An Analog-to-Digital Converter, ADC, system is provided. The ADC system comprises a plurality of ADC circuits and a first input for receiving a transmit signal of a transceiver. One ADC circuit of the plurality of ADC circuits is coupled to the first input and configured to provide first digital data based on the transmit signal. The ADC system further comprises a second input for receiving a receive signal of the transceiver. The other ADC circuits of the plurality of ADC circuits are coupled to the second input, wherein the other ADC circuits of the plurality of ADC circuits are time-interleaved and configured to provide second digital data based on the receive signal. Additionally, the ADC system comprises a first output configured to output digital feedback data based on the first digital data, and a second output configured to output digital receive data based on the second digital data.

Apparatus and methods for retraining digital pre-distortion are disclosed. In certain embodiments, a mobile device includes a transmit chain and a front end system. The transmit chain generates a transmit signal and converts the transmit signal to a radio frequency input signal, and includes a digital pre-distortion circuit that provides digital pre-distortion to the transmit signal. The front end system includes a power amplifier that amplifies the radio frequency input signal to generate a radio frequency output signal, and a power detector that generates a detection signal based on detecting an output power of the power amplifier. The detection signal controls initiation of a retraining sequence of the digital pre-distortion circuit.

Provided is a method of processing an input signal of an amplifier in an electronic device, the method including obtaining a pre-distorter configured to pre-distort an input signal of the amplifier by using a pretrained neural network model to pre-distort the input signal of the amplifier based on signals input to and output from the amplifier, which are obtained while the amplifier operates in a plurality of different environments, and a plurality of pieces of environmental information corresponding to the plurality of different environments, obtaining an input signal for the amplifier, obtaining information about an environment of the amplifier, pre-distorting the input signal by using the pre-distorter based on the obtained environmental information to prevent an output signal in response to the input signal to be processed by the amplifier from being distorted, and inputting the pre-distorted input signal to the amplifier.

Aspects relate to signaling relating to a non-linearity model for power amplifier circuitry of a transmitting device. The power amplifier circuitry may apply digital pre-distortion (DPD) to a signal prior to amplification and transmission of the signal. A receiving device may apply digital post-distortion (DPoD) to a signal received from the transmitting device where the DPoD is based on the non-linearity model. The transmitting device may send to the receiving device non-linearity parameters for the non-linearity model.

Apparatus and methods for power amplifier trimming based on coefficients for digital pre-distortion (DPD) are disclosed. In certain embodiments, a mobile device includes a transmit circuit that generates a plurality of digital transmit signals. The transmit circuit includes a plurality of DPD circuits each operable to provide DPD to a corresponding one of the digital transmit signals, a coefficient comparator circuit that generates a trimming control signal based on a plurality of coefficients of the plurality of DPD circuits, and a plurality of digital to radio frequency (RF) converters that convert the digital transmit signals into a plurality of RF signals. The mobile device further includes a front end system including a plurality of power amplifiers each amplifying a respective one of the RF signals, and a power amplifier trimming circuit that controls trimming of the power amplifiers based on the trimming control signal.

A radio communication device includes: a plurality of antenna elements; a phase shifter that applies weights for each of the antenna elements respectively to first-band data and second-band data of different frequency bands to form beams corresponding to the first-band data and the second-band data; a power amplifier that is arranged for each of the antenna elements; and a processor configured to compensate for non-linear distortion. The processor executes a process including calculating, using a first distortion compensation coefficient, a distortion compensation signal that compensates for in-band non-linear distortion of the first-band data and the second-band data, and calculating, using a second distortion compensation coefficient, an out-of-band compensation signal that compensates for out-of-band non-linear distortion of the first-band data and the second-band data, and the power amplifier amplifies a signal obtained by synthesizing the distortion compensation signal and the out-of-band compensation signal.

Disclosed is a transmission radio frequency (RF) circuit including a transmission mixer configured to receive an intermediate frequency (IF) signal and up-convert the IF signal into an RF signal, a driving amplifier configured to amplify the RF signal, and an LLC filter electrically connected to a differential output of the transmission mixer and a differential input of the driving amplifier, the LLC filter comprising a first inductor connecting a first node of the differential output of the transmission mixer to a first intermediate node, a second inductor connecting a second node of the differential output of the transmission mixer to a second intermediate node, a third inductor connecting the first intermediate node to the second intermediate node, and a capacitor in parallel with the third inductor.

In a dynamic signal traffic scenario, a narrowband to wideband transition in a DPD system results in a tilt in the output spectrum until the next DPD adaptation cycle occurs. To address this problem, regularization term is applied with a weighing factor when performing DPD coefficient estimation and adaptation. The regularization term can be obtained from in a variety of ways: using pre-stored waveforms, through factory or in-situ calibration, or through an adaptive or opportunistic update by observing the system. Application of the regularization term improves the spectrum flatness for a narrow to wideband signal transition, and does not require transmitting additional calibration tones to correct the gain flatness.

A wireless device includes a distortion compensation unit that imparts a distortion compensation component to a radio signal and outputs the radio signal, an amplifier that amplifies the radio signal to which the distortion compensation component is imparted by the distortion compensation unit, and a signal-to-noise-ratio adjustment unit that deteriorates a signal to noise ratio of an output signal of the amplifier and outputs the output signal as a feedback signal, in which the distortion compensation unit estimates, from the feedback signal, a distortion component contained in the output signal of the amplifier and imparts the distortion compensation component having an inverse characteristic of the estimated distortion component to the radio signal.

Systems and methods are described to perform wireless communication. The device includes a pre-distortion circuit configured to pre-distort an input signal based on a parameter set including a plurality of coefficients and generate a pre-distorted signal, a power amplifier configured to amplify the pre-distorted signal and generate an output signal, and a parameter obtaining circuit configured to perform an iterative approximation operation based on the output signal and the pre-distorted signal, which change over time, according to an indirect training structure configured to minimize a difference between an intermediate signal obtained based on the output signal and the pre-distorted signal, and obtain the parameter set.