A transmitting device may reduce a peak to average power ratio (PAPR) ratio by clipping samples that have an amplitude exceeding a threshold. For a downlink transmission, the transmitting device may transmit an incremental peak suppression information message (PSIM) to multiple user equipments (UEs). A UE may receive downlink control information (DCI) indicating a data and a modulation and coding scheme (MCS) for the UE, and at least a first incremental PSIM. The UE may decode at least the first incremental PSIM that is applicable to a MCS lower than or equal to the MCS for the UE. The UE may determine whether to decode one or more subsequent incremental PSIMs based on the MCS for the UE. The UE may apply peak information from the incremental PSIMs to the data channel. The UE may decode the data channel based on the MCS for the UE.

A method for signal distortion mitigation in a communication device with at least one transmitter in a communication system, generating a signal for transmission for each of the at least one transmitter; performing Peak-to-Average Power Ratio (PAPR) reduction and spectrum shaping of each of the generated signal to provide a distorted signal for transmission; determining signal distortions of the distorted signals, and precoding the determined signal distortions. The method further generating a composite signal for transmission based on the precoded determined signal distortions and the generated signal for transmission, to provide a composite signal, and transmitting the composite signal to at least one receiving communication device, wherein the precoding enables mitigating the signal distortion impact on the at least one receiver.

Systems and methods of wireless communication in which wireless devices are adapted to implement adaptive waveform selection are disclosed. For example, operation according to embodiments may provide for use of a waveform design that minimizes peak-to-average power ratio (PAPR), such as single-carrier frequency division multiplexing (SC-FDM), as well as a waveform design that provides higher spectral efficiency, such as orthogonal frequency division multiplexing (OFDM), for scenarios that are not power-limited and the higher PAPR is acceptable. Adaptive waveform selection may be based implicitly on one or more parameters or may be based on explicit signaling. Adaptive waveform selection may be utilized with respect to initially establishing a communication link and/or with respect to an established communication link.

A passive intermodulation elimination method, an apparatus, and a base station are disclosed. The method includes: receiving, by a network device, N pieces of backhauled information, where one piece of the backhauled information includes initial phase information of each carrier on one transmit channel, and N is an integer greater than or equal to 1; and eliminating, by the network device, a PIM of a received signal on a receive channel on the network device based on the N pieces of backhauled information.

Systems and methods for detecting peaks in a multi-band transmit signal are disclosed. In some embodiments, a method of operation of a multi-band transmitter for detecting peaks in a multi-band transmit signal which includes multiple transmit signals on a respective multiple frequency bands includes receiving a first band input signal for a first frequency band of the multi-band transmit signal and at least one additional band input signal for a respective at least one additional frequency band of the multi-band transmit signal. The method also includes detecting a peak of a combination of the first band input signal and the at least one additional band input signal taking into account phase information of the first band input signal and the at least one additional band input signal. In this manner, the detected peak might not be overestimated as when the peak detection fails to take into account the phase 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.

Methods, systems, and devices for wireless communications are described. In one example, a receiving device (e.g., a UE) may transmit, to a transmitting device (e.g., a base station), a capability indicator indicating a capability of the receiving device to perform peak reconstruction using soft metrics (e.g., expected value, covariance) on symbol decisions. The receiving device may receive, from the transmitting device and based on the capability indicator, control signaling indicating a clipping level applied to generate a signal and a subset of peaks clipped from the signal. The receiving device may receive the signal generated in accordance with the control signaling from the transmitting device and may decode a reconstructed signal based on performing the peak reconstruction on the signal using the soft metrics on symbol decisions, the clipping level, and the subset of the peaks clipped from the signal.

An apparatus, method and computer program is described comprising: receiving a first signal comprising one or more carrier signals comprising a plurality of resource blocks, wherein each resource block is assigned to a unique frequency and time slot of the respective carrier signal; generating a clipping pulse by modifying said first signal; converting the clipping pulse signal into a plurality of narrowband signals, wherein each narrowband signal is a frequency slice of the clipping pulse signal; modifying the plurality of narrowband signals to generate a plurality of modified narrowband signals, wherein said modifying is controlled based on filter weights that define a level of noise to be added to the respective narrowband signals in accordance with a desired error vector magnitude distribution or clipping noise distribution.

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.

Disclosed is a method of reducing the Instantaneous to Average Power Ratio, IAR, of a transmitter system, comprising the steps of: receiving an input digital signal comprising a plurality of samples; extracting magnitude information for each of the plurality of samples; selecting a plurality of samples whose magnitude exceeds a predefined threshold; sorting, by magnitude, the selected plurality of samples; selecting from the sorted plurality of samples, only those samples having a spacing more than a first pre-defined spacing and filtering those samples, using an FIR filter; subtracting the output of the FIR filter from a delayed version of the input digital signal to produce an output signal.