A system and method for calibrating digital pre-distortion in a wireless device. A pre-distortion circuit may output a first training signal while a power amplifier of the wireless device is on, to generate a first feedback signal. The first feedback signal may be fed back to the pre-distortion circuit via a receive path of the wireless device. The pre-distortion circuit may output a second training signal while the power amplifier is off, to generate a second feedback signal. The second feedback signal may be fed back to the pre-distortion circuit via the receive path. The pre-distortion circuit may then determine one or more pre-distortion coefficients based on the first and second feedback signals.

Described herein are technologies related to an implementation of a closed-loop system to measure and compensate non-linearity in a transceiver circuitry of a device.

Provided is a communication system using a space division multi-user multiple input multiple output (SD-MIMO) communication method. A transmission apparatus may transmit, to each of terminals included within a coverage, common control information commonly transmitted to the terminals and individual control information individually transmitted to each of the terminals. The transmission apparatus does not precode the common control information and transmits the non-precoded common control information. The transmission apparatus precodes the individual control information and transmits the precoded individual control information.

Mobile devices, base stations, and/or relay stations may implement methods for decreasing required guard bands while also minimizing Adjacent Channel Leakage Ratio, when multiple mobile devices communicate over different respective adjacent specified frequency bands. For communications over at least one specified frequency band of the different respective adjacent frequency bands, a first bandwidth of uplink communications and/or a second bandwidth of downlink communications may be adjusted to differ from each other, and/or a communications bandwidth within the specified frequency band may be adjusted to be of a first size during a first portion of a specified data transmission period and to be of a second size during a second portion of the specified data transmission period, when at least some of the communications over the specified frequency band take place at frequencies adjacent to frequencies at which at least some of the communications take place over another specified frequency band.

A very high frequency (VHF) transceiver can include an amplitude and phase shift keying (APSK) modulator configured to modulate signals for transmission across a first VHF channel of a plurality of VHF channels used to communicate between or among aircraft and one or more ground stations. Each of the VHF channels can have a bandwidth of at least 8.33 kilo Hertz (kHz) with a data rate per Hertz (Hz) greater than or equal to 3 bits per second per Hz (bps/Hz). The VHF transceiver can include a power amplifier configured to amplify the modulated signals prior to the transmission. The VHF transceiver can include a linearity controller configured to control linearity of the power amplifier according to at least one of a Cartesian feedback amplifier linearization, pre-distortion amplifier linearization or feedforward amplifier linearization to mitigate nonlinear distortion associated with signals output by the power amplifier.

Various aspects described herein relate to resolving failures in digital pre-distortion (DPD) training in wireless communications. A failure during DPD training can be identified for a transceiver. One or both of a severity of the failure or a type of the failure can be determined. It can also be determined whether to perform self-recovery from the failure to continue the DPD training based at least in part on one or both of the severity of the failure or the type of the failure.

Non-linear interference cancellation techniques are provided for wireless transceivers. Non-linear reduction of interference of a transmit signal on a received signal in a transceiver device, comprises applying the transmit signal to a first non-linear system; applying the received signal to a second non-linear system; and subtracting an output of the first non-linear system output from an output of second non-linear system output to produce an interference mitigated received signal. The first non-linear system and/or the second non-linear system can be implemented using one or more of a Volterra series and a Generalized Memory Polynomial Model. System parameters of the first non-linear system and/or the second non-linear system are adapted to reduce a power of the interference mitigated received signal.

A wireless communications system includes a pre-distortion actuator configured to receive a carrier-modulated signal and convert the carrier-modulated signal into an output signal. The system includes one or more antennas configured to receive the output signal and transmit the output signal, one or more power amplifiers electrically coupled between the pre-distortion actuator and the one or more antennas and a receiver configured to receive the output signal over-the-air and generate feedback based on the output signal. The pre-distortion actuator is configured to generate the output signal by applying a correction to the carrier-modulated signal that cancels out nonlinearities associated with the one or more antennas and/or the one or more power amplifiers. The pre-distortion actuator is configured based on the feedback.

Methods, systems, and devices for wireless communication are described. A communication device, such as a user equipment (UE) may receive control signaling (e.g., a downlink control information (DCI), a radio resource control (RRC) message, a medium access control-control element (MAC-CE)) including an indication of a set of constellation points for a set of constellation distortion points. The set of constellation distortion points may be of a constellation distribution associated with a modulation scheme (e.g., a quadrature amplitude modulation (QAM), an amplitude and phase-shift keying (APSK)). The UE may perform a digital post distortion operation based on the set of constellation points for the set of constellation distortion points of the constellation distribution, and decode the wireless communication based on performing of the digital post distortion operation.

Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.