Abstract: A method and apparatus for channel estimation for a three-phase communication system. In one embodiment, the method comprises generating a first plurality of preamble patterns for use in a first data stream of two independent data streams; generating a second plurality of preamble patterns for use in a second data stream of the two independent data streams; transmitting the first and the second data streams via a communications channel comprising a three-wire three-phase system; receiving a version of the first data stream comprising the first plurality of preamble patterns and a version of the second data stream comprising the second plurality of preamble patterns; and generating, based on the received version of the first plurality of preamble patterns and the received version of the second plurality of preamble patterns, a channel estimation matrix for estimating the imbalance of the communications channel.

Abstract: Apparatus and method for determining a phase connection for a power conditioning unit (PCU). In one embodiment, the method comprises determining, by a controller coupled to a multi-phase AC line, a reference phase stamp; determining, by the PCU, a local phase stamp, wherein the PCU is coupled to a subset of phase lines in the multi-phase AC line; determining a difference between the reference phase stamp and the local phase stamp; comparing the difference to one or more of a first range of values or at least a second range of values; and determining the phase connection for the PCU based on whether the difference is within the first range or the at least a second range.

Abstract: Method and apparatus for generating a power line communication (PLC) signal. In one embodiment, the method comprises generating a first modulation signal based on at least one data stream; modulating a first carrier signal by the first modulation signal to generate a first signal; generating a second signal by performing a phase shift based on the first signal; and coupling a balanced three-phase PLC signal comprising the first signal, the second signal and a third signal to a three-phase power line.

Abstract: A method and apparatus for channel estimation for a three-phase communication system. In one embodiment, the method comprises generating a first plurality of preamble patterns for use in a first data stream of two independent data streams; generating a second plurality of preamble patterns for use in a second data stream of the two independent data streams; transmitting the first and the second data streams via a communications channel comprising a three-wire three-phase system; receiving a version of the first data stream comprising the first plurality of preamble patterns and a version of the second data stream comprising the second plurality of preamble patterns; and generating, based on the received version of the first plurality of preamble patterns and the received version of the second plurality of preamble patterns, a channel estimation matrix for estimating the imbalance of the communications channel.

Abstract: A method and apparatus for harmonic distortion compensation in power line communications. In one embodiment, the method comprises analyzing a waveform generated by a transmitter of a power line communications transceiver (PLCT), wherein the waveform is analyzed to determine harmonic information for one or more harmonics of a carrier waveform of the PLCT; computing, based on the harmonic information, one or more harmonic compensation coefficients; and pre-distorting, based on the one or more harmonic compensation coefficients, the carrier waveform such that the one or more harmonics are reduced below a threshold.

Abstract: Method and apparatus for generating a power line communication (PLC) signal. In one embodiment, the method comprises generating a first modulation signal based on at least one data stream; modulating a first carrier signal by the first modulation signal to generate a first signal; generating a second signal by performing a phase shift based on the first signal; and coupling a balanced three-phase PLC signal comprising the first signal, the second signal and a third signal to a three-phase power line.

Abstract: Method and apparatus for generating a balanced three-phase power line communication signal. In one embodiment, the method comprises generating a plurality of modulation signals based on at least one data stream; modulating a plurality of carrier signals by the plurality of modulation signals to generate a balanced three-phase PLC signal comprising a first phase signal, a second phase signal, and a third phase signal; and coupling the balanced three-phase PLC signal to a three-phase power line.

Abstract: Apparatus and system for determining a phase connection for a power conditioning unit (PCU). In one embodiment, the comprises determining, by a controller coupled to a multi-phase AC line, a reference phase stamp; determining, by the PCU, a local phase stamp, wherein the PCU is coupled to a subset of phase lines in the multi-phase AC line; determining a difference between the reference phase stamp and the local phase stamp; comparing the difference to one or more of a first range of values or at least a second range of values; and determining the phase connection for the PCU based on whether the difference is within the first range or the at least a second range.

Abstract: A method and apparatus for impulse noise mitigation. In one embodiment, the method comprises identifying one or more impulse noise affected samples of a communication signal transmitted via power line communications; creating, based on the identified one or more impulse-noise affected samples, one or more erasures; and adaptively controlling a correlation threshold for packet preamble detection, wherein the correlation threshold is adaptively controlled based on the one or more erasure.

Abstract: A network communication device is receive packet-based orthogonal frequency division multiplexed (OFDM) transmissions from one or more other devices in a network over a communication channel. The network communication device may determine a delay spread of the communication channel based on receipt of a probe signal from a transmitting device, configure a channel filter to effectively shorten the channel based on the delay spread, and instruct the transmitting device to shorten a length of a cyclic prefix for subsequent packet-based OFDM transmissions to be received from the transmitting device over the channel.

Abstract: Method and apparatus for generating a balanced three-phase power line communication signal. In one embodiment, the method comprises generating a plurality of modulation signals based on at least one data stream; modulating a plurality of carrier signals by the plurality of modulation signals to generate a balanced three-phase PLC signal comprising a first phase signal, a second phase signal, and a third phase signal; and coupling the balanced three-phase PLC signal to a three-phase power line.

