Abstract: For corrupt symbol handling for providing high reliability sequences, an inter-symbol correlated (ISC) signal is received. During sequence estimation when demodulating the received ISC signal, partial response samples in the ISC may be processed utilizing an erasure mechanism. The partial response samples are spread (e.g. interleaved) over time during modulation by a modulator. A determination is made as to whether to utilize self erasure or external erasure to process the spread partial response samples. The determination may be based on whether or not events of low SNR for corresponding ones of the partial response samples are identified. The external erasure may be utilized for processing the corresponding ones of the partial response samples when the events of low SNR are identified and the self erasure is utilized when the events of low SNR are not identifiable. Erasure results maybe fed back to the modulator.

Abstract: A transmitter inserts parity samples into a stream of information symbols in an inter-symbol correlated (ISC) signal. The inserted parity samples may be utilized to generate estimates of corresponding information symbols when they are received by a receiver. The information symbols may be pulse shaped by a first pulse shaping filter characterized by a first response. The parity samples may be pulsed shaped by a second pulse shaping filter characterized by a second response. The first response and the second response are diverse or uncorrelated. The transmitter may transmit the ISC signal comprising the pulse shaped information symbols and the pulse shaped parity samples. The parity samples may be generated utilizing a non-linear function over a plurality of the information symbols. The non-linear function may be diverse from a partial response signal convolution corresponding to the information symbols and is designed according to a desired SNR value at the receiver.

Abstract: A method and system for dynamic configuring of 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). 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 reconfiguring may comprise obtaining data relating to changes affecting one or more of: the pulse-shaping filtering, and a channel and/or an interface used in the communication of data based on the total partial response, and adjusting the filter configuration, such as by determining a new optimized filtering configuration or changes to existing configurations (e.g., by applying a filtering optimization process).

Abstract: A receiver may process a received signal to generate a processed received signal. The receiver may generate, during a sequence estimation process, an estimate of a phase error of the processed received signal. The receiver may generate an estimate of a value of a transmitted symbol corresponding to the received signal based on the estimated phase error. The generation of the estimate of the phase error may comprise generation of one or more phase candidate vectors. The generation of the estimate may comprise calculation of a metric based on the one or more phase candidate vectors. The calculation of the metric may comprise phase shifting the processed received signal based on the estimated phase error resulting in a phase-corrected received signal. The calculation of the metric may comprise calculating a Euclidean distance based on the phase-corrected received signal and one or more symbol candidate vectors.

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: One or more embodiments describe a decision feedback equalizer utilizing symbol error rate biased adaptation function for highly spectrally efficient communications. A method may be performed in a decision feedback equalizer (DFE). The method may include determining values of tap coefficients used by the DFE based. The tap coefficients may be determined based on an error signal that is based on an estimated inter-symbol-correlated (ISC) signal. The tap coefficients may be determined based on a set of error vector(s), where each error vector in the set represents a difference between estimated symbols generated in the receiver and expected symbols. Determining the values of the tap coefficients may include using a symbol error rate function that estimates the actual symbol error rate in the receiver, wherein the symbol error rate function receives as input the set of error vector(s).

Abstract: A receiver may receive a signal that was generated by passage of symbols through a non-linear circuit. An equalizer of the receiver may equalize the received signal based on a first non-linearity compensated, inter-symbol correlated (ISC) feedback signal to generate an equalized signal. The receiver may correct a phase error of the equalized signal to generate a phase-corrected equalized signal. The phase correction may be based on a second, non-linearity compensated, inter-symbol correlated (ISC) feedback signal.

Abstract: Methods and systems are provided for timing synchronization for reception of highly-spectrally efficient communications. An example method may include, filtering, in a receiver, a received inter-symbol correlated (ISC) signal to generate a filtered ISC signal. The method may further include locking to a timing pilot signal of the filtered ISC signal. The timing pilot signal may include a sub-harmonic frequency of a clock signal associated with the received ISC signal. A timing pilot estimate signal of the timing pilot signal may be generated. The timing pilot estimate signal may be cancelled from the filtered partial response signal to generate an output ISC signal. The timing pilot signal includes a signal at ±(1/n*Fbaud), where n is an integer greater than 2, and Fbaud is a symbol rate of the clock signal. The clock signal may be recovered from the filtered ISC signal.

Abstract: A receiver may be operable to generate estimates of transmitted symbols using a sequence estimation process that may incorporate a non-linear model. The non-linear model may be adapted by the receiver based on particular communication information that may be indicative of non-linearity experienced by the transmitted symbols. The receiver may generate a reconstructed signal from the estimates of the transmitted symbols. The receiver may adapt the non-linear model based on values of an error signal generated from the reconstructed signal, and the values of the error signal may be generated from a portion of the generated estimates that may correspond to known symbols and/or information symbols. The values of the error signal corresponding to the known symbols may be given more weight in an adaptation algorithm, and the values of the error signal corresponding to the information symbols may be given less weight in the adaptation algorithm.

Abstract: Methods and systems are provided for timing synchronization for reception of highly-spectrally efficient communications. An example method may include, mapping, in a transmitter, a plurality of transmit bits to a plurality of symbols at a symbol rate that is based on an oscillator signal. The plurality of symbols may be processed via a filter. The processing may result in an inter-symbol correlated (ISC) signal. The oscillator signal may be frequency divided to generate one or more pilot signals having a frequency that is a sub-harmonic of a frequency of the oscillator signal. The pilot signal may be injected into the ISC signal. The injecting may result in an ISC signal with timing carrier. The ISC signal with timing carrier may be transmitted. Gain of the one or more pilot signals may be adjusted based on a spectral mask value associated with the transmitting.

