Magnacom Ltd.

Sigma Designs Israel S.d.i. Ltd.

Tioga Technologies, Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Avago Technologies International Sales Pte. Limited

Orckit Communications, Ltd.

Orckit Communication Ltd.

Ilan Reuven

Amir Dov Eliaz

Rami Verbin

Liron Frenkel

Gal Pitarasho

Roy Oren

Daniel Stopler

Ron Sterenson

Rethnakaran Pulikkoonattu

Ayelet Shahar-Doron

Reuven Franco

Gilad Ayalon

Shimon Benjo

Eric Paneth

Ayelet Shahar Doron

David Baum

An apparatus includes a demapper to receive a number of bit streams received by multiple radio-frequency (RF) antennas. The demapper can compute a first reliability metric associated with a first stream and a second reliability metric associated with a second stream. A channel decoder processes the first and the second reliability metrics to recover decoded data. The demapper is a reduced complexity demapper and uses a symbol subset of the first stream to compute, by employing look-up tables, the second reliability metric for the second stream.

Reduced complexity soft demapper for multi antenna communication system

An apparatus includes a demapper to compute a reliability metric associated with a number of bit streams received by multiple radio-frequency (RF) antennas. The apparatus further includes a channel decoder in a feedback loop with the demapper to process the reliability metric and to provide a feedback signal to the demapper. The demapper is an iterative demapper and can use a symbol subset of at least a first stream of the plurality of bit streams and the feedback signal to compute the reliability metric for a second stream of the plurality of bit streams.

Maximum a posteriori iterative demapper for multi antenna communication system

A device includes circuitry configured to determine one or more signal processing capabilities of another device in communication with the device. The device configures a signal compression mode of the device to correspond to a first signal compression mode of a plurality signal compression modes based on the one or more signal processing capabilities of the other device. The device s configured to modify, in response to detecting variations in one or more network configuration properties or the one or more signal processing capabilities of the other device, the signal compression mode of the device.

System, device, and method for multi-mode 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.

Multi-mode orthogonal frequency division multiplexing transmitter for highly-spectrally-efficient communications

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.

Reception of inter-symbol-correlated signals using symbol-by-symbol soft-output demodulator

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.

Signal acquisition in a multimode environment

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.

Power line communication method and apparatus

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.

Reduced state sequence estimation with soft decision outputs

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.

Nonlinearity compensation for reception of OFDM signals

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&#x2032; QAM symbols using a circulant matrix to generate a particular OFDM symbol consisting of C+&#x394; subcarriers, where C&#x2032; is a first integer, C is a second integer less than C&#x2032;, and &#x394; is an integer equal to the number of non-data-carrying subcarriers in the particular OFDM symbol. The circulant matrix may be a P&#xd7;P matrix, where P is an integer less than C&#x2032;. The system may comprise a nonlinear circuit that introduces nonlinear distortion to said particular OFDM symbol.

Highly-spectrally-efficient transmission using orthogonal frequency division multiplexing

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.

Hypotheses generation based on multidimensional slicing

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.

Power line communications 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.

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.

Communication methods and systems for nonlinear multi-user environments

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.

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