43results about "Lookup table adaptive predistortion" patented technology

Systems and techniques are provided for power amplifier gain error compensation for a Digital Power Amplifier (DPA). In some aspects, a compensation method includes obtaining in-phase (I) and quadrature-phase (Q) components of a baseband sample corresponding to in-phase input amplitude codes and quadrature-phase input amplitude codes. The in-phase input amplitude codes can be distorted based on first gain pre-compensation information corresponding to an in-phase signal branch of the DPA, to generate pre-distorted output amplitude codes of the I component. The quadrature-phase input amplitude codes can be distorted based on second gain pre-compensation information corresponding to a quadrature-phase signal branch of the DPA, to generate pre-distorted output amplitude codes of the Q component. The DPA can be driven using the pre-distorted output amplitude codes of the I and Q components to generate a Radio Frequency (RF) output.

Techniques are described for implementing multiband digital predistortion in a broadband transmitter in a manner that provides effective compensation of non-linear distortion arising from integration of a high-power amplifier (HPA). Embodiments segment the signal spectrum of a transmit signal into multiple sub-band signals and apply non-linear distortion compensation separately and concurrently for each sub-band signal. The resulting multi-band digital predistortion (mDPD) compensates both for in-band distortion and for distortions from non-linear interactions between the frequency sub-bands. The disclosed mDPD can provide enhanced performance features, such as handling of memory effects, reduced sampling rate requirements for DPD components, and minimizing detrimental spectral regrowth at the HPA output.

This application relates to a predistortion circuit for a wireless transmitter and a method for generating a predistorted baseband signal. Specifically, the invention discloses a predistortion circuit for a wireless transmitter, comprising a signal input configured to receive a baseband signal. Furthermore, the predistortion circuit includes a predistorter configured to generate a predistorted baseband signal using the baseband signal and a selection of a first predistorter configuration and a second predistorter configuration.

Systems and techniques are provided for power amplifier gain error compensation for a Digital Power Amplifier (DPA). In some aspects, a compensation method includes obtaining in-phase (I) and quadrature-phase (Q) components of a baseband sample corresponding to in-phase input amplitude codes and quadrature-phase input amplitude codes. The in-phase input amplitude codes can be distorted based on first gain pre-compensation information corresponding to an in-phase signal branch of the DPA, to generate pre-distorted output amplitude codes of the I component. The quadrature-phase input amplitude codes can be distorted based on second gain pre-compensation information corresponding to a quadrature-phase signal branch of the DPA, to generate pre-distorted output amplitude codes of the Q component. The DPA can be driven using the pre-distorted output amplitude codes of the I and Q components to generate a Radio Frequency (RF) output.

Systems, methods, apparatus, and computer-readable media for power amplifier gain error compensation for a digital power amplifier (DPA) are provided.SOLUTION: A signal compensation method for digitally correcting gain characteristics of a DPA includes obtaining an in-phase (I) component and a quadrature-phase (Q) component of baseband samples corresponding to an in-phase input amplitude code and a quadrature-phase input amplitude code, distorting the in-phase input amplitude code based on first gain predistortion information corresponding to an in-phase signal branch of the DPA to generate an I-component predistorted output amplitude code, distorting the quadrature-phase input amplitude code based on second gain predistortion information corresponding to a quadrature-phase signal branch of the DPA to generate a Q-component predistorted output amplitude code, and the DPA is driven using the I-component and Q-component predistorted output amplitude codes to generate a radio frequency (RF) output.SELECTED DRAWING: Figure 17

A linearization method for a power amplifier includes the following steps. An input signal and an error associated with the input signal are received. Fuzzy statistics is performed on the input signal and the error. A compensation value is calculated according to a fuzzy control table and a defuzzification equation. The compensation value is combined with the input signal to obtain an intermediate signal, and the intermediate signal is input into a power amplifier, so that the power amplifier outputs a first output signal. The first output signal from the power amplifier is fed back into an inverse model of an ideal power amplifier, so that the inverse model outputs a second output signal. A subtraction between the intermediate signal and the second output signal is calculated to obtain the error.

A digital pre-distortion circuit and technique for a signal being amplified. Digital pre-distortion is performed using a model-based pre-distortion function. Pre-distortion is further corrected using a data-driven pre-distortion function. The model-based pre-distortion function and the data-driven pre-distortion function are trained using training data including a digital loopback signal generated by sampling a loopback signal of an amplifier, the digital pre-distorted signal input to the amplifier for a time period, and an intermediate signal output from the model-based pre-distortion function driven by the digital loopback signal or an output of the data-driven pre-distortion function. Parameters may be continually updated in order to account for changes in characteristics of the amplifier.

