236 results about "Predistortion" patented technology

The invention discloses a power adaptive digital pre-distortion method, system and device based on sparse GRU and a medium. The method comprises the steps that input and output signals under different powers are collected, a composite feature vector is constructed through amplitude normalization and phase alignment, and a pre-distortion training target is generated in combination with indirect learning; constructing a sparse GRU neural network, introducing L1 regularization constraint, and obtaining a sparse pre-distortion model through joint optimization of mean square error and sparse constraint; partial weight updating is realized based on power grading, and weight fusion output is carried out during power interval switching so as to complete power adaptive optimization; pruning and compressing the sparse GRU model and then deploying the sparse GRU model in a pre-distortion module to compensate the nonlinearity of the power amplifier; according to the method, the model complexity is reduced through rarefaction, the dynamic working condition stability is improved through a power adaptive mechanism, pruning compression adapts to low-power-consumption hardware, high precision, low complexity and adaptive capacity are considered, and the method is suitable for the low-power-consumption and high-performance requirements of a broadband wireless communication system.

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.

Method and device(s) for supporting performance of machine learning based CFR and DPD on multiple digital input signals relating to different frequency bands, respectively, in order to signal condition said signals before power amplification and subsequent transmission in said frequency bands by a wireless communication network. The device(s) obtain said multiple digital input signals as complex valued signals. The device(s) perform feature construction that takes said multiple digital input signals as input and provides constructed feature signals according to predefined constructed feature types as output. Said predefined constructed feature types relate to at least the following per complex valued sample of the obtained complex valued multiple digital input signals the real part of the sample, the imaginary part of the sample and at least one of the absolute value of the sample and the phase of the sample.

The invention relates to the technical field of radio frequency generator circuits, and provides a phase-locking frequency-stabilizing multi-core control radio frequency system, which processes I / Q signals and constructs a multi-core task allocation and cooperation mechanism through a digital baseband processing module, and performs pre-distortion processing and system scheduling. The double-closed-loop control module is used for stabilizing fundamental frequency, correcting temperature drift and compensating and adjusting frequency swing amplitude; the hybrid power amplification module is used for performing multi-stage hybrid power amplification signal processing and temperature monitoring through a driving stage and output stage combined topology; and the feedback sampling network module collects output signals in real time through a directional coupler and feeds back, adjusts and precisely controls the frequency stability according to the output signals.

The invention relates to the technical field of qec correction of digital arrays, in particular to a feedback-based digital qec correction method for a digital array, and the method comprises the following steps: S1, constructing a transceiving channel distortion model, and calculating distortion model parameters; s2, constructing a transmitting terminal pre-distortion model according to the distortion model parameters, and performing transmitting terminal qec correction; and S3, constructing a post-distortion model of the receiving end according to the distortion model parameters, and performing qec correction of the receiving end. According to the scheme, the problem of mirror image and direct current correction of the receiving and transmitting end of the digital array antenna is solved digitally, the method does not depend on hardware design and does not need support of an external reference source, mirror image qec correction is carried out by using a digital method based on feedback, error correction of the mirror image and the local oscillator is also realized by the method, and the method is high in precision and good in portability.

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 first processing path, an envelope processing path comprising an envelope artificial neural network, multipliers configured to multiply respective output signals of the first 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 the input signal.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus may include first transceiver hardware comprising: first processing logic configured to generate a first plurality of output streams associated with a first sub-array of antenna elements of an antenna array by applying a first inverse power-amplifier- to-antenna-array network (A-l) matrix to one or more first input streams; and a first plurality of digital predistortion (DPD) circuits that are apply first DPD to the first plurality of output streams. The apparatus may include second transceiver hardware comprising: second processing logic configured to generate a second plurality of output streams associated with a second sub-array of antenna elements of the antenna array by applying a second A-l matrix to second one or more input streams, and a second plurality of DPD circuits configured to apply second DPD to the second plurality of output streams.

