Patent ID: 8675745

Claim:
A method for detecting a presence of an OFDM signal, said method comprising: obtaining a signal; subjecting said signal to a frequency down converting into baseband, passband filtering corresponding to a band of interest before being sampled, and then sampling to generate a sampled signal; determining interfering line(s) by calculating a spectral density of the sampled signal, a mean value m and a variance σ 2 of this spectral density, and obtaining points on the spectrum for which the spectral density is greater than m+λσ 2 , where λ is greater than 1; obtaining elementary transfer functions of a set of band-stop filters by determining for each point x in the spectrum whereof the spectral density value exceeds m+λσ 2 , the first point to the right thereof, x + =x+ε d , and the first point to the left thereof x − =x−ε g for which the spectral density value is equal to m, the corresponding elementary transfer function being adapted to reject the frequency band [x − x + ]; subjecting the thus sampled signal to a second filtering by using said set of band-stop filters for eliminating the interfering line(s) in the band of interest; and detecting the presence of an OFDM signal by checking whether the signal filtered by the second filtering is cyclostationary.