The present disclosure pertains to a power amplifier system that promotes enhanced signal linearity and overall system efficiency. The system includes a power amplifier with an amplification path for a radio frequency (RF) signal, and detector circuitry operationally linked to sample locations along this path. The detector circuitry captures and transmits signal characteristics of the RF signal. A voltage standing wave ratio (VSWR) quadrant data generator in communication with the detector circuitry generates VSWR quadrant data based on the detected signal characteristics. The baseband circuitry, comprised of a memory unit preconfigured with digital pre-distortion (DPD) coefficients and a DPD processor, controls the shaping of pre-distortion applied to the RF signal based on the VSWR data, thereby enhancing signal linearity. The components of the system interconnect and collaboratively function to optimize the performance and efficiency of the power amplifier system.

This electronic device may comprise: a memory for storing instructions; a transmission antenna; a power amplifier, a digital predistortion (DPD) circuit including a first DPD path and a second DPD path; and at least one processor. When executed by the at least one processor, the instructions can cause the electronic device to: predistort, on the basis of the first DPD path, a first digital signal having a first sampling rate; transmit a first output signal generated on the basis of the power amplifier from the predistorted first digital signal; provide, to the DPD circuit, on the basis of a correlation value for the first digital signal and the first output signal, a control signal for activating the second DPD path; predistort, on the basis of the second DPD path, a second digital signal having a second sampling rate; and transmit a second output signal generated on the basis of the power amplifier from the predistorted second digital signal.

Methods and devices are provided in which a processor of a user equipment (UE) combines loop-back signals from a plurality of antenna paths of the UE to generate a combined signal. The loop-back signals are based on a signal transmitted over the antenna paths. The processor determines power amplifier (PA) polynomials based on a comparison of the combined signal to the signal transmitted over the antenna paths. The processor generates a single look-up table (LUT) for the PA polynomials. The processor applies the single LUT to a transmitted signal of the UE to compensate for PA non-linearity.

An electronic device for predistortion of an input signal is provided. The electronic device may include: a memory for storing instructions; a transmission antenna; a power amplifier, a digital predistortion (DPD) circuit including a first DPD path and a second DPD path; and at least one processor. The electronic device may operate to predistort a first digital signal having a first sampling rate based on the first DPD path; transmit a first output signal generated from the predistorted first digital signal; provide to the DPD circuit a control signal for activating the second DPD path based on a correlation value between the first digital signal and the first output signal; predistort a second digital signal having a second sampling rate based on the second DPD path; and transmit a second output signal generated from the predistorted second digital signal.

Example embodiments relate to machine learning based power amplifier digital predistortion. A device can utilize a power amplifier to amplify and transmit a signal. The signal can be received by an internal feedback receiver of the device. The device can further include a first machine learning model configured to emulate an external feedback receiver and generate an emulated feedback signal based on the internal feedback signal. The device can further include a second machine learning model configured to determine a digital predistortion parameter for the power amplifier based on the emulated feedback signal. Apparatuses, methods, and computer programs are disclosed.

A method, apparatus and computer readable storage medium for power amplifier linearization are disclosed. In a method, a plurality of parameters is determined for a predistortion process of the at least one power amplifier to reduce a difference between a reference signal and a feedback signal and to enhance efficiency of the at least one power amplifier. The predistortion process is caused to be performed using at least the plurality of parameters to linearize the at least one power amplifier.

Systems and methods for front-end linearization using information from a baseband circuit are disclosed. In one aspect, a baseband circuit provides information to a front-end module that uses the information to adjust operating parameter settings such as how an analog predistortion (APD) circuit or power management integrated circuit behaves to provide more linear operation of the front-end module across the frequencies of interest. In exemplary aspects, the front-end module may receive raw information from which the front-end module determines what changes should be made. In alternate exemplary aspects, the baseband circuit provides instructions or coefficients that are then used by the front-end module to make the changes. In either event, the front-end module may optimize operation to reduce power consumption and provide more linear operation so that the transceiver may better operate within the parameters of a given wireless protocol.

Systems, devices, and methods are provided for using model architecture search for hardware configurations. The method includes receiving, by a computer-implemented system, information associated with a pool of processing units, receiving, by the computer-implemented system, a dataset associated with a data transformation operation, training a parameterized model associated with the data transformation operation based on the dataset and the information associated with the pool of processing units, where the training includes updating at least one parameter of the parameterized model associated with configuring at least a subset of the processing units in the pool, and outputting one or more configurations for at least a subset of the processing units in the pool based on the training.

An amplifier device may include a signal input configured to receive an analog signal, a signal output, and a main signal path between the signal input and the signal output. Amplifier circuitry is arranged in the main signal path. The amplifier device has signal predistortion circuitry including analog predistortion circuitry configured to generate a first predistortion signal and digital predistortion circuitry configured to generate a second predistortion signal. The signal predistortion circuitry is configured to adapt a signal in the main signal path based on the first predistortion signal and on the second predistortion signal for at least partially compensating a non-linearity of the amplifier circuitry. The analog predistortion circuitry and the digital predistortion circuitry are arranged in parallel signal paths.