The invention discloses a system for simultaneously suppressing second-order nonlinearity and third-order nonlinearity in a direct modulation laser (DML), which belongs to the field of optical communication, and can simultaneously suppress the second-order nonlinearity and the third-order nonlinearity in the system under the condition of DSP-FREE through the combined action of a broadband pre-distortion circuit and an optical path push-pull structure. Wherein at a transmitting end, a set of Schottky diodes and Chebyshev gradient transmission lines which are connected in parallel reversely are adopted to build a DC-10GHz broadband pre-distortion module, and a radio frequency signal generates a reverse third-order intermodulation (IMD3) component through an analog pre-distortion circuit so as to counteract forward third-order nonlinearity of a laser; at a receiving end, a second-order intermodulation (IMD2) component is differentially eliminated through an optical path push-pull modulation architecture. Compared with a traditional DSP scheme, digital signal processing is not needed, the method has the advantages of being low in complexity and wide in bandwidth, and nonlinear accurate compensation of an optical communication system can be achieved.

A transceiver system includes a signal generator and controller circuit, a first signal converter circuit, an attenuator circuit, and a second signal converter circuit. Signal generator and controller circuit generates a transmitting baseband signal. First signal converter circuit generates a transmitting radio frequency signal according to transmitting baseband signal. Attenuator circuit generates an attenuated radio frequency signal according to transmitting radio frequency signal. Second signal converter circuit generates an attenuation range baseband reference signal according to attenuated radio frequency signal. Signal generator and controller circuit determines a first attenuation range for attenuator circuit according to attenuation range baseband reference signal when transmitting baseband signal is a dual-tone signal, and determines a second attenuation range from first attenuation range for attenuator circuit according to attenuation range baseband reference signal when transmitting baseband signal is a single-tone signal, and second attenuation range is for a pre-distortion process.

Amplitude and phase error correction in a transceiver circuit is provided. In embodiments disclosed herein, a transceiver circuit is configured to equalize an input vector to thereby correct amplitude-amplitude (AM-AM) and amplitude-phase (AM-PM) errors across a modulation bandwidth of the wireless communication circuit. Unlike conventional methods where complicated memory digital predistortion (mDPD) coefficients must be defined and calibrated for each modulation frequency within the modulation bandwidth, the transceiver circuit is configured herein to eliminate modulation frequency dependency of the AM-AM and AM-PM errors. As a result, it is possible to correct the AM-AM and AM-PM errors across the modulation bandwidth with reduced complexity to thereby improve efficiency and linearity of the wireless communication circuit.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus may apply digital predistortion (DPD) to a wideband signal by splitting the wideband signal into respective distinct sub-bands, and inputting the respective distinct sub-bands to a multi-dimensional DPD apparatus. The multi-dimensional DPD apparatus may apply DPD based at least in part on using a multi-band DPD kernel that processes the respective distinct sub-bands. The multi-dimensional DPD apparatus may implement the multi-band DPD kernel as a DPD kernel set, and the DPD kernel set may be implemented using any combination of one or more envelope delay line components, one or more envelope selection components, one or more look-up-table (LUT) components, one or more computation delay line components, one or more computation selection components, one or more combiner components, and / or one or more adder components. Numerous other aspects are described.

The present disclosure provides a system and a method for linearization of a power amplifier chain. The system determines a predistorted signal associated with a coupled power output of a power amplifier along a first transmission path among one or more transmission paths based on a RF input signal received by the transceiver. The system determines, an output signal associated with the coupled power output of the PA along a second transmission path among the one or more transmission paths, where the coupled power output is based on the predistorted signal. The system monitors, the output signal associated with the PA. The system varies the predistorted signal to generate the power output through the PA.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus may include first transceiver hardware comprising: first processing logic configured to generate a first plurality of output streams associated with a first sub-array of antenna elements of an antenna array by applying a first inverse power-amplifier-to-antenna-array network (A-1) matrix to one or more first input streams; and a first plurality of digital predistortion (DPD) circuits that are apply first DPD to the first plurality of output streams. The apparatus may include second transceiver hardware comprising: second processing logic configured to generate a second plurality of output streams associated with a second sub-array of antenna elements of the antenna array by applying a second A-1 matrix to second one or more input streams, and a second plurality of DPD circuits configured to apply second DPD to the second plurality of output streams.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus may include first transceiver hardware comprising: first processing logic configured to generate a first plurality of output streams associated with a first sub-array of antenna elements of an antenna array by applying a first inverse power-amplifier-to-antenna-array network (A-1) matrix to one or more first input streams; and a first plurality of digital predistortion (DPD) circuits that are apply first DPD to the first plurality of output streams. The apparatus may include second transceiver hardware comprising: second processing logic configured to generate a second plurality of output streams associated with a second sub-array of antenna elements of the antenna array by applying a second A-1 matrix to second one or more input streams, and a second plurality of DPD circuits configured to apply second DPD to the second plurality of output streams.

