Abstract: Aspects of the subject disclosure may include a Doherty amplifier that includes a carrier amplifier having an output terminal, an output network coupled to the output terminal, and a peaking amplifier, wherein the output network comprises a non-linear reactance component, and wherein the non-linear reactance component changes an effective impedance of a load presented to the carrier amplifier when the peaking amplifier is off. Other embodiments are disclosed.

Abstract: Aspects of the subject disclosure may include a Doherty amplifier that includes a carrier amplifier having an output terminal, an output network coupled to the output terminal, and a peaking amplifier, wherein the output network comprises a non-linear reactance component, and wherein the non-linear reactance component changes an effective impedance of a load presented to the carrier amplifier when the peaking amplifier is off. Other embodiments are disclosed.

Abstract: A device and method to adapt a model in a underdetermined adaptive system that provides an output in response to an input. A controller provides parameters to the model in a transceiver system, composed of linearizers, equalizers, or estimators as a function of an error signal. The controller and the model parameters are manipulated to allow agnosticism with respect to input signals or model complexity, enabling robust operation and efficient implementation.

Abstract: In an RF transmitter, a digital predistortion circuit receives a sequence of input sample blocks, and performs a digital predistortion process to produce a predistorted output signal. The digital predistortion process includes selecting a set of predistortion coefficients for an input sample block from a plurality of different sets of predistortion coefficients. Each of the plurality of different sets of predistortion coefficients is associated with a different combination of one of a plurality of time slices within a radio frame and one of a plurality of power ranges. The selected set of predistortion coefficients is associated with a time slice within which the input sample block is positioned and a power range calculated for the input sample block based on block power statistics of the sample block. The process also includes applying the selected set of predistortion coefficients to the input sample block to produce the predistorted output signal.

Abstract: In an RF transmitter, a digital predistortion circuit receives a sequence of input sample blocks, and performs a digital predistortion process to produce a predistorted output signal. The digital predistortion process includes selecting a set of predistortion coefficients for an input sample block from a plurality of different sets of predistortion coefficients. Each of the plurality of different sets of predistortion coefficients is associated with a different combination of one of a plurality of time slices within a radio frame and one of a plurality of power ranges. The selected set of predistortion coefficients is associated with a time slice within which the input sample block is positioned and a power range calculated for the input sample block based on block power statistics of the sample block. The process also includes applying the selected set of predistortion coefficients to the input sample block to produce the predistorted output signal.

Abstract: A digital frontend circuit for a radio frequency (RF) comprises a digital predistortion (DPD) block, a plurality of sub-sample delay elements, and a selection circuit. The DPD block for computing predistorted transmit signals according to a Volterra series approximation model. The DPD block has an input for receiving input samples at a first sample rate and an output for providing the predistorted transmit signals at the first sample rate. Each of the sub-sample delay elements provides a delay to an input sample as specified by the Volterra series approximation model, where each of the delays is based on a fraction of the first sample rate. The selection circuit selects one of the plurality of sub-sample delay elements in response to a selection signal from the digital predistortion block. The selection signal for selecting a delay as specified by the Volterra series approximation model.

Abstract: A method is described for predistorting an input signal to compensate for non-linearities caused to the input signal in producing an output signal. The method comprises: providing an input for receiving a first input signal as a plurality of signal samples, x[n], to be transmitted over a non-linear element; providing at least one digital predistortion block comprising, a plurality of IQ predistorter cells coupled to the input, each comprising a lookup table (LUT) for generating an LUT output. The at least one digital predistortion block block is configured to apply interpolation between LUT entries for the plurality of LUTs; and generate an output signal, y[n], by each of the plurality of IQ predistorter cells by adaptively modifying the first input signal using interpolated LUT entries to compensate for distortion effects in the non-linear element.

Abstract: A digital front end channelization device for one or more carrier signals comprises a per carrier section and a composite section. The composite section may include signal processing units, each of which may include an inverse Fourier transform unit for transforming a composite carrier signal into a time domain signal, a sample detection and selection unit for detecting and selecting a peak of the time domain signal, a clipping unit for clipping the time domain composite carrier signal to produce an error signal, a Fourier transform unit for transforming the error signal into a frequency domain error signal, a frequency shaping unit for frequency shaping the frequency domain error signal, a summation unit for subtracting the frequency shaped frequency domain error signal from the composite carrier signal, and a phase selection unit for phase adjustment of the resulting signal.