Systems and methods for separate digital predistortion (S-DPD) for multi-band radios are disclosed. In one embodiment, a method of operation of a digital predistortion (DPD) actuator system for a radio node for a wireless network comprises receiving a plurality of input signals (x1, . . . , xB) for a plurality of frequency bands (b1, . . . , bB), respectively. The method further comprises, for each frequency band (bl) of the plurality of frequency bands (b1, . . . , bB), generating a plurality of predistorted signals for the frequency band (bl) based on the plurality of input signals (x1, . . . , xB) and a plurality of Look-Up Tables (LUTs) each having less than B dimensions and combining the plurality of predistorted signals for the frequency band (bl) to provide a combined predistorted signal for the frequency band (bl). In this manner, lower dimensionality LUTs are used, which in turn reduces cost and complexity of the DPD system.

A signal processing method and device, comprising: when a first radio frequency transmitting channel works in a first bandwidth, the first radio frequency transmitting channel is configured to provide a signal processed by digital pre-distortion to a first PA, and a first power supply module is configured to provide a non-envelope waveform power supply voltage to the first PA; the first PA is used to amplify the first signal output by the first radio frequency transmitting channel; when the first radio frequency transmitting channel works in a second bandwidth, the first power supply module is configured to provide an envelope waveform power supply voltage to the first PA; and the first radio frequency transmitting channel is configured to provide a signal not processed by digital pre-distortion to the first PA. In the above scheme, when the bandwidth is switched, the LUT required for digital pre-distortion processing does not need to be adjusted, and the LUT required for generating the envelope waveform power supply voltage does not need to be adjusted, so that the bandwidth can be quickly switched, and the non-linear distortion of the output signal of the first radio frequency transmitting channel can be reduced.

Aspects of this disclosure relate to Neural Volterra actuators. In an embodiment, a Neural Volterra actuator includes a first processing block that includes an artificial neural network, a second processing block that includes non-linear gain blocks, multipliers, a connection circuit configured to adjust an electrical connection to an input of a multiplier of the multipliers, and a combiner that generates a combined output signal based on output signals from the multipliers. The combined output signal can be a digitally predistorted version of an input signal received by the Neural Volterra actuator. Related methods and systems are also disclosed.

Aspects of this disclosure relate to digital compensators, such as digital predistortion systems. Digital predistortion systems disclosed herein use a neural Volterra approach. Such digital predistortion systems can include a feature processing path comprising a feature artificial neural network, an envelope processing path, multipliers configured to multiply respective output signals of the feature processing path and the envelope processing path, and a combiner configured to generate a combined output signal based on at least output signals of the multipliers. The combined output signal is a digitally predistorted version of an input signal.

Systems and methods for analog predistortion (APD) in power amplifiers are disclosed. In one aspect, APD may be provided in a front-end module (FEM) of a transmitter. More specifically, the APD may include different predistortions based on where within a frequency band the signal to be distorted is operating (i.e., sub-band APD). The APD in the FEM may further be based on operating conditions such as temperature within the FEM. Still further, the FEM may be configured to apply different APD based on whether or not a baseband processor (BBP) applies digital predistortion (DPD). At a minimum, the provision of the APD may make the operation of a power amplifier in FEM more linear. Further, where DPD is present, the use of the APD may simplify the requirements for the DPD provided in the BBP.

A distortion apparatus for a power amplifier comprises: pre-distortion circuitry that comprises a memory polynomial look-up-table (LUT) circuit; and post-distortion circuitry that updates the pre-distortion circuitry based on an output of the power amplifier. The pre-distortion circuitry comprises a plurality of LUTs. Each LUT corresponds to a different memory depth of a memory polynomial of a Volterra series. Each LUT indexed by an instantaneous power of an input sample delayed by an amount corresponds to a respective memory depth of each LUT. An output of the memory polynomial LUT circuit corresponds to a summation of an output of each LUT multiplied by the input sample delayed by the amount corresponding to the respective memory depth of each LUT, and an output of the pre-distortion circuitry is provided to the power amplifier.

A system and method for digital correction for a dynamically varying non-linear system. The system includes a correction circuitry including at least one look-up table (LUT). The correction circuitry is configured to receive an input signal and modify the input signal to be processed by the non-linear system using at least one LUT to correct non-linearity incurred by the non-linear system. The at least one LUT is addressed by a magnitude or power of the input signal and a dynamically varying parameter associated with the input signal. The dynamically varying parameter may be one of average signal power of the input signal, a differential of the average power of the input signal, a directional beam index, or temperature.

