The invention relates to a method of determining the presence of a telecommunications signal on a frequency band, said signal being assumed cyclostationary, comprising steps of: determining an energy vector {circumflex over (T)} (14) comprising m components respectively representative of energy values of an autocorrelation function of the signal received on said frequency band for m shift times, calculating correlation elements (15) between the m components of the energy vector {circumflex over (T)}, performing a statistical calculation (16) on the correlation elements calculated so as to determine a statistical indicator λ, comparing (17) the statistical indicator obtained λ with a predetermined threshold with the aim of determining the presence of a telecommunications signal on said frequency band.