The application provides an AM-PM distortion calibration method applied to an UWB transmitter and belongs to the field of UWB communication. The method adds a sampling resistor between a linear voltage stabilizing power supply LDO and a digital power amplifier DPA driving stage of the UWB transmitter using a digital power amplifier, so as to simulate the instantaneous change of the power supply voltage of the DPA driving stage when the UWB pulse is transmitted; an adjustable delay unit is added between a carrier input port LO and the DPA driving stage; the continuous sine wave is transmitted, the phase information under each digital baseband amplitude control word is collected to form original data of the AM-PM distortion of the UWB transmitter, the digital baseband output AM-PM control word is used to control the adjustable delay unit to output the phase which is opposite to the original data and has the same size, so that the phase predistortion of the transmitted UWB pulse is realized, and the AM-PM distortion calibration is completed. The application has the advantages of simple implementation and strong compensation capacity.

A communication device comprises: a digital predistortion (DPD) circuit; a digital-to-analog converter (DAC) configured to convert output signals of the DPD circuit into analog signals; a power amplifier configured to amplify the analog signals; and an antenna configured to transmit the amplified analog signals, wherein the DPD circuit may be configured to: generate first predistortion signals by performing a convolution operation on digital signals of a reference time unit over a time interval including a first set of time units before the reference time unit and a second set of time units after the reference time unit; generate second predistortion signals by performing predistortion on the digital signals; and generate the output signals of the DPD circuit on the basis of the first predistortion signals and the second predistortion signals.

The invention provides a digital pre-distortion coefficient updating method and device for a frequency hopping communication system, and the method comprises the steps: obtaining a corresponding historical digital pre-distortion coefficient when the system hops to a target frequency point, and collecting training data at the initial stage of a current hop; based on the historical digital pre-distortion coefficient and the training data, obtaining an intermediate vector used for representing the change degree of the system through an adaptive filtering algorithm, and determining a change metric based on the intermediate vector; comparing the change measurement with a preset threshold value so as to divide the system state change into different levels, and dynamically triggering a matched updating mode; wherein the updating mode comprises a holding mode, a lightweight tracking mode and a precise reconstruction mode. According to the method, the system state change is divided into different levels by quantitatively evaluating the change measurement of the coefficient update vector, and the update mode which is most matched with the change is dynamically triggered, so that the global optimization of the system performance and the resource overhead is realized.

The invention discloses a satellite synchronous detection signal transmitting device and applying method for an underwater large-burial-depth pipeline, and relates to the technical field of satellite synchronous detection, and the satellite synchronous detection signal transmitting device comprises a low-frequency shear force sensing module, a near-resonance recognition modeling module, a target detuning adjustment module, a pre-distortion beam generation module, a leakage spectrum suppression module and a closed-loop adaptive control module. And the low-frequency shear force sensing module is used for constructing a low-frequency shear force real-time sensing link. According to the method, through low-frequency shear force sensing, parameterized structure modeling, damping and rigidity cooperative adjustment, predistortion beam control and leakage spectrum screening, real-time prediction and active suppression of the antenna resonance risk in the deep sea environment are achieved, and the pipeline positioning precision is guaranteed. By combining satellite positioning residual error and time delay drift feedback, closed-loop adaptive control is constructed, a driving structure and signal collaborative optimization are realized, anti-resonance and leakage suppression effects are kept for a long time, an unattended operation period is prolonged, and detection reliability and data validity are improved.

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.

