Patent ID: 8280311

Claim:
A method of determining the presence of a cyclostationary telecommunications signal on a frequency band, said method comprising the steps of: /a/ determining an energy vector {circumflex over (T)} comprising m components respectively representative of energy values of an autocorrelation function of the signal received on said frequency band for m shift times; /b/ calculating correlation elements between the m components of the energy vector {circumflex over (T)}; /c/ performing a statistical calculation on the correlation elements calculated so as to determine a statistical indicator l; and /d/ comparing the statistical indicator obtained l with a predetermined threshold to determine the presence of a telecommunications signal on said frequency band, wherein step /a/ of determining the energy vector {circumflex over (T)} comprises: a sub-step of calculating a first vector with m components Y(n), a component of order n of the vector resulting from the product of the value of the signal received at a given instant n with the value of the signal received at a shifted instant n+τ: a sub-step of determining a filtering function h(n) whose coefficients are obtained on the basis of predetermined frequencies αmin and αmax; and a sub-step of calculating a second vector Z(n) with m components resulting from the convolution product of the filtering function h(n) with the first vector Y(n), wherein the m components of the vector {circumflex over (T)} are dependent on the sum for all the values of n of the product of the value of the component of the vector Y(n) at the instant n with the value of the component of the vector Z(n) at the same instant n.