Abstract: The invention relates to a process for detection of a signal in a frequency sub-band of a frequency band of an acquired signal y(t), the process comprising: acquisition of the signal y(t) in a frequency band; frequential analysis of said acquired signal y(t) to obtain at least one frequential signal Y with NFFT frequential components; breakdown into M frequency sub-bands i of size N of the frequential signal Y, the size of each frequency sub-band being a function of the bandwidth of the signal to be detected; determination, in the frequential domain, for each frequency sub-band, of a criterion Ti, i=1, . . . , M as a function of the energy of the signal in the frequency sub-band i and of the coefficient two of the autocorrelation function of the signal in the frequency sub-band i; decision, as a function of the criterion Ti, to determine whether a signal is detected in the sub-band i.

Abstract: A method of identifying an RF signal for a cognitive radio system. The signal is identified with a digital watermarking performed downstream from the digital modulation of the symbols to be transmitted. A method of detecting an RF signal watermarked is also disclosed. The identification method includes demodulating the received RF signal as a baseband, converting it digitally, and correlating the digital signal obtained with a predetermined digital signature. The correlation values are averaged using a recursive filter and the maximum value of the average values output from the filter is compared to a threshold to decide whether the RF signal is present.

Abstract: A method of identifying an RF signal for a cognitive radio system. The signal is identified with a digital watermarking performed downstream from the digital modulation of the symbols to be transmitted. A method of detecting an RF signal watermarked is also disclosed. The identification method includes demodulating the received RF signal as a baseband, converting it digitally, and correlating the digital signal obtained with a predetermined digital signature. The correlation values are averaged using a recursive filter and the maximum value of the average values output from the filter is compared to a threshold to decide whether the RF signal is present.