Abstract: A system may comprise a symbol mapper circuit that outputs C? quadrature amplitude modulation (QAM) symbols per orthogonal frequency division multiplexing (OFDM) symbol. The system may also comprise circuitry operable to process said C? QAM symbols using a circulant matrix to generate a particular OFDM symbol consisting of C+? subcarriers, where C? is a first integer, C is a second integer less than C?, and ? is an integer equal to the number of non-data-carrying subcarriers in the particular OFDM symbol. The circulant matrix may be a P×P matrix, where P is an integer less than C?. The system may comprise a nonlinear circuit that introduces nonlinear distortion to said particular OFDM symbol.

Abstract: A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on a slicing of the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver.

Abstract: An electronic receiver may comprise nonlinear distortion modeling circuitry, interference estimation circuitry, and sequence estimation circuitry. The receiver may receive an orthogonal frequency division multiplexing (OFDM) symbol in the form of an electromagnetic signal. The nonlinear distortion modeling circuitry may generate a nonlinear distortion model that models nonlinear distortion introduced to the received electromagnetic signal en route to the sequence estimation circuitry. The interference estimation circuitry may estimate inter-subcarrier interference present in the received OFDM symbol based on the generated nonlinear distortion model. The estimating of the inter-subcarrier interference may comprise applying the nonlinear distortion model to one or more candidate vectors generated by the sequence estimation circuitry. The sequence estimation circuitry may sequentially process a plurality of received virtual subcarrier values of the OFDM symbol using the estimated inter-subcarrier interference.

Abstract: Apparatus, for transmitting and receiving signals over residential electrical cables, includes a processor, at least one transmitter and at least one receiver. The transmitter and the receiver are coupled with the processor, for respectively transmitting and receiving the signals. The apparatus is coupled with an electrical cable including at least one active wire, one neutral wire and one ground wire. At least two of the wires form receive wire pairs wherein at least two of the wires form at least one transmit wire pair. The processor enables the at least one receiver to be coupled with the receive wire pairs and wherein the processor dynamically switches a coupling of the at least one receiver to another one of the plurality of receive wire pairs.

Abstract: A transmitter comprises a symbol mapper operable to map a frame of bits to a frame of symbols, where the symbols correspond to a determined modulation scheme, and circuitry operable to convert the frame of symbols to a physical layer signal and transmit the physical layer signal onto a communication medium. The circuitry is operable to process the physical layer signal such that a first portion of the physical layer signal is a first type of signal (e.g., a linear signal and/or non-ISC signal) and a second portion of the physical layer signal is a second type of signal (e.g., nonlinear signal and/or ISC signal). The first portion of the physical layer signal may comprise a header, a preamble, and/or a payload of the frame. The second portion of the physical layer signal may comprise a header, a preamble, and/or a payload of the frame.

Abstract: Circuitry of an electronic transmitter may determine characteristics of nonlinear distortion introduced by the electronic transmitter during transmission of electronic signals onto a communication medium, and transmit a training signal, from which the characteristics of the nonlinear distortion can be recovered, prior to transmitting data onto the communication medium. The circuitry may transmit the training signal as part of a preamble of each burst of data transmitted by the circuitry of the electronic transmitter. The circuitry may transmit the training signal as part of a handshaking protocol used for admission of the electronic transmitter to a network. The circuitry may transmit the training signal in response to a request from receiver. The characteristics of the nonlinear distortion comprise an indication of a type of nonlinear distortion model suited for replicating the nonlinear distortion introduced by the electronic transmitter.

Abstract: A system for transmitting and receiving signals over residential electrical cables includes at least one active wire, neutral wire and ground wire, including at least two power line modems, each coupling an electrical device with an electrical socket, each one of the power line modems including a processor. The system has transmitters and at least one receiver, the transmitters and the receiver including a coupling circuit, the coupling circuit including a first transformer and a second transformer, the first transformer including a center tap. Receive and transmit wire pairs are respectively formed from two of the active, neutral and ground wires and the midpoint, the transmitters defining a carrier wave set over the transmit wire pair. The processor determines a frequency carrier wave for the signals and provides the signals to a respective one of the transmitters according to the carrier wave set the frequency carrier wave is in.

