A method for generating mutually orthogonal signals having a controlled spectrum, includes the generation of a plurality of mutually orthogonal, controlled-power discrete spectra s(i) having dimension Q, i designating spectrum number. The aforementioned spectra represent time signals in the spectral range and have a modulus μ that is constant in a spectral line designation set G and zero everywhere else. The method includes determining at least part of a complex Hadamard matrix H of order dR=w in the case of spectra of real signals and dR=2.w in the case of spectra of complex signals; determining the extension P of matrix H from G and dimension Q; and obtaining controlled-power spectra s(i)=μ.P(H[.][i]), wherein H[.][i] designates the ith column of matrix H. In addition, a plurality of mutually orthogonal time signals s(i) is also generated from the discrete complex signals.