In described examples, a first isolation element electrically isolates a first circuit from a second circuit and passes AC signals between the first circuit and the second circuit. A second isolation element electrically isolates the first circuit from the second circuit and passes AC signals between the first circuit and the second circuit. A ground of the second circuit electrically floats relative to a ground of the first circuit, so that a digital signal is able to pass from the second circuit through a third isolation element to the first circuit. A supply voltage generation device converts AC signals from the first isolation element and the second isolation element into at least one DC voltage to power the second circuit.

A system including first and second network nodes that communicate with additional nodes in first and second networks, respectively, using a shared communication channel. In response to detecting presence of the first network node, the second network node transmits a first signal to the first network node including a predetermined sequence known to both the first and second network nodes. The first network node measures a strength of the transmitted signal based on knowledge of the predetermined sequence and calculates a throughput metric (throughput referring to amount of information transmitted per second) based on the measured strength. In response to the throughput metric being less than a unification threshold, the first network node selectively transmits a unification request to the second network node. The unification request invites the second network node to coordinate operation with the first network node to reduce interference between the first network and the second network.

Disclosed is a method and apparatus for reducing outbound interference in a broadband powerline communication system. Data is modulated on first and second carrier frequencies and is transmitted via respective first and second lines of the powerline system. A characteristic of at least one of the carrier signals (e.g., phase or amplitude) is adjusted in order to improve the electrical balance of the lines of the transmission system. This improvement in electrical balance reduces the radiated interference of the powerline system. Also disclosed is the use of a line balancing element on or more lines of the powerline system for altering the characteristics of at least one of the power lines in order to compensate for a known imbalance of the transmission system.

A method is for processing an analog channel signal from a transmission channel. The method may include converting of the analog channel signal to a digital channel signal, and performing a channel estimation digital processing of the digital channel signal. The channel estimation digital processing may include for at least one frame, generating transfer functions of the transmission channel, the transfer functions respectively associated with reference symbols of the frame, and averaging processing of the transfer functions to generate an average transfer function. The method may include decoding of symbols of the frame following the reference symbols using the average transfer function.

A power line communication method for realizing data communication between at least one first or sending power line communication partner device and at least one second or receiving power line communication partner device. The method checks transmission conditions of a plurality of possible communication channels, thereby generating transmission condition data descriptive for the communication conditions of the respective possible communication channels. Additionally, communication conditions of the plurality of possible communication channels are selected as actual communication conditions based on the transmission condition data.

This disclosure provides several mechanisms for adapting transmit power spectral density (PSD). A communications device may adapt the power spectrum utilized at the transmitter based, at least in part, on the channel conditions or PSD constraints associated with the communications medium between the transmitter and a receiver device. Additionally, the transmit PSD may be adapted based, at least in part, on a total power capability associated with a transmitter. Power is allocated to improve throughput and utilization of the communications channel. A transmission profile may be selected based, at least in part, on the notch depth. The transmission profile may be associated with symbol timing parameters. The communications device may maintain a plurality of selectable pulse shapes that are optimized for different notch depths.

In one embodiment, a device in a network receives a message from a neighboring device that identifies the electrical phase on which the message was sent. Crosstalk is identified between the device and the neighboring device by determining that the message was received on a different electrical phase than the phase on which the message was sent. One or more distinct communication channels between the device and the neighboring device are identified based on the identified crosstalk with each communication channel including or more electrical phases.

A device for power line communication is provided, including a transmitter adapted to transmit signals on at least two of a plurality of power line transmission paths of a power line network; a sensor adapted to determine one or a plurality of reflection parameters of one of the plurality of power line transmission paths; and a transmission impedance matching unit adapted to match the output impedance of at least two output ports of the device which each couple to one of the plurality of transmission paths to the impedance of the at least two of the power line transmission paths based on the one or the plurality of reflection parameters. Further, a device including a corresponding reception impedance matching unit is provided and corresponding methods for transmitting and receiving signals.

Various circuits and methods are disclosed for communications over AC power lines. In one example embodiment, a power line communication circuit includes an analog front end having a data-coupling circuit configured to communicatively couple communication signals to and from a set of AC power lines in the power line communication system. The analog front end also includes a noise reduction circuit that is coupled to the data-coupling circuit. The noise reduction circuit is configured to mitigate noise within a communication frequency band of the communication signals by filtering, from the communication signals, at least one frequency that is located outside of the communication frequency band and that has harmonics located within the communication frequency band and to demodulate data from the communication frequency band of the filtered communication signals.

Aspects of the subject disclosure may include, for example, a transmission medium for propagating electromagnetic waves. The transmission medium can include a plurality of cores for selectively guiding an electromagnetic wave of a plurality of electromagnetic waves longitudinally along each core, and a shell surrounding at least a portion of each core for reducing exposure of the electromagnetic wave of each core. Other embodiments are disclosed.