Eric A Udren: Power-line baseband communication system. Westinghouse Electric, D R Lackey, September 11, 1984: US04471399 (105 worldwide citation)

A communication system for transmitting baseband digital signals on an electrical power line. A pulse generator produces digital signals which are limited to a frequency spectrum of 30 kHz to 300 kHz and applied directly, i.e., without modulation, to an electrical power line. At the receiving termin ...