A method of a transmission apparatus in a wireless communication system, the method comprising: transmitting, through a first antenna, a first channel estimation field, CEF,, wherein: the first CEF sequentially comprises -Ga128, Gu512, Gv512, and -Gb128, the Gu512 sequentially comprises -Gb128, -Ga128, Gb128, and -Ga128, and the Gv512 sequentially comprises -Gb128, Ga128, -Gb128, and -Ga128; and transmitting, through a second antenna, a second CEF (810, 820), wherein: the second CEF sequentially comprises -Ga 128, G u512, G v512, and -Gb 128, the G u512 sequentially comprises -Gb 128, -Ga 128, Gb 128, and-Ga 128, and the G v512 sequentially comprises -Gb 128, Ga 128, -Gb 128, and-Ga 128, wherein the Ga128(k) is a golay sequence of length 128 equal to A 7 (128-k) and is generated based on a first seed and a common seed, wherein the Gb128(k) is a golay sequence of length 128 equal to B 7 (128-k) and is generated based on the first seed and the common seed, wherein the Ga 128(k) is a golay sequence of length 128 equal to A 7 (128-k) and is generated based on a second seed and the common seed, wherein the Gb 128(k) is a golay sequence of length 128 equal to B 7 (128-k) and is generated based on the second seed and the common seed, wherein the A 7 (128-k) and the B 7 (128-k) are generated based on a following recursive procedure: A 0 k = δ k. B 0 k = δ k; A n k = W n A n − 1 k + B n − 1 k − D n; and B n k = W n A n − 1 k − B n − 1 k − D n wherein, n=1, 2,..., N, represents a number of iterations, and k=0, 1,..., 2 N -1, δ(k) represents a delta function, D n represents an n th element of the common seed, and W n represents an n th element of the first seed or the second seed, wherein the common seed comprises a vector D=[1, 8, 2, 4, 16, 32, 64], and wherein the first seed comprises a vector W=[-1, -1, -1, -1, +1, -1 -1] for the first antenna and the second seed comprises a vector W=[1, -1, -1, -1, 1, -1 -1] for the second antenna. transmitting, through a first antenna, a first channel estimation field, CEF,, wherein: the first CEF sequentially comprises -Ga128, Gu512, Gv512, and -Gb128, the Gu512 sequentially comprises -Gb128, -Ga128, Gb128, and -Ga128, and the Gv512 sequentially comprises -Gb128, Ga128, -Gb128, and -Ga128; and the first CEF sequentially comprises -Ga128, Gu512, Gv512, and -Gb128, the Gu512 sequentially comprises -Gb128, -Ga128, Gb128, and -Ga128, and the Gv512 sequentially comprises -Gb128, Ga128, -Gb128, and -Ga128; and transmitting, through a second antenna, a second CEF (810, 820), wherein: the second CEF sequentially comprises -Ga 128, G u512, G v512, and -Gb 128, the G u512 sequentially comprises -Gb 128, -Ga 128, Gb 128, and-Ga 128, and the G v512 sequentially comprises -Gb 128, Ga 128, -Gb 128, and-Ga 128, the second CEF sequentially comprises -Ga 128, G u512, G v512, and -Gb 128, the G u512 sequentially comprises -Gb 128, -Ga 128, Gb 128, and-Ga 128, and the G v512 sequentially comprises -Gb 128, Ga 128, -Gb 128, and-Ga 128, wherein the Ga128(k) is a golay sequence of length 128 equal to A 7 (128-k) and is generated based on a first seed and a common seed, wherein the Gb128(k) is a golay sequence of length 128 equal to B 7 (128-k) and is generated based on the first seed and the common seed, wherein the Ga 128(k) is a golay sequence of length 128 equal to A 7 (128-k) and is generated based on a second seed and the common seed, wherein the Gb 128(k) is a golay sequence of length 128 equal to B 7 (128-k) and is generated based on the second seed and the common seed, wherein the A 7 (128-k) and the B 7 (128-k) are generated based on a following recursive procedure: A 0 k = δ k. B 0 k = δ k; A n k = W n A n − 1 k + B n − 1 k − D n; and B n k = W n A n − 1 k − B n − 1 k − D n wherein, n=1, 2,..., N, represents a number of iterations, and k=0, 1,..., 2 N -1, δ(k) represents a delta function, D n represents an n th element of the common seed, and W n represents an n th element of the first seed or the second seed, wherein the common seed comprises a vector D=[1, 8, 2, 4, 16, 32, 64], and wherein the first seed comprises a vector W=[-1, -1, -1, -1, +1, -1 -1] for the first antenna and the second seed comprises a vector W=[1, -1, -1, -1, 1, -1 -1] for the second antenna.