Phase and amplitude error correction in a transmission circuit is provided. The transmission circuit includes a transceiver circuit, a power management integrated circuit (PMIC), and a power amplifier circuit(s). The transceiver circuit generates a radio frequency (RF) signal(s) from an input vector, the PMIC generates a modulated voltage, and the power amplifier circuit(s) amplifies the RF signal(s) based on the modulated voltage. When the power amplifier circuit(s) is coupled to an RF front-end circuit, unwanted amplitude-amplitude (AM-AM) and amplitude-phase (AM-PM) errors may be created across a modulation bandwidth of the transmission circuit. In this regard, in embodiments disclosed herein, the input vector is equalized based on multiple complex filters to thereby cause the AM-AM and AM-PM errors to be corrected in the transmission circuit. As a result, it is possible to reduce undesired instantaneous excessive compression and / or spectrum regrowth across the modulation bandwidth of the transmission circuit.

The invention relates to a neural worthland system for digital pre-distortion. Aspects of the present disclosure relate to a neural wolfram actuator. In an embodiment, a neural Wollaston actuator comprises: a first processing block comprising an artificial neural network; a second processing block including a nonlinear gain block; a multiplier; a connection circuit configured to adjust an electrical connection to an input of a multiplier of the multipliers; and a combiner that generates a combined output signal based on the output signal from the multiplier. The combined output signal may be a digitally pre-distorted version of the input signal received by the Neural Wollaston actuator. Related methods and systems are also disclosed.

The present disclosure pertains to a power amplifier system that promotes enhanced signal linearity and overall system efficiency. The system includes a power amplifier with an amplification path for a radio frequency (RF) signal, and detector circuitry operationally linked to sample locations along this path. The detector circuitry captures and transmits signal characteristics of the RF signal. A voltage standing wave ratio (VSWR) quadrant data generator in communication with the detector circuitry generates VSWR quadrant data based on the detected signal characteristics. The baseband circuitry, comprised of a memory unit preconfigured with digital pre-distortion (DPD) coefficients and a DPD processor, controls the shaping of pre-distortion applied to the RF signal based on the VSWR data, thereby enhancing signal linearity. The components of the system interconnect and collaboratively function to optimize the performance and efficiency of the power amplifier system.

Systems and techniques are provided for power amplifier gain error compensation for a Digital Power Amplifier (DPA). In some aspects, a compensation method includes obtaining in-phase (I) and quadrature-phase (Q) components of a baseband sample corresponding to in-phase input amplitude codes and quadrature-phase input amplitude codes. The in-phase input amplitude codes can be distorted based on first gain pre-compensation information corresponding to an in-phase signal branch of the DPA, to generate pre-distorted output amplitude codes of the I component. The quadrature-phase input amplitude codes can be distorted based on second gain pre-compensation information corresponding to a quadrature-phase signal branch of the DPA, to generate pre-distorted output amplitude codes of the Q component. The DPA can be driven using the pre-distorted output amplitude codes of the I and Q components to generate a Radio Frequency (RF) output.

An amplifier device (10) comprises a signal input (11) configured to receive an analog signal, a signal output (12) and a main signal path (13) between the signal input and the signal output. Amplifier circuitry (14) is arranged in the main signal path. The amplifier device further comprises signal predistortion circuitry (15). The signal predistortion circuitry comprises analog predistortion circuitry (151) configured to generate a first predistortion signal and digital predistortion circuitry (152) configured to generate a second predistortion signal. The signal predistortion circuitry is configured to adapt a signal in the main signal path based on the first predistortion signal and on the second predistortion signal for at least partially compensating a non-linearity of the amplifier circuitry. The analog predistortion circuitry (151) and the digital predistortion circuitry (152) are arranged in parallel signal paths.

A digital pre-distortion achieving near ideal spectral regrowth suppression with a bandlimited loopback. To eliminate mismatch between the bandwidth of the pre-distortion model terms and the bandwidth of the signal used to determine the model a band limiting operation may be applied to both the loopback signal and the input to the power amplifier used for estimating the pre-distortion coefficients. In addition, oversampling may be performed in the digital domain to avoid aliasing in the nonlinear terms of the pre-distortion model.

Systems and methods for front-end linearization using information from a baseband circuit are disclosed. In one aspect, a baseband circuit provides information to a front-end module that uses the information to adjust operating parameter settings, such as how an analog predistortion (APD) circuit or power management integrated circuit behaves, to provide more linear operation of the front-end module across the frequencies of interest. In exemplary aspects, the front-end module may receive raw information from which the front-end module determines what changes should be made. In alternate exemplary aspects, the baseband circuit provides instructions or coefficients that are then used by the front-end module to make the changes. In either event, the front-end module may optimize operation to reduce power consumption and provide more linear operation so that the transceiver may better operate within the parameters of a given wireless protocol.