Abstract: A receiver may be operable to receive an inter-symbol correlated (ISC) signal, and generate a plurality of soft decisions as to information carried in the ISC signal. The soft decisions may be generated using a reduced-state sequence estimation (RSSE) process. The RSSE process may be such that the number of symbol survivors retained after each iteration of the RSSE process is less than the maximum likelihood state space. The plurality of soft decisions may comprise a plurality of log likelihood ratios (LLRs). Each of the plurality of LLRs may correspond to a respective one of a plurality of subwords of a forward error correction (FEC) codeword.

Abstract: An electronic receiver comprises a nonlinear distortion modeling circuit and a nonlinear distortion compensation circuit. The nonlinear distortion modeling circuit is operable to determine a plurality of sets of nonlinear distortion model parameter values, where each of the sets of nonlinear distortion model parameter values representing nonlinear distortion experienced by signals received by the electronic receiver from a respective one a plurality of communication partners. The nonlinear distortion compensation circuit is operable to use the sets of nonlinear distortion model parameter values for processing of signals from the plurality of communication partners. Each of the sets of nonlinear distortion model parameter values may comprises a plurality of values corresponding to a plurality of signal powers. The sets of nonlinear distortion model parameters may be stored in a lookup table indexed by a signal strength parameter.

Abstract: Circuitry for use in a receiver may comprise: a front-end circuit operable to receive an orthogonal frequency division multiplexing (OFDM) symbol on a first number of physical subcarriers. The circuitry may comprise a decoding circuit operable to decode the OFDM symbol using an inter-carrier interference (ICI) model, the decoding resulting in a determination of a sequence of symbols, comprising a second number of symbols, that most-likely correspond to the received OFDM symbol, where the second number is greater than the first number. The sequence of symbols may comprise N-QAM symbols, N being an integer. The ISCI model may be based, at least in part, on non-linearity experienced by the OFDM symbol during transmission by a transmitter, propagation over a channel, and/or reception by the receiver. The ISCI model may be based, at least in part, on phase-noise introduced to the OFDM symbol during transmission by a transmitter, propagation over a channel, and/or reception by the receiver.

Abstract: A receiver comprises a sequence estimation circuit and a soft-input-soft-output (SISO) decoder. The sequence estimation circuit comprises circuitry operable to generate first soft bit decisions for symbols of a received inter-symbol-correlated signal. The SISO decoder comprises circuitry operable to decode the first soft bit decisions to generate corrected soft bit decisions. The circuitry of the sequence estimation circuit is operable to generate, based on the corrected soft bit decisions, second soft bit decisions for the symbols of the received inter-symbol-correlated signal, which are improved/refined relative to the first soft bit decisions.

Abstract: An electronic receiver comprises a nonlinear distortion modeling circuit and a nonlinear distortion compensation circuit. The nonlinear distortion modeling circuit is operable to determine a plurality of sets of nonlinear distortion model parameter values, where each of the sets of nonlinear distortion model parameter values representing nonlinear distortion experienced by signals received by the electronic receiver from a respective one a plurality of communication partners. The nonlinear distortion compensation circuit is operable to use the sets of nonlinear distortion model parameter values for processing of signals from the plurality of communication partners. Each of the sets of nonlinear distortion model parameter values may comprises a plurality of values corresponding to a plurality of signal powers. The sets of nonlinear distortion model parameters may be stored in a lookup table indexed by a signal strength parameter.

Abstract: A sequence estimation circuit of a receiver may receive a sample of an inter-symbol correlated (ISC) signal corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The sequence estimation circuit may calculate a residual signal value based on the sample of the ISC signal and based on a survivor sequence. The sequence estimation circuit may generate one or more branch vector hypotheses based on the residual signal value, where each of the hypotheses comprises a plurality of symbols. The sequence estimation circuit may generate an estimate of one or more of the plurality of transmitted symbols based on the one or more branch vector hypotheses.

