| 摘要 |
<p>A communication system for transmitting baseband digital signals (16) on an electrical power line (12). A pulse generator (14) 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 terminal (25) an amplifier (32) compensates for attenuation characteristics of the electrical power line and the received signal is then sampled (34) to extract the information from it. To avoid interference when both a transmitting and receiving link are located at a substation, the baseband system incorporates a mimic network to mimic the interference signal erroneously picked up by the receiving link from the transmitting link located at the same substation. The mimic signal is then subtracted from the interference signal to neutralize the effect of the latter. When both a baseband digital communication system and a carrier communication system utilize the same electrical power lines, provision is made for interrupting the baseband digital signal to allow communications via the carrier system.</p> |
