Methods, systems, and devices for wireless communications are described. For example, a transmitting wireless device, such as a user equipment or a base station, may apply a first set of digital pre-distortion (DPD) coefficients to a plurality of antenna elements to form a first transmit beam. The wireless device may determine to switch from using the first transmit beam to using a second transmit beam that is different from the first transmit beam and may apply a second set of DPD coefficients to the plurality of antenna elements to form the second transmit beam, where the second set of DPD coefficients is different from the first set of DPD coefficients. The wireless device may transmit signaling using the second transmit beam based at least in part on applying the second set of DPD coefficients.

Methods, systems, and devices for wireless communications are described. Some wireless communications systems may support adaptation of digital pre-distortion (DPD) coefficients based on a temperature of a user equipment (UE). The UE may determine a power offset value based on a first temperature value associated with a training procedure for the UE, a second temperature value associated with the UE, and a constant value. The training procedure may be associated with multiple sets of coefficients for the UE. The UE may apply the power offset value to a transmission power level for transmission of a message. The UE may determine a set of coefficients of the multiple sets of coefficients based on the training procedure and the power offset value applied to the transmission power level. The UE may apply the coefficients to a DPD engine of the UE to generate the message for transmission at the transmission power level.

A cross-division duplex (XDD) system includes an apparatus having a transceiver configured to communicate via an uplink channel and a downlink channel concurrently. The apparatus also includes a transmit antenna, a receive antenna, and a processor. The processor is configured to: estimate a non-linear component corresponding to a transmit path in the transceiver; apply an equalizer function to a received signal; and subtract, in a self-interference cancel (SIC) circuitry, the estimated non-linear component from the equalized signal.

Disclosed is a multi-band transmitter for transmitting a multi-band signal. The multi-band transmitter comprises: a pre-distortion unit including a first digital pre-distorter (DPD) which pre-distorts a first band signal and a second DPD which pre-distorts a second band signal discontinuous from the first band signal; a conversion unit which analog-converts the pre-distorted first band signal and the pre-distorted second band signal; an amplification unit including a first power amplifier (PA), which amplifies the analog-converted first band signal, and a second PA, which amplifies the analog-converted second band signal; and a feedback unit which digital-converts the amplified first band signal to feed the digital-converted first band signal back to the first DPD and digital-converts the amplified second band signal to feed the digital-converted second band signal back to the second DPD. The pre-distortion unit performs pre-distortion by using the fed-back first band signal and the fed-back second band signal.

A processing device is provided. The processing device comprises one or more interfaces configured to transmit information to a nonlinear device and processing circuitry configured to control the one or more interfaces and to. Further, the processing circuitry is configured to transmit an excitation signal to the nonlinear device and to receive response information from the nonlinear device. Further, the processing circuitry is configured to determine a linear response of the nonlinear device based on the response information and to determine a nonlinear response of the nonlinear device based on the determined linear response.

A wideband transmission circuit is provided. The wideband transmission circuit includes a transceiver circuit and a power amplifier circuit(s). The transceiver circuit generates a radio frequency (RF) signal(s) from a time-variant input vector and provides the RF signal(s) to the power amplifier circuit(s). The power amplifier circuit(s) amplifies the RF signal(s) based on a modulated voltage and provides the amplified RF signal(s) to a coupled RF front-end circuit (e.g., filter/multiplexer circuit). In embodiments disclosed herein, the transceiver circuit is configured to apply an equalization filter to the time-variant input vector to thereby compensate for a voltage distortion filter caused by a coupling of the power amplifier circuit(s) and the RF front-end circuit. As a result, it is possible to reduce undesired instantaneous excessive compression and/or spectrum regrowth resulting from the voltage distortion filter to thereby improve efficiency and linearity of the power amplifier circuit(s).

A wideband transmission circuit is provided. The wideband transmission circuit includes a power amplifier circuit(s) and an envelope tracking (ET) integrated circuit (ETIC). The ETIC is configured to generate a modulated voltage based on a modulated target voltage. The power amplifier circuit(s) amplifies a radio frequency (RF) signal(s) based on the modulated voltage and provides the amplified RF signal(s) to a coupled RF front-end circuit. In embodiments disclosed herein, the ETIC is configured to cause the modulated target voltage to be equalized by a real equalization filter to thereby compensate for a complex voltage distortion filter resulting from a coupling between the power amplifier circuit(s) and the RF front-end circuit. As a result, it is possible to reduce undesired instantaneous excessive compression and/or spectrum regrowth resulting from the complex voltage distortion filter to thereby improve efficiency and linearity of the power amplifier circuit(s).

In one embodiment, a multi-transceiver RF signal processing system comprises: a controller; a DPD core and CFR engine; and a plurality of transceiver paths comprising at least a first transceiver path for a first frequency block, and a second transceiver path for a second frequency block. The first frequency block is adjacent to the second frequency block. Signal processing outputs a stream of digital RF based on wireless RF signals received into the first and second transceiver paths. Signal processing inputs a first stream of digital RF and outputs a first digital RF signal corresponding to the first frequency block to the first transceiver path, and outputs a second digital RF signal corresponding to the second frequency block to the second transceiver path for wireless transmission via the at least one antenna. The DPD core applies a distortion that covers the first and second frequency blocks.

Some embodiments herein describe a radio frequency power semiconductor device that include a first non-linear filter network for compensating for lower frequency noise of a power amplifier. The first non-linear filter network can include a plurality of infinite impulse response filters and corresponding corrective elements to correct for a non-linear portion of the power amplifier. The radio frequency power semiconductor device can further include a second non-linear filter network for compensating for broadband distortion. The second non-linear filter network can be connected in parallel to the first non-linear filter network. The broadband distortion can include digital predistortion and the narrowband distortion can include charge trapping effects. The first non-linear filter network can comprise Laguerre filters. The second non-linear filter network can comprise general memory polynomial filters.

Examples described herein include methods, devices, and systems which may compensate input data for non-linear power amplifier noise to generate compensated input data. In compensating the noise, during an uplink transmission time interval (TTI), a switch path is activated to provide amplified input data to a receiver stage including a coefficient calculator. The coefficient calculator may calculate an error representative of the noise based partly on the input signal to be transmitted and a feedback signal to generate coefficient data associated with the power amplifier noise. The feedback signal is provided, after processing through the receiver, to a coefficient calculator. During an uplink TTI, the amplified input data may also be transmitted as the RF wireless transmission via an RF antenna. During a downlink TTI, the switch path may be deactivated and the receiver stage may receive an additional RF wireless transmission to be processed in the receiver stage.