1. A method of fighting interference in a frequency-hopping communication system, the system comprising at least one main sensor and one or more auxiliary sensors, the method comprising: receiving frequency-hopping signals, the frequency-hopping signals being arranged to include useful bands and one or more guard bands inserted between the useful bands, a ratio of the useful bands to the one or more guard bands being chosen according to a predetermined value of probability of interference interception, a first number of bands including the useful bands and the one or more guard bands being grouped as an extended block, and a number of contiguous extended blocks being grouped as a time slot; selecting signals of the inserted one or more guard bands having a signal level greater than a predetermined threshold; calculating a set of spatial-filtering weightings, for the time slot, according to a correlation matrix of noise plus jammers alone on the signals selected; and filtering, by the set of the calculated spatial-filtering weightings, baseband signals of the received frequency-hopping signals, wherein a number and a position of the one or more guard bands inserted between the useful bands are chosen so as to discriminate useful emitters from the interference and so as to guarantee the probability of interference interception in PB max % of cases if a waveform tolerates (100−PB max )% of jammed time slots, wherein the insertion of the one or more guard bands comprises: spectrally inserting at least one first guard band of the one or more guard bands, between each useful bands, at a boundary and in common to neighboring extended blocks, and at a start and at an end of the time slot; and spectrally inserting, at least one second guard band of the one or more guard bands in a corresponding one of the useful bands, the second guard band having a width greater than that of the first guard band.