Abstract: A receiver may comprise a sequence estimation circuit and operate in at least two modes. In a first mode, the sequence estimation circuit may process OFDM symbols received on a first number of data-carrying subcarriers to recover a number of mapped symbols per OFDM symbol that is greater than the first number. In a second mode, the sequence estimation circuit may process OFDM symbols received on a second number of data-carrying subcarriers to recover a number of mapped symbols per OFDM symbol that is equal to the second number. The second number may be equal to or different from the first number. While the receiver operates in the first mode, the sequence estimation circuit may be operable to generate candidate vectors and process the candidate vectors using a controlled ISCI model to generate reconstructed physical subcarrier values.

Abstract: A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on a slicing of the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver.

Abstract: A receiver comprises a sequence estimation circuit and a soft-input-soft-output (SISO) decoder. The sequence estimation circuit comprises circuitry operable to generate first soft bit decisions for symbols of a received inter-symbol-correlated signal. The SISO decoder comprises circuitry operable to decode the first soft bit decisions to generate corrected soft bit decisions. The circuitry of the sequence estimation circuit is operable to generate, based on the corrected soft bit decisions, second soft bit decisions for the symbols of the received inter-symbol-correlated signal, which are improved/refined relative to the first soft bit decisions.

Abstract: Method for transmitting and receiving signals over at least one channel between at least one transmitter and at least one receiver, the channel comprising at least one group of sub-channels, the group comprising at least one sub-channel, including the procedures of estimating at least one line characteristic of the channel and selecting a transmission scheme for each group of the at least one group of sub-channels according to the estimated line characteristic, wherein the transmission scheme is selected between a single spatial stream transmission scheme and a multiple spatial stream transmission scheme.

Abstract: A transmitter may comprise a symbol mapper circuit and operate in at least two modes. In a first mode, the number of symbols output by the mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter may be greater than the number of data-carrying subcarriers used to transmit the OFDM symbol. In a second mode, the number of symbols output by said mapper circuit per orthogonal frequency division multiplexing (OFDM) symbol transmitted by said transmitter is less than or equal to the number of data-carrying subcarriers used to transmit said OFDM symbol. The symbols output by the symbol mapper circuit may be N-QAM symbols. While the circuitry operates in the first mode, the symbols output by the mapper may be converted to physical subcarrier values via filtering and decimation prior to being input to an IFFT circuit.

Abstract: In accordance with an example implementation of this disclosure, a receiver may comprise a signal reconstruction circuit and a nonlinearity modeling circuit. The nonlinearity modeling circuit may be operable to generate a look-up table (LUT)-based model of nonlinear distortion present in a received signal. An entry of the LUT may comprise a signal power parameter value and a distortion parameter value. The signal reconstruction circuit may be operable to generate one or more candidates for a transmitted signal corresponding to the received signal. The signal reconstruction circuit may be operable to distort the one or more candidates according to the model, the distortion resulting in one or more reconstructed signals. The signal reconstruction circuit may be operable to decide a best one of the candidates based on the one or more reconstructed signals.

Abstract: Circuitry of a transmitter may comprise a predistortion circuit cascaded with a nonlinear circuit. The nonlinear circuit may be characterized by a first response corresponding to a first error vector magnitude. A response of the predistortion circuit may be configured based on the first response of the nonlinear circuit such that a composite response of the predistortion circuit cascaded with the nonlinear circuit differs from the first response and is characterized by a second error vector magnitude that is greater or equal than the first error vector magnitude. The response of the predistortion circuit may be configured based on feedback of an output of the nonlinear circuit. The response of the predistortion circuit may be configured based on parameters received from a receiver partner of the transmitter during connection setup, in preambles, in message headers, and/or in dedicated messages.