Abstract: Methods and systems are provided for coarse phase estimation for highly-spectrally efficient communications. An example method may include, equalizing, in a receiver, a received inter-symbol correlated (ISC) signal to generate an equalized ISC signal. A phase adjustment signal may be generated based on an ISC feedback signal. The ISC feedback signal may be generated using a sequence estimation process and a non-linearity function. A phase of the equalized ISC signal may be adjusted using the generated phase adjustment signal, to generate a phase adjusted partial response signal. The phase adjustment signal may be generated based on a phase difference between the equalized ISC signal and the partial response feedback signal. At least one ISC vector may be generated by buffering samples of the phase adjusted ISC signal.

Abstract: A receiver may be operable to receive a QAM-based, inter-symbol correlated (ISC) signal at a signal-to-noise ratio of between 29 dB and 31 dB and process the QAM-based, ISC signal to output estimated symbols at a symbol error rate of between 2×10?1 and 1×10?3. The QAM-based, ISC signal may be a partial response signal generated by passing a first signal through a partial response pulse shaping filter. The partial response pulse shaping filter may provide greater capacity than a capacity achieved by passing the first signal through a root-raised-cosine-based pulse shaping filter. The receiver may comprises an input filter, and the processing of the QAM-based, ISC signal may comprises filtering the QAM-based, ISC signal via a filter configured to achieve a desired total partial response in combination with the partial response pulse shaping filter.

Abstract: A low power color image capturing system having a power source, the system comprising: a narrow bandwidth illuminator adapted to provide illumination having a peak intensity defining a narrow bandwidth; an image capturing device adapted to capture a raw image from an object illuminated by the narrow bandwidth illuminator; and a processor adapted to control the system and having an algorithm operatable upon the raw image to provide a modified image; wherein the modified image has enhanced color intensities over substantially all visible wavelengths.

Abstract: A frequency conversion apparatus includes a frequency generation circuit, which is based on a first semiconductor material having a first elemental composition and is coupled to generate one or more Local Oscillator (LO) signals. The apparatus further includes a conversion circuit, which is based on a second semiconductor material having a second elemental composition different from the first elemental composition. The conversion circuit is coupled to accept an input signal in a first frequency range and to convert the input signal to an output signal in a second frequency range by mixing the input signal with the one or more LO signals.

Abstract: A configurable frequency conversion device includes an up-converter, which is arranged to convert an input transmit signal to an interim transmit signal at an intermediate transmit frequency and to convert the interim transmit signal to an output transmit signal at an output frequency. A down-converter is arranged to convert an input receive signal at an input frequency to an interim receive signal at an intermediate receive frequency and to convert the interim receive signal to an output receive signal. Local Oscillator (LO) generation circuitry is arranged to generate multiple LO signals having respective LO frequencies and is coupled to drive the up- and down-converter with the LO signals, and is externally configurable to modify one or more of the LO frequencies so as to modify any of the output frequency, the input frequency, and a separation between the output and input frequencies without changing the intermediate receive and transmit frequencies.

Abstract: A method of allocating channels in a PTMP (point-to-multi-point) system having a master and a plurality of nodes comprising the steps of: transmission by the master to the nodes of a synch beacon, the sync beacon having a first frequency and a substantially fixed time period between successive sync beacon transmissions; dividing the time period into a slotted time and an unslotted time; allocating a plurality of slots in the slotted time for RF activity of the nodes that have resolved the sync beacon; and identifying the unslotted time for unallocated RF activity of the nodes that have not resolved the sync beacon.

Abstract: A low power color image capturing system having a power source, the system comprising: a narrow bandwidth illuminator adapted to provide illumination having a peak intensity defining a narrow bandwidth; an image capturing device adapted to capture a raw image from an object illuminated by the narrow bandwidth illuminator; and a processor adapted to control the system and having an algorithm operatable upon the raw image to provide a modified image; wherein the modified image has enhanced color intensities over substantially all visible wavelengths.

Abstract: A receiver includes an input circuit, which is coupled to at least one antenna so as to receive, process and digitize first and second signals, thus generating first and second streams of input samples. An interference cancellation circuit in the receiver includes first and second adaptive filters, which are respectively coupled to filter the first and second streams of input samples using respective first and second coefficients to generate respective first and second filter outputs. A phase rotator is adapted to apply a variable phase shift compensating for a phase deviation between the first and second signals, the phase rotator having at least one configuration parameter. A control module is operative to estimate signal characteristics of the interference cancellation circuit and to set the at least one configuration parameter of the phase rotator responsively to the estimated signal characteristics.

Abstract: A method for jointly designing a transmitter pulse-shaping filter and a receiver pulse-shaping filter having respective filter coefficients includes defining one or more performance-related variables based on at least some of the filter coefficients of the transmitter and receiver pulse-shaping filters. One or more constraints applicable to one or more of the filter coefficients and variables are set. A cost function defined over the variables is evaluated. Optimized filter coefficient values of the transmitter and receiver pulse-shaping filters are jointly calculated by applying an optimization process to the cost function while meeting the one or more constraints.

Abstract: A frequency conversion apparatus includes a frequency generation circuit, which is based on a first semiconductor material having a first elemental composition and is coupled to generate one or more Local Oscillator (LO) signals. The apparatus further includes a conversion circuit, which is based on a second semiconductor material having a second elemental composition different from the first elemental composition. The conversion circuit is coupled to accept an input signal in a first frequency range and to convert the input signal to an output signal in a second frequency range by mixing the input signal with the one or more LO signals.