Systems, circuitries, and methods for predistorting a digital signal in a transmit chain based on a predistortion function are provided. A method includes shifting a center frequency of an input signal by an offset to generate an adapted signal; predistorting the adapted signal based on a predistortion function to generate a predistorted adapted signal; reverting the shifting of the center frequency of the predistorted adapted signal by the offset to generate a predistorted signal; and causing transmission of the predistorted signal by a transmit chain.

Disclosed are a predistortion method and system, a device, and a non-transitory computer-readable storage medium. The predistortion method is applicable to a predistortion system which may include a predistortion multiplier, a complex neural network, and a radio frequency power amplifier output feedback circuit. The method may include: inputting a training complex vector to the predistortion system to obtain a complex scalar corresponding to the training complex vector, which is output by the predistortion system; training the predistortion system based on the training complex vector and the complex scalar until a generalization error vector magnitude and a generalization adjacent channel leakage ratio corresponding to the predistortion system meet set requirements; and inputting a service complex vector to the trained predistortion system to obtain a predistortion corrected complex scalar.

Dynamic optimization of transistor array in power amplifier. In some embodiments, a power amplification system can include a power amplifier including an array of transistors, with the array configured to receive an input signal and provide an amplified signal. The power amplification system can further include a monitoring system including a plurality of sensing circuits implemented at respective locations of the array, and a control system configured to obtain sensed information from the plurality of sensing circuits, and based on the information, generate a pattern of one or more transistor properties over the array to allow operation of the array in a desired manner based on the pattern.

A digital pre-distortion method for a multiband signal, an electronic device and a non-transitory computer-readable storage medium are disclosed. The digital pre-distortion method may include: determining a possible power amplifier distortion according to configuration of a signal issued by a cell; selecting a basis function of pre-distortion according to the possible power amplifier distortion; solving, according to a pre-collected reference multiband signal and a corresponding feedback signal, the selected basis function to obtain a pre-distortion parameter; and processing an input multiband signal according to the selected basis function and the pre-distortion parameter to generate a pre-distortion signal.

An object is to provide a method and a system of adjusting a power amplifier which makes it possible to adjust a linearizer using signals of two carriers by the same power, to reduce the influence of the non-linearity on a multicarrier signal compared with the conventional. A method of adjusting a power amplifier, the power amplifier including a linearizer to reduce an intermodulation caused by non-linearity of the power amplifier, includes: inputting two signals generated by a signal generator into the power amplifier; measuring power of each order of first intermodulations of the two signals output from the power amplifier; calculating a power sum of second intermodulations by the plurality of signals using the measured power of each order of the first intermodulations; and adjusting the linearizer so that the power sum of the second intermodulations by the plurality of signals takes a minimum value or at most a predetermined value.

Power amplifiers with adaptive bias for envelope tracking applications are provided herein. In certain embodiments, an envelope tracking system includes a power amplifier that amplifies a radio frequency (RF) signal and that receives power from a power amplifier supply voltage, and an envelope tracker that generates the power amplifier supply voltage based on an envelope of the RF signal. The power amplifier includes a field-effect transistor (FET) for amplifying the RF signal, and a current mirror including an input that receives a reference current and an output connected to the power amplifier supply voltage. An internal voltage of the current mirror is used to bias the gate of the FET to compensate the FET for changes in the power amplifier supply voltage arising from envelope tracking.

This application discloses a wireless communication apparatus and a signal processing method. The wireless communication apparatus includes a power amplifier and a bias circuit. The power amplifier includes a signal input port, a signal output port, a power supply port, and a bias port. The power amplifier is configured to: receive a power supply signal through the power supply port, receive a bias signal through the bias port, receive a radio frequency signal through the signal input port, and output a power amplified radio frequency signal. The bias circuit is configured to generate the bias signal. A timing feature of the bias signal is synchronized with a timing feature of a switch signal of a power amplifier, to compensate for a nonlinear change in the TDD scenario.

A method comprises obtaining a transmission signal to be power-amplified in a power amplifier (361) prior to transmission; separating the transmission signal into two or more polyphase components of the transmission signal; feeding one or more polyphase components of the transmission signal comprised in the two or more polyphase components to each of two or more parallel predistortion circuits (320,321,322); selecting a dedicated predistortion model and dedicated predistortion coefficients for each of the two or more parallel predistortion circuits (320,321,322); performing non-linear memory-based modeling on the transmission signal according to the selected dedicated predistortion models and coefficients using the one or more polyphase components; and combining output signals of the two or more parallel predistortion circuits (320,321,322) to form a predistorted transmission signal (y[n]) to be applied to the power amplifier (361).

Radio frequency systems and methods adjust power amplifier operation based on power amplifier operating mode or power level to achieve a tradeoff between improved linearity at lower power levels and improved out of band noise performance and coexistence at higher power levels.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a configuration indicating one or more directions for applying directional digital pre-distortion (DPD) to mitigate interference in a direction to another UE. The UE may transmit a communication to a wireless node based at least in part on applying the directional DPD according to the configuration. Numerous other aspects are described.