Abstract: An approach to digital compensation uses a particular structure for a digital pre-distorter (DPD) which acts as a relatively accurate pre-inverse of a non-linear circuit (e.g., a non-linear transmit chain involving digital-to-analog converter (DAC), lowpass filter, modulator, bandpass filter, and power amplifier) while making use of a relatively small number of parameters that characterize the non-linearity and/or parameters that provide accurate linearization without requiring continual updating.

Abstract: A linearization system computes a robust set of quantities characterizing a nonlinearity of a transmit chain including a power amplifier by combining a current set of quantities characterizing the nonlinearity of the transmit chain with a weighted combination of prior sets of quantities characterizing the nonlinearity of the transmit chain.

Abstract: Disclosed are implementations, including a method for digital predistortion of multiband signals that includes receiving an input signal comprising multiple signal portions in different frequency bands, the input signal configured to be processed by a transmit chain, of a power amplification system, comprising at least a power amplifier that produces output with non-linear distortions, with the non-linear distortions of the transmit chain being represented using a set of basis functions derived according to a single-band model of the non-linear distortions. The method further includes performing digital predistortion on signal components derived from the multiple signal portions of the input signal using a reduced set of the basis functions that excludes at least some basis functions for at least some cross-terms resulting from a full expansion of the single-band model applied to the multiple signal portions, to produce a digital predistorted signal provided to the transmit chain.

Abstract: An approach to predistortion of a first set of signals for an antenna array allows beam-steering without corrupting spectrum away from the main beam and where other users may be located. In some implementations, the predistorter uses fewer than one predistorter per signal (i.e., per power amplifier or per antenna), and/or has the computational complexity of such fewer predistorters, to generate predistortions of the first set of signals for amplification and transmission via the antenna array.

Abstract: An approach to digital compensation uses a particular structure for a digital pre-distorter (DPD) which acts as a relatively accurate pre-inverse of a non-linear circuit (e.g., a non-linear transmit chain involving digital-to-analog converter (DAC), lowpass filter, modulator, bandpass filter, and power amplifier) while making use of a relatively small number of parameters that characterize the non-linearity and/or parameters that provide accurate linearization without requiring continual updating.

Abstract: A received signal is enhanced by removing distortion components of a concurrently transmitted signal. A received signal is acquired in a receive frequency band concurrently with transmission of a transmit signal in a transmit frequency band. The received signal includes an intermodulation distortion component of the transmit signal. A representation of the transmit signal is processed using a non-linear predictor to output a distortion signal representing predicted distortion components in the received signal. The received signal is enhanced using the distortion signal by removing the predicted distortion components from the received signal corresponding to the distortion signal.

Abstract: A received signal is enhanced by removing distortion components of a concurrently transmitted signal. A received signal is acquired in a receive frequency band concurrently with transmission of a transmit signal in a transmit frequency band. The received signal includes an intermodulation distortion component of the transmit signal. A representation of the transmit signal is processed using a non-linear predictor to output a distortion signal representing predicted distortion components in the received signal. The received signal is enhanced using the distortion signal by removing the predicted distortion components from the received signal corresponding to the distortion signal.

Abstract: An approach to digital compensation uses a particular structure for a digital pre-distorter (DPD) which acts as a relatively accurate pre-inverse of a non-linear circuit (e.g., a non-linear transmit chain involving digital-to-analog converter (DAC), lowpass filter, modulator, bandpass filter, and power amplifier) while making use of a relatively small number of parameters that characterize the non-linearity and/or parameters that provide accurate linearization without requiring continual updating.

Abstract: Aspects and embodiments are directed to non-linear systems including a digital compensator structure, a method of digital compensation, and methods for designing digital compensator structures for analog receivers. A digital compensator is configured to substantially reduce the one or more nonlinear distortion components in the sampled digital output signal from the analog receiver to provide an output signal achieving a receiver linearity requirement for the combination of the analog receiver and a digital compensator.

Abstract: Aspects and embodiments are directed to non-linear systems including a digital compensator structure, a method of digital compensation, and methods for designing digital compensator structures for analog receivers. A digital compensator is configured to substantially reduce the one or more nonlinear distortion components in the sampled digital output signal from the analog receiver to provide an output signal achieving a receiver linearity requirement for the combination of the analog receiver and a digital compensator.

Abstract: A method for digital compensation of a nonlinear system comprises identifying a plurality of circuit parameters of a nonlinear system. Each circuit parameter determines a nonlinear response of the nonlinear system. A first circuit parameter is chosen from the plurality of circuit parameters. The first circuit parameter determines a first effect on the nonlinear response. The first effect is at least as large a second effect from a second circuit parameter from the plurality of circuit parameters. At least one stimulus is applied to the nonlinear system. The nonlinear response of the nonlinear system is measured in response to the at least one stimulus. A compensation architecture is synthesized to substantially linearize the nonlinear response. The compensation architecture receives the nonlinear response of the nonlinear system and provides a substantially linear response.

Abstract: Described is a frequency synthesizer having a wide output frequency range and small frequency tuning steps. In-band spurious components are maintained at low levels and phase noise is significantly reduced. The frequency synthesizer can be fabricated as an integrated circuit device having a small area and low power dissipation. The frequency synthesizer can be used in wideband frequency systems to reduce cost and size by replacing multiple frequency synthesizers each devoted to a portion of the overall system frequency range.

Abstract: A method for digital compensation of a nonlinear system comprises identifying a plurality of circuit parameters of a nonlinear system. Each circuit parameter determines a nonlinear response of the nonlinear system. A first circuit parameter is chosen from the plurality of circuit parameters. The first circuit parameter determines a first effect on the nonlinear response. The first effect is at least as large a second effect from a second circuit parameter from the plurality of circuit parameters. At least one stimulus is applied to the nonlinear system. The nonlinear response of the nonlinear system is measured in response to the at least one stimulus. A compensation architecture is synthesized to substantially linearize the nonlinear response. The compensation architecture receives the nonlinear response of the nonlinear system and provides a substantially linear response.

Abstract: Described is a frequency synthesizer having a wide output frequency range and small frequency tuning steps. In-band spurious components are maintained at low levels and phase noise is significantly reduced. The frequency synthesizer can be fabricated as an integrated circuit device having a small area and low power dissipation. The frequency synthesizer can be used in wideband frequency systems to reduce cost and size by replacing multiple frequency synthesizers each devoted to a portion of the overall system frequency range.

Abstract: A receiver for a received signal having two or more different data levels comprises two or more channel estimators, (at least) one channel estimator for each different data level, where each channel estimator preferably implements an adaptive 2nd order or higher model of the transmission channel over which the received signals was transmitted to generate an estimated signal for one of the different data levels. The receiver also has a comparator that compares the current received signal to the estimated signals generated by the different channel estimators to select an output data value for the current received signal. The adaptive model of the transmission channel has coefficients that are dynamically controlled based on an error signal generated by the comparator. Each channel estimator relies on an output signal generated by an adaptive equalizer.

Abstract: An integrated circuit device with a light-emitting diode thereon is disclosed. The device has discrete regions which function in concert to emit light when a suitable amount of voltage is provided. The device has four discrete regions: a first doped silicon region; a second silicon dioxide region; a third organic material region; and a fourth conducting material region. The first and fourth regions are electrodes which inject holes and electrons into the conducting organic material. The second region lowers the energy barrier between the first and third regions which improves the efficiency with which the polymer emits light. The diode of the present invention is fabricated on an integrated circuit using conventional integrated circuit fabrication techniques.