A method is provided for transmitting a downlink signal by a base station with an antenna array including a plurality of antenna elements in a wireless communication system. The downlink signal is precoded using a precoding matrix for the antenna array. The precoded downlink signal is transmitted to a user equipment (UE). Each element of the precoding matrix is expressed by ∑ n = 1 N ⁢ A n ⁢ ⅇ j ⁢ { ( n - 1 ) ⁢ kd ⁢ ⁢ cos ⁢ ⁢ θ + ϕ n } , where ⁢ ⁢ A n = ( N - 1 ) ! ( N - n ) ! ⁢ ( n - 1 ) ! , N denotes a number of antenna elements, n denotes an index of each of the antenna elements corresponding to 1 to N−1, k denotes a propagation constant, d denotes a distance between the antenna elements, θ denotes an azimuth, ϕ n ⁡ ( y n ) = ϕ set ⁡ ( 2 ⁢ y n ( N - 1 ) ⁢ d ) 2 , yn=(n−(N+1)/2)d, φset denotes a phase value to be applied to an antenna array 1, “!” denotes a symbol of factorial operations, and N! denotes a factorial of a non-negative integer N which is equal to a product of all positive integers less than or equal to N.