Adaptive impedance matching in power line communication

Power line communication is a promising communication method. Yet it is not widely used for the reason of relative high BER (bit error rate) and instability during communication. A primary cause of this poor performance is the time varying characteristics of power line. It leads to the variation in line impedance, and thus the impedance on the interface of communication equipment cannot match with it. So there are heavy attenuation and distortion during signal transfer, and the power cannot be sent out or received completely. In this paper, a new method that performs impedance matching using auto adaptation is presented. It measures the current line impedance, compares it with a typical value, and then selects the proper parameters of matching components to make a good matching. Since it makes a continuous adaptation between power line and communication equipment, the power sent out to the line and received by the receiver is maximized.