Abstract: A digital front end channelization device for one or more carrier signals comprises a per carrier section and a composite section. The composite section may include signal processing units, each of which may include an inverse Fourier transform unit for transforming a composite carrier signal into a time domain signal, a sample detection and selection unit for detecting and selecting a peak of the time domain signal, a clipping unit for clipping the time domain composite carrier signal to produce an error signal, a Fourier transform unit, for transforming the error signal into a frequency domain error signal, a frequency shaping unit for frequency shaping the frequency domain error signal, a summation unit for subtracting the frequency shaped frequency domain error signal from the composite carrier signal, and a phase selection unit for phase adjustment of the resulting signal.

Abstract: A method is described for predistorting an input signal to compensate for non-linearities caused to the input signal in producing an output signal. The method comprises: providing an input for receiving a first input signal as a plurality of signal samples, x[n], to be transmitted over a non-linear element; providing at least one digital predistortion block comprising, a plurality of IQ predistorter cells coupled to the input, each comprising a lookup table (LUT) for generating an LUT output The at least one digital predistortion block block is configured to apply interpolation between LUT entries for the, plurality of LUTs; and generate an output signal, y[n], by each of the plurality of IQ predistorter cells by adaptively modifying the first input signal using interpolated LUT entries to compensate for distortion effects in the non-linear element.

Abstract: A transceiver for a cellular telephone network includes a transmitter and a receiver that receives transmitted signals, as well as a receiver. A spectral analyzer analyzes the received signals and a controller coupled to the spectral analyzer controls the transmitter and receiver as a function of the spectral analyzer analysis.

Abstract: A device and method to adapt a model in a underdetermined adaptive system that provides an output in response to an input. A controller provides parameters to the model in a transceiver system, composed of linearizers, equalizers, or estimators as a function of an error signal. The controller and the model parameters are manipulated to allow agnosticism with respect to input signals or model complexity, enabling robust operation and efficient implementation.

Abstract: A device and method to adapt a model in a underdetermined adaptive system that provides an output in response to an input. A controller provides parameters to the model in a transceiver system, composed of linearizers, equalizers, or estimators as a function of an error signal. The controller and the model parameters are manipulated to allow agnosticism with respect to input signals or model complexity, enabling robust operation and efficient implementation.

Abstract: Pre-distortion techniques, devices and systems for a multi-channel transmitter are described. An adaptation time is provided for each of the transmit chains in the multi-channel transmitter. During each adaptation time an output of a transmit chain is coupled to a shared feedback receiver. The shared feedback receiver generates a feedback signal that is used to vary pre-distortion for that transmit chain. A commutation controller varies at least one of: (a) an amount of the adaptation time for a transmit chain and (b) an order in which each of the transmit chains receives its adaptation time.

Abstract: A linearizer for a non-linear transmitter includes a tap delay line that provides samples of an input signal at selected times. At least one Volterra tap is coupled to the tape delay line. The Volterra tap includes a lookup table representation of a polynomial. An adaptive controller is coupled to the Volterra tap for modifying values in the lookup table.

Abstract: Devices and methods related to devices capable to perform digital output power measurement besides attenuation control are provided. A device includes a digital signal processing unit, a transmitter and a feedback receiver. The digital signal processing unit is configured to control attenuation along a transmission path and a feedback path based on a comparison of a power of a digital input signal with a raw power of a corresponding digital feedback signal, and to calculate an output power value of an analog RF signal to be broadcasted, using the raw power of the digital feedback signal and one or more feedback gain factors related to gain in the feedback receiver.

Abstract: A linearizer for a non-linear transmitter and method include a gain regulator and predistorter adapted to be coupled to a non-linear transmitter in various configurations. Bounding controllers are coupled to the gain regulator and predistorter to maintain normal operation of a transmit path to prevent unstable transmitter operation.

Abstract: Peak power reduction in transmit chains of radiocommunication devices is performed using a low sample rate. Filtering and, optionally, interpolation of a signal being processed for peak power reduction can be performed only in an error signal path or in both an error signal path and a primary signal path.

Abstract: Adaptive gain regulation is performed by measuring one or more real-time closed-loop statistics for a signal output from a gain-controllable circuit and blindly adjusting the gain of the gain-controllable circuit based on the one or more real-time closed-loop statistics measured for the signal so that the signal output by the gain-controllable circuit satisfies a predetermined criteria without using a priori information about the signal.

Abstract: Pre-distortion techniques, devices and systems for a multi-channel transmitter are described. An adaptation time is provided for each of the transmit chains in the multi-channel transmitter. During each adaptation time an output of a transmit chain is coupled to a shared feedback receiver. The shared feedback receiver generates a feedback signal that is used to vary pre-distortion for that transmit chain. A commutation controller varies at least one of: (a) an amount of the adaptation time for a transmit chain and (b) an order in which each of the transmit chains receives its adaptation time.