64results about "Lookup table adaptive predistortion" patented technology

Certain aspects of the present disclosure provide techniques for pre-distortion training feedback via inductive coupling. An example apparatus includes a receive path; a transmit path comprising an amplifier having a first output that is inductively coupled to the receive path; a memory; and a processor coupled to the memory. The processor is configured to cause the apparatus to obtain a first signal, based on a second signal output by the amplifier, via the receive path being inductively coupled to the first output of the amplifier; determine a parameter for pre-distortion associated with the amplifier based at least in part on the first signal; pre-distort a third signal based at least in part on the parameter; amplify the pre-distorted third signal via the amplifier; and transmit the amplified third signal.

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.

A power amplifier and a method of controlling a power amplifier are described. The power amplifier (300) comprises a hybrid combiner (310) comprising a first input port and a second input port, an isolated port and an output port, wherein the hybrid combiner (310) delivers an output power at the output port. A balanced amplifier arrangement (320) is comprised, the balanced amplifier arrangement (320) comprising a main amplifier arrangement, a first peaking amplifier and a second peaking amplifier, wherein the output of the main amplifier arrangement and the outputs of the first and second peaking amplifiers are coupled to the first and second input ports of the hybrid combiner (310) to provide the output power at the output port. A third peaking amplifier (330) has an output coupled to the isolated port of the hybrid combiner (310). A peaking signal distribution circuit distributes a peaking amplification signal to the input ports of the first, second and third peaking amplifiers.

The present disclosure provides a compensation circuit module, a power amplifier component, a compensation method and an apparatus. The compensation circuit module includes at least: a variable resistor, a detection component and a control component; the detection end of the detection component is connected to the DC blocking capacitor of the power amplifier for detecting the voltage swing of the input signal of the DC blocking capacitor; the control component is connected to the detection component for outputting a control signal according to the input signal detected by the detection component; the variable resistor is connected to the output end of the control component for changing the resistance connected to the power amplifier according to the control signal, and the resistance of the variable resistor connected to the power amplifier is used to constitute the feedback resistance of the power amplifier; the feedback resistance is used to increase when the gain of the power amplifier decreases; the increased feedback resistance is used to keep the gain in the flat section of the gain change curve; the resistance of the variable resistor can be adjusted by the input signal to achieve compensation for the gain of the power amplifier and maintain the linearity of the input and output of the power amplifier.

A predistortion circuit for a wireless transmitter includes a signal input configured to receive a baseband signal. Further, the predistortion circuit includes a predistorter configured to generate a predistorted baseband signal using the baseband signal and a select of one of a first predistorter configuration and a second predistorter configuration.

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.

There is provided mechanisms for operating a digital pre-distorter for a non-linear electronic device. A method comprises receiving an input signal destined to be input to the non-linear electronic device. The method comprises selecting, for basis functions that represent input-output characteristics of the non-linear electronic device, a set of tap delays. The set of tap delays is selected using a block orthogonal matching pursuit algorithm. The method comprises obtaining an output signal by subjecting the input signal to a linearization function defined by the basis functions with the selected set of tap delays. The method comprises providing the output signal as input to the non-linear electronic device.

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.

The present disclosure is a novel utility of a software defined radio (SDR) based Distributed Antenna System (DAS) that is field reconfigurable and support multi-modulation schemes (modulation-independent), multi-carriers, multi-frequency bands and multi-channels. The present invention enables a high degree of flexibility to manage, control, enhance, facilitate the usage and performance of a distributed wireless network such as Flexible Simulcast, automatic traffic load-balancing, network and radio resource optimization, network calibration, autonomous / assisted commissioning, carrier pooling, automatic frequency selection, frequency carrier placement, traffic monitoring, traffic tagging, pilot beacon, etc. As a result, a DAS in accordance with the present invention can increase the efficiency and traffic capacity of the operators' wireless network.

An apparatus may be configured to receive a signal to be transmitted via an array of antennas by a zero-forcing precoder, wherein the signal is processed by the linear precoder based on one or more input power criteria for power amplifiers of the array of antennas; apply a distortion reducing matrix to the processed signal, wherein the distortion reducing matrix is trained to reduce the distortion at each output of the power amplifiers based on minimizing an error signal corresponding to a difference between measured and calculated outputs of the power amplifiers after a coupling effect between the power amplifiers based on the applied matrices; and provide an output of the distortion reducing matrix to be used in digital pre-distortion processing of an input signal for the power amplifiers.

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 method for determining a plurality of digital predistortion, DPD, models. The method comprising obtaining test data indicating a set of test cases. The method further comprising dividing the set of test cases into subsets of test cases. The method further comprising determining a DPD model for each subset of test cases, thereby determining the plurality of DPD models.

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.