Abstract: A power line communication device for communicating data over a power line in a frequency shifted communication band is provided. One embodiment includes a controller having a memory, a modem in communication with the controller, a clock generation circuit to provide a first clock output controlled by the controller. The embodiment also includes a first mixer configured to receive the first clock output from the clock generation circuit and a data signal input from the modem and to provide a shifted data signal output. The embodiment may also include a second mixer configured to receive a second clock output from the clock generation circuit and an external data signal input and to provide a shifted data signal input to the modem for demodulation. The controller is configured to receive information from the modem and to cause the clock generation circuit to adjust the first and second clock outputs accordingly.