The computed tomography (CT) scanner gantry rotates relative to the fixed substrate of the CT scanner. During gantry rotation, digital data is transmitted from a data source via a modulator, transmission channel, and demodulator to a data receiver between the gantry and the substrate. A predistortion device located upstream of the transmission channel predistorts the transmitted signal generated by the modulator from the data source through modulation according to a predistortion rule. Only the predistorted transmitted signal is transmitted to the transmission channel. Alternatively or additionally, a postdistortion device located downstream of the transmission channel postdistorts the signal transmitted via the transmission channel according to a postdistortion rule, and only the postdistorted signal is transmitted to the demodulator. The predistortion rule and / or postdistortion rule are repeatedly reset by a setting device during gantry rotation.

The utility model provides a radio frequency circuit and communication equipment. The radio frequency circuit comprises a signal processing module, a circulator, a switching module, a transceiving switching module, an antenna, a pre-distortion correction module, a circulator correction module and a load, wherein in the correction stage, a first communication link is formed, and the circulator correction module is configured to obtain a first feedback signal input to the switching module by the circulator, obtain an expected correction coefficient of the circulator correction module, and correct the circulator after the correction coefficient of the circulator correction module is set as the expected correction coefficient; and in the working stage, a second communication link is formed, and the predistortion correction module is configured to input the first radio frequency signal, obtain a second feedback signal input to the circulator by the signal processing module and correct the radio frequency signal according to the second feedback signal and an expected correction coefficient. Through the above mode, non-linear correction of the circulator is realized.

The invention relates to the technical field of radar interference high-speed transmission, in particular to an SAR (Synthetic Aperture Radar) interference method based on high-speed data transmission, which comprises the following steps of: receiving a radio-frequency signal transmitted by an interfered SAR, performing down-conversion and analog-to-digital conversion on the radio-frequency signal by a radio-frequency receiving front end to obtain an original sampling data stream, and transmitting the original sampling data stream to a programmable logic part through a high-speed serial interface; the method comprises the following steps: extracting pulse description words including pulse arrival time, pulse width, pulse repetition interval and carrier frequency, reconstructing a coherent interference signal baseband waveform in real time according to the pulse description words, and performing digital up-conversion and digital pre-distortion processing on the baseband waveform to generate a target interference intermediate frequency digital signal; and after digital-to-analog conversion and up-conversion are completed, an interference radio frequency signal is radiated. According to the method, data transmission and signal processing delay can be reduced, interference signal coherence is guaranteed, and intermediate frequency signal generation precision and processing real-time performance are improved.

The application relates to the technical field of wireless communication, and discloses a digital predistortion method for improving the linearity of a power amplifier in a phased array system, which comprises the following steps: step one, acquiring nonlinear parameters of a power amplifier under dynamic load in real time, wherein the nonlinear parameters comprise input signal amplitude and phase characteristics, temperature parameters and quantum tunneling current parameters; step two, generating a predistortion compensation signal based on the nonlinear parameters, wherein the predistortion compensation signal comprises a quantum phase compensation term and a dynamic phase change compensation term; and step three, superimposing the predistortion compensation signal to an original input signal to generate a predistortion modulation signal. The application improves the linearity of the power amplifier by introducing the quantum phase compensation term and the dynamic phase change compensation term, and improves the accuracy of predistortion compensation by accurately acquiring the nonlinear parameters in real time under the dynamic load environment.

Embodiments of circuits, apparatuses, and methods for envelope tracking are disclosed. In one example, a circuit for envelope tracking may include a digital predistorter that receives an input signal representing a signal to be transmitted. The circuit may also include a filtered envelope tracking generator that receives the input signal and provides one or more output signals. The one or more output signals may include a signal that is a filtered tracking envelope of the input signal. One of the one or more output signals may be provided to the digital predistorter. The circuit may also include an envelope tracker that receives the filtered tracking envelope and provides an envelope tracking input to a power amplifier.

A power amplification system (7) is provided with: a power amplifier (2); an output switching circuit (30) configured so as to selectively output at least one of the three or more discrete voltages to the power amplifier (2); and a DPD circuit (71) configured so as to pre-distort an input signal of the power amplifier (2), the output switching circuit (30) having a first mode in which at least one of a first subset of the three or more discrete voltages is selectively output, and a second mode in which at least one of a second subset of the three or more discrete voltages is selectively output. The average voltage of the first subset is higher than the average voltage of the second subset, the DPD circuit (71) predistorts an input signal of the power amplifier (2) using a first parameter in a first mathematical model in a first mode, uses a second parameter in a second mathematical model, or uses a third parameter in the first mathematical model, an input signal of a power amplifier (2) is pre-distorted.

