Method and device for eliminating interference signals in a direct sequence spread spectrum link

Device for eliminating interference signals in a direct sequence spread spectrum link, which comprises:

• a first serial-parallel conversion module for blocks of size M, in which there is an overlapping of the blocks by M/2, which receives a complex input signal (S.sub.E (n)),
• a second discrete Fourier transformation module using a direct, complex, fast Fourier transform, on blocks of size M, to thus pass into the frequency domain, which receives the phase output (Phs) and amplitude output (Magnetic) from the first module,
• a third inverse Fourier transformation module using an inverse fast Fourier transform, on blocks of size M, receiving the amplitude and phase outputs from the second module,
• a fourth parallel-serial conversion module for blocks of size M, with rejection of M/2 samples of the ends of the block obtained, which supplies a complex output signal S.sub.s (n),
• a fifth module for generating a time truncation window supplied to an input of a first vector multiplier, positioned between the amplitude output of the first module and the amplitude input of the second module,
• a comparator of the module of each discrete spectral sample with a threshold for producing a jig for the location of the interference signals (Gb(k)), which receives the amplitude signal at the output of the second module as well as a threshold signal,
• a band pass, finite impulse response filter, whose output is supplied to a second vector multiplier, which also receives the output of the comparator and whose output is supplied to a third vector multiplier between the amplitude output of the second module and the amplitude input of the third module,
• an estimator of the optimum threshold such that:
• ##EQU42## a module for averaging on P consecutive blocks such that:
• ##EQU43## an estimator of the optimum threshold such that:
• Seuil Opt=S.sub.tot +.DELTA.Opt.