Abstract: A method and apparatus for impulse noise mitigation. In one embodiment, the method comprises identifying one or more impulse noise affected samples of a communication signal transmitted via power line communications; creating, based on the identified one or more impulse-noise affected samples, one or more erasures; and adaptively controlling a correlation threshold for packet preamble detection, wherein the correlation threshold is adaptively controlled based on the one or more erasure.

Abstract: A method and apparatus for harmonic distortion compensation in power line communications. In one embodiment, the method comprises analyzing a waveform generated by a transmitter of a power line communications transceiver (PLCT), wherein the waveform is analyzed to determine harmonic information for one or more harmonics of a carrier waveform of the PLCT; computing, based on the harmonic information, one or more harmonic compensation coefficients; and pre-distorting, based on the one or more harmonic compensation coefficients, the carrier waveform such that the one or more harmonics are reduced below a threshold.

Abstract: Methods and systems to synchronize to a remote node counting rate, symbol rate, and carrier frequency as functions of an estimated frequency offset and relationships between the remote node carrier frequency and counting rate, and between the remote node carrier frequency and symbol rate. The carrier frequency offset may be scaled in accordance with a ratio between the carrier frequency and the remote counting rate to synchronize the local counting rate with the remote counting rate, and/or scaled in accordance with a relationship between the carrier frequency and the remote symbol rate to synchronize the local receive path and/or transmit path sample rate with the remote symbol rate. The carrier frequency offset may be applied as compensation in the receive path and/or the transmit path. The remote and local nodes may correspond to a network coordinator and an existing node, respectively, in a Multimedia Over Coax (MoCA) environment.

Abstract: Methods and systems to receive a multiple-carrier signal having periodic control packets, wherein each bit of a control packet is redundant on a plurality of the carrier signals, and to recover the control packet from a subset of the carrier signals in a standby mode. In an operational mode, a full bandwidth of the multiple-carrier signal digitized and processed. In a standby mode, the digitized signal may be digitally low pass filtered and decimated to obtain sample points corresponding to the subset of the carrier signals, and the samples may be processed with a reduced-bandwidth FFT and a reduced-bandwidth equalizer. Standby mode parameters corresponding to the subset of carrier signals may be selected based on signal to noise ratios (SNRs) of the signal sub-carriers. A minimum set of carrier signals needed to recover a control packet, and corresponding bit locations, may be determined from bit loading information and SNR.

Abstract: A network communication device is receive packet-based orthogonal frequency division multiplexed (OFDM) transmissions from one or more other devices in a network over a communication channel. The network communication device may determine a delay spread of the communication channel based on receipt of a probe signal from a transmitting device, configure a channel filter to effectively shorten the channel based on the delay spread, and instruct the transmitting device to shorten a length of a cyclic prefix for subsequent packet-based OFDM transmissions to be received from the transmitting device over the channel.

Abstract: A full spectrum modulator processes a plurality of CATV channels from separate paths. Each path has (i) a first filter for pulse shaping an input channel signal and upsampling a channel frequency thereof, (ii) an interpolator for interpolating the output of the first filter to a common sample rate, and (iii) a decimator for centering the output of the interpolator on a predetermined channel bandwidth. An IDFT processor receives channel signal outputs from the decimators. A polyphase filter bank receives IDFT processed parallel channel signals from the IDFT processor. A commutator converts the processed parallel channel signals from the polyphase filter bank to a single stream of data. A second filter upsamples the single stream of data to a fixed output sampling rate and low pass filters alias signals therefrom. Both standard and harmonically related carrier CATV channel frequency plans are accommodated.

Abstract: A network communication device is receive packet-based orthogonal frequency division multiplexed (OFDM) transmissions from one or more other devices in a network over a communication channel. The network communication device may determine a delay spread of the communication channel based on receipt of a probe signal from a transmitting device, configure a channel filter to effectively shorten the channel based on the delay spread, and instruct the transmitting device to shorten a length of a cyclic prefix for subsequent packet-based OFDM transmissions to be received from the transmitting device over the channel.

Abstract: A coaxial network communication node receives multimedia content with one or more other nodes in a Multimedia over Coax Alliance (MoCA®) coaxial network. The node determines a delay-spread of a coaxial channel based on a probe received from a transmitting node during a link-maintenance operation (LMO) cycle. The probe is stored and reused during the LMO until the channel-shortening TEQ filter converges. The node configures a channel-shortening time-domain equalizer (TEQ) filter to effectively shorten the channel and instructs the transmitting node to shorten a length of a cyclic prefix for subsequent packet-based transmissions.

Abstract: A full spectrum modulator processes a plurality of CATV channels from separate paths. Each path has (i) a first filter for pulse shaping an input channel signal and upsampling a channel frequency thereof, (ii) an interpolator for interpolating the output of the first filter to a common sample rate, and (iii) a decimator for centering the output of the interpolator on a predetermined channel bandwidth. An IDFT processor receives channel signal outputs from the decimators. A polyphase filter bank receives IDFT processed parallel channel signals from the IDFT processor. A commutator converts the processed parallel channel signals from the polyphase filter bank to a single stream of data. A second filter upsamples the single stream of data to a fixed output sampling rate and low pass filters alias signals therefrom. Both standard and harmonically related carrier CATV channel frequency plans are accommodated.