METHOD AND SYSTEM FOR POWER LINE NULL DETECTION AND AUTOMATIC FREQUENCY AND GAIN CONTROL

摘要

A system and method for detecting power line null frequencies and for adjusting the transmit frequency and transmit power to maximize the reliability and efficiency of the AC power line transmission link. The syste m includes a programmable logic device (102) in the transmitter, which receive s information (101) and generatesa control signal (103) which controls the gai n of amplifier (109) and provides a PPL control signal (104) for directing the Phase Locked Loop (105) in its selection of multiple frequencies for transmission to a receiver. A receiver detects and records the bit error rat e and/or the received noise per frequency and communicates this information to the transmitter. When all desired frequencies have been transmitted and tested, the optimal frequency is identified or selected. Generally, the optimal frequency is the frequency requiring the lowest transmit power while maintaining an acceptable bit error rate or an acceptable noise level.