Methods, systems, and devices for wireless communications are described. A transmitting device (e.g., a user equipment (UE) or base station) may reduce a peak to average power ratio (PAPR) by clipping signals transmitted to a receiving device according to a clipping level. The receiving device may receive, from the transmitting device, an indication of the clipping level associated with a reference signal. The receiving device may receive the reference signal and identify distortions based on the clipping level. The receiving device may iteratively reconstruct peaks of the clipped reference signal until the receiving device is able to obtain accurate pilot symbols for use in channel estimation. The techniques described herein may enable receiving devices to improve efficiency and reliability of communications by improving channel estimation, which may increase the probability of successfully decoding transmitted information.

A system for peak-to-average-power ratio (PAPR) reduction of a frequency shifted plurality of digital broadcast signals taking into account the combined signal peaks in order to transmit the signals more efficiently in a single broadcast transmission system. The PAPR algorithm takes into account a rotating constellation phase offset for the shifted signals corresponding to the amount of applied frequency shift. In the case of a dual sideband In-Band-On-Channel (IBOC) signal typically used in conjunction with an FM carrier in the center, the sidebands can be interleaved to create a new IBOC signal definition and take the place of the FM carrier for an all-digital transmission that is backward compatible with IBOC receivers allowing for a gradual migration to all digital broadcasting.

There is provided a method of transmitting and receiving data across a network. A receiver device comprises a recovery module comprising a neural network trained to recover signals from clipped signals. The transmitter device may clip the original signal more aggressively due to the improved performance of the machine-learning based recovery module, thereby reducing the Peak to Average Power Ratio (PAPR) of the signal.

A radio transmitter circuit (10) for transmitting signals within an uplink or sidelink frequency band of a cellular communications system is disclosed. It comprises a signal-generation circuit (20) configured to generate a transmission signal to be transmitted, and a radio front-end circuit (30), connected to the signal-generation circuit (20) at an input of the radio front-end circuit (30), for receiving the transmission signal, and configured to be connected to an antenna (40) at an output of the radio front-end circuit and to transmit the transmission signal to a remote node via said antenna (40). The signal-generation circuit (20) is configured to select a distortion function (D1, D2) based on a location of an allocated radio frequency resource, within said uplink or sidelink frequency band, for the transmission signal. Furthermore, the signal-generation circuit (20) is configured to generate an intermediate transmission signal, based on information to be transmitted in the transmission signal. Moreover, the signal-generation circuit (20) is configured to generate the transmission signal by applying the distortion function (D1, D2) to the intermediate transmission signal.

The present disclosure relates to a method of reducing a Peak to Average Power Ratio (PAPR) in a communication device, and more particularly, to a method of Crest Factor Reduction (CFR) processing of a signal in order to reduce a PAPR in a communication device such as a repeater. The communication device includes: a first CFR module configured generate a first processed signal by CFR processing an original signal; and a second CFR module configured generate a second processed signal by CFR processing the first processed signal, wherein the first processed signal is generated using a first sampling rate, and the second processed signal is generated using a second sampling rate. According to the disclosure, even a communication device with a low sampling rate may effectively remove a peak component of an input signal.

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.

Methods, systems, and devices for wireless communications are described. In some examples, a transmitting device (e.g., a base station) may utilize machine learning to modify a signal as conditions of a channel change to reduce a peak to average power (PAPR). For example, a base station may select a type of machine learning. The base station may receive one or more feedback messages related to a condition of a channel and modify a downlink signal based on the selected type of machine learning and the one or more feedback messages. In some cases, the base station may transmit the modified downlink signal to a user equipment (UE) along with information indicating the modified downlink signal and the UE may reconstruct the downlink signal based on the information.

Preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA). An element, disposed prior to the Radio Frequency (RF) power amplifier (RFPA) in a signal path of a RF signal input to the RFPA, may enforce a maximum allowable amplitude in a high PAPR instantaneous high peak of the RF signal. An element may also increase or supplement a bias of the Radio Frequency (RF) power amplifier (RFPA) when a high PAPR instantaneous high peak is detected in the RF signal prior to receipt by the RFPA. Additionally, a first element operable detects when an instantaneous output voltage of the Radio Frequency (RF) power amplifier (RFPA) is below a predetermined voltage, and in response, a second element supplies additional current to prevent the output voltage of the RFPA from falling below a predetermined threshold voltage.

Efficient amplifier operation. In one aspect, there is a radio transceiver device. The radio transceiver device includes a distorting unit configured to receive an input signal and distort the received input signal, thereby producing a distorted input signal. The radio transceiver device further includes a limiter configured to receive the distorted input signal and produce a limited signal based on the received distorted input signal. The radio transceiver device further includes a power amplifier configured to receive the limited signal and amplify the limited signal, thereby producing an amplified limited signal.

Aspects relate to reconstructing a received non-linearly distorted (e.g., clipped) signal. A transmitting device may non-linearly distort a signal to be transmitted (e.g., by clipping peaks of the signal). This non-linear distortion may adversely affect decoding of the signal at a receiving device. To improve decoding performance at the receiving device, the transmitting device provides information regarding some of the non-linear distortion (e.g., information regarding a subset of the peaks that have been clipped) to the receiving device. The receiving device may reconstruct the signal based on this information (e.g., by reconstructing the subset of the peaks and adding the reconstructed peaks to the received clipped signal). In addition, the receiving device estimates the remaining non-linear distortion in the reconstructed signal (e.g., due to clipped peaks that were not indicated in the clipping information) by slicing the reconstructed signal and clipping the sliced signal, and provides a final reconstructed signal.