The invention relates to a communication device using power line communication provided in a first system coupled to a second system via a power cable comprising a pilot line having a first impedance, which encounters at least second and third impedances and through which a first analog signal passes in a first frequency band. The device is arranged so as to: i) generate, from a local digital signal, a second analog power line communication signal having frequencies included in a second frequency band that has minimal overlap with the first frequency band; ii) supply the second analog signal to the pilot line via a capacitive means and iii) extract, from the analog signals passing through the pilot line, each second analog signal in order to convert the latter into a digital signal to be processed by the system.