Patent ID: 7924990

Claim:
A communication apparatus for connecting to a power line connected to at least a first communication device and a second communication device, the first communication device being configured to perform a data transmission with said communication apparatus, and the second communication device being incapable of performing the data transmission with said communication apparatus, said communication apparatus comprising: a receiver for receiving a multi-carrier signal including a plurality of sub-carriers from the second communication device; a carrier detector for detecting predetermined data in the signal: a channel setting unit for setting at least one of time and frequency band used for the first communication device in response to the carrier detector detecting the predetermined data, the time or the frequency band used for the first communication device being different from a time or a frequency band used for the second communication device; a transmitter for performing the data transmission with the first communication device in at least one of the time and the frequency band used for the first communication device; and a phase rotator for rotating phase of the plurality of sub-carriers with a phase vector, the phase vector representing a predetermined rotation degree, wherein the carrier detector detects the predetermined data in the multi-carrier signal including the plurality of sub-carriers the phase of which is rotated with the phase vector.