POWER LINE COMMUNICATION APPARATUS

摘要

A power line communication system specially designed for use in local network (LAN) configurations has receiver and transmitter sections for fast, highly reliable data communication. The receiver (Fig. 1) includes controlled adaptive second order filters (34, 38) for ensuring data reception in virtually any signal environment having noise and distorsion characteristics, especially alternating current (AC) power lines. A wideband phase shift-keyed (PSK) carrier is impressed on the transmission medium (20), the carrier having power spread approximately uniformly across a useful frequency bandwidth. A transmitter section (Fig. 4) is arranged for adaptive feedback control of the transmitted signal power, so as to prevent possible damage to the transmitter when the transmission medium impedance is low. A logic control circuit (44) provides a correlation count of a received signal in comparison with a known reference signal in order to effectively achieve phase synchronization between the receiver and transmitter.