A signal pre-compensation method is provided. In the method, at least one target frequency subband is determined from a plurality of frequency subbands of a first optical signal and an optical signal of the at least one target frequency subband in the first optical signal is demodulated based on the at least one target frequency subband. A first electrical signal is obtained after demodulation, and a pre-compensation parameter is updated based on the at least one target frequency subband, the first electrical signal, and a second electrical signal. Herein the pre-compensation parameter is used to perform signal pre-compensation on the second electrical signal, and the first optical signal is generated after the pre-compensation is performed on the second electrical signal.

The invention relates to a device for linearising a power amplifier by employing digital predistortion, comprising: a digital predistortion module, configured to infer a polar domain predistortion to be applied to a signal, and comprising a first neural network and a second neural network respectively configured to correct amplitude and phase distortion produced by the amplifier; an optimisation module of each of said neural networks configured to implement meta-learning, using: a meta-initialisation providing a prior initialisation of the initial weights of each of said neural networks; a meta-matching of the initial weights into optimal weights of each of said neural networks.

A receiver circuit is disclosed. The receiver circuit includes an amplifier configured to generate an RF signal based on a received signal, where the RF signal includes an information signal and a blocker signal modulating an RF carrier frequency. The receiver circuit also includes an RF filter connected to the amplifier, where the RF filter is configured to selectively attenuate the blocker signal.

A method for determining a noise shaped quantized parameter contributing to generation of an output signal comprises estimating an error within the output signal using a quantization of the parameter and a quantization of a further parameter contributing to generation of the output signal. The quantization of the parameter is used as the noise shaped quantized parameter according to a selection criterion.

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.

Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

According to one configuration, a system includes a first wireless station in communication with a second wireless station. A phase noise predictor model such as associated with the first wireless station receives phase noise information. The phase noise information captures an estimate of: i) first phase noise associated with a first wireless station, and ii) second phase noise associated with a second wireless station. Based on the received phase noise information, the predictor produces phase noise adjustment information. The predictor applies the phase noise adjustment information to adjust (compensate) a signal of the first wireless station. Adjustment of the signal results in phase noise adjustment with respect to both the first phase noise associated with the first wireless station and the second phase noise associated with the second wireless station.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for applying non-linearity to digital subcarriers. A receiver includes a detector circuit operable to receive a first optical signal over an optical link, the first optical signal carrying first data. The receiver includes a carrier recovery estimation circuit operable to generate compensated data by correcting errors in the first data. The receiver includes a non-linear coefficient estimation circuit operable to (i) receive the compensated data, and (ii) estimate one or more non-linear coefficients, wherein information indicative of the estimated non-linear coefficients is transmitted over an optical network, such that a second optical signal is transmitted based, at least in part, on the estimated non-linear coefficients, the second optical signal being received by the receiver.

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).

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.