A method for generating broadcast beam patterns in massive MIMO systems comprising: - defining a sector area of a cell covered by a MIMO transmitter (10, 31), the sector area being where at least one user equipment (12, 34) requests from the MIMO transmitter (10, 31) access to the cell; - generating broadcast beam patterns with determined beam widths in horizontal and vertical dimensions to cover the sector area by a rectangular antenna array (11, 32) of the MIMO transmitter (10, 31), the rectangular antenna array (11, 32) formed by a number N 1 of antenna elements in the horizontal direction and a number N 2 of antenna elements in the vertical direction radiating N 1 ×N 2 radiofrequency signals at a carrier frequency, with inter-antenna spacing in the horizontal and vertical directions given by d x and d y respectively, the beam widths in horizontal and vertical directions being determined by using an optimum set of excitation coefficients; characterized in that the excitation coefficients are calculated by means of the following steps: - discretizing a continuous-space array factor ψ(θ, φ) to obtain a discretized array factor ψ( u k, v l) ≡ ψ kl ∈, formed by a discrete set of complex values ψ kl ∈, k = 0,..., N 1 - 1, l = 0,..., N 2 - 1, where the indices k, I obey to a discretization over the elevation angle θ and the azimuth angle φ of the antenna elements; and - obtaining the optimum set of excitation coefficients { a nm}, in which a nm ∈ are complex excitation coefficients that minimize the following expression: A vec = argmin − H A vec − H Ψ vec, where A vec = a nm, n = 0,..., N 1 − 1, m = 0,..., N 2 − 1 N 1 N 2 × 1, Ψ vec = ψ kl, k = 0,..., N 1 − 1, l = 0,..., N 2 − 1 N 1 N 2 × 1, and H denotes the Shannon entropy for a sequence of N complex numbers { X n} which is defined as: H X = − ∑ n = 0 N − 1 X n 2 ln X n 2. - defining a sector area of a cell covered by a MIMO transmitter (10, 31), the sector area being where at least one user equipment (12, 34) requests from the MIMO transmitter (10, 31) access to the cell; - generating broadcast beam patterns with determined beam widths in horizontal and vertical dimensions to cover the sector area by a rectangular antenna array (11, 32) of the MIMO transmitter (10, 31), the rectangular antenna array (11, 32) formed by a number N 1 of antenna elements in the horizontal direction and a number N 2 of antenna elements in the vertical direction radiating N 1 ×N 2 radiofrequency signals at a carrier frequency, with inter-antenna spacing in the horizontal and vertical directions given by d x and d y respectively, the beam widths in horizontal and vertical directions being determined by using an optimum set of excitation coefficients; characterized in that the excitation coefficients are calculated by means of the following steps: - discretizing a continuous-space array factor ψ(θ, φ) to obtain a discretized array factor ψ( u k, v l) ≡ ψ kl ∈, formed by a discrete set of complex values ψ kl ∈, k = 0,..., N 1 - 1, l = 0,..., N 2 - 1, where the indices k, I obey to a discretization over the elevation angle θ and the azimuth angle φ of the antenna elements; and - obtaining the optimum set of excitation coefficients { a nm}, in which a nm ∈ are complex excitation coefficients that minimize the following expression: A vec = argmin − H A vec − H Ψ vec, where A vec = a nm, n = 0,..., N 1 − 1, m = 0,..., N 2 − 1 N 1 N 2 × 1, Ψ vec = ψ kl, k = 0,..., N 1 − 1, l = 0,..., N 2 − 1 N 1 N 2 × 1, and H denotes the Shannon entropy for a sequence of N complex numbers { X n} which is defined as: H X = − ∑ n = 0 N − 1 X n 2 ln X n 2.