Patent application number | Description | Published |
20130343446 | HIGHLY-SPECTRALLY-EFFICIENT RECEPTION USING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING - 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. | 12-26-2013 |
20130343473 | Highly-Spectrally-Efficient Transmission Using Orthogonal Frequency Division Multiplexing - A transmitter may map, using a selected modulation constellation, each of C′ bit sequences to a respective one of C′ symbols, where C′ is a number greater than one. The transmitter may process the C′ symbols to generate C′ inter-carrier correlated virtual subcarrier values. The transmitter may decimate the C′ virtual subcarrier values down to C physical subcarrier values, C being a number less than C′. The transmitter may transmit the C physical subcarrier values on C orthogonal frequency division multiplexed (OFDM) subcarriers. The modulation constellation may be an N-QAM constellation, where N is an integer. The processing may comprise filtering the C′ symbols using an array of C′ filter tap coefficients. The filtering may comprise cyclic filtering. The filtering may comprise multiplication by a circulant matrix populated with the C′ filter tap coefficients. | 12-26-2013 |
20130343480 | Multi-Mode Orthogonal Frequency Division Multiplexing Transmitter for Highly-Spectrally-Efficient Communications - 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. | 12-26-2013 |
20130343491 | MULTI-MODE ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING RECEIVER FOR HIGHLY-SPECTRALLY-EFFICIENT COMMUNICATIONS - 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. | 12-26-2013 |
20130343496 | REDUCED STATE SEQUENCE ESTIMATION WITH SOFT DECISION OUTPUTS - 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. | 12-26-2013 |
20140112399 | POWER LINE COMMUNICATION METHOD AND APPARATUS - An Apparatus for transmitting and receiving signals over residential electrical cables includes a processor, at least one transmitter and at least one receiver, both coupled with the processor. The apparatus coupled with an electrical cable includes at least one active wire, one neutral wire and one ground wire, the transmitter and the receiver each including a coupling circuit for coupling the apparatus to the residential electrical cables. The coupling circuit has a first transformer and a second transformer, the first transformer including a center tap, receive wire pairs and transmit wire pairs each being formed from at least two of the active wire, the neutral wire, the ground wire and the midpoint. The processor dynamically switches a coupling of the receiver and the transmitter respectively between the receive wire pairs and the transmit wire pairs. | 04-24-2014 |
20140112400 | POWER LINE COMMUNICATION METHOD AND APPARATUS - 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. | 04-24-2014 |
20140133608 | HYPOTHESES GENERATION BASED ON MULTIDIMENSIONAL SLICING - 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. | 05-15-2014 |
20140233683 | REDUCED STATE SEQUENCE ESTIMATION WITH SOFT DECISION OUTPUTS - 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. | 08-21-2014 |
20140286459 | MULTI-MODE ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING RECEIVER FOR HIGHLY-SPECTRALLY-EFFICIENT COMMUNICATIONS - 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. | 09-25-2014 |
20140321525 | HIGHLY-SPECTRALLY-EFFICIENT RECEPTION USING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING - 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. | 10-30-2014 |
20150043684 | HYPOTHESES GENERATION BASED ON MULTIDIMENSIONAL SLICING - 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. | 02-12-2015 |
20150049843 | Combined Transmission Precompensation and Receiver Nonlinearity Mitigation - 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. | 02-19-2015 |
20150070089 | ADAPTIVE NONLINEAR MODEL LEARNING - 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. | 03-12-2015 |
20150078491 | Highly-Spectrally-Efficient OFDM Receiver - 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. | 03-19-2015 |
20150124912 | RECEPTION OF INTER-SYMBOL-CORRELATED SIGNALS USING SYMBOL-BY-SYMBOL SOFT-OUTPUT DEMODULATOR - 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. | 05-07-2015 |
20150131759 | HYPOTHESES GENERATION BASED ON MULTIDIMENSIONAL SLICING - 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. | 05-14-2015 |