The invention belongs to the technical field of filters, and particularly relates to a reconfigurable electric tuning frequency hopping filter and a multi-target optimization control method thereof.The filter comprises an MCU module, a resonance circuit module, a pre-distortion module and a signal receiving and transmitting module, the MCU module is provided with two main control CPUs and used for radio frequency signal processing, parameter control and communication coordination, address codes are calculated through the main control CPUs, and the signal receiving and transmitting module is used for receiving and transmitting signals. Radio frequency signal processing is set to be straight-through processing or filtering processing, a C-V curve and tuning voltage-frequency response of a variable capacitance diode are measured, a nonlinear model is established, and the non-linear model is used for radio frequency signal preprocessing of the MCU module, sending the radio frequency signal to the pre-distortion module or outputting the radio frequency signal after straight-through processing through parameter control of the MCU module. According to the invention, non-linear compensation can be carried out on signals with different frequencies in advance, and then the signals are distributed to corresponding resonance circuits through a digital chip in an address code calculation mode, so that the out-of-band rejection performance is improved, and distortion is reduced.

This invention relates to a high-precision digital predistortion phase interpolator with a constant input load, comprising: a multi-phase clock generation circuit, an input buffer circuit, two pre-filter circuits, a phase interpolation core circuit, a CML2CMOS circuit, and a control code decoder circuit. The two pre-filter circuits convert two full-swing square wave signals into two sinusoidal clocks. The phase interpolation core circuit performs nonlinear interpolation on the two sinusoidal clocks with a constant input load based on two weighted control codes, outputting a small-swing signal. This phase interpolator significantly improves interpolation accuracy. Digital predistortion of the interpolation weights can be achieved by adjusting the control code decoder, further enhancing the accuracy of the phase interpolator and enabling high-speed, high-precision output clocks. It is suitable for clock data recovery circuits and phase-locked loops in high-speed SerDes systems.

The invention discloses a temperature sensing type dense gating circulation unit digital predistorter model and a design method thereof, and the method comprises the steps: introducing real-time temperature information as a key feature into the model input, and combining the time sequence modeling capability of a gating circulation unit with a dense jump connection structure, thereby obtaining a temperature sensing type dense gating circulation unit digital predistorter model. And high-precision and robust compensation of nonlinear and memory effects of the PA under different temperature working conditions is realized. The design method comprises the following steps: S1, synchronously acquiring and aligning data; s2, performing input preprocessing and framing; s3, multi-dimensional feature extraction: for each time step n in each frame, extracting an eight-dimensional feature vector Ft from the preprocessed signals Ix [n] and Qx [n] and the temperature T [n]; s4, carrying out GRU time sequence modeling and dense feature fusion; and S5, performing model deployment and an adaptive mechanism.

The invention discloses a digital pre-distortion algorithm verification method and device suitable for a large-scale antenna array, and the method comprises the steps: constructing a single-channel radio frequency link, and obtaining the input data and output data of a power amplifier; taking input data and output data of the power amplifier as a training set, and training by using a target digital pre-distortion algorithm to obtain a pre-distorter model and a pre-distorter model correlation coefficient; modeling input data and output data of a power amplifier into a high-precision mathematical model through a neural network method, loading the high-precision mathematical model into a radio frequency channel of the large-scale phased array system-level simulation model, and adding actual damage into the large-scale phased array system-level simulation model; deploying a predistorter model in a radio frequency channel of the large-scale phased array system-level simulation model, and evaluating the final performance of a target digital predistortion algorithm from multiple dimensions; modeling and digital pre-distortion training are carried out based on hardware actual measurement data, the research and development cost is reduced, and algorithm optimization and system design are guided.

A power amplification system (20) has the following features: a power amplifier (11) configured to amplify a first WLAN signal in a first frequency band; a power amplifier (12) configured to amplify a second WLAN signal in a second frequency band higher than the first frequency band; and a (DPD) circuit (311) configured to pre-distort the second WLAN signal without pre-distorting the first WLAN signal.