Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: High peak-to-average ratio of OFDM signals requires large back-off from an RF power amplifier's saturation power. A spectral shaper device therefore increases the output power and efficiency of the power amplifier. The shaper device performs linearization through digital predistortion, based on an out-of-band regrowth limit, as well as the EVM requirement for a particular data rate. The shaper can distribute the error energy, precisely, over frequencies such that each of the inband and out-of-band requirements is independently and individually met. The shaper distributes error energy to frequency regions in the spectrum to the maximally allowed by the standards and regulations, while not increasing the total error. The error energy is kept to the minimum where it is crucial in meeting EVM requirements. In this way, the shaper maximizes the allowable output power of the nonlinear power amplifier.

Abstract: 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.

Abstract: High peak-to-average ratio of OFDM signals requires large back-off from an RF power amplifier's saturation power. A spectral shaper device therefore increases the output power and efficiency of the power amplifier. The shaper device performs linearization through digital predistortion, based on an out-of-band regrowth limit, as well as the EVM requirement for a particular data rate. The shaper can distribute the error energy, precisely, over frequencies such that each of the inband and out-of-band requirements is independently and individually met. The shaper distributes error energy to frequency regions in the spectrum to the maximally allowed by the standards and regulations, while not increasing the total error. The error energy is kept to the minimum where it is crucial in meeting EVM requirements. In this way, the shaper maximizes the allowable output power of the nonlinear power amplifier.

Abstract: A modulator and demodulator pair may switch configurations without introducing errors as a result of the switch. Different configurations may, for example, correspond to different symbol rates and/or different amounts of controlled inter-symbol interference (ISI) introduced to the transmitted signal. For example, a first configuration may use be a near-zero ISI configuration (e.g., using Nyquist signaling) and a second configuration may introduce a significant (e.g., amount that would result in errors above a desired threshold if demodulation relied on symbol-by-symbol slicing) but controlled amount of ISI (e.g., using partial response or faster-than-Nyquist-rate signaling). Switching between modulator/demodulator configurations may be needed to maintain a stable link in the case of dynamic channels. At any given time, a modulator and demodulator pair may, for example, switch to a configuration that provides maximal throughput for the current channel conditions.

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: A system that includes combiner circuitry configured to combine a first signal and a second signal to generate a third signal, wherein said third signal is output for transmission onto a communication medium. The system also includes nonlinearity modeling circuitry configured to model a nonlinear response of a nonlinear circuit, and generate a fourth signal through nonlinear distortion of a fifth signal using said model. The system also includes bin modification circuitry configured to generate said second signal through application of one or more weighting factors to frequency bins of said fourth signal, or of a transformed version of said fourth signal, and determine said weighting factors based on a difference, or squared difference, error metric.

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: 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.

Abstract: A transmitter may be operable to generate a sequence of symbols which may comprise information symbols and one or more pilot symbols. The transmitter may transmit the information symbols at a first power and transmit the one or more pilot symbols at a second power. In instances when a particular performance indicator is below a determined threshold, the first power may be set to a first value and the second power may be set to zero value. In instances when the particular performance indicator is above the determined threshold, the first power may be set to a second value and the second power may be set to a non-zero value. A value of the first power and a value of the second power may be based on an applicable average power limit determined by a communications standard with which the transmitter is to comply.

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: A receiver receives an inter-symbol correlated (ISC) signal with information symbols and a corresponding parity symbol. Values of information symbols are estimated utilizing parity samples that are generated from the parity symbols. One or more maximum likelihood (ML) decoding metrics are generated for the information symbols. One or more estimations are generated for the information symbols based on the one or more ML decoding metrics. A parity metric is generated for each of the one or more generated estimations of the information symbols. The parity metric is generated by summing a plurality of values of one of the generated estimations to generate a sum, and wrapping the sum to obtain a parity check value that is within the boundaries of a symbol constellation utilized in generating the information symbols.

Abstract: A method and system for configuring one or both of a transmitter pulse-shaping filter and a receiver pulse-shaping filter to generate a total partial response that incorporates a predetermined amount of inter-symbol interference (ISI), based on one or more defined performance-related variables and one or more set constraints that are applicable to one or both of the transmitter pulse-shaping filter and the receiver pulse-shaping filters. The predetermined amount of ISI is determined based on an estimation process during extraction of data from an output of the receiver pulse-shaping filter, such that performance of total partial response based communication matches or surpasses performance of communication incorporating filtering based on no or near-zero ISI. The configuring may comprise determining optimized filtering configuration, by applying an optimization process which is based on, at least in part, the one or more constraints and the one or more performance-related variables.

Abstract: A modulator and demodulator pair may switch configurations without introducing errors as a result of the switch. Different configurations may, for example, correspond to different symbol rates and/or different amounts of controlled inter-symbol interference (ISI) introduced to the transmitted signal. For example, a first configuration may use be a near-zero ISI configuration (e.g., using Nyquist signaling) and a second configuration may introduce a significant (e.g., amount that would result in errors above a desired threshold if demodulation relied on symbol-by-symbol slicing) but controlled amount of ISI (e.g., using partial response or faster-than-Nyquist-rate signaling). Switching between modulator/demodulator configurations may be needed to maintain a stable link in the case of dynamic channels. At any given time, a modulator and demodulator pair may, for example, switch to a configuration that provides maximal throughput for the current channel conditions.

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: A transmitter comprises at least one nonlinear circuit, and a power spectral density (PSD) shaping circuit. The PSD shaping circuit is operable to receive a symbol of a modulated signal, wherein the symbol corresponds to a first one or more frequency bins. The PSD shaping circuit is operable to perform iterative processing of the symbol, wherein each iteration of the processing comprises: generation of a pre-distortion signal based on a model of the at least one nonlinear circuit, wherein the nonlinearly distorted signal corresponds to a second one or more frequency bins; and combination of the symbol, or a pre-distorted version of the symbol, with the nonlinearly-distorted signal. The generation of the pre-distorted signal may comprise generation of a nonlinearly-distorted signal, and adjustment of one or more components of the nonlinearly-distorted signal.

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 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.