layer of the index 4, among the plurality of reference signal sequences are multiplied by -1.