A method for transmission, from at least one emitter antenna, of a source signal that includes a plurality of binary sequences, to all or part of n receiver antennas, n being an integer greater than or equal to 2, the method implementing, before a step of emitting a given one of the binary sequences of the source signal, a prefiltering of focusing the given binary sequence towards one or more target antennas out of the n receiver antennas, the associated focusing prefiltering being chosen according to a value of the given binary sequence, the method further including:
- transmitting a first piece of binary information by using the simultaneous absence of focusing towards each of the n receiver antennas, during a predetermined integer k of symbol times.