Abstract: A signal repeater includes a port, an amplifier, and an adaptive device. The port is configured to connect to an electrical line of an electrical grid between devices. Communication over the electrical line and between the devices includes transmission of a first signal. The port is configured to receive the first signal from the electrical line. An amplifier is configured to receive a second signal based on the first signal, and amplify the second signal. The port is configured to receive the amplified second signal, and provide the amplified second signal to the electrical line. An adaptive device is configured to, based on the first signal, adjust an output impedance of the signal repeater to match a first impedance of a load on the signal repeater. The first impedance is seen by the signal repeater at the port, and wherein the first impedance includes an impedance of the electrical line.

Abstract: A system for determining a frequency error of an orthogonal frequency division multiplexing (OFDM) signal having a first frequency. The system includes a plurality of filters configured to output a plurality of second signals, each of the plurality of second signals corresponding to a respective one of a plurality of different frequency bands of the OFDM signal. Each of the plurality of second signals includes a corresponding synchronization symbol associated with the OFDM signal. A Fourier transform circuit is configured to receive the plurality of second signals from each of the plurality of filters and output the plurality of second signals. The system is configured to determine the frequency error of the OFDM signal based on the synchronization symbols of the plurality of second signals.

Abstract: A method including receiving power, from a power line, at a device configured to communicate via the power line. The power from the power line is received at the device via a power cord of the device being connected, via a connector, to a power outlet from which the power of the power line is supplied. The connector is coupled to a first end of the power cord. The device is coupled to a second end of the power cord. The method further includes supplying a signal generated by the device to a choke located on the power cord. The choke is located closer to the first end of the power cord than to the second end of the power cord. The method further includes transmitting the signal from the choke to the power line for communication via the power line.